+++ /dev/null
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-//
-// ignore-lexer-test FIXME #15883
-
-//! Unordered containers, implemented as hash-tables (`HashSet` and `HashMap` types)
-
-use clone::Clone;
-use cmp::{max, Eq, Equiv, PartialEq};
-use collections::{Collection, Mutable, Set, MutableSet, Map, MutableMap};
-use default::Default;
-use fmt::Show;
-use fmt;
-use hash::{Hash, Hasher, RandomSipHasher};
-use iter::{Iterator, FromIterator, FilterMap, Chain, Repeat, Zip, Extendable, range};
-use iter;
-use mem::replace;
-use num;
-use ops::Deref;
-use option::{Some, None, Option};
-use result::{Ok, Err};
-use ops::Index;
-
-use self::table::{BucketWithTable, FullBucketImm, RawTable, FullBucket, FullBucketMut, Bucket};
-
-mod table {
- use clone::Clone;
- use cmp;
- use hash::{Hash, Hasher};
- use iter::{Iterator, count};
- use mem::{min_align_of, size_of};
- use mem;
- use num::{CheckedMul, is_power_of_two};
- use ops::{Deref, Drop};
- use option::{Some, None, Option};
- use ptr::RawPtr;
- use ptr::set_memory;
- use ptr::write;
- use ptr;
- use rt::heap::{allocate, deallocate};
-
- static EMPTY_BUCKET: u64 = 0u64;
-
- /// The raw hashtable, providing safe-ish access to the unzipped and highly
- /// optimized arrays of hashes, keys, and values.
- ///
- /// This design uses less memory and is a lot faster than the naive
- /// `Vec<Option<u64, K, V>>`, because we don't pay for the overhead of an
- /// option on every element, and we get a generally more cache-aware design.
- ///
- /// Key invariants of this structure:
- ///
- /// - if hashes[i] == EMPTY_BUCKET, then keys[i] and vals[i] have
- /// 'undefined' contents. Don't read from them. This invariant is
- /// enforced outside this module with the `EmptyIndex`, `FullIndex`,
- /// and `SafeHash` types.
- ///
- /// - An `EmptyIndex` is only constructed for a bucket at an index with
- /// a hash of EMPTY_BUCKET.
- ///
- /// - A `FullIndex` is only constructed for a bucket at an index with a
- /// non-EMPTY_BUCKET hash.
- ///
- /// - A `SafeHash` is only constructed for non-`EMPTY_BUCKET` hash. We get
- /// around hashes of zero by changing them to 0x8000_0000_0000_0000,
- /// which will likely map to the same bucket, while not being confused
- /// with "empty".
- ///
- /// - All three "arrays represented by pointers" are the same length:
- /// `capacity`. This is set at creation and never changes. The arrays
- /// are unzipped to save space (we don't have to pay for the padding
- /// between odd sized elements, such as in a map from u64 to u8), and
- /// be more cache aware (scanning through 8 hashes brings in 2 cache
- /// lines, since they're all right beside each other).
- ///
- /// You can kind of think of this module/data structure as a safe wrapper
- /// around just the "table" part of the hashtable. It enforces some
- /// invariants at the type level and employs some performance trickery,
- /// but in general is just a tricked out `Vec<Option<u64, K, V>>`.
- ///
- /// FIXME(cgaebel):
- ///
- /// Feb 11, 2014: This hashtable was just implemented, and, hard as I tried,
- /// isn't yet totally safe. There's a "known exploit" that you can create
- /// multiple FullIndexes for a bucket, `take` one, and then still `take`
- /// the other causing undefined behavior. Currently, there's no story
- /// for how to protect against this statically. Therefore, there are asserts
- /// on `take`, `get`, `get_mut`, and `put` which check the bucket state.
- /// With time, and when we're confident this works correctly, they should
- /// be removed. Also, the bounds check in `peek` is especially painful,
- /// as that's called in the innermost loops of the hashtable and has the
- /// potential to be a major performance drain. Remove this too.
- ///
- /// Or, better than remove, only enable these checks for debug builds.
- /// There's currently no "debug-only" asserts in rust, so if you're reading
- /// this and going "what? of course there are debug-only asserts!", then
- /// please make this use them!
- #[unsafe_no_drop_flag]
- pub struct RawTable<K, V> {
- capacity: uint,
- size: uint,
- hashes: *mut u64
- }
-
- /// A bucket that holds a reference to the table
- pub trait BucketWithTable<M> {
- /// A bucket that holds a reference to the table
- fn table<'a>(&'a self) -> &'a M;
-
- /// Move out the reference to the table.
- fn into_table(self) -> M;
-
- /// Get the raw index.
- fn index(&self) -> uint;
- }
-
- struct RawBucket<K, V> {
- hash: *mut u64,
- key: *mut K,
- val: *mut V
- }
-
- pub struct Bucket<K, V, M> {
- raw: RawBucket<K, V>,
- idx: uint,
- table: M
- }
-
- pub struct EmptyBucket<K, V, M> {
- raw: RawBucket<K, V>,
- idx: uint,
- table: M
- }
-
- pub struct FullBucket<K, V, M> {
- raw: RawBucket<K, V>,
- idx: uint,
- table: M
- }
-
- pub type EmptyBucketImm<'table,K,V> = EmptyBucket<K, V, &'table RawTable<K,V>>;
- pub type FullBucketImm<'table,K,V> = FullBucket<K, V, &'table RawTable<K,V>>;
-
- pub type EmptyBucketMut<'table,K,V> = EmptyBucket<K, V, &'table mut RawTable<K,V>>;
- pub type FullBucketMut<'table,K,V> = FullBucket<K, V, &'table mut RawTable<K,V>>;
-
- struct GapThenFull<K, V, M> {
- gap: EmptyBucket<K, V, ()>,
- full: FullBucket<K, V, M>
- }
-
- impl<K, V, M: Deref<RawTable<K,V>>> GapThenFull<K, V, M> {
- pub fn full<'a>(&'a self) -> &'a FullBucket<K, V, M> {
- &self.full
- }
-
- pub fn shift(mut self) -> Option<GapThenFull<K, V, M>> {
- unsafe {
- *self.gap.raw.hash = mem::replace(&mut *self.full.raw.hash, EMPTY_BUCKET);
- mem::overwrite(self.gap.raw.key, ptr::read(self.full.raw.key as *const K));
- mem::overwrite(self.gap.raw.val, ptr::read(self.full.raw.val as *const V));
- }
-
- let FullBucket { raw, idx, .. } = self.full;
-
- match self.full.next().peek() {
- Empty(_) => None,
- Full(bucket) => {
- self.gap.raw = raw;
- self.gap.idx = idx;
-
- self.full = bucket;
- self.full.idx &= self.full.table.capacity - 1;
-
- Some(self)
- }
- }
- }
- }
-
- impl<K, V> RawPtr<u64> for RawBucket<K, V> {
- unsafe fn offset(self, count: int) -> RawBucket<K, V> {
- RawBucket {
- hash: self.hash.offset(count),
- key: self.key.offset(count),
- val: self.val.offset(count),
- }
- }
-
- fn null() -> RawBucket<K, V> {
- RawBucket {
- hash: RawPtr::null(),
- key: RawPtr::null(),
- val: RawPtr::null()
- }
- }
-
- fn is_null(&self) -> bool {
- self.hash.is_null()
- }
-
- fn to_uint(&self) -> uint {
- self.hash.to_uint()
- }
-
- unsafe fn to_option(&self) -> Option<&u64> {
- self.hash.to_option()
- }
- }
-
- impl<K, V, M: Deref<RawTable<K,V>>> EmptyBucket<K, V, M> {
- pub fn next(self) -> Bucket<K, V, M> {
- let mut bucket = self.into_bucket();
- bucket.next();
- bucket
- }
-
- pub fn into_bucket(self) -> Bucket<K, V, M> {
- Bucket {
- raw: self.raw,
- idx: self.idx,
- table: self.table
- }
- }
-
- pub fn gap_peek(self) -> Option<GapThenFull<K, V, M>> {
- let gap = EmptyBucket {
- raw: self.raw,
- idx: self.idx,
- table: ()
- };
-
- match self.next().peek() {
- Empty(_) => None,
- Full(bucket) => {
- Some(GapThenFull {
- gap: gap,
- full: bucket
- })
- }
- }
- }
- }
-
- impl<K, V, M: DerefMut<RawTable<K,V>>> EmptyBucket<K, V, M> {
- pub fn put(mut self, hash: SafeHash, key: K, value: V)
- -> FullBucket<K, V, M> {
- unsafe {
- *self.raw.hash = hash.inspect();
- write(self.raw.key, key);
- write(self.raw.val, value);
- }
-
- self.table.size += 1;
-
- FullBucket { raw: self.raw, idx: self.idx, table: self.table }
- }
- }
-
- impl<K, V, M: Deref<RawTable<K,V>>> FullBucket<K, V, M> {
- pub fn next(self) -> Bucket<K, V, M> {
- let mut bucket = self.into_bucket();
- bucket.next();
- bucket
- }
-
- pub fn into_bucket(self) -> Bucket<K, V, M> {
- Bucket {
- raw: self.raw,
- idx: self.idx,
- table: self.table
- }
- }
-
- pub fn distance(&self) -> uint {
- (self.idx - self.hash().inspect() as uint) & (self.table.capacity() - 1)
- }
-
- pub fn hash(&self) -> SafeHash {
- unsafe {
- SafeHash {
- hash: *self.raw.hash
- }
- }
- }
-
- pub fn read<'a>(&'a self) -> (&'a K, &'a V) {
- unsafe {
- (&*self.raw.key,
- &*self.raw.val)
- }
- }
-
- pub fn into_refs(self) -> (&K, &V) {
- unsafe {
- // debug_assert!(*self.raw.hash != EMPTY_BUCKET);
- (&*self.raw.key,
- &*self.raw.val)
- }
- }
- }
-
- impl<K, V, M: DerefMut<RawTable<K,V>>> FullBucket<K, V, M> {
- pub fn take(mut self) -> (EmptyBucket<K, V, M>, K, V) {
- let key = self.raw.key as *const K;
- let val = self.raw.val as *const V;
-
- self.table.size -= 1;
-
- unsafe {
- *self.raw.hash = EMPTY_BUCKET;
- (
- EmptyBucket {
- raw: self.raw,
- idx: self.idx,
- table: self.table
- },
- ptr::read(key),
- ptr::read(val)
- )
- }
- }
-
- pub fn replace(&mut self, h: SafeHash, k: K, v: V) -> (SafeHash, K, V) {
- unsafe {
- let old_hash = ptr::replace(self.raw.hash as *mut SafeHash, h);
- let old_key = ptr::replace(self.raw.key, k);
- let old_val = ptr::replace(self.raw.val, v);
-
- (old_hash, old_key, old_val)
- }
- }
-
- pub fn read_mut<'a>(&'a self) -> (&'a mut K, &'a mut V) {
- unsafe {
- // debug_assert!(*self.raw.hash != EMPTY_BUCKET);
- (&mut *self.raw.key,
- &mut *self.raw.val)
- }
- }
-
- pub fn into_mut_refs(self) -> (&mut K, &mut V) {
- unsafe {
- // debug_assert!(*self.raw.hash != EMPTY_BUCKET);
- (&mut *self.raw.key,
- &mut *self.raw.val)
- }
- }
- }
-
- impl<K, V, M: Deref<RawTable<K,V>>> Bucket<K, V, M> {
- pub fn new(table: M, hash: &SafeHash) -> Bucket<K, V, M> {
- let ib_index = (hash.inspect() as uint) & (table.capacity() - 1);
- Bucket {
- raw: unsafe {
- table.as_mut_ptrs().offset(ib_index as int)
- },
- idx: ib_index,
- table: table
- }
- }
-
- pub fn at_index(table: M, ib_index: uint) -> Bucket<K, V, M> {
- let ib_index = ib_index & (table.capacity() - 1);
- Bucket {
- raw: unsafe {
- table.as_mut_ptrs().offset(ib_index as int)
- },
- idx: ib_index,
- table: table
- }
- }
-
- pub fn first(table: M) -> Bucket<K, V, M> {
- Bucket {
- raw: table.as_mut_ptrs(),
- idx: 0,
- table: table
- }
- }
-
- pub fn peek(self) -> BucketState<K, V, M> {
- match unsafe { *self.raw.hash } {
- EMPTY_BUCKET =>
- Empty(EmptyBucket {
- raw: self.raw,
- idx: self.idx,
- table: self.table
- }),
- _ =>
- Full(FullBucket {
- raw: self.raw,
- idx: self.idx,
- table: self.table
- })
- }
- }
-
- pub fn next(&mut self) {
- self.idx += 1;
-
- let dist = if self.idx == self.table.capacity() {
- -(self.table.capacity() as int - 1)
- } else {
- 1i
- };
-
- unsafe {
- self.raw = self.raw.offset(dist);
- }
- }
- }
-
- impl<K, V, M> BucketWithTable<M> for FullBucket<K, V, M> {
- fn table<'a>(&'a self) -> &'a M {
- &self.table
- }
-
- fn into_table(self) -> M {
- self.table
- }
-
- fn index(&self) -> uint {
- self.idx
- }
- }
-
- impl<K, V, M> BucketWithTable<M> for EmptyBucket<K, V, M> {
- fn table<'a>(&'a self) -> &'a M {
- &self.table
- }
-
- fn into_table(self) -> M {
- self.table
- }
-
- fn index(&self) -> uint {
- self.idx
- }
- }
-
- impl<K, V, M> BucketWithTable<M> for Bucket<K, V, M> {
- fn table<'a>(&'a self) -> &'a M {
- &self.table
- }
-
- fn into_table(self) -> M {
- self.table
- }
-
- fn index(&self) -> uint {
- self.idx
- }
- }
-
- impl<'table,K,V> Deref<RawTable<K,V>> for &'table RawTable<K,V> {
- fn deref<'a>(&'a self) -> &'a RawTable<K,V> {
- &**self
- }
- }
-
- impl<'table,K,V> Deref<RawTable<K,V>> for &'table mut RawTable<K,V> {
- fn deref<'a>(&'a self) -> &'a RawTable<K,V> {
- &**self
- }
- }
-
- impl<'table,K,V> DerefMut<RawTable<K,V>> for &'table mut RawTable<K,V> {
- fn deref_mut<'a>(&'a mut self) -> &'a mut RawTable<K,V> {
- &mut **self
- }
- }
-
- pub enum BucketState<K, V, M> {
- Empty(EmptyBucket<K, V, M>),
- Full(FullBucket<K, V, M>),
- }
-
- /// A hash that is not zero, since we use a hash of zero to represent empty
- /// buckets.
- #[deriving(PartialEq)]
- pub struct SafeHash {
- hash: u64,
- }
-
- impl SafeHash {
- /// Peek at the hash value, which is guaranteed to be non-zero.
- #[inline(always)]
- pub fn inspect(&self) -> u64 { self.hash }
- }
-
- /// We need to remove hashes of 0. That's reserved for empty buckets.
- /// This function wraps up `hash_keyed` to be the only way outside this
- /// module to generate a SafeHash.
- pub fn make_hash<T: Hash<S>, S, H: Hasher<S>>(hasher: &H, t: &T) -> SafeHash {
- match hasher.hash(t) {
- // This constant is exceedingly likely to hash to the same
- // bucket, but it won't be counted as empty!
- EMPTY_BUCKET => SafeHash { hash: 0x8000_0000_0000_0000 },
- h => SafeHash { hash: h },
- }
- }
-
- fn round_up_to_next(unrounded: uint, target_alignment: uint) -> uint {
- assert!(is_power_of_two(target_alignment));
- (unrounded + target_alignment - 1) & !(target_alignment - 1)
- }
-
- #[test]
- fn test_rounding() {
- assert_eq!(round_up_to_next(0, 4), 0);
- assert_eq!(round_up_to_next(1, 4), 4);
- assert_eq!(round_up_to_next(2, 4), 4);
- assert_eq!(round_up_to_next(3, 4), 4);
- assert_eq!(round_up_to_next(4, 4), 4);
- assert_eq!(round_up_to_next(5, 4), 8);
- }
-
- // Returns a tuple of (minimum required malloc alignment, hash_offset,
- // key_offset, val_offset, array_size), from the start of a mallocated array.
- fn calculate_offsets(
- hash_size: uint, hash_align: uint,
- keys_size: uint, keys_align: uint,
- vals_size: uint, vals_align: uint) -> (uint, uint, uint, uint, uint) {
-
- let hash_offset = 0;
- let end_of_hashes = hash_offset + hash_size;
-
- let keys_offset = round_up_to_next(end_of_hashes, keys_align);
- let end_of_keys = keys_offset + keys_size;
-
- let vals_offset = round_up_to_next(end_of_keys, vals_align);
- let end_of_vals = vals_offset + vals_size;
-
- let min_align = cmp::max(hash_align, cmp::max(keys_align, vals_align));
-
- (min_align, hash_offset, keys_offset, vals_offset, end_of_vals)
- }
-
- #[test]
- fn test_offset_calculation() {
- assert_eq!(calculate_offsets(128, 8, 15, 1, 4, 4 ), (8, 0, 128, 144, 148));
- assert_eq!(calculate_offsets(3, 1, 2, 1, 1, 1 ), (1, 0, 3, 5, 6));
- assert_eq!(calculate_offsets(6, 2, 12, 4, 24, 8), (8, 0, 8, 24, 48));
- }
-
- impl<K, V> RawTable<K, V> {
-
- /// Does not initialize the buckets. The caller should ensure they,
- /// at the very least, set every hash to EMPTY_BUCKET.
- unsafe fn new_uninitialized(capacity: uint) -> RawTable<K, V> {
- if capacity == 0 {
- return RawTable {
- size: 0,
- capacity: 0,
- hashes: 0 as *mut u64,
- };
- }
- let hashes_size = capacity.checked_mul(&size_of::<u64>())
- .expect("capacity overflow");
- let keys_size = capacity.checked_mul(&size_of::< K >())
- .expect("capacity overflow");
- let vals_size = capacity.checked_mul(&size_of::< V >())
- .expect("capacity overflow");
-
- // Allocating hashmaps is a little tricky. We need to allocate three
- // arrays, but since we know their sizes and alignments up front,
- // we just allocate a single array, and then have the subarrays
- // point into it.
- //
- // This is great in theory, but in practice getting the alignment
- // right is a little subtle. Therefore, calculating offsets has been
- // factored out into a different function.
- let (malloc_alignment, hash_offset, _, _, size) =
- calculate_offsets(
- hashes_size, min_align_of::<u64>(),
- keys_size, min_align_of::< K >(),
- vals_size, min_align_of::< V >());
-
- let buffer = allocate(size, malloc_alignment);
-
- let hashes = buffer.offset(hash_offset as int) as *mut u64;
-
- RawTable {
- capacity: capacity,
- size: 0,
- hashes: hashes,
- }
- }
-
- fn as_mut_ptrs(&self) -> RawBucket<K, V> {
- let hashes_size = self.capacity * size_of::<u64>();
- let keys_size = self.capacity * size_of::<K>();
-
- let keys_offset = (hashes_size + min_align_of::< K >() - 1) & !(min_align_of::< K >() - 1);
- let end_of_keys = keys_offset + keys_size;
-
- let vals_offset = (end_of_keys + min_align_of::< V >() - 1) & !(min_align_of::< V >() - 1);
-
- let buffer = self.hashes as *mut u8;
-
- unsafe {
- RawBucket {
- hash: self.hashes,
- key: buffer.offset(keys_offset as int) as *mut K,
- val: buffer.offset(vals_offset as int) as *mut V
- }
- }
- }
-
- /// Creates a new raw table from a given capacity. All buckets are
- /// initially empty.
- #[allow(experimental)]
- pub fn new(capacity: uint) -> RawTable<K, V> {
- unsafe {
- let ret = RawTable::new_uninitialized(capacity);
- set_memory(ret.hashes, 0u8, capacity);
- ret
- }
- }
-
- /// The hashtable's capacity, similar to a vector's.
- pub fn capacity(&self) -> uint {
- self.capacity
- }
-
- /// The number of elements ever `put` in the hashtable, minus the number
- /// of elements ever `take`n.
- pub fn size(&self) -> uint {
- self.size
- }
-
- fn ptrs<'a>(&'a self) -> RawBuckets<'a, K, V> {
- RawBuckets {
- raw: self.as_mut_ptrs(),
- hashes_end: unsafe {
- self.hashes.offset(self.capacity as int)
- }
- }
- }
-
- pub fn iter<'a>(&'a self) -> Entries<'a, K, V> {
- Entries {
- iter: self.ptrs(),
- elems_left: self.size(),
- }
- }
-
- pub fn mut_iter<'a>(&'a mut self) -> MutEntries<'a, K, V> {
- MutEntries {
- iter: self.ptrs(),
- elems_left: self.size(),
- }
- }
-
- pub fn move_iter(self) -> MoveEntries<K, V> {
- MoveEntries {
- iter: self.ptrs(),
- table: self,
- }
- }
-
- pub fn rev_move_buckets<'a>(&'a mut self) -> RevMoveBuckets<'a, K, V> {
- let raw_bucket = self.as_mut_ptrs();
- unsafe {
- RevMoveBuckets {
- raw: raw_bucket.offset(self.capacity as int),
- hashes_end: raw_bucket.hash,
- elems_left: self.size
- }
- }
- }
- }
-
- pub struct RawBuckets<'a, K, V> {
- raw: RawBucket<K, V>,
- hashes_end: *mut u64
- }
-
- impl<'a, K, V> Iterator<RawBucket<K, V>> for RawBuckets<'a, K, V> {
- fn next(&mut self) -> Option<RawBucket<K, V>> {
- while self.raw.hash != self.hashes_end {
- unsafe {
- let prev = ptr::replace(&mut self.raw, self.raw.offset(1));
- if *prev.hash != EMPTY_BUCKET {
- return Some(prev);
- }
- }
- }
-
- None
- }
- }
-
- pub struct RevMoveBuckets<'a, K, V> {
- raw: RawBucket<K, V>,
- hashes_end: *mut u64,
- elems_left: uint
- }
-
- impl<'a, K, V> Iterator<(K, V)> for RevMoveBuckets<'a, K, V> {
- fn next(&mut self) -> Option<(K, V)> {
- if self.elems_left == 0 {
- return None;
- }
-
- loop {
- debug_assert!(self.raw.hash != self.hashes_end);
-
- unsafe {
- self.raw = self.raw.offset(-1);
-
- if *self.raw.hash != EMPTY_BUCKET {
- self.elems_left -= 1;
- return Some((
- ptr::read(self.raw.key as *const K),
- ptr::read(self.raw.val as *const V)
- ));
- }
- }
- }
- }
- }
-
- // `read_all_mut` casts a `*u64` to a `*SafeHash`. Since we statically
- // ensure that a `FullIndex` points to an index with a non-zero hash,
- // and a `SafeHash` is just a `u64` with a different name, this is
- // safe.
- //
- // This test ensures that a `SafeHash` really IS the same size as a
- // `u64`. If you need to change the size of `SafeHash` (and
- // consequently made this test fail), `read_all_mut` needs to be
- // modified to no longer assume this.
- #[test]
- fn can_alias_safehash_as_u64() {
- assert_eq!(size_of::<SafeHash>(), size_of::<u64>())
- }
-
- /// Iterator over shared references to entries in a table.
- pub struct Entries<'a, K:'a, V:'a> {
- table: &'a RawTable<K, V>,
- idx: uint,
- elems_seen: uint,
- }
-
- /// Iterator over mutable references to entries in a table.
- pub struct MutEntries<'a, K:'a, V:'a> {
- table: &'a mut RawTable<K, V>,
- idx: uint,
- elems_seen: uint,
- }
-
- /// Iterator over the entries in a table, consuming the table.
- pub struct MoveEntries<K, V> {
- table: RawTable<K, V>,
- iter: RawBuckets<'static, K, V>
- }
-
- impl<'a, K, V> Iterator<(&'a K, &'a V)> for Entries<'a, K, V> {
- fn next(&mut self) -> Option<(&'a K, &'a V)> {
- self.iter.next().map(|bucket| {
- self.elems_left -= 1;
- unsafe {
- (&*bucket.key,
- &*bucket.val)
- }
- })
- }
-
- fn size_hint(&self) -> (uint, Option<uint>) {
- (self.elems_left, Some(self.elems_left))
- }
- }
-
- impl<'a, K, V> Iterator<(&'a K, &'a mut V)> for MutEntries<'a, K, V> {
- fn next(&mut self) -> Option<(&'a K, &'a mut V)> {
- self.iter.next().map(|bucket| {
- self.elems_left -= 1;
- unsafe {
- (&*bucket.key,
- &mut *bucket.val)
- }
- })
- }
-
- fn size_hint(&self) -> (uint, Option<uint>) {
- (self.elems_left, Some(self.elems_left))
- }
- }
-
- impl<K, V> Iterator<(SafeHash, K, V)> for MoveEntries<K, V> {
- fn next(&mut self) -> Option<(SafeHash, K, V)> {
- self.iter.next().map(|bucket| {
- self.table.size -= 1;
- unsafe {
- (
- SafeHash {
- hash: *bucket.hash,
- },
- ptr::read(bucket.key as *const K),
- ptr::read(bucket.val as *const V)
- )
- }
- })
- }
-
- fn size_hint(&self) -> (uint, Option<uint>) {
- let size = self.table.size();
- (size, Some(size))
- }
- }
-
- impl<K: Clone, V: Clone> Clone for RawTable<K, V> {
- fn clone(&self) -> RawTable<K, V> {
- unsafe {
- let mut new_ht = RawTable::new_uninitialized(self.capacity());
-
- {
- let cap = self.capacity();
- let mut new_buckets = Bucket::first(&mut new_ht);
- let mut buckets = Bucket::first(self);
- while buckets.index() != cap {
- match buckets.peek() {
- Full(full) => {
- let (h, k, v) = {
- let (k, v) = full.read();
- (full.hash(), k.clone(), v.clone())
- };
- *new_buckets.raw.hash = h.inspect();
- mem::overwrite(new_buckets.raw.key, k);
- mem::overwrite(new_buckets.raw.val, v);
- }
- _ => {
- *new_buckets.raw.hash = EMPTY_BUCKET;
- }
- }
- new_buckets.next();
- buckets.next();
- }
- }
-
- new_ht.size = self.size();
-
- new_ht
- }
- }
- }
-
- #[unsafe_destructor]
- impl<K, V> Drop for RawTable<K, V> {
- fn drop(&mut self) {
- if self.hashes.is_null() {
- return;
- }
- // This is in reverse because we're likely to have partially taken
- // some elements out with `.move_iter()` from the front.
- // Check if the size is 0, so we don't do a useless scan when
- // dropping empty tables such as on resize.
- // Avoid double free of elements already moved out.
- for _ in self.rev_move_buckets() {}
-
- let hashes_size = self.capacity * size_of::<u64>();
- let keys_size = self.capacity * size_of::<K>();
- let vals_size = self.capacity * size_of::<V>();
- let (align, _, _, _, size) = calculate_offsets(hashes_size, min_align_of::<u64>(),
- keys_size, min_align_of::<K>(),
- vals_size, min_align_of::<V>());
-
- unsafe {
- deallocate(self.hashes as *mut u8, size, align);
- // Remember how everything was allocated out of one buffer
- // during initialization? We only need one call to free here.
- }
-
- self.hashes = RawPtr::null();
- }
- }
-}
-
-static INITIAL_LOG2_CAP: uint = 5;
-static INITIAL_CAPACITY: uint = 1 << INITIAL_LOG2_CAP; // 2^5
-
-/// The default behavior of HashMap implements a load factor of 90.9%.
-/// This behavior is characterized by the following conditions:
-///
-/// - if `size * 1.1 < cap < size * 4` then shouldn't resize
-/// - if `cap < minimum_capacity * 2` then shouldn't shrink
-#[deriving(Clone)]
-struct DefaultResizePolicy {
- /// Doubled minimal capacity. The capacity must never drop below
- /// the minimum capacity. (The check happens before the capacity
- /// is potentially halved.)
- minimum_capacity2: uint
-}
-
-impl DefaultResizePolicy {
- fn new(new_capacity: uint) -> DefaultResizePolicy {
- DefaultResizePolicy {
- minimum_capacity2: new_capacity << 1
- }
- }
-
- #[inline]
- fn capacity_range(&self, new_size: uint) -> (uint, uint) {
- ((new_size * 11) / 10, max(new_size << 3, self.minimum_capacity2))
- }
-
- #[inline]
- fn reserve(&mut self, new_capacity: uint) {
- self.minimum_capacity2 = new_capacity << 1;
- }
-}
-
-// The main performance trick in this hashmap is called Robin Hood Hashing.
-// It gains its excellent performance from one crucial operation:
-//
-// If an insertion collides with an existing element, and that elements
-// "probe distance" (how far away the element is from its ideal location)
-// is higher than how far we've already probed, swap the elements.
-//
-// This massively lowers variance in probe distance, and allows us to get very
-// high load factors with good performance. The 90% load factor I use is rather
-// conservative.
-//
-// > Why a load factor of approximately 90%?
-//
-// In general, all the distances to initial buckets will converge on the mean.
-// At a load factor of α, the odds of finding the target bucket after k
-// probes is approximately 1-α^k. If we set this equal to 50% (since we converge
-// on the mean) and set k=8 (64-byte cache line / 8-byte hash), α=0.92. I round
-// this down to make the math easier on the CPU and avoid its FPU.
-// Since on average we start the probing in the middle of a cache line, this
-// strategy pulls in two cache lines of hashes on every lookup. I think that's
-// pretty good, but if you want to trade off some space, it could go down to one
-// cache line on average with an α of 0.84.
-//
-// > Wait, what? Where did you get 1-α^k from?
-//
-// On the first probe, your odds of a collision with an existing element is α.
-// The odds of doing this twice in a row is approximately α^2. For three times,
-// α^3, etc. Therefore, the odds of colliding k times is α^k. The odds of NOT
-// colliding after k tries is 1-α^k.
-//
-// Future Improvements (FIXME!)
-// ============================
-//
-// Allow the load factor to be changed dynamically and/or at initialization.
-//
-// Also, would it be possible for us to reuse storage when growing the
-// underlying table? This is exactly the use case for 'realloc', and may
-// be worth exploring.
-//
-// Future Optimizations (FIXME!)
-// =============================
-//
-// The paper cited below mentions an implementation which keeps track of the
-// distance-to-initial-bucket histogram. I'm suspicious of this approach because
-// it requires maintaining an internal map. If this map were replaced with a
-// hashmap, it would be faster, but now our data structure is self-referential
-// and blows up. Also, this allows very good first guesses, but array accesses
-// are no longer linear and in one direction, as we have now. There is also
-// memory and cache pressure that this map would entail that would be very
-// difficult to properly see in a microbenchmark.
-//
-// Another possible design choice that I made without any real reason is
-// parameterizing the raw table over keys and values. Technically, all we need
-// is the size and alignment of keys and values, and the code should be just as
-// efficient (well, we might need one for power-of-two size and one for not...).
-// This has the potential to reduce code bloat in rust executables, without
-// really losing anything except 4 words (key size, key alignment, val size,
-// val alignment) which can be passed in to every call of a `RawTable` function.
-// This would definitely be an avenue worth exploring if people start complaining
-// about the size of rust executables.
-//
-// There's also an "optimization" that has been omitted regarding how the
-// hashtable allocates. The vector type has set the expectation that a hashtable
-// which never has an element inserted should not allocate. I'm suspicious of
-// implementing this for hashtables, because supporting it has no performance
-// benefit over using an `Option<HashMap<K, V>>`, and is significantly more
-// complicated.
-
-/// A hash map implementation which uses linear probing with Robin
-/// Hood bucket stealing.
-///
-/// The hashes are all keyed by the task-local random number generator
-/// on creation by default. This means that the ordering of the keys is
-/// randomized, but makes the tables more resistant to
-/// denial-of-service attacks (Hash DoS). This behaviour can be
-/// overridden with one of the constructors.
-///
-/// It is required that the keys implement the `Eq` and `Hash` traits, although
-/// this can frequently be achieved by using `#[deriving(Eq, Hash)]`.
-///
-/// Relevant papers/articles:
-///
-/// 1. Pedro Celis. ["Robin Hood Hashing"](https://cs.uwaterloo.ca/research/tr/1986/CS-86-14.pdf)
-/// 2. Emmanuel Goossaert. ["Robin Hood
-/// hashing"](http://codecapsule.com/2013/11/11/robin-hood-hashing/)
-/// 3. Emmanuel Goossaert. ["Robin Hood hashing: backward shift
-/// deletion"](http://codecapsule.com/2013/11/17/robin-hood-hashing-backward-shift-deletion/)
-///
-/// # Example
-///
-/// ```
-/// use std::collections::HashMap;
-///
-/// // type inference lets us omit an explicit type signature (which
-/// // would be `HashMap<&str, &str>` in this example).
-/// let mut book_reviews = HashMap::new();
-///
-/// // review some books.
-/// book_reviews.insert("Adventures of Huckleberry Finn", "My favorite book.");
-/// book_reviews.insert("Grimms' Fairy Tales", "Masterpiece.");
-/// book_reviews.insert("Pride and Prejudice", "Very enjoyable.");
-/// book_reviews.insert("The Adventures of Sherlock Holmes", "Eye lyked it alot.");
-///
-/// // check for a specific one.
-/// if !book_reviews.contains_key(&("Les Misérables")) {
-/// println!("We've got {} reviews, but Les Misérables ain't one.",
-/// book_reviews.len());
-/// }
-///
-/// // oops, this review has a lot of spelling mistakes, let's delete it.
-/// book_reviews.remove(&("The Adventures of Sherlock Holmes"));
-///
-/// // look up the values associated with some keys.
-/// let to_find = ["Pride and Prejudice", "Alice's Adventure in Wonderland"];
-/// for book in to_find.iter() {
-/// match book_reviews.find(book) {
-/// Some(review) => println!("{}: {}", *book, *review),
-/// None => println!("{} is unreviewed.", *book)
-/// }
-/// }
-///
-/// // iterate over everything.
-/// for (book, review) in book_reviews.iter() {
-/// println!("{}: \"{}\"", *book, *review);
-/// }
-/// ```
-///
-/// The easiest way to use `HashMap` with a custom type is to derive `Eq` and `Hash`.
-/// We must also derive `PartialEq`.
-///
-/// ```
-/// use std::collections::HashMap;
-///
-/// #[deriving(Hash, Eq, PartialEq, Show)]
-/// struct Viking<'a> {
-/// name: &'a str,
-/// power: uint,
-/// }
-///
-/// let mut vikings = HashMap::new();
-///
-/// vikings.insert("Norway", Viking { name: "Einar", power: 9u });
-/// vikings.insert("Denmark", Viking { name: "Olaf", power: 4u });
-/// vikings.insert("Iceland", Viking { name: "Harald", power: 8u });
-///
-/// // Use derived implementation to print the vikings.
-/// for (land, viking) in vikings.iter() {
-/// println!("{} at {}", viking, land);
-/// }
-/// ```
-#[deriving(Clone)]
-pub struct HashMap<K, V, H = RandomSipHasher> {
- // All hashes are keyed on these values, to prevent hash collision attacks.
- hasher: H,
-
- table: table::RawTable<K, V>,
-
- // We keep this at the end since it might as well have tail padding.
- resize_policy: DefaultResizePolicy,
-}
-
-/// Search for a pre-hashed key.
-fn search_hashed_generic<K, V, M: Deref<RawTable<K, V>>>(table: M, hash: &table::SafeHash, is_match: |&K| -> bool)
- -> Option<FullBucket<K, V, M>> {
- let size = table.size();
- let mut probe = Bucket::new(table, hash);
- let ib = probe.index();
-
- while probe.index() != ib + size {
- let full = match probe.peek() {
- table::Empty(_) => return None, // hit an empty bucket
- table::Full(b) => b
- };
-
- if full.distance() + ib < full.index() {
- return None;
- }
-
- // If the hash doesn't match, it can't be this one..
- if *hash == full.hash() {
- let matched = {
- let (k, _) = full.read();
- is_match(k)
- };
-
- // If the key doesn't match, it can't be this one..
- if matched {
- return Some(full);
- }
- }
-
- probe = full.next();
- }
-
- None
-}
-
-fn search_hashed<K: Eq, V, M: Deref<RawTable<K, V>>>(table: M, hash: &table::SafeHash, k: &K)
- -> Option<table::FullBucket<K, V, M>> {
- search_hashed_generic(table, hash, |k_| *k == *k_)
-}
-
-fn pop_internal<K, V>(starting_bucket: FullBucketMut<K, V>) -> V {
- let size = {
- let table = starting_bucket.table();
- table.size()
- };
- let (empty, _k, retval) = starting_bucket.take();
- let mut gap = match empty.gap_peek() {
- Some(b) => b,
- None => return retval
- };
- // COMPILER error! wrong enum optimization. sets ptr to 0
-
- for _ in range(0, size) {
- if gap.full().distance() != 0 {
- gap = match gap.shift() {
- Some(b) => b,
- None => return retval
- };
- continue;
- }
-
- break;
- }
-
- // Now we're done all our shifting. Return the value we grabbed
- // earlier.
- return retval;
-}
-
-impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> HashMap<K, V, H> {
- fn make_hash<X: Hash<S>>(&self, x: &X) -> table::SafeHash {
- table::make_hash(&self.hasher, x)
- }
-
- fn search_equiv<'a, Q: Hash<S> + Equiv<K>>(&'a self, q: &Q)
- -> Option<FullBucketImm<'a, K, V>> {
- let hash = self.make_hash(q);
- search_hashed_generic(&self.table, &hash, |k| q.equiv(k))
- }
-
- fn search_equiv_mut<'a, Q: Hash<S> + Equiv<K>>(&'a mut self, q: &Q)
- -> Option<FullBucketMut<'a, K, V>> {
- let hash = self.make_hash(q);
- search_hashed_generic(&mut self.table, &hash, |k| q.equiv(k))
- }
-
- /// Search for a key, yielding the index if it's found in the hashtable.
- /// If you already have the hash for the key lying around, use
- /// search_hashed.
- fn search<'a>(&'a self, k: &K) -> Option<FullBucketImm<'a, K, V>> {
- let hash = self.make_hash(k);
- search_hashed(&self.table, &hash, k)
- }
-
- fn search_mut<'a>(&'a mut self, k: &K) -> Option<FullBucketMut<'a, K, V>> {
- let hash = self.make_hash(k);
- search_hashed(&mut self.table, &hash, k)
- }
-
- fn insert_hashed_ordered(&mut self, hash: table::SafeHash, k: K, v: V) {
- let cap = self.table.capacity();
- let mut buckets = Bucket::new(&mut self.table, &hash);
- let ib = buckets.index();
- while buckets.index() != ib + cap {
- buckets = match buckets.peek() {
- table::Empty(empty) => {
- empty.put(hash, k, v);
- return;
- }
- table::Full(b) => b.into_bucket()
- };
- buckets.next();
- }
- fail!("Internal HashMap error: Out of space.");
- }
-}
-
-impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> Collection for HashMap<K, V, H> {
- /// Return the number of elements in the map.
- fn len(&self) -> uint { self.table.size() }
-}
-
-impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> Mutable for HashMap<K, V, H> {
- /// Clear the map, removing all key-value pairs. Keeps the allocated memory
- /// for reuse.
- fn clear(&mut self) {
- // Prevent reallocations from happening from now on. Makes it possible
- // for the map to be reused but has a downside: reserves permanently.
- self.resize_policy.reserve(self.table.size());
-
- let cap = self.table.capacity();
- let mut buckets = Bucket::first(&mut self.table);
-
- while buckets.index() != cap {
- buckets = match buckets.peek() {
- table::Empty(b) => b.next(),
- table::Full(full) => {
- let (b, _, _) = full.take();
- b.next()
- }
- };
- }
- }
-}
-
-impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> Map<K, V> for HashMap<K, V, H> {
- fn find<'a>(&'a self, k: &K) -> Option<&'a V> {
- self.search(k).map(|bucket| {
- let (_, v) = bucket.into_refs();
- v
- })
- }
-
- fn contains_key(&self, k: &K) -> bool {
- self.search(k).is_some()
- }
-}
-
-impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> MutableMap<K, V> for HashMap<K, V, H> {
- fn find_mut<'a>(&'a mut self, k: &K) -> Option<&'a mut V> {
- match self.search_mut(k) {
- Some(bucket) => {
- let (_, v) = bucket.into_mut_refs();
- Some(v)
- }
- _ => None
- }
- }
-
- fn swap(&mut self, k: K, v: V) -> Option<V> {
- let hash = self.make_hash(&k);
- let potential_new_size = self.table.size() + 1;
- self.make_some_room(potential_new_size);
-
- let mut retval = None;
- self.insert_or_replace_with(hash, k, v, |val_ref, val| {
- retval = Some(replace(val_ref, val));
- });
- retval
- }
-
-
- fn pop(&mut self, k: &K) -> Option<V> {
- if self.table.size() == 0 {
- return None
- }
-
- let potential_new_size = self.table.size() - 1;
- self.make_some_room(potential_new_size);
-
- self.search_mut(k).map(|bucket| {
- pop_internal(bucket)
- })
- }
-}
-
-impl<K: Hash + Eq, V> HashMap<K, V, RandomSipHasher> {
- /// Create an empty HashMap.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- /// let mut map: HashMap<&str, int> = HashMap::new();
- /// ```
- #[inline]
- pub fn new() -> HashMap<K, V, RandomSipHasher> {
- let hasher = RandomSipHasher::new();
- HashMap::with_hasher(hasher)
- }
-
- /// Creates an empty hash map with the given initial capacity.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- /// let mut map: HashMap<&str, int> = HashMap::with_capacity(10);
- /// ```
- #[inline]
- pub fn with_capacity(capacity: uint) -> HashMap<K, V, RandomSipHasher> {
- let hasher = RandomSipHasher::new();
- HashMap::with_capacity_and_hasher(capacity, hasher)
- }
-}
-
-impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> HashMap<K, V, H> {
- /// Creates an empty hashmap which will use the given hasher to hash keys.
- ///
- /// The creates map has the default initial capacity.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- /// use std::hash::sip::SipHasher;
- ///
- /// let h = SipHasher::new();
- /// let mut map = HashMap::with_hasher(h);
- /// map.insert(1i, 2u);
- /// ```
- #[inline]
- pub fn with_hasher(hasher: H) -> HashMap<K, V, H> {
- HashMap {
- hasher: hasher,
- resize_policy: DefaultResizePolicy::new(INITIAL_CAPACITY),
- table: table::RawTable::new(0),
- }
- }
-
- /// Create an empty HashMap with space for at least `capacity`
- /// elements, using `hasher` to hash the keys.
- ///
- /// Warning: `hasher` is normally randomly generated, and
- /// is designed to allow HashMaps to be resistant to attacks that
- /// cause many collisions and very poor performance. Setting it
- /// manually using this function can expose a DoS attack vector.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- /// use std::hash::sip::SipHasher;
- ///
- /// let h = SipHasher::new();
- /// let mut map = HashMap::with_capacity_and_hasher(10, h);
- /// map.insert(1i, 2u);
- /// ```
- #[inline]
- pub fn with_capacity_and_hasher(capacity: uint, hasher: H) -> HashMap<K, V, H> {
- let cap = num::next_power_of_two(max(INITIAL_CAPACITY, capacity));
- HashMap {
- hasher: hasher,
- resize_policy: DefaultResizePolicy::new(cap),
- table: table::RawTable::new(cap),
- }
- }
-
- /// The hashtable will never try to shrink below this size. You can use
- /// this function to reduce reallocations if your hashtable frequently
- /// grows and shrinks by large amounts.
- ///
- /// This function has no effect on the operational semantics of the
- /// hashtable, only on performance.
- ///
- /// ```
- /// use std::collections::HashMap;
- /// let mut map: HashMap<&str, int> = HashMap::new();
- /// map.reserve(10);
- /// ```
- pub fn reserve(&mut self, new_minimum_capacity: uint) {
- let cap = num::next_power_of_two(
- max(INITIAL_CAPACITY, new_minimum_capacity));
-
- self.resize_policy.reserve(cap);
-
- if self.table.capacity() < cap {
- self.resize(cap);
- }
- }
-
- /// Resizes the internal vectors to a new capacity. It's your responsibility to:
- /// 1) Make sure the new capacity is enough for all the elements, accounting
- /// for the load factor.
- /// 2) Ensure new_capacity is a power of two.
- fn resize(&mut self, new_capacity: uint) {
- assert!(self.table.size() <= new_capacity);
- assert!(num::is_power_of_two(new_capacity));
-
- let mut old_table = replace(&mut self.table, table::RawTable::new(new_capacity));
- let old_size = old_table.size();
-
- if old_table.capacity() == 0 {
- return;
- }
-
- if new_capacity < old_table.capacity() {
- for (h, k, v) in old_table.move_iter() {
- self.insert_hashed_nocheck(h, k, v);
- }
- } else {
- let mut bucket = Bucket::first(&mut old_table);
-
- loop {
- match bucket.peek() {
- table::Full(full) => {
- if full.distance() == 0 {
- bucket = full.into_bucket();
- break;
- }
- bucket = full.next();
- }
- table::Empty(b) => {
- bucket = b.next();
- break;
- }
- };
- }
-
- loop {
- bucket = match bucket.peek() {
- table::Full(bucket) => {
- {
- let t = bucket.table();
- if t.size() == 0 { break }
- }
- let h = bucket.hash();
- let (b, k, v) = bucket.take();
- self.insert_hashed_ordered(h, k, v);
- b.into_bucket()
- }
- table::Empty(b) => b.into_bucket()
- };
- bucket.next();
- }
- }
-
- assert_eq!(self.table.size(), old_size);
- }
-
- /// Performs any necessary resize operations, such that there's space for
- /// new_size elements.
- fn make_some_room(&mut self, new_size: uint) {
- let (grow_at, shrink_at) = self.resize_policy.capacity_range(new_size);
- let cap = self.table.capacity();
-
- // An invalid value shouldn't make us run out of space.
- debug_assert!(grow_at >= new_size);
-
- if cap <= grow_at {
- let new_capacity = max(cap << 1, INITIAL_CAPACITY);
- self.resize(new_capacity);
- } else if shrink_at <= cap {
- let new_capacity = cap >> 1;
- self.resize(new_capacity);
- }
- }
-
- /// Insert a pre-hashed key-value pair, without first checking
- /// that there's enough room in the buckets. Returns a reference to the
- /// newly insert value.
- ///
- /// If the key already exists, the hashtable will be returned untouched
- /// and a reference to the existing element will be returned.
- fn insert_hashed_nocheck<'a>(
- &'a mut self, hash: table::SafeHash, k: K, v: V) -> &'a mut V {
- self.insert_or_replace_with(hash, k, v, |_, _| ())
- }
-
- fn insert_or_replace_with<'a>(
- &'a mut self, hash: table::SafeHash, k: K, v: V,
- found_existing: |&mut V, V|
- ) -> &'a mut V {
-
- // Worst case, we'll find one empty bucket among `size + 1` buckets.
- let size = self.table.size();
- let mut rbucket = Bucket::new(&mut self.table, &hash);
- let ib = rbucket.index();
-
- loop {
- let mut bucket = match rbucket.peek() {
- table::Empty(bucket) => {
- // Found a hole!
- let bucket = bucket.put(hash, k, v);
- let (_, val) = bucket.into_mut_refs();
- return val;
- },
- table::Full(bucket) => bucket
- };
-
- if bucket.hash() == hash {
- let (bucket_k, bucket_v) = bucket.read_mut();
- // FIXME #12147 the conditional return confuses
- // borrowck if we return bucket_v directly
- let bv: *mut V = bucket_v;
- if k == *bucket_k {
- // Key already exists. Get its reference.
- found_existing(bucket_v, v);
- return unsafe {&mut *bv};
- }
- }
-
- let robin_ib = bucket.index() as int - bucket.distance() as int;
-
- if (ib as int) < robin_ib {
- // Found a luckier bucket than me. Better steal his spot.
- let (mut hash, mut k, mut v) = bucket.replace(hash, k, v);
- let robin_index = bucket.index();
- let mut robin_ib = robin_ib as uint;
- let mut rbucket = bucket.next();
- loop {
- let mut bucket = match rbucket.peek() {
- table::Empty(bucket) => {
- // Found a hole!
- let b = bucket.put(hash, k, v);
- // Now that it's stolen, just read the value's pointer
- // right out of the table!
- let (_, v) = match Bucket::at_index(b.into_table(), robin_index).peek() {
- table::Full(b) => b.into_mut_refs(),
- _ => fail!()
- };
- return v;
- },
- table::Full(bucket) => bucket
- };
-
- let probe_ib = bucket.index() - bucket.distance();
-
- // Robin hood! Steal the spot.
- if robin_ib < probe_ib {
- robin_ib = probe_ib;
- let (old_hash, old_key, old_val) = bucket.replace(hash, k, v);
- hash = old_hash;
- k = old_key;
- v = old_val;
- }
- rbucket = bucket.next();
- if rbucket.index() == ib + size + 1 {
- fail!("HashMap fatal error: 100% load factor?")
- }
- }
- }
- rbucket = bucket.next();
- if rbucket.index() == ib + size + 1 {
- fail!("Internal HashMap error: Out of space.")
- }
- }
- }
-
- /// Inserts an element which has already been hashed, returning a reference
- /// to that element inside the hashtable. This is more efficient that using
- /// `insert`, since the key will not be rehashed.
- fn insert_hashed<'a>(&'a mut self, hash: table::SafeHash, k: K, v: V) -> &'a mut V {
- let potential_new_size = self.table.size() + 1;
- self.make_some_room(potential_new_size);
- self.insert_hashed_nocheck(hash, k, v)
- }
-
- /// Return the value corresponding to the key in the map, or insert
- /// and return the value if it doesn't exist.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- /// let mut map = HashMap::new();
- ///
- /// // Insert 1i with key "a"
- /// assert_eq!(*map.find_or_insert("a", 1i), 1);
- ///
- /// // Find the existing key
- /// assert_eq!(*map.find_or_insert("a", -2), 1);
- /// ```
- pub fn find_or_insert<'a>(&'a mut self, k: K, v: V) -> &'a mut V {
- self.find_with_or_insert_with(k, v, |_k, _v, _a| (), |_k, a| a)
- }
-
- /// Return the value corresponding to the key in the map, or create,
- /// insert, and return a new value if it doesn't exist.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- /// let mut map = HashMap::new();
- ///
- /// // Insert 10 with key 2
- /// assert_eq!(*map.find_or_insert_with(2i, |&key| 5 * key as uint), 10u);
- ///
- /// // Find the existing key
- /// assert_eq!(*map.find_or_insert_with(2, |&key| key as uint), 10);
- /// ```
- pub fn find_or_insert_with<'a>(&'a mut self, k: K, f: |&K| -> V)
- -> &'a mut V {
- self.find_with_or_insert_with(k, (), |_k, _v, _a| (), |k, _a| f(k))
- }
-
- /// Insert a key-value pair into the map if the key is not already present.
- /// Otherwise, modify the existing value for the key.
- /// Returns the new or modified value for the key.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- /// let mut map = HashMap::new();
- ///
- /// // Insert 2 with key "a"
- /// assert_eq!(*map.insert_or_update_with("a", 2u, |_key, val| *val = 3), 2);
- ///
- /// // Update and return the existing value
- /// assert_eq!(*map.insert_or_update_with("a", 9, |_key, val| *val = 7), 7);
- /// assert_eq!(map["a"], 7);
- /// ```
- pub fn insert_or_update_with<'a>(
- &'a mut self,
- k: K,
- v: V,
- f: |&K, &mut V|)
- -> &'a mut V {
- self.find_with_or_insert_with(k, v, |k, v, _a| f(k, v), |_k, a| a)
- }
-
- /// Modify and return the value corresponding to the key in the map, or
- /// insert and return a new value if it doesn't exist.
- ///
- /// This method allows for all insertion behaviours of a hashmap;
- /// see methods like
- /// [`insert`](../trait.MutableMap.html#tymethod.insert),
- /// [`find_or_insert`](#method.find_or_insert) and
- /// [`insert_or_update_with`](#method.insert_or_update_with)
- /// for less general and more friendly variations of this.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- ///
- /// // map some strings to vectors of strings
- /// let mut map = HashMap::new();
- /// map.insert("a key", vec!["value"]);
- /// map.insert("z key", vec!["value"]);
- ///
- /// let new = vec!["a key", "b key", "z key"];
- ///
- /// for k in new.move_iter() {
- /// map.find_with_or_insert_with(
- /// k, "new value",
- /// // if the key does exist either prepend or append this
- /// // new value based on the first letter of the key.
- /// |key, already, new| {
- /// if key.as_slice().starts_with("z") {
- /// already.insert(0, new);
- /// } else {
- /// already.push(new);
- /// }
- /// },
- /// // if the key doesn't exist in the map yet, add it in
- /// // the obvious way.
- /// |_k, v| vec![v]);
- /// }
- ///
- /// assert_eq!(map.len(), 3);
- /// assert_eq!(map["a key"], vec!["value", "new value"]);
- /// assert_eq!(map["b key"], vec!["new value"]);
- /// assert_eq!(map["z key"], vec!["new value", "value"]);
- /// ```
- pub fn find_with_or_insert_with<'a, A>(&'a mut self,
- k: K,
- a: A,
- found: |&K, &mut V, A|,
- not_found: |&K, A| -> V)
- -> &'a mut V {
- let hash = self.make_hash(&k);
- {
- match search_hashed(&mut self.table, &hash, &k) {
- Some(bucket) => {
- let (_, v_ref) = bucket.into_mut_refs();
- found(&k, v_ref, a);
- return v_ref;
- }
- _ => {
- }
- };
- }
- let v = not_found(&k, a);
- self.insert_hashed(hash, k, v)
- }
-
- /// Retrieves a value for the given key.
- /// See [`find`](../trait.Map.html#tymethod.find) for a non-failing alternative.
- ///
- /// # Failure
- ///
- /// Fails if the key is not present.
- ///
- /// # Example
- ///
- /// ```
- /// #![allow(deprecated)]
- ///
- /// use std::collections::HashMap;
- ///
- /// let mut map = HashMap::new();
- /// map.insert("a", 1i);
- /// assert_eq!(map.get(&"a"), &1);
- /// ```
- #[deprecated = "prefer indexing instead, e.g., map[key]"]
- pub fn get<'a>(&'a self, k: &K) -> &'a V {
- match self.find(k) {
- Some(v) => v,
- None => fail!("no entry found for key")
- }
- }
-
- /// Retrieves a mutable value for the given key.
- /// See [`find_mut`](../trait.MutableMap.html#tymethod.find_mut) for a non-failing alternative.
- ///
- /// # Failure
- ///
- /// Fails if the key is not present.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- ///
- /// let mut map = HashMap::new();
- /// map.insert("a", 1i);
- /// {
- /// // val will freeze map to prevent usage during its lifetime
- /// let val = map.get_mut(&"a");
- /// *val = 40;
- /// }
- /// assert_eq!(map["a"], 40);
- ///
- /// // A more direct way could be:
- /// *map.get_mut(&"a") = -2;
- /// assert_eq!(map["a"], -2);
- /// ```
- pub fn get_mut<'a>(&'a mut self, k: &K) -> &'a mut V {
- match self.find_mut(k) {
- Some(v) => v,
- None => fail!("no entry found for key")
- }
- }
-
- /// Return true if the map contains a value for the specified key,
- /// using equivalence.
- ///
- /// See [pop_equiv](#method.pop_equiv) for an extended example.
- pub fn contains_key_equiv<Q: Hash<S> + Equiv<K>>(&self, key: &Q) -> bool {
- self.search_equiv(key).is_some()
- }
-
- /// Return the value corresponding to the key in the map, using
- /// equivalence.
- ///
- /// See [pop_equiv](#method.pop_equiv) for an extended example.
- pub fn find_equiv<'a, Q: Hash<S> + Equiv<K>>(&'a self, k: &Q) -> Option<&'a V> {
- match self.search_equiv(k) {
- None => None,
- Some(bucket) => {
- let (_, v_ref) = bucket.into_refs();
- Some(v_ref)
- }
- }
- }
-
- /// Remove an equivalent key from the map, returning the value at the
- /// key if the key was previously in the map.
- ///
- /// # Example
- ///
- /// This is a slightly silly example where we define the number's parity as
- /// the equivalence class. It is important that the values hash the same,
- /// which is why we override `Hash`.
- ///
- /// ```
- /// use std::collections::HashMap;
- /// use std::hash::Hash;
- /// use std::hash::sip::SipState;
- ///
- /// #[deriving(Eq, PartialEq)]
- /// struct EvenOrOdd {
- /// num: uint
- /// };
- ///
- /// impl Hash for EvenOrOdd {
- /// fn hash(&self, state: &mut SipState) {
- /// let parity = self.num % 2;
- /// parity.hash(state);
- /// }
- /// }
- ///
- /// impl Equiv<EvenOrOdd> for EvenOrOdd {
- /// fn equiv(&self, other: &EvenOrOdd) -> bool {
- /// self.num % 2 == other.num % 2
- /// }
- /// }
- ///
- /// let mut map = HashMap::new();
- /// map.insert(EvenOrOdd { num: 3 }, "foo");
- ///
- /// assert!(map.contains_key_equiv(&EvenOrOdd { num: 1 }));
- /// assert!(!map.contains_key_equiv(&EvenOrOdd { num: 4 }));
- ///
- /// assert_eq!(map.find_equiv(&EvenOrOdd { num: 5 }), Some(&"foo"));
- /// assert_eq!(map.find_equiv(&EvenOrOdd { num: 2 }), None);
- ///
- /// assert_eq!(map.pop_equiv(&EvenOrOdd { num: 1 }), Some("foo"));
- /// assert_eq!(map.pop_equiv(&EvenOrOdd { num: 2 }), None);
- ///
- /// ```
- #[experimental]
- pub fn pop_equiv<Q:Hash<S> + Equiv<K>>(&mut self, k: &Q) -> Option<V> {
- if self.table.size() == 0 {
- return None
- }
-
- let potential_new_size = self.table.size() - 1;
- self.make_some_room(potential_new_size);
-
- match self.search_equiv_mut(k) {
- Some(bucket) => {
- Some(pop_internal(bucket))
- }
- _ => None
- }
- }
-
- /// An iterator visiting all keys in arbitrary order.
- /// Iterator element type is `&'a K`.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- ///
- /// let mut map = HashMap::new();
- /// map.insert("a", 1i);
- /// map.insert("b", 2);
- /// map.insert("c", 3);
- ///
- /// for key in map.keys() {
- /// println!("{}", key);
- /// }
- /// ```
- pub fn keys<'a>(&'a self) -> Keys<'a, K, V> {
- self.iter().map(|(k, _v)| k)
- }
-
- /// An iterator visiting all values in arbitrary order.
- /// Iterator element type is `&'a V`.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- ///
- /// let mut map = HashMap::new();
- /// map.insert("a", 1i);
- /// map.insert("b", 2);
- /// map.insert("c", 3);
- ///
- /// for key in map.values() {
- /// println!("{}", key);
- /// }
- /// ```
- pub fn values<'a>(&'a self) -> Values<'a, K, V> {
- self.iter().map(|(_k, v)| v)
- }
-
- /// An iterator visiting all key-value pairs in arbitrary order.
- /// Iterator element type is `(&'a K, &'a V)`.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- ///
- /// let mut map = HashMap::new();
- /// map.insert("a", 1i);
- /// map.insert("b", 2);
- /// map.insert("c", 3);
- ///
- /// for (key, val) in map.iter() {
- /// println!("key: {} val: {}", key, val);
- /// }
- /// ```
- pub fn iter<'a>(&'a self) -> Entries<'a, K, V> {
- self.table.iter()
- }
-
- /// An iterator visiting all key-value pairs in arbitrary order,
- /// with mutable references to the values.
- /// Iterator element type is `(&'a K, &'a mut V)`.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- ///
- /// let mut map = HashMap::new();
- /// map.insert("a", 1i);
- /// map.insert("b", 2);
- /// map.insert("c", 3);
- ///
- /// // Update all values
- /// for (_, val) in map.mut_iter() {
- /// *val *= 2;
- /// }
- ///
- /// for (key, val) in map.iter() {
- /// println!("key: {} val: {}", key, val);
- /// }
- /// ```
- pub fn mut_iter<'a>(&'a mut self) -> MutEntries<'a, K, V> {
- self.table.mut_iter()
- }
-
- /// Creates a consuming iterator, that is, one that moves each key-value
- /// pair out of the map in arbitrary order. The map cannot be used after
- /// calling this.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- ///
- /// let mut map = HashMap::new();
- /// map.insert("a", 1i);
- /// map.insert("b", 2);
- /// map.insert("c", 3);
- ///
- /// // Not possible with .iter()
- /// let vec: Vec<(&str, int)> = map.move_iter().collect();
- /// ```
- pub fn move_iter(self) -> MoveEntries<K, V> {
- self.table.move_iter().map(|(_, k, v)| (k, v))
- }
-}
-
-impl<K: Eq + Hash<S>, V: Clone, S, H: Hasher<S>> HashMap<K, V, H> {
- /// Return a copy of the value corresponding to the key.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- ///
- /// let mut map: HashMap<uint, String> = HashMap::new();
- /// map.insert(1u, "foo".to_string());
- /// let s: String = map.find_copy(&1).unwrap();
- /// ```
- pub fn find_copy(&self, k: &K) -> Option<V> {
- self.find(k).map(|v| (*v).clone())
- }
-
- /// Return a copy of the value corresponding to the key.
- ///
- /// # Failure
- ///
- /// Fails if the key is not present.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashMap;
- ///
- /// let mut map: HashMap<uint, String> = HashMap::new();
- /// map.insert(1u, "foo".to_string());
- /// let s: String = map.get_copy(&1);
- /// ```
- pub fn get_copy(&self, k: &K) -> V {
- (*self.get(k)).clone()
- }
-}
-
-impl<K: Eq + Hash<S>, V: PartialEq, S, H: Hasher<S>> PartialEq for HashMap<K, V, H> {
- fn eq(&self, other: &HashMap<K, V, H>) -> bool {
- if self.len() != other.len() { return false; }
-
- self.iter()
- .all(|(key, value)| {
- match other.find(key) {
- None => false,
- Some(v) => *value == *v
- }
- })
- }
-}
-
-impl<K: Eq + Hash<S>, V: Eq, S, H: Hasher<S>> Eq for HashMap<K, V, H> {}
-
-impl<K: Eq + Hash<S> + Show, V: Show, S, H: Hasher<S>> Show for HashMap<K, V, H> {
- fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
- try!(write!(f, "{{"));
-
- for (i, (k, v)) in self.iter().enumerate() {
- if i != 0 { try!(write!(f, ", ")); }
- try!(write!(f, "{}: {}", *k, *v));
- }
-
- write!(f, "}}")
- }
-}
-
-impl<K: Eq + Hash<S>, V, S, H: Hasher<S> + Default> Default for HashMap<K, V, H> {
- fn default() -> HashMap<K, V, H> {
- HashMap::with_hasher(Default::default())
- }
-}
-
-impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> Index<K, V> for HashMap<K, V, H> {
- #[inline]
- fn index<'a>(&'a self, index: &K) -> &'a V {
- self.get(index)
- }
-}
-
-// FIXME(#12825) Indexing will always try IndexMut first and that causes issues.
-/*impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> ops::IndexMut<K, V> for HashMap<K, V, H> {
- #[inline]
- fn index_mut<'a>(&'a mut self, index: &K) -> &'a mut V {
- self.get_mut(index)
- }
-}*/
-
-/// HashMap iterator
-pub type Entries<'a, K, V> = table::Entries<'a, K, V>;
-
-/// HashMap mutable values iterator
-pub type MutEntries<'a, K, V> = table::MutEntries<'a, K, V>;
-
-/// HashMap move iterator
-pub type MoveEntries<K, V> =
- iter::Map<'static, (table::SafeHash, K, V), (K, V), table::MoveEntries<K, V>>;
-
-/// HashMap keys iterator
-pub type Keys<'a, K, V> =
- iter::Map<'static, (&'a K, &'a V), &'a K, Entries<'a, K, V>>;
-
-/// HashMap values iterator
-pub type Values<'a, K, V> =
- iter::Map<'static, (&'a K, &'a V), &'a V, Entries<'a, K, V>>;
-
-impl<K: Eq + Hash<S>, V, S, H: Hasher<S> + Default> FromIterator<(K, V)> for HashMap<K, V, H> {
- fn from_iter<T: Iterator<(K, V)>>(iter: T) -> HashMap<K, V, H> {
- let (lower, _) = iter.size_hint();
- let mut map = HashMap::with_capacity_and_hasher(lower, Default::default());
- map.extend(iter);
- map
- }
-}
-
-impl<K: Eq + Hash<S>, V, S, H: Hasher<S> + Default> Extendable<(K, V)> for HashMap<K, V, H> {
- fn extend<T: Iterator<(K, V)>>(&mut self, mut iter: T) {
- for (k, v) in iter {
- self.insert(k, v);
- }
- }
-}
-
-/// HashSet iterator
-pub type SetItems<'a, K> =
- iter::Map<'static, (&'a K, &'a ()), &'a K, Entries<'a, K, ()>>;
-
-/// HashSet move iterator
-pub type SetMoveItems<K> =
- iter::Map<'static, (K, ()), K, MoveEntries<K, ()>>;
-
-/// An implementation of a hash set using the underlying representation of a
-/// HashMap where the value is (). As with the `HashMap` type, a `HashSet`
-/// requires that the elements implement the `Eq` and `Hash` traits.
-///
-/// # Example
-///
-/// ```
-/// use std::collections::HashSet;
-///
-/// // Type inference lets us omit an explicit type signature (which
-/// // would be `HashSet<&str>` in this example).
-/// let mut books = HashSet::new();
-///
-/// // Add some books.
-/// books.insert("A Dance With Dragons");
-/// books.insert("To Kill a Mockingbird");
-/// books.insert("The Odyssey");
-/// books.insert("The Great Gatsby");
-///
-/// // Check for a specific one.
-/// if !books.contains(&("The Winds of Winter")) {
-/// println!("We have {} books, but The Winds of Winter ain't one.",
-/// books.len());
-/// }
-///
-/// // Remove a book.
-/// books.remove(&"The Odyssey");
-///
-/// // Iterate over everything.
-/// for book in books.iter() {
-/// println!("{}", *book);
-/// }
-/// ```
-///
-/// The easiest way to use `HashSet` with a custom type is to derive
-/// `Eq` and `Hash`. We must also derive `PartialEq`, this will in the
-/// future be implied by `Eq`.
-///
-/// ```rust
-/// use std::collections::HashSet;
-///
-/// #[deriving(Hash, Eq, PartialEq, Show)]
-/// struct Viking<'a> {
-/// name: &'a str,
-/// power: uint,
-/// }
-///
-/// let mut vikings = HashSet::new();
-///
-/// vikings.insert(Viking { name: "Einar", power: 9u });
-/// vikings.insert(Viking { name: "Einar", power: 9u });
-/// vikings.insert(Viking { name: "Olaf", power: 4u });
-/// vikings.insert(Viking { name: "Harald", power: 8u });
-///
-/// // Use derived implementation to print the vikings.
-/// for x in vikings.iter() {
-/// println!("{}", x);
-/// }
-/// ```
-#[deriving(Clone)]
-pub struct HashSet<T, H = RandomSipHasher> {
- map: HashMap<T, (), H>
-}
-
-impl<T: Hash + Eq> HashSet<T, RandomSipHasher> {
- /// Create an empty HashSet.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashSet;
- /// let mut set: HashSet<int> = HashSet::new();
- /// ```
- #[inline]
- pub fn new() -> HashSet<T, RandomSipHasher> {
- HashSet::with_capacity(INITIAL_CAPACITY)
- }
-
- /// Create an empty HashSet with space for at least `n` elements in
- /// the hash table.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashSet;
- /// let mut set: HashSet<int> = HashSet::with_capacity(10);
- /// ```
- #[inline]
- pub fn with_capacity(capacity: uint) -> HashSet<T, RandomSipHasher> {
- HashSet { map: HashMap::with_capacity(capacity) }
- }
-}
-
-impl<T: Eq + Hash<S>, S, H: Hasher<S>> HashSet<T, H> {
- /// Creates a new empty hash set which will use the given hasher to hash
- /// keys.
- ///
- /// The hash set is also created with the default initial capacity.
- ///
- /// # Example
- ///
- /// ```rust
- /// use std::collections::HashSet;
- /// use std::hash::sip::SipHasher;
- ///
- /// let h = SipHasher::new();
- /// let mut set = HashSet::with_hasher(h);
- /// set.insert(2u);
- /// ```
- #[inline]
- pub fn with_hasher(hasher: H) -> HashSet<T, H> {
- HashSet::with_capacity_and_hasher(INITIAL_CAPACITY, hasher)
- }
-
- /// Create an empty HashSet with space for at least `capacity`
- /// elements in the hash table, using `hasher` to hash the keys.
- ///
- /// Warning: `hasher` is normally randomly generated, and
- /// is designed to allow `HashSet`s to be resistant to attacks that
- /// cause many collisions and very poor performance. Setting it
- /// manually using this function can expose a DoS attack vector.
- ///
- /// # Example
- ///
- /// ```rust
- /// use std::collections::HashSet;
- /// use std::hash::sip::SipHasher;
- ///
- /// let h = SipHasher::new();
- /// let mut set = HashSet::with_capacity_and_hasher(10u, h);
- /// set.insert(1i);
- /// ```
- #[inline]
- pub fn with_capacity_and_hasher(capacity: uint, hasher: H) -> HashSet<T, H> {
- HashSet { map: HashMap::with_capacity_and_hasher(capacity, hasher) }
- }
-
- /// Reserve space for at least `n` elements in the hash table.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashSet;
- /// let mut set: HashSet<int> = HashSet::new();
- /// set.reserve(10);
- /// ```
- pub fn reserve(&mut self, n: uint) {
- self.map.reserve(n)
- }
-
- /// Returns true if the hash set contains a value equivalent to the
- /// given query value.
- ///
- /// # Example
- ///
- /// This is a slightly silly example where we define the number's
- /// parity as the equivalence class. It is important that the
- /// values hash the same, which is why we implement `Hash`.
- ///
- /// ```rust
- /// use std::collections::HashSet;
- /// use std::hash::Hash;
- /// use std::hash::sip::SipState;
- ///
- /// #[deriving(Eq, PartialEq)]
- /// struct EvenOrOdd {
- /// num: uint
- /// };
- ///
- /// impl Hash for EvenOrOdd {
- /// fn hash(&self, state: &mut SipState) {
- /// let parity = self.num % 2;
- /// parity.hash(state);
- /// }
- /// }
- ///
- /// impl Equiv<EvenOrOdd> for EvenOrOdd {
- /// fn equiv(&self, other: &EvenOrOdd) -> bool {
- /// self.num % 2 == other.num % 2
- /// }
- /// }
- ///
- /// let mut set = HashSet::new();
- /// set.insert(EvenOrOdd { num: 3u });
- ///
- /// assert!(set.contains_equiv(&EvenOrOdd { num: 3u }));
- /// assert!(set.contains_equiv(&EvenOrOdd { num: 5u }));
- /// assert!(!set.contains_equiv(&EvenOrOdd { num: 4u }));
- /// assert!(!set.contains_equiv(&EvenOrOdd { num: 2u }));
- ///
- /// ```
- pub fn contains_equiv<Q: Hash<S> + Equiv<T>>(&self, value: &Q) -> bool {
- self.map.contains_key_equiv(value)
- }
-
- /// An iterator visiting all elements in arbitrary order.
- /// Iterator element type is &'a T.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashSet;
- /// let mut set = HashSet::new();
- /// set.insert("a");
- /// set.insert("b");
- ///
- /// // Will print in an arbitrary order.
- /// for x in set.iter() {
- /// println!("{}", x);
- /// }
- /// ```
- pub fn iter<'a>(&'a self) -> SetItems<'a, T> {
- self.map.keys()
- }
-
- /// Creates a consuming iterator, that is, one that moves each value out
- /// of the set in arbitrary order. The set cannot be used after calling
- /// this.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashSet;
- /// let mut set = HashSet::new();
- /// set.insert("a".to_string());
- /// set.insert("b".to_string());
- ///
- /// // Not possible to collect to a Vec<String> with a regular `.iter()`.
- /// let v: Vec<String> = set.move_iter().collect();
- ///
- /// // Will print in an arbitrary order.
- /// for x in v.iter() {
- /// println!("{}", x);
- /// }
- /// ```
- pub fn move_iter(self) -> SetMoveItems<T> {
- self.map.move_iter().map(|(k, _)| k)
- }
-
- /// Visit the values representing the difference.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashSet;
- /// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
- /// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
- ///
- /// // Can be seen as `a - b`.
- /// for x in a.difference(&b) {
- /// println!("{}", x); // Print 1
- /// }
- ///
- /// let diff: HashSet<int> = a.difference(&b).map(|&x| x).collect();
- /// assert_eq!(diff, [1i].iter().map(|&x| x).collect());
- ///
- /// // Note that difference is not symmetric,
- /// // and `b - a` means something else:
- /// let diff: HashSet<int> = b.difference(&a).map(|&x| x).collect();
- /// assert_eq!(diff, [4i].iter().map(|&x| x).collect());
- /// ```
- pub fn difference<'a>(&'a self, other: &'a HashSet<T, H>) -> SetAlgebraItems<'a, T, H> {
- Repeat::new(other).zip(self.iter())
- .filter_map(|(other, elt)| {
- if !other.contains(elt) { Some(elt) } else { None }
- })
- }
-
- /// Visit the values representing the symmetric difference.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashSet;
- /// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
- /// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
- ///
- /// // Print 1, 4 in arbitrary order.
- /// for x in a.symmetric_difference(&b) {
- /// println!("{}", x);
- /// }
- ///
- /// let diff1: HashSet<int> = a.symmetric_difference(&b).map(|&x| x).collect();
- /// let diff2: HashSet<int> = b.symmetric_difference(&a).map(|&x| x).collect();
- ///
- /// assert_eq!(diff1, diff2);
- /// assert_eq!(diff1, [1i, 4].iter().map(|&x| x).collect());
- /// ```
- pub fn symmetric_difference<'a>(&'a self, other: &'a HashSet<T, H>)
- -> Chain<SetAlgebraItems<'a, T, H>, SetAlgebraItems<'a, T, H>> {
- self.difference(other).chain(other.difference(self))
- }
-
- /// Visit the values representing the intersection.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashSet;
- /// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
- /// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
- ///
- /// // Print 2, 3 in arbitrary order.
- /// for x in a.intersection(&b) {
- /// println!("{}", x);
- /// }
- ///
- /// let diff: HashSet<int> = a.intersection(&b).map(|&x| x).collect();
- /// assert_eq!(diff, [2i, 3].iter().map(|&x| x).collect());
- /// ```
- pub fn intersection<'a>(&'a self, other: &'a HashSet<T, H>)
- -> SetAlgebraItems<'a, T, H> {
- Repeat::new(other).zip(self.iter())
- .filter_map(|(other, elt)| {
- if other.contains(elt) { Some(elt) } else { None }
- })
- }
-
- /// Visit the values representing the union.
- ///
- /// # Example
- ///
- /// ```
- /// use std::collections::HashSet;
- /// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
- /// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
- ///
- /// // Print 1, 2, 3, 4 in arbitrary order.
- /// for x in a.union(&b) {
- /// println!("{}", x);
- /// }
- ///
- /// let diff: HashSet<int> = a.union(&b).map(|&x| x).collect();
- /// assert_eq!(diff, [1i, 2, 3, 4].iter().map(|&x| x).collect());
- /// ```
- pub fn union<'a>(&'a self, other: &'a HashSet<T, H>)
- -> Chain<SetItems<'a, T>, SetAlgebraItems<'a, T, H>> {
- self.iter().chain(other.difference(self))
- }
-}
-
-impl<T: Eq + Hash<S>, S, H: Hasher<S>> PartialEq for HashSet<T, H> {
- fn eq(&self, other: &HashSet<T, H>) -> bool {
- if self.len() != other.len() { return false; }
-
- self.iter().all(|key| other.contains(key))
- }
-}
-
-impl<T: Eq + Hash<S>, S, H: Hasher<S>> Eq for HashSet<T, H> {}
-
-impl<T: Eq + Hash<S>, S, H: Hasher<S>> Collection for HashSet<T, H> {
- fn len(&self) -> uint { self.map.len() }
-}
-
-impl<T: Eq + Hash<S>, S, H: Hasher<S>> Mutable for HashSet<T, H> {
- fn clear(&mut self) { self.map.clear() }
-}
-
-impl<T: Eq + Hash<S>, S, H: Hasher<S>> Set<T> for HashSet<T, H> {
- fn contains(&self, value: &T) -> bool { self.map.contains_key(value) }
-
- fn is_disjoint(&self, other: &HashSet<T, H>) -> bool {
- self.iter().all(|v| !other.contains(v))
- }
-
- fn is_subset(&self, other: &HashSet<T, H>) -> bool {
- self.iter().all(|v| other.contains(v))
- }
-}
-
-impl<T: Eq + Hash<S>, S, H: Hasher<S>> MutableSet<T> for HashSet<T, H> {
- fn insert(&mut self, value: T) -> bool { self.map.insert(value, ()) }
-
- fn remove(&mut self, value: &T) -> bool { self.map.remove(value) }
-}
-
-
-impl<T: Eq + Hash<S> + fmt::Show, S, H: Hasher<S>> fmt::Show for HashSet<T, H> {
- fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
- try!(write!(f, "{{"));
-
- for (i, x) in self.iter().enumerate() {
- if i != 0 { try!(write!(f, ", ")); }
- try!(write!(f, "{}", *x));
- }
-
- write!(f, "}}")
- }
-}
-
-impl<T: Eq + Hash<S>, S, H: Hasher<S> + Default> FromIterator<T> for HashSet<T, H> {
- fn from_iter<I: Iterator<T>>(iter: I) -> HashSet<T, H> {
- let (lower, _) = iter.size_hint();
- let mut set = HashSet::with_capacity_and_hasher(lower, Default::default());
- set.extend(iter);
- set
- }
-}
-
-impl<T: Eq + Hash<S>, S, H: Hasher<S> + Default> Extendable<T> for HashSet<T, H> {
- fn extend<I: Iterator<T>>(&mut self, mut iter: I) {
- for k in iter {
- self.insert(k);
- }
- }
-}
-
-impl<T: Eq + Hash<S>, S, H: Hasher<S> + Default> Default for HashSet<T, H> {
- fn default() -> HashSet<T, H> {
- HashSet::with_hasher(Default::default())
- }
-}
-
-// `Repeat` is used to feed the filter closure an explicit capture
-// of a reference to the other set
-/// Set operations iterator
-pub type SetAlgebraItems<'a, T, H> =
- FilterMap<'static, (&'a HashSet<T, H>, &'a T), &'a T,
- Zip<Repeat<&'a HashSet<T, H>>, SetItems<'a, T>>>;
-
-#[cfg(test)]
-mod test_map {
- use prelude::*;
-
- use super::HashMap;
- use cmp::Equiv;
- use hash;
- use iter::{Iterator,range_inclusive,range_step_inclusive};
- use cell::RefCell;
-
- struct KindaIntLike(int);
-
- impl Equiv<int> for KindaIntLike {
- fn equiv(&self, other: &int) -> bool {
- let KindaIntLike(this) = *self;
- this == *other
- }
- }
- impl<S: hash::Writer> hash::Hash<S> for KindaIntLike {
- fn hash(&self, state: &mut S) {
- let KindaIntLike(this) = *self;
- this.hash(state)
- }
- }
-
- #[test]
- fn test_create_capacity_zero() {
- let mut m = HashMap::with_capacity(0);
-
- assert!(m.insert(1i, 1i));
-
- assert!(m.contains_key(&1));
- assert!(!m.contains_key(&0));
- }
-
- #[test]
- fn test_insert() {
- let mut m = HashMap::new();
- assert_eq!(m.len(), 0);
- assert!(m.insert(1i, 2i));
- assert_eq!(m.len(), 1);
- assert!(m.insert(2i, 4i));
- assert_eq!(m.len(), 2);
- assert_eq!(*m.find(&1).unwrap(), 2);
- assert_eq!(*m.find(&2).unwrap(), 4);
- }
-
- local_data_key!(drop_vector: RefCell<Vec<int>>)
-
- #[deriving(Hash, PartialEq, Eq)]
- struct Dropable {
- k: uint
- }
-
-
- impl Dropable {
- fn new(k: uint) -> Dropable {
- let v = drop_vector.get().unwrap();
- v.borrow_mut().as_mut_slice()[k] += 1;
-
- Dropable { k: k }
- }
- }
-
- impl Drop for Dropable {
- fn drop(&mut self) {
- let v = drop_vector.get().unwrap();
- v.borrow_mut().as_mut_slice()[self.k] -= 1;
- }
- }
-
- impl Clone for Dropable {
- fn clone(&self) -> Dropable {
- Dropable::new(self.k)
- }
- }
-
- #[test]
- fn test_drops() {
- drop_vector.replace(Some(RefCell::new(Vec::from_elem(200, 0i))));
-
- {
- let mut m = HashMap::new();
-
- let v = drop_vector.get().unwrap();
- for i in range(0u, 200) {
- assert_eq!(v.borrow().as_slice()[i], 0);
- }
- drop(v);
-
- for i in range(0u, 100) {
- let d1 = Dropable::new(i);
- let d2 = Dropable::new(i+100);
- m.insert(d1, d2);
- }
-
- let v = drop_vector.get().unwrap();
- for i in range(0u, 200) {
- assert_eq!(v.borrow().as_slice()[i], 1);
- }
- drop(v);
-
- for i in range(0u, 50) {
- let k = Dropable::new(i);
- let v = m.pop(&k);
-
- assert!(v.is_some());
-
- let v = drop_vector.get().unwrap();
- assert_eq!(v.borrow().as_slice()[i], 1);
- assert_eq!(v.borrow().as_slice()[i+100], 1);
- }
-
- let v = drop_vector.get().unwrap();
- for i in range(0u, 50) {
- assert_eq!(v.borrow().as_slice()[i], 0);
- assert_eq!(v.borrow().as_slice()[i+100], 0);
- }
-
- for i in range(50u, 100) {
- assert_eq!(v.borrow().as_slice()[i], 1);
- assert_eq!(v.borrow().as_slice()[i+100], 1);
- }
- }
-
- let v = drop_vector.get().unwrap();
- for i in range(0u, 200) {
- assert_eq!(v.borrow().as_slice()[i], 0);
- }
- }
-
- #[test]
- fn test_move_iter_drops() {
- drop_vector.replace(Some(RefCell::new(Vec::from_elem(200, 0i))));
-
- let hm = {
- let mut hm = HashMap::new();
-
- let v = drop_vector.get().unwrap();
- for i in range(0u, 200) {
- assert_eq!(v.borrow().as_slice()[i], 0);
- }
- drop(v);
-
- for i in range(0u, 100) {
- let d1 = Dropable::new(i);
- let d2 = Dropable::new(i+100);
- hm.insert(d1, d2);
- }
-
- let v = drop_vector.get().unwrap();
- for i in range(0u, 200) {
- assert_eq!(v.borrow().as_slice()[i], 1);
- }
- drop(v);
-
- hm
- };
-
- drop(hm.clone());
-
- {
- let mut half = hm.move_iter().take(50);
-
- let v = drop_vector.get().unwrap();
- for i in range(0u, 200) {
- assert_eq!(v.borrow().as_slice()[i], 1);
- }
- drop(v);
-
- for _ in half {}
-
- let v = drop_vector.get().unwrap();
- let nk = range(0u, 100).filter(|&i| {
- v.borrow().as_slice()[i] == 1
- }).count();
-
- let nv = range(0u, 100).filter(|&i| {
- v.borrow().as_slice()[i+100] == 1
- }).count();
-
- assert_eq!(nk, 50);
- assert_eq!(nv, 50);
- };
-
- let v = drop_vector.get().unwrap();
- for i in range(0u, 200) {
- assert_eq!(v.borrow().as_slice()[i], 0);
- }
- }
-
- #[test]
- fn test_empty_pop() {
- let mut m: HashMap<int, bool> = HashMap::new();
- assert_eq!(m.pop(&0), None);
- }
-
- #[test]
- fn test_lots_of_insertions() {
- let mut m = HashMap::new();
-
- // Try this a few times to make sure we never screw up the hashmap's
- // internal state.
- for _ in range(0i, 10) {
- assert!(m.is_empty());
-
- for i in range_inclusive(1i, 1000) {
- assert!(m.insert(i, i));
-
- for j in range_inclusive(1, i) {
- let r = m.find(&j);
- assert_eq!(r, Some(&j));
- }
-
- for j in range_inclusive(i+1, 1000) {
- let r = m.find(&j);
- assert_eq!(r, None);
- }
- }
-
- for i in range_inclusive(1001i, 2000) {
- assert!(!m.contains_key(&i));
- }
-
- // remove forwards
- for i in range_inclusive(1i, 1000) {
- assert!(m.remove(&i));
-
- for j in range_inclusive(1, i) {
- assert!(!m.contains_key(&j));
- }
-
- for j in range_inclusive(i+1, 1000) {
- assert!(m.contains_key(&j));
- }
- }
-
- for i in range_inclusive(1i, 1000) {
- assert!(!m.contains_key(&i));
- }
-
- for i in range_inclusive(1i, 1000) {
- assert!(m.insert(i, i));
- }
-
- // remove backwards
- for i in range_step_inclusive(1000i, 1, -1) {
- assert!(m.remove(&i));
-
- for j in range_inclusive(i, 1000) {
- assert!(!m.contains_key(&j));
- }
-
- for j in range_inclusive(1, i-1) {
- assert!(m.contains_key(&j));
- }
- }
- }
- }
-
- #[test]
- fn test_find_mut() {
- let mut m = HashMap::new();
- assert!(m.insert(1i, 12i));
- assert!(m.insert(2i, 8i));
- assert!(m.insert(5i, 14i));
- let new = 100;
- match m.find_mut(&5) {
- None => fail!(), Some(x) => *x = new
- }
- assert_eq!(m.find(&5), Some(&new));
- }
-
- #[test]
- fn test_insert_overwrite() {
- let mut m = HashMap::new();
- assert!(m.insert(1i, 2i));
- assert_eq!(*m.find(&1).unwrap(), 2);
- assert!(!m.insert(1i, 3i));
- assert_eq!(*m.find(&1).unwrap(), 3);
- }
-
- #[test]
- fn test_insert_conflicts() {
- let mut m = HashMap::with_capacity(4);
- assert!(m.insert(1i, 2i));
- assert!(m.insert(5i, 3i));
- assert!(m.insert(9i, 4i));
- assert_eq!(*m.find(&9).unwrap(), 4);
- assert_eq!(*m.find(&5).unwrap(), 3);
- assert_eq!(*m.find(&1).unwrap(), 2);
- }
-
- #[test]
- fn test_conflict_remove() {
- let mut m = HashMap::with_capacity(4);
- assert!(m.insert(1i, 2i));
- assert_eq!(*m.find(&1).unwrap(), 2);
- assert!(m.insert(5, 3));
- assert_eq!(*m.find(&1).unwrap(), 2);
- assert_eq!(*m.find(&5).unwrap(), 3);
- assert!(m.insert(9, 4));
- assert_eq!(*m.find(&1).unwrap(), 2);
- assert_eq!(*m.find(&5).unwrap(), 3);
- assert_eq!(*m.find(&9).unwrap(), 4);
- assert!(m.remove(&1));
- assert_eq!(*m.find(&9).unwrap(), 4);
- assert_eq!(*m.find(&5).unwrap(), 3);
- }
-
- #[test]
- fn test_is_empty() {
- let mut m = HashMap::with_capacity(4);
- assert!(m.insert(1i, 2i));
- assert!(!m.is_empty());
- assert!(m.remove(&1));
- assert!(m.is_empty());
- }
-
- #[test]
- fn test_pop() {
- let mut m = HashMap::new();
- m.insert(1i, 2i);
- assert_eq!(m.pop(&1), Some(2));
- assert_eq!(m.pop(&1), None);
- }
-
- #[test]
- #[allow(experimental)]
- fn test_pop_equiv() {
- let mut m = HashMap::new();
- m.insert(1i, 2i);
- assert_eq!(m.pop_equiv(&KindaIntLike(1)), Some(2));
- assert_eq!(m.pop_equiv(&KindaIntLike(1)), None);
- }
-
- #[test]
- fn test_swap() {
- let mut m = HashMap::new();
- assert_eq!(m.swap(1i, 2i), None);
- assert_eq!(m.swap(1i, 3i), Some(2));
- assert_eq!(m.swap(1i, 4i), Some(3));
- }
-
- #[test]
- fn test_iterate() {
- let mut m = HashMap::with_capacity(4);
- for i in range(0u, 32) {
- assert!(m.insert(i, i*2));
- }
- assert_eq!(m.len(), 32);
-
- let mut observed: u32 = 0;
-
- for (k, v) in m.iter() {
- assert_eq!(*v, *k * 2);
- observed |= 1 << *k;
- }
- assert_eq!(observed, 0xFFFF_FFFF);
- }
-
- #[test]
- fn test_keys() {
- let vec = vec![(1i, 'a'), (2i, 'b'), (3i, 'c')];
- let map = vec.move_iter().collect::<HashMap<int, char>>();
- let keys = map.keys().map(|&k| k).collect::<Vec<int>>();
- assert_eq!(keys.len(), 3);
- assert!(keys.contains(&1));
- assert!(keys.contains(&2));
- assert!(keys.contains(&3));
- }
-
- #[test]
- fn test_values() {
- let vec = vec![(1i, 'a'), (2i, 'b'), (3i, 'c')];
- let map = vec.move_iter().collect::<HashMap<int, char>>();
- let values = map.values().map(|&v| v).collect::<Vec<char>>();
- assert_eq!(values.len(), 3);
- assert!(values.contains(&'a'));
- assert!(values.contains(&'b'));
- assert!(values.contains(&'c'));
- }
-
- #[test]
- fn test_find() {
- let mut m = HashMap::new();
- assert!(m.find(&1i).is_none());
- m.insert(1i, 2i);
- match m.find(&1) {
- None => fail!(),
- Some(v) => assert_eq!(*v, 2)
- }
- }
-
- #[test]
- fn test_find_copy() {
- let mut m = HashMap::new();
- assert!(m.find(&1i).is_none());
-
- for i in range(1i, 10000) {
- m.insert(i, i + 7);
- match m.find_copy(&i) {
- None => fail!(),
- Some(v) => assert_eq!(v, i + 7)
- }
- for j in range(1i, i/100) {
- match m.find_copy(&j) {
- None => fail!(),
- Some(v) => assert_eq!(v, j + 7)
- }
- }
- }
- }
-
- #[test]
- fn test_eq() {
- let mut m1 = HashMap::new();
- m1.insert(1i, 2i);
- m1.insert(2i, 3i);
- m1.insert(3i, 4i);
-
- let mut m2 = HashMap::new();
- m2.insert(1i, 2i);
- m2.insert(2i, 3i);
-
- assert!(m1 != m2);
-
- m2.insert(3i, 4i);
-
- assert_eq!(m1, m2);
- }
-
- #[test]
- fn test_show() {
- let mut map: HashMap<int, int> = HashMap::new();
- let empty: HashMap<int, int> = HashMap::new();
-
- map.insert(1i, 2i);
- map.insert(3i, 4i);
-
- let map_str = format!("{}", map);
-
- assert!(map_str == "{1: 2, 3: 4}".to_string() || map_str == "{3: 4, 1: 2}".to_string());
- assert_eq!(format!("{}", empty), "{}".to_string());
- }
-
- #[test]
- fn test_expand() {
- let mut m = HashMap::new();
-
- assert_eq!(m.len(), 0);
- assert!(m.is_empty());
-
- let mut i = 0u;
- let old_cap = m.table.capacity();
- while old_cap == m.table.capacity() {
- m.insert(i, i);
- i += 1;
- }
-
- assert_eq!(m.len(), i);
- assert!(!m.is_empty());
- }
-
- #[test]
- fn test_resize_policy() {
- let mut m = HashMap::new();
-
- assert_eq!(m.len(), 0);
- assert_eq!(m.table.capacity(), 0);
- assert!(m.is_empty());
-
- m.insert(0, 0);
- m.remove(&0);
- assert!(m.is_empty());
- let initial_cap = m.table.capacity();
- m.reserve(initial_cap * 2);
- let cap = m.table.capacity();
-
- assert_eq!(cap, initial_cap * 2);
-
- let mut i = 0u;
- for _ in range(0, cap * 3 / 4) {
- m.insert(i, i);
- i += 1;
- }
-
- assert_eq!(m.len(), i);
- assert_eq!(m.table.capacity(), cap);
-
- for _ in range(0, cap / 4) {
- m.insert(i, i);
- i += 1;
- }
-
- let new_cap = m.table.capacity();
- assert_eq!(new_cap, cap * 2);
-
- for _ in range(0, cap / 2) {
- i -= 1;
- m.remove(&i);
- assert_eq!(m.table.capacity(), new_cap);
- }
-
- for _ in range(0, cap / 2 - 1) {
- i -= 1;
- m.remove(&i);
- }
-
- assert_eq!(m.len(), i);
- assert!(!m.is_empty());
- assert_eq!(m.table.capacity(), cap);
- }
-
- #[test]
- fn test_find_equiv() {
- let mut m = HashMap::new();
-
- let (foo, bar, baz) = (1i,2i,3i);
- m.insert("foo".to_string(), foo);
- m.insert("bar".to_string(), bar);
- m.insert("baz".to_string(), baz);
-
-
- assert_eq!(m.find_equiv(&("foo")), Some(&foo));
- assert_eq!(m.find_equiv(&("bar")), Some(&bar));
- assert_eq!(m.find_equiv(&("baz")), Some(&baz));
-
- assert_eq!(m.find_equiv(&("qux")), None);
- }
-
- #[test]
- fn test_from_iter() {
- let xs = [(1i, 1i), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
-
- let map: HashMap<int, int> = xs.iter().map(|&x| x).collect();
-
- for &(k, v) in xs.iter() {
- assert_eq!(map.find(&k), Some(&v));
- }
- }
-
- #[test]
- fn test_size_hint() {
- let xs = [(1i, 1i), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
-
- let map: HashMap<int, int> = xs.iter().map(|&x| x).collect();
-
- let mut iter = map.iter();
-
- for _ in iter.by_ref().take(3) {}
-
- assert_eq!(iter.size_hint(), (3, Some(3)));
- }
-
- #[test]
- fn test_mut_size_hint() {
- let xs = [(1i, 1i), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
-
- let mut map: HashMap<int, int> = xs.iter().map(|&x| x).collect();
-
- let mut iter = map.mut_iter();
-
- for _ in iter.by_ref().take(3) {}
-
- assert_eq!(iter.size_hint(), (3, Some(3)));
- }
-
- #[test]
- fn test_index() {
- let mut map: HashMap<int, int> = HashMap::new();
-
- map.insert(1, 2);
- map.insert(2, 1);
- map.insert(3, 4);
-
- assert_eq!(map[2], 1);
- }
-
- #[test]
- #[should_fail]
- fn test_index_nonexistent() {
- let mut map: HashMap<int, int> = HashMap::new();
-
- map.insert(1, 2);
- map.insert(2, 1);
- map.insert(3, 4);
-
- map[4];
- }
-}
-
-#[cfg(test)]
-mod test_set {
- use prelude::*;
-
- use super::HashSet;
- use slice::ImmutablePartialEqSlice;
- use collections::Collection;
-
- #[test]
- fn test_disjoint() {
- let mut xs = HashSet::new();
- let mut ys = HashSet::new();
- assert!(xs.is_disjoint(&ys));
- assert!(ys.is_disjoint(&xs));
- assert!(xs.insert(5i));
- assert!(ys.insert(11i));
- assert!(xs.is_disjoint(&ys));
- assert!(ys.is_disjoint(&xs));
- assert!(xs.insert(7));
- assert!(xs.insert(19));
- assert!(xs.insert(4));
- assert!(ys.insert(2));
- assert!(ys.insert(-11));
- assert!(xs.is_disjoint(&ys));
- assert!(ys.is_disjoint(&xs));
- assert!(ys.insert(7));
- assert!(!xs.is_disjoint(&ys));
- assert!(!ys.is_disjoint(&xs));
- }
-
- #[test]
- fn test_subset_and_superset() {
- let mut a = HashSet::new();
- assert!(a.insert(0i));
- assert!(a.insert(5));
- assert!(a.insert(11));
- assert!(a.insert(7));
-
- let mut b = HashSet::new();
- assert!(b.insert(0i));
- assert!(b.insert(7));
- assert!(b.insert(19));
- assert!(b.insert(250));
- assert!(b.insert(11));
- assert!(b.insert(200));
-
- assert!(!a.is_subset(&b));
- assert!(!a.is_superset(&b));
- assert!(!b.is_subset(&a));
- assert!(!b.is_superset(&a));
-
- assert!(b.insert(5));
-
- assert!(a.is_subset(&b));
- assert!(!a.is_superset(&b));
- assert!(!b.is_subset(&a));
- assert!(b.is_superset(&a));
- }
-
- #[test]
- fn test_iterate() {
- let mut a = HashSet::new();
- for i in range(0u, 32) {
- assert!(a.insert(i));
- }
- let mut observed: u32 = 0;
- for k in a.iter() {
- observed |= 1 << *k;
- }
- assert_eq!(observed, 0xFFFF_FFFF);
- }
-
- #[test]
- fn test_intersection() {
- let mut a = HashSet::new();
- let mut b = HashSet::new();
-
- assert!(a.insert(11i));
- assert!(a.insert(1));
- assert!(a.insert(3));
- assert!(a.insert(77));
- assert!(a.insert(103));
- assert!(a.insert(5));
- assert!(a.insert(-5));
-
- assert!(b.insert(2i));
- assert!(b.insert(11));
- assert!(b.insert(77));
- assert!(b.insert(-9));
- assert!(b.insert(-42));
- assert!(b.insert(5));
- assert!(b.insert(3));
-
- let mut i = 0;
- let expected = [3, 5, 11, 77];
- for x in a.intersection(&b) {
- assert!(expected.contains(x));
- i += 1
- }
- assert_eq!(i, expected.len());
- }
-
- #[test]
- fn test_difference() {
- let mut a = HashSet::new();
- let mut b = HashSet::new();
-
- assert!(a.insert(1i));
- assert!(a.insert(3));
- assert!(a.insert(5));
- assert!(a.insert(9));
- assert!(a.insert(11));
-
- assert!(b.insert(3i));
- assert!(b.insert(9));
-
- let mut i = 0;
- let expected = [1, 5, 11];
- for x in a.difference(&b) {
- assert!(expected.contains(x));
- i += 1
- }
- assert_eq!(i, expected.len());
- }
-
- #[test]
- fn test_symmetric_difference() {
- let mut a = HashSet::new();
- let mut b = HashSet::new();
-
- assert!(a.insert(1i));
- assert!(a.insert(3));
- assert!(a.insert(5));
- assert!(a.insert(9));
- assert!(a.insert(11));
-
- assert!(b.insert(-2i));
- assert!(b.insert(3));
- assert!(b.insert(9));
- assert!(b.insert(14));
- assert!(b.insert(22));
-
- let mut i = 0;
- let expected = [-2, 1, 5, 11, 14, 22];
- for x in a.symmetric_difference(&b) {
- assert!(expected.contains(x));
- i += 1
- }
- assert_eq!(i, expected.len());
- }
-
- #[test]
- fn test_union() {
- let mut a = HashSet::new();
- let mut b = HashSet::new();
-
- assert!(a.insert(1i));
- assert!(a.insert(3));
- assert!(a.insert(5));
- assert!(a.insert(9));
- assert!(a.insert(11));
- assert!(a.insert(16));
- assert!(a.insert(19));
- assert!(a.insert(24));
-
- assert!(b.insert(-2i));
- assert!(b.insert(1));
- assert!(b.insert(5));
- assert!(b.insert(9));
- assert!(b.insert(13));
- assert!(b.insert(19));
-
- let mut i = 0;
- let expected = [-2, 1, 3, 5, 9, 11, 13, 16, 19, 24];
- for x in a.union(&b) {
- assert!(expected.contains(x));
- i += 1
- }
- assert_eq!(i, expected.len());
- }
-
- #[test]
- fn test_from_iter() {
- let xs = [1i, 2, 3, 4, 5, 6, 7, 8, 9];
-
- let set: HashSet<int> = xs.iter().map(|&x| x).collect();
-
- for x in xs.iter() {
- assert!(set.contains(x));
- }
- }
-
- #[test]
- fn test_move_iter() {
- let hs = {
- let mut hs = HashSet::new();
-
- hs.insert('a');
- hs.insert('b');
-
- hs
- };
-
- let v = hs.move_iter().collect::<Vec<char>>();
- assert!(['a', 'b'] == v.as_slice() || ['b', 'a'] == v.as_slice());
- }
-
- #[test]
- fn test_eq() {
- // These constants once happened to expose a bug in insert().
- // I'm keeping them around to prevent a regression.
- let mut s1 = HashSet::new();
-
- s1.insert(1i);
- s1.insert(2);
- s1.insert(3);
-
- let mut s2 = HashSet::new();
-
- s2.insert(1i);
- s2.insert(2);
-
- assert!(s1 != s2);
-
- s2.insert(3);
-
- assert_eq!(s1, s2);
- }
-
- #[test]
- fn test_show() {
- let mut set: HashSet<int> = HashSet::new();
- let empty: HashSet<int> = HashSet::new();
-
- set.insert(1i);
- set.insert(2);
-
- let set_str = format!("{}", set);
-
- assert!(set_str == "{1, 2}".to_string() || set_str == "{2, 1}".to_string());
- assert_eq!(format!("{}", empty), "{}".to_string());
- }
-}
-
-#[cfg(test)]
-mod bench {
- extern crate test;
- use prelude::*;
-
- use self::test::Bencher;
- use iter::{range_inclusive};
-
- #[bench]
- fn new_drop(b : &mut Bencher) {
- use super::HashMap;
-
- b.iter(|| {
- let m : HashMap<int, int> = HashMap::new();
- assert_eq!(m.len(), 0);
- })
- }
-
- #[bench]
- fn new_insert_drop(b : &mut Bencher) {
- use super::HashMap;
-
- b.iter(|| {
- let mut m = HashMap::new();
- m.insert(0i, 0i);
- assert_eq!(m.len(), 1);
- })
- }
-
- #[bench]
- fn insert(b: &mut Bencher) {
- use super::HashMap;
-
- let mut m = HashMap::new();
-
- for i in range_inclusive(1i, 1000) {
- m.insert(i, i);
- }
-
- let mut k = 1001;
-
- b.iter(|| {
- m.insert(k, k);
- k += 1;
- });
- }
-
- #[bench]
- fn find_existing(b: &mut Bencher) {
- use super::HashMap;
-
- let mut m = HashMap::new();
-
- for i in range_inclusive(1i, 1000) {
- m.insert(i, i);
- }
-
- b.iter(|| {
- for i in range_inclusive(1i, 1000) {
- m.contains_key(&i);
- }
- });
- }
-
- #[bench]
- fn find_nonexisting(b: &mut Bencher) {
- use super::HashMap;
-
- let mut m = HashMap::new();
-
- for i in range_inclusive(1i, 1000) {
- m.insert(i, i);
- }
-
- b.iter(|| {
- for i in range_inclusive(1001i, 2000) {
- m.contains_key(&i);
- }
- });
- }
-
- #[bench]
- fn hashmap_as_queue(b: &mut Bencher) {
- use super::HashMap;
-
- let mut m = HashMap::new();
-
- for i in range_inclusive(1i, 1000) {
- m.insert(i, i);
- }
-
- let mut k = 1i;
-
- b.iter(|| {
- m.pop(&k);
- m.insert(k + 1000, k + 1000);
- k += 1;
- });
- }
-
- #[bench]
- fn find_pop_insert(b: &mut Bencher) {
- use super::HashMap;
-
- let mut m = HashMap::new();
-
- for i in range_inclusive(1i, 1000) {
- m.insert(i, i);
- }
-
- let mut k = 1i;
-
- b.iter(|| {
- m.find(&(k + 400));
- m.find(&(k + 2000));
- m.pop(&k);
- m.insert(k + 1000, k + 1000);
- k += 1;
- })
- }
-}
--- /dev/null
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![cfg(test)]
+
+extern crate test;
+use prelude::*;
+
+use self::test::Bencher;
+use iter::{range_inclusive};
+
+#[bench]
+fn new_drop(b : &mut Bencher) {
+ use super::HashMap;
+
+ b.iter(|| {
+ let m : HashMap<int, int> = HashMap::new();
+ assert_eq!(m.len(), 0);
+ })
+}
+
+#[bench]
+fn new_insert_drop(b : &mut Bencher) {
+ use super::HashMap;
+
+ b.iter(|| {
+ let mut m = HashMap::new();
+ m.insert(0i, 0i);
+ assert_eq!(m.len(), 1);
+ })
+}
+
+#[bench]
+fn insert(b: &mut Bencher) {
+ use super::HashMap;
+
+ let mut m = HashMap::new();
+
+ for i in range_inclusive(1i, 1000) {
+ m.insert(i, i);
+ }
+
+ let mut k = 1001;
+
+ b.iter(|| {
+ m.insert(k, k);
+ k += 1;
+ });
+}
+
+#[bench]
+fn find_existing(b: &mut Bencher) {
+ use super::HashMap;
+
+ let mut m = HashMap::new();
+
+ for i in range_inclusive(1i, 1000) {
+ m.insert(i, i);
+ }
+
+ b.iter(|| {
+ for i in range_inclusive(1i, 1000) {
+ m.contains_key(&i);
+ }
+ });
+}
+
+#[bench]
+fn find_nonexisting(b: &mut Bencher) {
+ use super::HashMap;
+
+ let mut m = HashMap::new();
+
+ for i in range_inclusive(1i, 1000) {
+ m.insert(i, i);
+ }
+
+ b.iter(|| {
+ for i in range_inclusive(1001i, 2000) {
+ m.contains_key(&i);
+ }
+ });
+}
+
+#[bench]
+fn hashmap_as_queue(b: &mut Bencher) {
+ use super::HashMap;
+
+ let mut m = HashMap::new();
+
+ for i in range_inclusive(1i, 1000) {
+ m.insert(i, i);
+ }
+
+ let mut k = 1i;
+
+ b.iter(|| {
+ m.pop(&k);
+ m.insert(k + 1000, k + 1000);
+ k += 1;
+ });
+}
+
+#[bench]
+fn find_pop_insert(b: &mut Bencher) {
+ use super::HashMap;
+
+ let mut m = HashMap::new();
+
+ for i in range_inclusive(1i, 1000) {
+ m.insert(i, i);
+ }
+
+ let mut k = 1i;
+
+ b.iter(|| {
+ m.find(&(k + 400));
+ m.find(&(k + 2000));
+ m.pop(&k);
+ m.insert(k + 1000, k + 1000);
+ k += 1;
+ })
+}
--- /dev/null
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+//
+// ignore-lexer-test FIXME #15883
+
+use clone::Clone;
+use cmp::{max, Eq, Equiv, PartialEq};
+use collections::{Collection, Mutable, MutableSet, Map, MutableMap};
+use default::Default;
+use fmt::Show;
+use fmt;
+use RandomSipHasher;
+use hash::{Hash, Hasher};
+use iter::{Iterator, FromIterator, Extendable, range};
+use iter;
+use mem::replace;
+use num;
+use ops::Deref;
+use option::{Some, None, Option};
+use result::{Ok, Err};
+use ops::Index;
+
+use super::table::{BucketWithTable, FullBucketImm, RawTable, FullBucket, FullBucketMut, Bucket};
+use super::table;
+
+static INITIAL_LOG2_CAP: uint = 5;
+pub static INITIAL_CAPACITY: uint = 1 << INITIAL_LOG2_CAP; // 2^5
+
+/// The default behavior of HashMap implements a load factor of 90.9%.
+/// This behavior is characterized by the following conditions:
+///
+/// - if `size * 1.1 < cap < size * 4` then shouldn't resize
+/// - if `cap < minimum_capacity * 2` then shouldn't shrink
+#[deriving(Clone)]
+struct DefaultResizePolicy {
+ /// Doubled minimal capacity. The capacity must never drop below
+ /// the minimum capacity. (The check happens before the capacity
+ /// is potentially halved.)
+ minimum_capacity2: uint
+}
+
+impl DefaultResizePolicy {
+ fn new(new_capacity: uint) -> DefaultResizePolicy {
+ DefaultResizePolicy {
+ minimum_capacity2: new_capacity << 1
+ }
+ }
+
+ #[inline]
+ fn capacity_range(&self, new_size: uint) -> (uint, uint) {
+ ((new_size * 11) / 10, max(new_size << 3, self.minimum_capacity2))
+ }
+
+ #[inline]
+ fn reserve(&mut self, new_capacity: uint) {
+ self.minimum_capacity2 = new_capacity << 1;
+ }
+}
+
+// The main performance trick in this hashmap is called Robin Hood Hashing.
+// It gains its excellent performance from one crucial operation:
+//
+// If an insertion collides with an existing element, and that elements
+// "probe distance" (how far away the element is from its ideal location)
+// is higher than how far we've already probed, swap the elements.
+//
+// This massively lowers variance in probe distance, and allows us to get very
+// high load factors with good performance. The 90% load factor I use is rather
+// conservative.
+//
+// > Why a load factor of approximately 90%?
+//
+// In general, all the distances to initial buckets will converge on the mean.
+// At a load factor of α, the odds of finding the target bucket after k
+// probes is approximately 1-α^k. If we set this equal to 50% (since we converge
+// on the mean) and set k=8 (64-byte cache line / 8-byte hash), α=0.92. I round
+// this down to make the math easier on the CPU and avoid its FPU.
+// Since on average we start the probing in the middle of a cache line, this
+// strategy pulls in two cache lines of hashes on every lookup. I think that's
+// pretty good, but if you want to trade off some space, it could go down to one
+// cache line on average with an α of 0.84.
+//
+// > Wait, what? Where did you get 1-α^k from?
+//
+// On the first probe, your odds of a collision with an existing element is α.
+// The odds of doing this twice in a row is approximately α^2. For three times,
+// α^3, etc. Therefore, the odds of colliding k times is α^k. The odds of NOT
+// colliding after k tries is 1-α^k.
+//
+// Future Improvements (FIXME!)
+// ============================
+//
+// Allow the load factor to be changed dynamically and/or at initialization.
+//
+// Also, would it be possible for us to reuse storage when growing the
+// underlying table? This is exactly the use case for 'realloc', and may
+// be worth exploring.
+//
+// Future Optimizations (FIXME!)
+// =============================
+//
+// The paper cited below mentions an implementation which keeps track of the
+// distance-to-initial-bucket histogram. I'm suspicious of this approach because
+// it requires maintaining an internal map. If this map were replaced with a
+// hashmap, it would be faster, but now our data structure is self-referential
+// and blows up. Also, this allows very good first guesses, but array accesses
+// are no longer linear and in one direction, as we have now. There is also
+// memory and cache pressure that this map would entail that would be very
+// difficult to properly see in a microbenchmark.
+//
+// Another possible design choice that I made without any real reason is
+// parameterizing the raw table over keys and values. Technically, all we need
+// is the size and alignment of keys and values, and the code should be just as
+// efficient (well, we might need one for power-of-two size and one for not...).
+// This has the potential to reduce code bloat in rust executables, without
+// really losing anything except 4 words (key size, key alignment, val size,
+// val alignment) which can be passed in to every call of a `RawTable` function.
+// This would definitely be an avenue worth exploring if people start complaining
+// about the size of rust executables.
+//
+// There's also an "optimization" that has been omitted regarding how the
+// hashtable allocates. The vector type has set the expectation that a hashtable
+// which never has an element inserted should not allocate. I'm suspicious of
+// implementing this for hashtables, because supporting it has no performance
+// benefit over using an `Option<HashMap<K, V>>`, and is significantly more
+// complicated.
+
+/// A hash map implementation which uses linear probing with Robin
+/// Hood bucket stealing.
+///
+/// The hashes are all keyed by the task-local random number generator
+/// on creation by default. This means that the ordering of the keys is
+/// randomized, but makes the tables more resistant to
+/// denial-of-service attacks (Hash DoS). This behaviour can be
+/// overridden with one of the constructors.
+///
+/// It is required that the keys implement the `Eq` and `Hash` traits, although
+/// this can frequently be achieved by using `#[deriving(Eq, Hash)]`.
+///
+/// Relevant papers/articles:
+///
+/// 1. Pedro Celis. ["Robin Hood Hashing"](https://cs.uwaterloo.ca/research/tr/1986/CS-86-14.pdf)
+/// 2. Emmanuel Goossaert. ["Robin Hood
+/// hashing"](http://codecapsule.com/2013/11/11/robin-hood-hashing/)
+/// 3. Emmanuel Goossaert. ["Robin Hood hashing: backward shift
+/// deletion"](http://codecapsule.com/2013/11/17/robin-hood-hashing-backward-shift-deletion/)
+///
+/// # Example
+///
+/// ```
+/// use std::collections::HashMap;
+///
+/// // type inference lets us omit an explicit type signature (which
+/// // would be `HashMap<&str, &str>` in this example).
+/// let mut book_reviews = HashMap::new();
+///
+/// // review some books.
+/// book_reviews.insert("Adventures of Huckleberry Finn", "My favorite book.");
+/// book_reviews.insert("Grimms' Fairy Tales", "Masterpiece.");
+/// book_reviews.insert("Pride and Prejudice", "Very enjoyable.");
+/// book_reviews.insert("The Adventures of Sherlock Holmes", "Eye lyked it alot.");
+///
+/// // check for a specific one.
+/// if !book_reviews.contains_key(&("Les Misérables")) {
+/// println!("We've got {} reviews, but Les Misérables ain't one.",
+/// book_reviews.len());
+/// }
+///
+/// // oops, this review has a lot of spelling mistakes, let's delete it.
+/// book_reviews.remove(&("The Adventures of Sherlock Holmes"));
+///
+/// // look up the values associated with some keys.
+/// let to_find = ["Pride and Prejudice", "Alice's Adventure in Wonderland"];
+/// for book in to_find.iter() {
+/// match book_reviews.find(book) {
+/// Some(review) => println!("{}: {}", *book, *review),
+/// None => println!("{} is unreviewed.", *book)
+/// }
+/// }
+///
+/// // iterate over everything.
+/// for (book, review) in book_reviews.iter() {
+/// println!("{}: \"{}\"", *book, *review);
+/// }
+/// ```
+///
+/// The easiest way to use `HashMap` with a custom type is to derive `Eq` and `Hash`.
+/// We must also derive `PartialEq`.
+///
+/// ```
+/// use std::collections::HashMap;
+///
+/// #[deriving(Hash, Eq, PartialEq, Show)]
+/// struct Viking<'a> {
+/// name: &'a str,
+/// power: uint,
+/// }
+///
+/// let mut vikings = HashMap::new();
+///
+/// vikings.insert("Norway", Viking { name: "Einar", power: 9u });
+/// vikings.insert("Denmark", Viking { name: "Olaf", power: 4u });
+/// vikings.insert("Iceland", Viking { name: "Harald", power: 8u });
+///
+/// // Use derived implementation to print the vikings.
+/// for (land, viking) in vikings.iter() {
+/// println!("{} at {}", viking, land);
+/// }
+/// ```
+#[deriving(Clone)]
+pub struct HashMap<K, V, H = RandomSipHasher> {
+ // All hashes are keyed on these values, to prevent hash collision attacks.
+ hasher: H,
+
+ table: table::RawTable<K, V>,
+
+ // We keep this at the end since it might as well have tail padding.
+ resize_policy: DefaultResizePolicy,
+}
+
+/// Search for a pre-hashed key.
+fn search_hashed_generic<K, V, M: Deref<RawTable<K, V>>>(table: M, hash: &table::SafeHash, is_match: |&K| -> bool)
+ -> Option<FullBucket<K, V, M>> {
+ let size = table.size();
+ let mut probe = Bucket::new(table, hash);
+ let ib = probe.index();
+
+ while probe.index() != ib + size {
+ let full = match probe.peek() {
+ table::Empty(_) => return None, // hit an empty bucket
+ table::Full(b) => b
+ };
+
+ if full.distance() + ib < full.index() {
+ return None;
+ }
+
+ // If the hash doesn't match, it can't be this one..
+ if *hash == full.hash() {
+ let matched = {
+ let (k, _) = full.read();
+ is_match(k)
+ };
+
+ // If the key doesn't match, it can't be this one..
+ if matched {
+ return Some(full);
+ }
+ }
+
+ probe = full.next();
+ }
+
+ None
+}
+
+fn search_hashed<K: Eq, V, M: Deref<RawTable<K, V>>>(table: M, hash: &table::SafeHash, k: &K)
+ -> Option<table::FullBucket<K, V, M>> {
+ search_hashed_generic(table, hash, |k_| *k == *k_)
+}
+
+fn pop_internal<K, V>(starting_bucket: FullBucketMut<K, V>) -> V {
+ let size = {
+ let table = starting_bucket.table();
+ table.size()
+ };
+ let (empty, _k, retval) = starting_bucket.take();
+ let mut gap = match empty.gap_peek() {
+ Some(b) => b,
+ None => return retval
+ };
+ // COMPILER error! wrong enum optimization. sets ptr to 0
+
+ for _ in range(0, size) {
+ if gap.full().distance() != 0 {
+ gap = match gap.shift() {
+ Some(b) => b,
+ None => return retval
+ };
+ continue;
+ }
+
+ break;
+ }
+
+ // Now we're done all our shifting. Return the value we grabbed
+ // earlier.
+ return retval;
+}
+
+impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> HashMap<K, V, H> {
+ fn make_hash<X: Hash<S>>(&self, x: &X) -> table::SafeHash {
+ table::make_hash(&self.hasher, x)
+ }
+
+ fn search_equiv<'a, Q: Hash<S> + Equiv<K>>(&'a self, q: &Q)
+ -> Option<FullBucketImm<'a, K, V>> {
+ let hash = self.make_hash(q);
+ search_hashed_generic(&self.table, &hash, |k| q.equiv(k))
+ }
+
+ fn search_equiv_mut<'a, Q: Hash<S> + Equiv<K>>(&'a mut self, q: &Q)
+ -> Option<FullBucketMut<'a, K, V>> {
+ let hash = self.make_hash(q);
+ search_hashed_generic(&mut self.table, &hash, |k| q.equiv(k))
+ }
+
+ /// Search for a key, yielding the index if it's found in the hashtable.
+ /// If you already have the hash for the key lying around, use
+ /// search_hashed.
+ fn search<'a>(&'a self, k: &K) -> Option<FullBucketImm<'a, K, V>> {
+ let hash = self.make_hash(k);
+ search_hashed(&self.table, &hash, k)
+ }
+
+ fn search_mut<'a>(&'a mut self, k: &K) -> Option<FullBucketMut<'a, K, V>> {
+ let hash = self.make_hash(k);
+ search_hashed(&mut self.table, &hash, k)
+ }
+
+ fn insert_hashed_ordered(&mut self, hash: table::SafeHash, k: K, v: V) {
+ let cap = self.table.capacity();
+ let mut buckets = Bucket::new(&mut self.table, &hash);
+ let ib = buckets.index();
+ while buckets.index() != ib + cap {
+ buckets = match buckets.peek() {
+ table::Empty(empty) => {
+ empty.put(hash, k, v);
+ return;
+ }
+ table::Full(b) => b.into_bucket()
+ };
+ buckets.next();
+ }
+ fail!("Internal HashMap error: Out of space.");
+ }
+}
+
+impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> Collection for HashMap<K, V, H> {
+ /// Return the number of elements in the map.
+ fn len(&self) -> uint { self.table.size() }
+}
+
+impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> Mutable for HashMap<K, V, H> {
+ /// Clear the map, removing all key-value pairs. Keeps the allocated memory
+ /// for reuse.
+ fn clear(&mut self) {
+ // Prevent reallocations from happening from now on. Makes it possible
+ // for the map to be reused but has a downside: reserves permanently.
+ self.resize_policy.reserve(self.table.size());
+
+ let cap = self.table.capacity();
+ let mut buckets = Bucket::first(&mut self.table);
+
+ while buckets.index() != cap {
+ buckets = match buckets.peek() {
+ table::Empty(b) => b.next(),
+ table::Full(full) => {
+ let (b, _, _) = full.take();
+ b.next()
+ }
+ };
+ }
+ }
+}
+
+impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> Map<K, V> for HashMap<K, V, H> {
+ fn find<'a>(&'a self, k: &K) -> Option<&'a V> {
+ self.search(k).map(|bucket| {
+ let (_, v) = bucket.into_refs();
+ v
+ })
+ }
+
+ fn contains_key(&self, k: &K) -> bool {
+ self.search(k).is_some()
+ }
+}
+
+impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> MutableMap<K, V> for HashMap<K, V, H> {
+ fn find_mut<'a>(&'a mut self, k: &K) -> Option<&'a mut V> {
+ match self.search_mut(k) {
+ Some(bucket) => {
+ let (_, v) = bucket.into_mut_refs();
+ Some(v)
+ }
+ _ => None
+ }
+ }
+
+ fn swap(&mut self, k: K, v: V) -> Option<V> {
+ let hash = self.make_hash(&k);
+ let potential_new_size = self.table.size() + 1;
+ self.make_some_room(potential_new_size);
+
+ let mut retval = None;
+ self.insert_or_replace_with(hash, k, v, |val_ref, val| {
+ retval = Some(replace(val_ref, val));
+ });
+ retval
+ }
+
+
+ fn pop(&mut self, k: &K) -> Option<V> {
+ if self.table.size() == 0 {
+ return None
+ }
+
+ let potential_new_size = self.table.size() - 1;
+ self.make_some_room(potential_new_size);
+
+ self.search_mut(k).map(|bucket| {
+ pop_internal(bucket)
+ })
+ }
+}
+
+impl<K: Hash + Eq, V> HashMap<K, V, RandomSipHasher> {
+ /// Create an empty HashMap.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ /// let mut map: HashMap<&str, int> = HashMap::with_capacity(10);
+ /// ```
+ #[inline]
+ pub fn new() -> HashMap<K, V, RandomSipHasher> {
+ let hasher = RandomSipHasher::new();
+ HashMap::with_hasher(hasher)
+ }
+
+ /// Creates an empty hash map with the given initial capacity.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ /// let mut map: HashMap<&str, int> = HashMap::with_capacity(10);
+ /// ```
+ #[inline]
+ pub fn with_capacity(capacity: uint) -> HashMap<K, V, RandomSipHasher> {
+ let hasher = RandomSipHasher::new();
+ HashMap::with_capacity_and_hasher(capacity, hasher)
+ }
+}
+
+impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> HashMap<K, V, H> {
+ /// Creates an empty hashmap which will use the given hasher to hash keys.
+ ///
+ /// The creates map has the default initial capacity.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ /// use std::hash::sip::SipHasher;
+ ///
+ /// let h = SipHasher::new();
+ /// let mut map = HashMap::with_hasher(h);
+ /// map.insert(1i, 2u);
+ /// ```
+ #[inline]
+ pub fn with_hasher(hasher: H) -> HashMap<K, V, H> {
+ HashMap {
+ hasher: hasher,
+ resize_policy: DefaultResizePolicy::new(INITIAL_CAPACITY),
+ table: table::RawTable::new(0),
+ }
+ }
+
+ /// Create an empty HashMap with space for at least `capacity`
+ /// elements, using `hasher` to hash the keys.
+ ///
+ /// Warning: `hasher` is normally randomly generated, and
+ /// is designed to allow HashMaps to be resistant to attacks that
+ /// cause many collisions and very poor performance. Setting it
+ /// manually using this function can expose a DoS attack vector.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ /// use std::hash::sip::SipHasher;
+ ///
+ /// let h = SipHasher::new();
+ /// let mut map = HashMap::with_capacity_and_hasher(10, h);
+ /// map.insert(1i, 2u);
+ /// ```
+ #[inline]
+ pub fn with_capacity_and_hasher(capacity: uint, hasher: H) -> HashMap<K, V, H> {
+ let cap = num::next_power_of_two(max(INITIAL_CAPACITY, capacity));
+ HashMap {
+ hasher: hasher,
+ resize_policy: DefaultResizePolicy::new(cap),
+ table: table::RawTable::new(cap),
+ }
+ }
+
+ /// The hashtable will never try to shrink below this size. You can use
+ /// this function to reduce reallocations if your hashtable frequently
+ /// grows and shrinks by large amounts.
+ ///
+ /// This function has no effect on the operational semantics of the
+ /// hashtable, only on performance.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ /// let mut map: HashMap<&str, int> = HashMap::new();
+ /// map.reserve(10);
+ /// ```
+ pub fn reserve(&mut self, new_minimum_capacity: uint) {
+ let cap = num::next_power_of_two(
+ max(INITIAL_CAPACITY, new_minimum_capacity));
+
+ self.resize_policy.reserve(cap);
+
+ if self.table.capacity() < cap {
+ self.resize(cap);
+ }
+ }
+
+ /// Resizes the internal vectors to a new capacity. It's your responsibility to:
+ /// 1) Make sure the new capacity is enough for all the elements, accounting
+ /// for the load factor.
+ /// 2) Ensure new_capacity is a power of two.
+ fn resize(&mut self, new_capacity: uint) {
+ assert!(self.table.size() <= new_capacity);
+ assert!(num::is_power_of_two(new_capacity));
+
+ let mut old_table = replace(&mut self.table, table::RawTable::new(new_capacity));
+ let old_size = old_table.size();
+
+ if old_table.capacity() == 0 {
+ return;
+ }
+
+ if new_capacity < old_table.capacity() {
+ for (h, k, v) in old_table.move_iter() {
+ self.insert_hashed_nocheck(h, k, v);
+ }
+ } else {
+ let mut bucket = Bucket::first(&mut old_table);
+
+ loop {
+ match bucket.peek() {
+ table::Full(full) => {
+ if full.distance() == 0 {
+ bucket = full.into_bucket();
+ break;
+ }
+ bucket = full.next();
+ }
+ table::Empty(b) => {
+ bucket = b.next();
+ break;
+ }
+ };
+ }
+
+ loop {
+ bucket = match bucket.peek() {
+ table::Full(bucket) => {
+ {
+ let t = bucket.table();
+ if t.size() == 0 { break }
+ }
+ let h = bucket.hash();
+ let (b, k, v) = bucket.take();
+ self.insert_hashed_ordered(h, k, v);
+ b.into_bucket()
+ }
+ table::Empty(b) => b.into_bucket()
+ };
+ bucket.next();
+ }
+ }
+
+ assert_eq!(self.table.size(), old_size);
+ }
+
+ /// Performs any necessary resize operations, such that there's space for
+ /// new_size elements.
+ fn make_some_room(&mut self, new_size: uint) {
+ let (grow_at, shrink_at) = self.resize_policy.capacity_range(new_size);
+ let cap = self.table.capacity();
+
+ // An invalid value shouldn't make us run out of space.
+ debug_assert!(grow_at >= new_size);
+
+ if cap <= grow_at {
+ let new_capacity = max(cap << 1, INITIAL_CAPACITY);
+ self.resize(new_capacity);
+ } else if shrink_at <= cap {
+ let new_capacity = cap >> 1;
+ self.resize(new_capacity);
+ }
+ }
+
+ /// Insert a pre-hashed key-value pair, without first checking
+ /// that there's enough room in the buckets. Returns a reference to the
+ /// newly insert value.
+ ///
+ /// If the key already exists, the hashtable will be returned untouched
+ /// and a reference to the existing element will be returned.
+ fn insert_hashed_nocheck<'a>(
+ &'a mut self, hash: table::SafeHash, k: K, v: V) -> &'a mut V {
+ self.insert_or_replace_with(hash, k, v, |_, _| ())
+ }
+
+ fn insert_or_replace_with<'a>(
+ &'a mut self, hash: table::SafeHash, k: K, v: V,
+ found_existing: |&mut V, V|
+ ) -> &'a mut V {
+
+ // Worst case, we'll find one empty bucket among `size + 1` buckets.
+ let size = self.table.size();
+ let mut rbucket = Bucket::new(&mut self.table, &hash);
+ let ib = rbucket.index();
+
+ loop {
+ let mut bucket = match rbucket.peek() {
+ table::Empty(bucket) => {
+ // Found a hole!
+ let bucket = bucket.put(hash, k, v);
+ let (_, val) = bucket.into_mut_refs();
+ return val;
+ },
+ table::Full(bucket) => bucket
+ };
+
+ if bucket.hash() == hash {
+ let (bucket_k, bucket_v) = bucket.read_mut();
+ // FIXME #12147 the conditional return confuses
+ // borrowck if we return bucket_v directly
+ let bv: *mut V = bucket_v;
+ if k == *bucket_k {
+ // Key already exists. Get its reference.
+ found_existing(bucket_v, v);
+ return unsafe {&mut *bv};
+ }
+ }
+
+ let robin_ib = bucket.index() as int - bucket.distance() as int;
+
+ if (ib as int) < robin_ib {
+ // Found a luckier bucket than me. Better steal his spot.
+ let (mut hash, mut k, mut v) = bucket.replace(hash, k, v);
+ let robin_index = bucket.index();
+ let mut robin_ib = robin_ib as uint;
+ let mut rbucket = bucket.next();
+ loop {
+ let mut bucket = match rbucket.peek() {
+ table::Empty(bucket) => {
+ // Found a hole!
+ let b = bucket.put(hash, k, v);
+ // Now that it's stolen, just read the value's pointer
+ // right out of the table!
+ let (_, v) = match Bucket::at_index(b.into_table(), robin_index).peek() {
+ table::Full(b) => b.into_mut_refs(),
+ _ => fail!()
+ };
+ return v;
+ },
+ table::Full(bucket) => bucket
+ };
+
+ let probe_ib = bucket.index() - bucket.distance();
+
+ // Robin hood! Steal the spot.
+ if robin_ib < probe_ib {
+ robin_ib = probe_ib;
+ let (old_hash, old_key, old_val) = bucket.replace(hash, k, v);
+ hash = old_hash;
+ k = old_key;
+ v = old_val;
+ }
+ rbucket = bucket.next();
+ if rbucket.index() == ib + size + 1 {
+ fail!("HashMap fatal error: 100% load factor?")
+ }
+ }
+ }
+ rbucket = bucket.next();
+ if rbucket.index() == ib + size + 1 {
+ fail!("Internal HashMap error: Out of space.")
+ }
+ }
+ }
+
+ /// Inserts an element which has already been hashed, returning a reference
+ /// to that element inside the hashtable. This is more efficient that using
+ /// `insert`, since the key will not be rehashed.
+ fn insert_hashed<'a>(&'a mut self, hash: table::SafeHash, k: K, v: V) -> &'a mut V {
+ let potential_new_size = self.table.size() + 1;
+ self.make_some_room(potential_new_size);
+ self.insert_hashed_nocheck(hash, k, v)
+ }
+
+ /// Return the value corresponding to the key in the map, or insert
+ /// and return the value if it doesn't exist.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ /// let mut map = HashMap::new();
+ ///
+ /// // Insert 1i with key "a"
+ /// assert_eq!(*map.find_or_insert("a", 1i), 1);
+ ///
+ /// // Find the existing key
+ /// assert_eq!(*map.find_or_insert("a", -2), 1);
+ /// ```
+ pub fn find_or_insert<'a>(&'a mut self, k: K, v: V) -> &'a mut V {
+ self.find_with_or_insert_with(k, v, |_k, _v, _a| (), |_k, a| a)
+ }
+
+ /// Return the value corresponding to the key in the map, or create,
+ /// insert, and return a new value if it doesn't exist.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ /// let mut map = HashMap::new();
+ ///
+ /// // Insert 10 with key 2
+ /// assert_eq!(*map.find_or_insert_with(2i, |&key| 5 * key as uint), 10u);
+ ///
+ /// // Find the existing key
+ /// assert_eq!(*map.find_or_insert_with(2, |&key| key as uint), 10);
+ /// ```
+ pub fn find_or_insert_with<'a>(&'a mut self, k: K, f: |&K| -> V)
+ -> &'a mut V {
+ self.find_with_or_insert_with(k, (), |_k, _v, _a| (), |k, _a| f(k))
+ }
+
+ /// Insert a key-value pair into the map if the key is not already present.
+ /// Otherwise, modify the existing value for the key.
+ /// Returns the new or modified value for the key.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ /// let mut map = HashMap::new();
+ ///
+ /// // Insert 2 with key "a"
+ /// assert_eq!(*map.insert_or_update_with("a", 2u, |_key, val| *val = 3), 2);
+ ///
+ /// // Update and return the existing value
+ /// assert_eq!(*map.insert_or_update_with("a", 9, |_key, val| *val = 7), 7);
+ /// assert_eq!(map["a"], 7);
+ /// ```
+ pub fn insert_or_update_with<'a>(
+ &'a mut self,
+ k: K,
+ v: V,
+ f: |&K, &mut V|)
+ -> &'a mut V {
+ self.find_with_or_insert_with(k, v, |k, v, _a| f(k, v), |_k, a| a)
+ }
+
+ /// Modify and return the value corresponding to the key in the map, or
+ /// insert and return a new value if it doesn't exist.
+ ///
+ /// This method allows for all insertion behaviours of a hashmap;
+ /// see methods like
+ /// [`insert`](../trait.MutableMap.html#tymethod.insert),
+ /// [`find_or_insert`](#method.find_or_insert) and
+ /// [`insert_or_update_with`](#method.insert_or_update_with)
+ /// for less general and more friendly variations of this.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// // map some strings to vectors of strings
+ /// let mut map = HashMap::new();
+ /// map.insert("a key", vec!["value"]);
+ /// map.insert("z key", vec!["value"]);
+ ///
+ /// let new = vec!["a key", "b key", "z key"];
+ ///
+ /// for k in new.move_iter() {
+ /// map.find_with_or_insert_with(
+ /// k, "new value",
+ /// // if the key does exist either prepend or append this
+ /// // new value based on the first letter of the key.
+ /// |key, already, new| {
+ /// if key.as_slice().starts_with("z") {
+ /// already.insert(0, new);
+ /// } else {
+ /// already.push(new);
+ /// }
+ /// },
+ /// // if the key doesn't exist in the map yet, add it in
+ /// // the obvious way.
+ /// |_k, v| vec![v]);
+ /// }
+ ///
+ /// assert_eq!(map.len(), 3);
+ /// assert_eq!(map["a key"], vec!["value", "new value"]);
+ /// assert_eq!(map["b key"], vec!["new value"]);
+ /// assert_eq!(map["z key"], vec!["new value", "value"]);
+ /// ```
+ pub fn find_with_or_insert_with<'a, A>(&'a mut self,
+ k: K,
+ a: A,
+ found: |&K, &mut V, A|,
+ not_found: |&K, A| -> V)
+ -> &'a mut V {
+ let hash = self.make_hash(&k);
+ {
+ match search_hashed(&mut self.table, &hash, &k) {
+ Some(bucket) => {
+ let (_, v_ref) = bucket.into_mut_refs();
+ found(&k, v_ref, a);
+ return v_ref;
+ }
+ _ => {
+ }
+ };
+ }
+ let v = not_found(&k, a);
+ self.insert_hashed(hash, k, v)
+ }
+
+ /// Retrieves a value for the given key.
+ /// See [`find`](../trait.Map.html#tymethod.find) for a non-failing alternative.
+ ///
+ /// # Failure
+ ///
+ /// Fails if the key is not present.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// #![allow(deprecated)]
+ ///
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert("a", 1i);
+ /// assert_eq!(map.get(&"a"), &1);
+ /// ```
+ #[deprecated = "prefer indexing instead, e.g., map[key]"]
+ pub fn get<'a>(&'a self, k: &K) -> &'a V {
+ match self.find(k) {
+ Some(v) => v,
+ None => fail!("no entry found for key")
+ }
+ }
+
+ /// Retrieves a mutable value for the given key.
+ /// See [`find_mut`](../trait.MutableMap.html#tymethod.find_mut) for a non-failing alternative.
+ ///
+ /// # Failure
+ ///
+ /// Fails if the key is not present.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert("a", 1i);
+ /// {
+ /// // val will freeze map to prevent usage during its lifetime
+ /// let val = map.get_mut(&"a");
+ /// *val = 40;
+ /// }
+ /// assert_eq!(map["a"], 40);
+ ///
+ /// // A more direct way could be:
+ /// *map.get_mut(&"a") = -2;
+ /// assert_eq!(map["a"], -2);
+ /// ```
+ pub fn get_mut<'a>(&'a mut self, k: &K) -> &'a mut V {
+ match self.find_mut(k) {
+ Some(v) => v,
+ None => fail!("no entry found for key")
+ }
+ }
+
+ /// Return true if the map contains a value for the specified key,
+ /// using equivalence.
+ ///
+ /// See [pop_equiv](#method.pop_equiv) for an extended example.
+ pub fn contains_key_equiv<Q: Hash<S> + Equiv<K>>(&self, key: &Q) -> bool {
+ self.search_equiv(key).is_some()
+ }
+
+ /// Return the value corresponding to the key in the map, using
+ /// equivalence.
+ ///
+ /// See [pop_equiv](#method.pop_equiv) for an extended example.
+ pub fn find_equiv<'a, Q: Hash<S> + Equiv<K>>(&'a self, k: &Q) -> Option<&'a V> {
+ match self.search_equiv(k) {
+ None => None,
+ Some(bucket) => {
+ let (_, v_ref) = bucket.into_refs();
+ Some(v_ref)
+ }
+ }
+ }
+
+ /// Remove an equivalent key from the map, returning the value at the
+ /// key if the key was previously in the map.
+ ///
+ /// # Example
+ ///
+ /// This is a slightly silly example where we define the number's
+ /// parity as the equivalence class. It is important that the
+ /// values hash the same, which is why we implement `Hash`.
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ /// use std::hash::Hash;
+ /// use std::hash::sip::SipState;
+ ///
+ /// #[deriving(Eq, PartialEq)]
+ /// struct EvenOrOdd {
+ /// num: uint
+ /// };
+ ///
+ /// impl Hash for EvenOrOdd {
+ /// fn hash(&self, state: &mut SipState) {
+ /// let parity = self.num % 2;
+ /// parity.hash(state);
+ /// }
+ /// }
+ ///
+ /// impl Equiv<EvenOrOdd> for EvenOrOdd {
+ /// fn equiv(&self, other: &EvenOrOdd) -> bool {
+ /// self.num % 2 == other.num % 2
+ /// }
+ /// }
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert(EvenOrOdd { num: 3 }, "foo");
+ ///
+ /// assert!(map.contains_key_equiv(&EvenOrOdd { num: 1 }));
+ /// assert!(!map.contains_key_equiv(&EvenOrOdd { num: 4 }));
+ ///
+ /// assert_eq!(map.find_equiv(&EvenOrOdd { num: 5 }), Some(&"foo"));
+ /// assert_eq!(map.find_equiv(&EvenOrOdd { num: 2 }), None);
+ ///
+ /// assert_eq!(map.pop_equiv(&EvenOrOdd { num: 1 }), Some("foo"));
+ /// assert_eq!(map.pop_equiv(&EvenOrOdd { num: 2 }), None);
+ ///
+ /// ```
+ #[experimental]
+ pub fn pop_equiv<Q:Hash<S> + Equiv<K>>(&mut self, k: &Q) -> Option<V> {
+ if self.table.size() == 0 {
+ return None
+ }
+
+ let potential_new_size = self.table.size() - 1;
+ self.make_some_room(potential_new_size);
+
+ match self.search_equiv_mut(k) {
+ Some(bucket) => {
+ Some(pop_internal(bucket))
+ }
+ _ => None
+ }
+ }
+
+ /// An iterator visiting all keys in arbitrary order.
+ /// Iterator element type is `&'a K`.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert("a", 1i);
+ /// map.insert("b", 2);
+ /// map.insert("c", 3);
+ ///
+ /// for key in map.keys() {
+ /// println!("{}", key);
+ /// }
+ /// ```
+ pub fn keys<'a>(&'a self) -> Keys<'a, K, V> {
+ self.iter().map(|(k, _v)| k)
+ }
+
+ /// An iterator visiting all values in arbitrary order.
+ /// Iterator element type is `&'a V`.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert("a", 1i);
+ /// map.insert("b", 2);
+ /// map.insert("c", 3);
+ ///
+ /// for key in map.values() {
+ /// println!("{}", key);
+ /// }
+ /// ```
+ pub fn values<'a>(&'a self) -> Values<'a, K, V> {
+ self.iter().map(|(_k, v)| v)
+ }
+
+ /// An iterator visiting all key-value pairs in arbitrary order.
+ /// Iterator element type is `(&'a K, &'a V)`.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert("a", 1i);
+ /// map.insert("b", 2);
+ /// map.insert("c", 3);
+ ///
+ /// for (key, val) in map.iter() {
+ /// println!("key: {} val: {}", key, val);
+ /// }
+ /// ```
+ pub fn iter<'a>(&'a self) -> Entries<'a, K, V> {
+ self.table.iter()
+ }
+
+ /// An iterator visiting all key-value pairs in arbitrary order,
+ /// with mutable references to the values.
+ /// Iterator element type is `(&'a K, &'a mut V)`.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert("a", 1i);
+ /// map.insert("b", 2);
+ /// map.insert("c", 3);
+ ///
+ /// // Update all values
+ /// for (_, val) in map.mut_iter() {
+ /// *val *= 2;
+ /// }
+ ///
+ /// for (key, val) in map.iter() {
+ /// println!("key: {} val: {}", key, val);
+ /// }
+ /// ```
+ pub fn mut_iter<'a>(&'a mut self) -> MutEntries<'a, K, V> {
+ self.table.mut_iter()
+ }
+
+ /// Creates a consuming iterator, that is, one that moves each key-value
+ /// pair out of the map in arbitrary order. The map cannot be used after
+ /// calling this.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map = HashMap::new();
+ /// map.insert("a", 1i);
+ /// map.insert("b", 2);
+ /// map.insert("c", 3);
+ ///
+ /// // Not possible with .iter()
+ /// let vec: Vec<(&str, int)> = map.move_iter().collect();
+ /// ```
+ pub fn move_iter(self) -> MoveEntries<K, V> {
+ self.table.move_iter().map(|(_, k, v)| (k, v))
+ }
+}
+
+impl<K: Eq + Hash<S>, V: Clone, S, H: Hasher<S>> HashMap<K, V, H> {
+ /// Return a copy of the value corresponding to the key.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map: HashMap<uint, String> = HashMap::new();
+ /// map.insert(1u, "foo".to_string());
+ /// let s: String = map.find_copy(&1).unwrap();
+ /// ```
+ pub fn find_copy(&self, k: &K) -> Option<V> {
+ self.find(k).map(|v| (*v).clone())
+ }
+
+ /// Return a copy of the value corresponding to the key.
+ ///
+ /// # Failure
+ ///
+ /// Fails if the key is not present.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashMap;
+ ///
+ /// let mut map: HashMap<uint, String> = HashMap::new();
+ /// map.insert(1u, "foo".to_string());
+ /// let s: String = map.get_copy(&1);
+ /// ```
+ pub fn get_copy(&self, k: &K) -> V {
+ (*self.get(k)).clone()
+ }
+}
+
+impl<K: Eq + Hash<S>, V: PartialEq, S, H: Hasher<S>> PartialEq for HashMap<K, V, H> {
+ fn eq(&self, other: &HashMap<K, V, H>) -> bool {
+ if self.len() != other.len() { return false; }
+
+ self.iter()
+ .all(|(key, value)| {
+ match other.find(key) {
+ None => false,
+ Some(v) => *value == *v
+ }
+ })
+ }
+}
+
+impl<K: Eq + Hash<S>, V: Eq, S, H: Hasher<S>> Eq for HashMap<K, V, H> {}
+
+impl<K: Eq + Hash<S> + Show, V: Show, S, H: Hasher<S>> Show for HashMap<K, V, H> {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ try!(write!(f, "{{"));
+
+ for (i, (k, v)) in self.iter().enumerate() {
+ if i != 0 { try!(write!(f, ", ")); }
+ try!(write!(f, "{}: {}", *k, *v));
+ }
+
+ write!(f, "}}")
+ }
+}
+
+impl<K: Eq + Hash<S>, V, S, H: Hasher<S> + Default> Default for HashMap<K, V, H> {
+ fn default() -> HashMap<K, V, H> {
+ HashMap::with_hasher(Default::default())
+ }
+}
+
+impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> Index<K, V> for HashMap<K, V, H> {
+ #[inline]
+ fn index<'a>(&'a self, index: &K) -> &'a V {
+ self.get(index)
+ }
+}
+
+// FIXME(#12825) Indexing will always try IndexMut first and that causes issues.
+/*impl<K: Eq + Hash<S>, V, S, H: Hasher<S>> ops::IndexMut<K, V> for HashMap<K, V, H> {
+ #[inline]
+ fn index_mut<'a>(&'a mut self, index: &K) -> &'a mut V {
+ self.get_mut(index)
+ }
+}*/
+
+/// HashMap iterator
+pub type Entries<'a, K, V> = table::Entries<'a, K, V>;
+
+/// HashMap mutable values iterator
+pub type MutEntries<'a, K, V> = table::MutEntries<'a, K, V>;
+
+/// HashMap move iterator
+pub type MoveEntries<K, V> =
+ iter::Map<'static, (table::SafeHash, K, V), (K, V), table::MoveEntries<K, V>>;
+
+/// HashMap keys iterator
+pub type Keys<'a, K, V> =
+ iter::Map<'static, (&'a K, &'a V), &'a K, Entries<'a, K, V>>;
+
+/// HashMap values iterator
+pub type Values<'a, K, V> =
+ iter::Map<'static, (&'a K, &'a V), &'a V, Entries<'a, K, V>>;
+
+impl<K: Eq + Hash<S>, V, S, H: Hasher<S> + Default> FromIterator<(K, V)> for HashMap<K, V, H> {
+ fn from_iter<T: Iterator<(K, V)>>(iter: T) -> HashMap<K, V, H> {
+ let (lower, _) = iter.size_hint();
+ let mut map = HashMap::with_capacity_and_hasher(lower, Default::default());
+ map.extend(iter);
+ map
+ }
+}
+
+impl<K: Eq + Hash<S>, V, S, H: Hasher<S> + Default> Extendable<(K, V)> for HashMap<K, V, H> {
+ fn extend<T: Iterator<(K, V)>>(&mut self, mut iter: T) {
+ for (k, v) in iter {
+ self.insert(k, v);
+ }
+ }
+}
+
+#[cfg(test)]
+mod test_map {
+ use prelude::*;
+
+ use super::HashMap;
+ use cmp::Equiv;
+ use hash;
+ use iter::{Iterator,range_inclusive,range_step_inclusive};
+ use cell::RefCell;
+
+ struct KindaIntLike(int);
+
+ impl Equiv<int> for KindaIntLike {
+ fn equiv(&self, other: &int) -> bool {
+ let KindaIntLike(this) = *self;
+ this == *other
+ }
+ }
+ impl<S: hash::Writer> hash::Hash<S> for KindaIntLike {
+ fn hash(&self, state: &mut S) {
+ let KindaIntLike(this) = *self;
+ this.hash(state)
+ }
+ }
+
+ #[test]
+ fn test_create_capacity_zero() {
+ let mut m = HashMap::with_capacity(0);
+
+ assert!(m.insert(1i, 1i));
+
+ assert!(m.contains_key(&1));
+ assert!(!m.contains_key(&0));
+ }
+
+ #[test]
+ fn test_insert() {
+ let mut m = HashMap::new();
+ assert_eq!(m.len(), 0);
+ assert!(m.insert(1i, 2i));
+ assert_eq!(m.len(), 1);
+ assert!(m.insert(2i, 4i));
+ assert_eq!(m.len(), 2);
+ assert_eq!(*m.find(&1).unwrap(), 2);
+ assert_eq!(*m.find(&2).unwrap(), 4);
+ }
+
+ local_data_key!(drop_vector: RefCell<Vec<int>>)
+
+ #[deriving(Hash, PartialEq, Eq)]
+ struct Dropable {
+ k: uint
+ }
+
+
+ impl Dropable {
+ fn new(k: uint) -> Dropable {
+ let v = drop_vector.get().unwrap();
+ v.borrow_mut().as_mut_slice()[k] += 1;
+
+ Dropable { k: k }
+ }
+ }
+
+ impl Drop for Dropable {
+ fn drop(&mut self) {
+ let v = drop_vector.get().unwrap();
+ v.borrow_mut().as_mut_slice()[self.k] -= 1;
+ }
+ }
+
+ impl Clone for Dropable {
+ fn clone(&self) -> Dropable {
+ Dropable::new(self.k)
+ }
+ }
+
+ #[test]
+ fn test_drops() {
+ drop_vector.replace(Some(RefCell::new(Vec::from_elem(200, 0i))));
+
+ {
+ let mut m = HashMap::new();
+
+ let v = drop_vector.get().unwrap();
+ for i in range(0u, 200) {
+ assert_eq!(v.borrow().as_slice()[i], 0);
+ }
+ drop(v);
+
+ for i in range(0u, 100) {
+ let d1 = Dropable::new(i);
+ let d2 = Dropable::new(i+100);
+ m.insert(d1, d2);
+ }
+
+ let v = drop_vector.get().unwrap();
+ for i in range(0u, 200) {
+ assert_eq!(v.borrow().as_slice()[i], 1);
+ }
+ drop(v);
+
+ for i in range(0u, 50) {
+ let k = Dropable::new(i);
+ let v = m.pop(&k);
+
+ assert!(v.is_some());
+
+ let v = drop_vector.get().unwrap();
+ assert_eq!(v.borrow().as_slice()[i], 1);
+ assert_eq!(v.borrow().as_slice()[i+100], 1);
+ }
+
+ let v = drop_vector.get().unwrap();
+ for i in range(0u, 50) {
+ assert_eq!(v.borrow().as_slice()[i], 0);
+ assert_eq!(v.borrow().as_slice()[i+100], 0);
+ }
+
+ for i in range(50u, 100) {
+ assert_eq!(v.borrow().as_slice()[i], 1);
+ assert_eq!(v.borrow().as_slice()[i+100], 1);
+ }
+ }
+
+ let v = drop_vector.get().unwrap();
+ for i in range(0u, 200) {
+ assert_eq!(v.borrow().as_slice()[i], 0);
+ }
+ }
+
+ #[test]
+ fn test_move_iter_drops() {
+ drop_vector.replace(Some(RefCell::new(Vec::from_elem(200, 0i))));
+
+ let hm = {
+ let mut hm = HashMap::new();
+
+ let v = drop_vector.get().unwrap();
+ for i in range(0u, 200) {
+ assert_eq!(v.borrow().as_slice()[i], 0);
+ }
+ drop(v);
+
+ for i in range(0u, 100) {
+ let d1 = Dropable::new(i);
+ let d2 = Dropable::new(i+100);
+ hm.insert(d1, d2);
+ }
+
+ let v = drop_vector.get().unwrap();
+ for i in range(0u, 200) {
+ assert_eq!(v.borrow().as_slice()[i], 1);
+ }
+ drop(v);
+
+ hm
+ };
+
+ drop(hm.clone());
+
+ {
+ let mut half = hm.move_iter().take(50);
+
+ let v = drop_vector.get().unwrap();
+ for i in range(0u, 200) {
+ assert_eq!(v.borrow().as_slice()[i], 1);
+ }
+ drop(v);
+
+ for _ in half {}
+
+ let v = drop_vector.get().unwrap();
+ let nk = range(0u, 100).filter(|&i| {
+ v.borrow().as_slice()[i] == 1
+ }).count();
+
+ let nv = range(0u, 100).filter(|&i| {
+ v.borrow().as_slice()[i+100] == 1
+ }).count();
+
+ assert_eq!(nk, 50);
+ assert_eq!(nv, 50);
+ };
+
+ let v = drop_vector.get().unwrap();
+ for i in range(0u, 200) {
+ assert_eq!(v.borrow().as_slice()[i], 0);
+ }
+ }
+
+ #[test]
+ fn test_empty_pop() {
+ let mut m: HashMap<int, bool> = HashMap::new();
+ assert_eq!(m.pop(&0), None);
+ }
+
+ #[test]
+ fn test_lots_of_insertions() {
+ let mut m = HashMap::new();
+
+ // Try this a few times to make sure we never screw up the hashmap's
+ // internal state.
+ for _ in range(0i, 10) {
+ assert!(m.is_empty());
+
+ for i in range_inclusive(1i, 1000) {
+ assert!(m.insert(i, i));
+
+ for j in range_inclusive(1, i) {
+ let r = m.find(&j);
+ assert_eq!(r, Some(&j));
+ }
+
+ for j in range_inclusive(i+1, 1000) {
+ let r = m.find(&j);
+ assert_eq!(r, None);
+ }
+ }
+
+ for i in range_inclusive(1001i, 2000) {
+ assert!(!m.contains_key(&i));
+ }
+
+ // remove forwards
+ for i in range_inclusive(1i, 1000) {
+ assert!(m.remove(&i));
+
+ for j in range_inclusive(1, i) {
+ assert!(!m.contains_key(&j));
+ }
+
+ for j in range_inclusive(i+1, 1000) {
+ assert!(m.contains_key(&j));
+ }
+ }
+
+ for i in range_inclusive(1i, 1000) {
+ assert!(!m.contains_key(&i));
+ }
+
+ for i in range_inclusive(1i, 1000) {
+ assert!(m.insert(i, i));
+ }
+
+ // remove backwards
+ for i in range_step_inclusive(1000i, 1, -1) {
+ assert!(m.remove(&i));
+
+ for j in range_inclusive(i, 1000) {
+ assert!(!m.contains_key(&j));
+ }
+
+ for j in range_inclusive(1, i-1) {
+ assert!(m.contains_key(&j));
+ }
+ }
+ }
+ }
+
+ #[test]
+ fn test_find_mut() {
+ let mut m = HashMap::new();
+ assert!(m.insert(1i, 12i));
+ assert!(m.insert(2i, 8i));
+ assert!(m.insert(5i, 14i));
+ let new = 100;
+ match m.find_mut(&5) {
+ None => fail!(), Some(x) => *x = new
+ }
+ assert_eq!(m.find(&5), Some(&new));
+ }
+
+ #[test]
+ fn test_insert_overwrite() {
+ let mut m = HashMap::new();
+ assert!(m.insert(1i, 2i));
+ assert_eq!(*m.find(&1).unwrap(), 2);
+ assert!(!m.insert(1i, 3i));
+ assert_eq!(*m.find(&1).unwrap(), 3);
+ }
+
+ #[test]
+ fn test_insert_conflicts() {
+ let mut m = HashMap::with_capacity(4);
+ assert!(m.insert(1i, 2i));
+ assert!(m.insert(5i, 3i));
+ assert!(m.insert(9i, 4i));
+ assert_eq!(*m.find(&9).unwrap(), 4);
+ assert_eq!(*m.find(&5).unwrap(), 3);
+ assert_eq!(*m.find(&1).unwrap(), 2);
+ }
+
+ #[test]
+ fn test_conflict_remove() {
+ let mut m = HashMap::with_capacity(4);
+ assert!(m.insert(1i, 2i));
+ assert_eq!(*m.find(&1).unwrap(), 2);
+ assert!(m.insert(5, 3));
+ assert_eq!(*m.find(&1).unwrap(), 2);
+ assert_eq!(*m.find(&5).unwrap(), 3);
+ assert!(m.insert(9, 4));
+ assert_eq!(*m.find(&1).unwrap(), 2);
+ assert_eq!(*m.find(&5).unwrap(), 3);
+ assert_eq!(*m.find(&9).unwrap(), 4);
+ assert!(m.remove(&1));
+ assert_eq!(*m.find(&9).unwrap(), 4);
+ assert_eq!(*m.find(&5).unwrap(), 3);
+ }
+
+ #[test]
+ fn test_is_empty() {
+ let mut m = HashMap::with_capacity(4);
+ assert!(m.insert(1i, 2i));
+ assert!(!m.is_empty());
+ assert!(m.remove(&1));
+ assert!(m.is_empty());
+ }
+
+ #[test]
+ fn test_pop() {
+ let mut m = HashMap::new();
+ m.insert(1i, 2i);
+ assert_eq!(m.pop(&1), Some(2));
+ assert_eq!(m.pop(&1), None);
+ }
+
+ #[test]
+ #[allow(experimental)]
+ fn test_pop_equiv() {
+ let mut m = HashMap::new();
+ m.insert(1i, 2i);
+ assert_eq!(m.pop_equiv(&KindaIntLike(1)), Some(2));
+ assert_eq!(m.pop_equiv(&KindaIntLike(1)), None);
+ }
+
+ #[test]
+ fn test_swap() {
+ let mut m = HashMap::new();
+ assert_eq!(m.swap(1i, 2i), None);
+ assert_eq!(m.swap(1i, 3i), Some(2));
+ assert_eq!(m.swap(1i, 4i), Some(3));
+ }
+
+ #[test]
+ fn test_iterate() {
+ let mut m = HashMap::with_capacity(4);
+ for i in range(0u, 32) {
+ assert!(m.insert(i, i*2));
+ }
+ assert_eq!(m.len(), 32);
+
+ let mut observed: u32 = 0;
+
+ for (k, v) in m.iter() {
+ assert_eq!(*v, *k * 2);
+ observed |= 1 << *k;
+ }
+ assert_eq!(observed, 0xFFFF_FFFF);
+ }
+
+ #[test]
+ fn test_keys() {
+ let vec = vec![(1i, 'a'), (2i, 'b'), (3i, 'c')];
+ let map = vec.move_iter().collect::<HashMap<int, char>>();
+ let keys = map.keys().map(|&k| k).collect::<Vec<int>>();
+ assert_eq!(keys.len(), 3);
+ assert!(keys.contains(&1));
+ assert!(keys.contains(&2));
+ assert!(keys.contains(&3));
+ }
+
+ #[test]
+ fn test_values() {
+ let vec = vec![(1i, 'a'), (2i, 'b'), (3i, 'c')];
+ let map = vec.move_iter().collect::<HashMap<int, char>>();
+ let values = map.values().map(|&v| v).collect::<Vec<char>>();
+ assert_eq!(values.len(), 3);
+ assert!(values.contains(&'a'));
+ assert!(values.contains(&'b'));
+ assert!(values.contains(&'c'));
+ }
+
+ #[test]
+ fn test_find() {
+ let mut m = HashMap::new();
+ assert!(m.find(&1i).is_none());
+ m.insert(1i, 2i);
+ match m.find(&1) {
+ None => fail!(),
+ Some(v) => assert_eq!(*v, 2)
+ }
+ }
+
+ #[test]
+ fn test_find_copy() {
+ let mut m = HashMap::new();
+ assert!(m.find(&1i).is_none());
+
+ for i in range(1i, 10000) {
+ m.insert(i, i + 7);
+ match m.find_copy(&i) {
+ None => fail!(),
+ Some(v) => assert_eq!(v, i + 7)
+ }
+ for j in range(1i, i/100) {
+ match m.find_copy(&j) {
+ None => fail!(),
+ Some(v) => assert_eq!(v, j + 7)
+ }
+ }
+ }
+ }
+
+ #[test]
+ fn test_eq() {
+ let mut m1 = HashMap::new();
+ m1.insert(1i, 2i);
+ m1.insert(2i, 3i);
+ m1.insert(3i, 4i);
+
+ let mut m2 = HashMap::new();
+ m2.insert(1i, 2i);
+ m2.insert(2i, 3i);
+
+ assert!(m1 != m2);
+
+ m2.insert(3i, 4i);
+
+ assert_eq!(m1, m2);
+ }
+
+ #[test]
+ fn test_show() {
+ let mut map: HashMap<int, int> = HashMap::new();
+ let empty: HashMap<int, int> = HashMap::new();
+
+ map.insert(1i, 2i);
+ map.insert(3i, 4i);
+
+ let map_str = format!("{}", map);
+
+ assert!(map_str == "{1: 2, 3: 4}".to_string() || map_str == "{3: 4, 1: 2}".to_string());
+ assert_eq!(format!("{}", empty), "{}".to_string());
+ }
+
+ #[test]
+ fn test_expand() {
+ let mut m = HashMap::new();
+
+ assert_eq!(m.len(), 0);
+ assert!(m.is_empty());
+
+ let mut i = 0u;
+ let old_cap = m.table.capacity();
+ while old_cap == m.table.capacity() {
+ m.insert(i, i);
+ i += 1;
+ }
+
+ assert_eq!(m.len(), i);
+ assert!(!m.is_empty());
+ }
+
+ #[test]
+ fn test_resize_policy() {
+ let mut m = HashMap::new();
+
+ assert_eq!(m.len(), 0);
+ assert_eq!(m.table.capacity(), 0);
+ assert!(m.is_empty());
+
+ m.insert(0, 0);
+ m.remove(&0);
+ assert!(m.is_empty());
+ let initial_cap = m.table.capacity();
+ m.reserve(initial_cap * 2);
+ let cap = m.table.capacity();
+
+ assert_eq!(cap, initial_cap * 2);
+
+ let mut i = 0u;
+ for _ in range(0, cap * 3 / 4) {
+ m.insert(i, i);
+ i += 1;
+ }
+
+ assert_eq!(m.len(), i);
+ assert_eq!(m.table.capacity(), cap);
+
+ for _ in range(0, cap / 4) {
+ m.insert(i, i);
+ i += 1;
+ }
+
+ let new_cap = m.table.capacity();
+ assert_eq!(new_cap, cap * 2);
+
+ for _ in range(0, cap / 2) {
+ i -= 1;
+ m.remove(&i);
+ assert_eq!(m.table.capacity(), new_cap);
+ }
+
+ for _ in range(0, cap / 2 - 1) {
+ i -= 1;
+ m.remove(&i);
+ }
+
+ assert_eq!(m.len(), i);
+ assert!(!m.is_empty());
+ assert_eq!(m.table.capacity(), cap);
+ }
+
+ #[test]
+ fn test_find_equiv() {
+ let mut m = HashMap::new();
+
+ let (foo, bar, baz) = (1i,2i,3i);
+ m.insert("foo".to_string(), foo);
+ m.insert("bar".to_string(), bar);
+ m.insert("baz".to_string(), baz);
+
+
+ assert_eq!(m.find_equiv(&("foo")), Some(&foo));
+ assert_eq!(m.find_equiv(&("bar")), Some(&bar));
+ assert_eq!(m.find_equiv(&("baz")), Some(&baz));
+
+ assert_eq!(m.find_equiv(&("qux")), None);
+ }
+
+ #[test]
+ fn test_from_iter() {
+ let xs = [(1i, 1i), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
+
+ let map: HashMap<int, int> = xs.iter().map(|&x| x).collect();
+
+ for &(k, v) in xs.iter() {
+ assert_eq!(map.find(&k), Some(&v));
+ }
+ }
+
+ #[test]
+ fn test_size_hint() {
+ let xs = [(1i, 1i), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
+
+ let map: HashMap<int, int> = xs.iter().map(|&x| x).collect();
+
+ let mut iter = map.iter();
+
+ for _ in iter.by_ref().take(3) {}
+
+ assert_eq!(iter.size_hint(), (3, Some(3)));
+ }
+
+ #[test]
+ fn test_mut_size_hint() {
+ let xs = [(1i, 1i), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
+
+ let mut map: HashMap<int, int> = xs.iter().map(|&x| x).collect();
+
+ let mut iter = map.mut_iter();
+
+ for _ in iter.by_ref().take(3) {}
+
+ assert_eq!(iter.size_hint(), (3, Some(3)));
+ }
+
+ #[test]
+ fn test_index() {
+ let mut map: HashMap<int, int> = HashMap::new();
+
+ map.insert(1, 2);
+ map.insert(2, 1);
+ map.insert(3, 4);
+
+ assert_eq!(map[2], 1);
+ }
+
+ #[test]
+ #[should_fail]
+ fn test_index_nonexistent() {
+ let mut map: HashMap<int, int> = HashMap::new();
+
+ map.insert(1, 2);
+ map.insert(2, 1);
+ map.insert(3, 4);
+
+ map[4];
+ }
+}
--- /dev/null
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Unordered containers, implemented as hash-tables
+
+pub use self::map::HashMap;
+pub use self::map::Entries;
+pub use self::map::MoveEntries;
+pub use self::map::Keys;
+pub use self::map::Values;
+pub use self::map::INITIAL_CAPACITY;
+pub use self::set::HashSet;
+pub use self::set::SetItems;
+pub use self::set::SetMoveItems;
+pub use self::set::SetAlgebraItems;
+
+mod bench;
+mod map;
+mod set;
+mod table;
--- /dev/null
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+//
+// ignore-lexer-test FIXME #15883
+
+use clone::Clone;
+use cmp::{Eq, Equiv, PartialEq};
+use collections::{Collection, Mutable, Set, MutableSet, Map, MutableMap};
+use default::Default;
+use fmt::Show;
+use fmt;
+use RandomSipHasher;
+use hash::{Hash, Hasher};
+use iter::{Iterator, FromIterator, FilterMap, Chain, Repeat, Zip, Extendable};
+use iter;
+use option::{Some, None};
+use result::{Ok, Err};
+
+use super::{HashMap, Entries, MoveEntries, INITIAL_CAPACITY};
+
+/// HashSet iterator
+pub type SetItems<'a, K> =
+ iter::Map<'static, (&'a K, &'a ()), &'a K, Entries<'a, K, ()>>;
+
+/// HashSet move iterator
+pub type SetMoveItems<K> =
+ iter::Map<'static, (K, ()), K, MoveEntries<K, ()>>;
+
+/// An implementation of a hash set using the underlying representation of a
+/// HashMap where the value is (). As with the `HashMap` type, a `HashSet`
+/// requires that the elements implement the `Eq` and `Hash` traits.
+///
+/// # Example
+///
+/// ```
+/// use std::collections::HashSet;
+/// // Type inference lets us omit an explicit type signature (which
+/// // would be `HashSet<&str>` in this example).
+/// let mut books = HashSet::new();
+///
+/// // Add some books.
+/// books.insert("A Dance With Dragons");
+/// books.insert("To Kill a Mockingbird");
+/// books.insert("The Odyssey");
+/// books.insert("The Great Gatsby");
+///
+/// // Check for a specific one.
+/// if !books.contains(&("The Winds of Winter")) {
+/// println!("We have {} books, but The Winds of Winter ain't one.",
+/// books.len());
+/// }
+///
+/// // Remove a book.
+/// books.remove(&"The Odyssey");
+///
+/// // Iterate over everything.
+/// for book in books.iter() {
+/// println!("{}", *book);
+/// }
+/// ```
+///
+/// The easiest way to use `HashSet` with a custom type is to derive
+/// `Eq` and `Hash`. We must also derive `PartialEq`, this will in the
+/// future be implied by `Eq`.
+///
+/// ```
+/// use std::collections::HashSet;
+/// #[deriving(Hash, Eq, PartialEq, Show)]
+/// struct Viking<'a> {
+/// name: &'a str,
+/// power: uint,
+/// }
+///
+/// let mut vikings = HashSet::new();
+///
+/// vikings.insert(Viking { name: "Einar", power: 9u });
+/// vikings.insert(Viking { name: "Einar", power: 9u });
+/// vikings.insert(Viking { name: "Olaf", power: 4u });
+/// vikings.insert(Viking { name: "Harald", power: 8u });
+///
+/// // Use derived implementation to print the vikings.
+/// for x in vikings.iter() {
+/// println!("{}", x);
+/// }
+/// ```
+#[deriving(Clone)]
+pub struct HashSet<T, H = RandomSipHasher> {
+ map: HashMap<T, (), H>
+}
+
+impl<T: Hash + Eq> HashSet<T, RandomSipHasher> {
+ /// Create an empty HashSet.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashSet;
+ /// let mut set: HashSet<int> = HashSet::new();
+ /// ```
+ #[inline]
+ pub fn new() -> HashSet<T, RandomSipHasher> {
+ HashSet::with_capacity(INITIAL_CAPACITY)
+ }
+
+ /// Create an empty HashSet with space for at least `n` elements in
+ /// the hash table.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashSet;
+ /// let mut set: HashSet<int> = HashSet::with_capacity(10);
+ /// ```
+ #[inline]
+ pub fn with_capacity(capacity: uint) -> HashSet<T, RandomSipHasher> {
+ HashSet { map: HashMap::with_capacity(capacity) }
+ }
+}
+
+impl<T: Eq + Hash<S>, S, H: Hasher<S>> HashSet<T, H> {
+ /// Creates a new empty hash set which will use the given hasher to hash
+ /// keys.
+ ///
+ /// The hash set is also created with the default initial capacity.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashSet;
+ /// use std::hash::sip::SipHasher;
+ ///
+ /// let h = SipHasher::new();
+ /// let mut set = HashSet::with_hasher(h);
+ /// set.insert(2u);
+ /// ```
+ #[inline]
+ pub fn with_hasher(hasher: H) -> HashSet<T, H> {
+ HashSet::with_capacity_and_hasher(INITIAL_CAPACITY, hasher)
+ }
+
+ /// Create an empty HashSet with space for at least `capacity`
+ /// elements in the hash table, using `hasher` to hash the keys.
+ ///
+ /// Warning: `hasher` is normally randomly generated, and
+ /// is designed to allow `HashSet`s to be resistant to attacks that
+ /// cause many collisions and very poor performance. Setting it
+ /// manually using this function can expose a DoS attack vector.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashSet;
+ /// use std::hash::sip::SipHasher;
+ ///
+ /// let h = SipHasher::new();
+ /// let mut set = HashSet::with_capacity_and_hasher(10u, h);
+ /// set.insert(1i);
+ /// ```
+ #[inline]
+ pub fn with_capacity_and_hasher(capacity: uint, hasher: H) -> HashSet<T, H> {
+ HashSet { map: HashMap::with_capacity_and_hasher(capacity, hasher) }
+ }
+
+ /// Reserve space for at least `n` elements in the hash table.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashSet;
+ /// let mut set: HashSet<int> = HashSet::new();
+ /// set.reserve(10);
+ /// ```
+ pub fn reserve(&mut self, n: uint) {
+ self.map.reserve(n)
+ }
+
+ /// Returns true if the hash set contains a value equivalent to the
+ /// given query value.
+ ///
+ /// # Example
+ ///
+ /// This is a slightly silly example where we define the number's
+ /// parity as the equivilance class. It is important that the
+ /// values hash the same, which is why we implement `Hash`.
+ ///
+ /// ```
+ /// use std::collections::HashSet;
+ /// use std::hash::Hash;
+ /// use std::hash::sip::SipState;
+ ///
+ /// #[deriving(Eq, PartialEq)]
+ /// struct EvenOrOdd {
+ /// num: uint
+ /// };
+ ///
+ /// impl Hash for EvenOrOdd {
+ /// fn hash(&self, state: &mut SipState) {
+ /// let parity = self.num % 2;
+ /// parity.hash(state);
+ /// }
+ /// }
+ ///
+ /// impl Equiv<EvenOrOdd> for EvenOrOdd {
+ /// fn equiv(&self, other: &EvenOrOdd) -> bool {
+ /// self.num % 2 == other.num % 2
+ /// }
+ /// }
+ ///
+ /// let mut set = HashSet::new();
+ /// set.insert(EvenOrOdd { num: 3u });
+ ///
+ /// assert!(set.contains_equiv(&EvenOrOdd { num: 3u }));
+ /// assert!(set.contains_equiv(&EvenOrOdd { num: 5u }));
+ /// assert!(!set.contains_equiv(&EvenOrOdd { num: 4u }));
+ /// assert!(!set.contains_equiv(&EvenOrOdd { num: 2u }));
+ ///
+ /// ```
+ pub fn contains_equiv<Q: Hash<S> + Equiv<T>>(&self, value: &Q) -> bool {
+ self.map.contains_key_equiv(value)
+ }
+
+ /// An iterator visiting all elements in arbitrary order.
+ /// Iterator element type is &'a T.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashSet;
+ /// let mut set = HashSet::new();
+ /// set.insert("a");
+ /// set.insert("b");
+ ///
+ /// // Will print in an arbitrary order.
+ /// for x in set.iter() {
+ /// println!("{}", x);
+ /// }
+ /// ```
+ pub fn iter<'a>(&'a self) -> SetItems<'a, T> {
+ self.map.keys()
+ }
+
+ /// Creates a consuming iterator, that is, one that moves each value out
+ /// of the set in arbitrary order. The set cannot be used after calling
+ /// this.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashSet;
+ /// let mut set = HashSet::new();
+ /// set.insert("a".to_string());
+ /// set.insert("b".to_string());
+ ///
+ /// // Not possible to collect to a Vec<String> with a regular `.iter()`.
+ /// let v: Vec<String> = set.move_iter().collect();
+ ///
+ /// // Will print in an arbitrary order.
+ /// for x in v.iter() {
+ /// println!("{}", x);
+ /// }
+ /// ```
+ pub fn move_iter(self) -> SetMoveItems<T> {
+ self.map.move_iter().map(|(k, _)| k)
+ }
+
+ /// Visit the values representing the difference.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashSet;
+ /// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
+ /// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
+ ///
+ /// // Can be seen as `a - b`.
+ /// for x in a.difference(&b) {
+ /// println!("{}", x); // Print 1
+ /// }
+ ///
+ /// let diff: HashSet<int> = a.difference(&b).map(|&x| x).collect();
+ /// assert_eq!(diff, [1i].iter().map(|&x| x).collect());
+ ///
+ /// // Note that difference is not symmetric,
+ /// // and `b - a` means something else:
+ /// let diff: HashSet<int> = b.difference(&a).map(|&x| x).collect();
+ /// assert_eq!(diff, [4i].iter().map(|&x| x).collect());
+ /// ```
+ pub fn difference<'a>(&'a self, other: &'a HashSet<T, H>) -> SetAlgebraItems<'a, T, H> {
+ Repeat::new(other).zip(self.iter())
+ .filter_map(|(other, elt)| {
+ if !other.contains(elt) { Some(elt) } else { None }
+ })
+ }
+
+ /// Visit the values representing the symmetric difference.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashSet;
+ /// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
+ /// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
+ ///
+ /// // Print 1, 4 in arbitrary order.
+ /// for x in a.symmetric_difference(&b) {
+ /// println!("{}", x);
+ /// }
+ ///
+ /// let diff1: HashSet<int> = a.symmetric_difference(&b).map(|&x| x).collect();
+ /// let diff2: HashSet<int> = b.symmetric_difference(&a).map(|&x| x).collect();
+ ///
+ /// assert_eq!(diff1, diff2);
+ /// assert_eq!(diff1, [1i, 4].iter().map(|&x| x).collect());
+ /// ```
+ pub fn symmetric_difference<'a>(&'a self, other: &'a HashSet<T, H>)
+ -> Chain<SetAlgebraItems<'a, T, H>, SetAlgebraItems<'a, T, H>> {
+ self.difference(other).chain(other.difference(self))
+ }
+
+ /// Visit the values representing the intersection.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashSet;
+ /// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
+ /// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
+ ///
+ /// // Print 2, 3 in arbitrary order.
+ /// for x in a.intersection(&b) {
+ /// println!("{}", x);
+ /// }
+ ///
+ /// let diff: HashSet<int> = a.intersection(&b).map(|&x| x).collect();
+ /// assert_eq!(diff, [2i, 3].iter().map(|&x| x).collect());
+ /// ```
+ pub fn intersection<'a>(&'a self, other: &'a HashSet<T, H>)
+ -> SetAlgebraItems<'a, T, H> {
+ Repeat::new(other).zip(self.iter())
+ .filter_map(|(other, elt)| {
+ if other.contains(elt) { Some(elt) } else { None }
+ })
+ }
+
+ /// Visit the values representing the union.
+ ///
+ /// # Example
+ ///
+ /// ```
+ /// use std::collections::HashSet;
+ /// let a: HashSet<int> = [1i, 2, 3].iter().map(|&x| x).collect();
+ /// let b: HashSet<int> = [4i, 2, 3, 4].iter().map(|&x| x).collect();
+ ///
+ /// // Print 1, 2, 3, 4 in arbitrary order.
+ /// for x in a.union(&b) {
+ /// println!("{}", x);
+ /// }
+ ///
+ /// let diff: HashSet<int> = a.union(&b).map(|&x| x).collect();
+ /// assert_eq!(diff, [1i, 2, 3, 4].iter().map(|&x| x).collect());
+ /// ```
+ pub fn union<'a>(&'a self, other: &'a HashSet<T, H>)
+ -> Chain<SetItems<'a, T>, SetAlgebraItems<'a, T, H>> {
+ self.iter().chain(other.difference(self))
+ }
+}
+
+impl<T: Eq + Hash<S>, S, H: Hasher<S>> PartialEq for HashSet<T, H> {
+ fn eq(&self, other: &HashSet<T, H>) -> bool {
+ if self.len() != other.len() { return false; }
+
+ self.iter().all(|key| other.contains(key))
+ }
+}
+
+impl<T: Eq + Hash<S>, S, H: Hasher<S>> Eq for HashSet<T, H> {}
+
+impl<T: Eq + Hash<S>, S, H: Hasher<S>> Collection for HashSet<T, H> {
+ fn len(&self) -> uint { self.map.len() }
+}
+
+impl<T: Eq + Hash<S>, S, H: Hasher<S>> Mutable for HashSet<T, H> {
+ fn clear(&mut self) { self.map.clear() }
+}
+
+impl<T: Eq + Hash<S>, S, H: Hasher<S>> Set<T> for HashSet<T, H> {
+ fn contains(&self, value: &T) -> bool { self.map.contains_key(value) }
+
+ fn is_disjoint(&self, other: &HashSet<T, H>) -> bool {
+ self.iter().all(|v| !other.contains(v))
+ }
+
+ fn is_subset(&self, other: &HashSet<T, H>) -> bool {
+ self.iter().all(|v| other.contains(v))
+ }
+}
+
+impl<T: Eq + Hash<S>, S, H: Hasher<S>> MutableSet<T> for HashSet<T, H> {
+ fn insert(&mut self, value: T) -> bool { self.map.insert(value, ()) }
+
+ fn remove(&mut self, value: &T) -> bool { self.map.remove(value) }
+}
+
+impl<T: Eq + Hash<S> + fmt::Show, S, H: Hasher<S>> fmt::Show for HashSet<T, H> {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ try!(write!(f, "{{"));
+
+ for (i, x) in self.iter().enumerate() {
+ if i != 0 { try!(write!(f, ", ")); }
+ try!(write!(f, "{}", *x));
+ }
+
+ write!(f, "}}")
+ }
+}
+
+impl<T: Eq + Hash<S>, S, H: Hasher<S> + Default> FromIterator<T> for HashSet<T, H> {
+ fn from_iter<I: Iterator<T>>(iter: I) -> HashSet<T, H> {
+ let (lower, _) = iter.size_hint();
+ let mut set = HashSet::with_capacity_and_hasher(lower, Default::default());
+ set.extend(iter);
+ set
+ }
+}
+
+impl<T: Eq + Hash<S>, S, H: Hasher<S> + Default> Extendable<T> for HashSet<T, H> {
+ fn extend<I: Iterator<T>>(&mut self, mut iter: I) {
+ for k in iter {
+ self.insert(k);
+ }
+ }
+}
+
+impl<T: Eq + Hash<S>, S, H: Hasher<S> + Default> Default for HashSet<T, H> {
+ fn default() -> HashSet<T, H> {
+ HashSet::with_hasher(Default::default())
+ }
+}
+
+// `Repeat` is used to feed the filter closure an explicit capture
+// of a reference to the other set
+/// Set operations iterator
+pub type SetAlgebraItems<'a, T, H> =
+ FilterMap<'static, (&'a HashSet<T, H>, &'a T), &'a T,
+ Zip<Repeat<&'a HashSet<T, H>>, SetItems<'a, T>>>;
+
+#[cfg(test)]
+mod test_set {
+ use prelude::*;
+
+ use super::HashSet;
+ use slice::ImmutablePartialEqSlice;
+ use collections::Collection;
+
+ #[test]
+ fn test_disjoint() {
+ let mut xs = HashSet::new();
+ let mut ys = HashSet::new();
+ assert!(xs.is_disjoint(&ys));
+ assert!(ys.is_disjoint(&xs));
+ assert!(xs.insert(5i));
+ assert!(ys.insert(11i));
+ assert!(xs.is_disjoint(&ys));
+ assert!(ys.is_disjoint(&xs));
+ assert!(xs.insert(7));
+ assert!(xs.insert(19));
+ assert!(xs.insert(4));
+ assert!(ys.insert(2));
+ assert!(ys.insert(-11));
+ assert!(xs.is_disjoint(&ys));
+ assert!(ys.is_disjoint(&xs));
+ assert!(ys.insert(7));
+ assert!(!xs.is_disjoint(&ys));
+ assert!(!ys.is_disjoint(&xs));
+ }
+
+ #[test]
+ fn test_subset_and_superset() {
+ let mut a = HashSet::new();
+ assert!(a.insert(0i));
+ assert!(a.insert(5));
+ assert!(a.insert(11));
+ assert!(a.insert(7));
+
+ let mut b = HashSet::new();
+ assert!(b.insert(0i));
+ assert!(b.insert(7));
+ assert!(b.insert(19));
+ assert!(b.insert(250));
+ assert!(b.insert(11));
+ assert!(b.insert(200));
+
+ assert!(!a.is_subset(&b));
+ assert!(!a.is_superset(&b));
+ assert!(!b.is_subset(&a));
+ assert!(!b.is_superset(&a));
+
+ assert!(b.insert(5));
+
+ assert!(a.is_subset(&b));
+ assert!(!a.is_superset(&b));
+ assert!(!b.is_subset(&a));
+ assert!(b.is_superset(&a));
+ }
+
+ #[test]
+ fn test_iterate() {
+ let mut a = HashSet::new();
+ for i in range(0u, 32) {
+ assert!(a.insert(i));
+ }
+ let mut observed: u32 = 0;
+ for k in a.iter() {
+ observed |= 1 << *k;
+ }
+ assert_eq!(observed, 0xFFFF_FFFF);
+ }
+
+ #[test]
+ fn test_intersection() {
+ let mut a = HashSet::new();
+ let mut b = HashSet::new();
+
+ assert!(a.insert(11i));
+ assert!(a.insert(1));
+ assert!(a.insert(3));
+ assert!(a.insert(77));
+ assert!(a.insert(103));
+ assert!(a.insert(5));
+ assert!(a.insert(-5));
+
+ assert!(b.insert(2i));
+ assert!(b.insert(11));
+ assert!(b.insert(77));
+ assert!(b.insert(-9));
+ assert!(b.insert(-42));
+ assert!(b.insert(5));
+ assert!(b.insert(3));
+
+ let mut i = 0;
+ let expected = [3, 5, 11, 77];
+ for x in a.intersection(&b) {
+ assert!(expected.contains(x));
+ i += 1
+ }
+ assert_eq!(i, expected.len());
+ }
+
+ #[test]
+ fn test_difference() {
+ let mut a = HashSet::new();
+ let mut b = HashSet::new();
+
+ assert!(a.insert(1i));
+ assert!(a.insert(3));
+ assert!(a.insert(5));
+ assert!(a.insert(9));
+ assert!(a.insert(11));
+
+ assert!(b.insert(3i));
+ assert!(b.insert(9));
+
+ let mut i = 0;
+ let expected = [1, 5, 11];
+ for x in a.difference(&b) {
+ assert!(expected.contains(x));
+ i += 1
+ }
+ assert_eq!(i, expected.len());
+ }
+
+ #[test]
+ fn test_symmetric_difference() {
+ let mut a = HashSet::new();
+ let mut b = HashSet::new();
+
+ assert!(a.insert(1i));
+ assert!(a.insert(3));
+ assert!(a.insert(5));
+ assert!(a.insert(9));
+ assert!(a.insert(11));
+
+ assert!(b.insert(-2i));
+ assert!(b.insert(3));
+ assert!(b.insert(9));
+ assert!(b.insert(14));
+ assert!(b.insert(22));
+
+ let mut i = 0;
+ let expected = [-2, 1, 5, 11, 14, 22];
+ for x in a.symmetric_difference(&b) {
+ assert!(expected.contains(x));
+ i += 1
+ }
+ assert_eq!(i, expected.len());
+ }
+
+ #[test]
+ fn test_union() {
+ let mut a = HashSet::new();
+ let mut b = HashSet::new();
+
+ assert!(a.insert(1i));
+ assert!(a.insert(3));
+ assert!(a.insert(5));
+ assert!(a.insert(9));
+ assert!(a.insert(11));
+ assert!(a.insert(16));
+ assert!(a.insert(19));
+ assert!(a.insert(24));
+
+ assert!(b.insert(-2i));
+ assert!(b.insert(1));
+ assert!(b.insert(5));
+ assert!(b.insert(9));
+ assert!(b.insert(13));
+ assert!(b.insert(19));
+
+ let mut i = 0;
+ let expected = [-2, 1, 3, 5, 9, 11, 13, 16, 19, 24];
+ for x in a.union(&b) {
+ assert!(expected.contains(x));
+ i += 1
+ }
+ assert_eq!(i, expected.len());
+ }
+
+ #[test]
+ fn test_from_iter() {
+ let xs = [1i, 2, 3, 4, 5, 6, 7, 8, 9];
+
+ let set: HashSet<int> = xs.iter().map(|&x| x).collect();
+
+ for x in xs.iter() {
+ assert!(set.contains(x));
+ }
+ }
+
+ #[test]
+ fn test_move_iter() {
+ let hs = {
+ let mut hs = HashSet::new();
+
+ hs.insert('a');
+ hs.insert('b');
+
+ hs
+ };
+
+ let v = hs.move_iter().collect::<Vec<char>>();
+ assert!(['a', 'b'] == v.as_slice() || ['b', 'a'] == v.as_slice());
+ }
+
+ #[test]
+ fn test_eq() {
+ // These constants once happened to expose a bug in insert().
+ // I'm keeping them around to prevent a regression.
+ let mut s1 = HashSet::new();
+
+ s1.insert(1i);
+ s1.insert(2);
+ s1.insert(3);
+
+ let mut s2 = HashSet::new();
+
+ s2.insert(1i);
+ s2.insert(2);
+
+ assert!(s1 != s2);
+
+ s2.insert(3);
+
+ assert_eq!(s1, s2);
+ }
+
+ #[test]
+ fn test_show() {
+ let mut set: HashSet<int> = HashSet::new();
+ let empty: HashSet<int> = HashSet::new();
+
+ set.insert(1i);
+ set.insert(2);
+
+ let set_str = format!("{}", set);
+
+ assert!(set_str == "{1, 2}".to_string() || set_str == "{2, 1}".to_string());
+ assert_eq!(format!("{}", empty), "{}".to_string());
+ }
+}
--- /dev/null
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+//
+// ignore-lexer-test FIXME #15883
+
+use clone::Clone;
+use cmp;
+use hash::{Hash, Hasher};
+use iter::{Iterator, count};
+use mem::{min_align_of, size_of};
+use mem;
+use num::{CheckedMul, is_power_of_two};
+use ops::{Deref, DerefMut, Drop};
+use option::{Some, None, Option};
+use ptr::RawPtr;
+use ptr::set_memory;
+use ptr::write;
+use ptr;
+use rt::heap::{allocate, deallocate};
+
+static EMPTY_BUCKET: u64 = 0u64;
+
+/// The raw hashtable, providing safe-ish access to the unzipped and highly
+/// optimized arrays of hashes, keys, and values.
+///
+/// This design uses less memory and is a lot faster than the naive
+/// `Vec<Option<u64, K, V>>`, because we don't pay for the overhead of an
+/// option on every element, and we get a generally more cache-aware design.
+///
+/// Key invariants of this structure:
+///
+/// - if hashes[i] == EMPTY_BUCKET, then keys[i] and vals[i] have
+/// 'undefined' contents. Don't read from them. This invariant is
+/// enforced outside this module with the `EmptyIndex`, `FullIndex`,
+/// and `SafeHash` types.
+///
+/// - An `EmptyIndex` is only constructed for a bucket at an index with
+/// a hash of EMPTY_BUCKET.
+///
+/// - A `FullIndex` is only constructed for a bucket at an index with a
+/// non-EMPTY_BUCKET hash.
+///
+/// - A `SafeHash` is only constructed for non-`EMPTY_BUCKET` hash. We get
+/// around hashes of zero by changing them to 0x8000_0000_0000_0000,
+/// which will likely map to the same bucket, while not being confused
+/// with "empty".
+///
+/// - All three "arrays represented by pointers" are the same length:
+/// `capacity`. This is set at creation and never changes. The arrays
+/// are unzipped to save space (we don't have to pay for the padding
+/// between odd sized elements, such as in a map from u64 to u8), and
+/// be more cache aware (scanning through 8 hashes brings in 2 cache
+/// lines, since they're all right beside each other).
+///
+/// You can kind of think of this module/data structure as a safe wrapper
+/// around just the "table" part of the hashtable. It enforces some
+/// invariants at the type level and employs some performance trickery,
+/// but in general is just a tricked out `Vec<Option<u64, K, V>>`.
+///
+/// FIXME(cgaebel):
+///
+/// Feb 11, 2014: This hashtable was just implemented, and, hard as I tried,
+/// isn't yet totally safe. There's a "known exploit" that you can create
+/// multiple FullIndexes for a bucket, `take` one, and then still `take`
+/// the other causing undefined behavior. Currently, there's no story
+/// for how to protect against this statically. Therefore, there are asserts
+/// on `take`, `get`, `get_mut`, and `put` which check the bucket state.
+/// With time, and when we're confident this works correctly, they should
+/// be removed. Also, the bounds check in `peek` is especially painful,
+/// as that's called in the innermost loops of the hashtable and has the
+/// potential to be a major performance drain. Remove this too.
+///
+/// Or, better than remove, only enable these checks for debug builds.
+/// There's currently no "debug-only" asserts in rust, so if you're reading
+/// this and going "what? of course there are debug-only asserts!", then
+/// please make this use them!
+#[unsafe_no_drop_flag]
+pub struct RawTable<K, V> {
+ capacity: uint,
+ size: uint,
+ hashes: *mut u64
+}
+
+/// A bucket that holds a reference to the table
+pub trait BucketWithTable<M> {
+ /// A bucket that holds a reference to the table
+ fn table<'a>(&'a self) -> &'a M;
+
+ /// Move out the reference to the table.
+ fn into_table(self) -> M;
+
+ /// Get the raw index.
+ fn index(&self) -> uint;
+}
+
+struct RawBucket<K, V> {
+ hash: *mut u64,
+ key: *mut K,
+ val: *mut V
+}
+
+pub struct Bucket<K, V, M> {
+ raw: RawBucket<K, V>,
+ idx: uint,
+ table: M
+}
+
+pub struct EmptyBucket<K, V, M> {
+ raw: RawBucket<K, V>,
+ idx: uint,
+ table: M
+}
+
+pub struct FullBucket<K, V, M> {
+ raw: RawBucket<K, V>,
+ idx: uint,
+ table: M
+}
+
+pub type EmptyBucketImm<'table,K,V> = EmptyBucket<K, V, &'table RawTable<K,V>>;
+pub type FullBucketImm<'table,K,V> = FullBucket<K, V, &'table RawTable<K,V>>;
+
+pub type EmptyBucketMut<'table,K,V> = EmptyBucket<K, V, &'table mut RawTable<K,V>>;
+pub type FullBucketMut<'table,K,V> = FullBucket<K, V, &'table mut RawTable<K,V>>;
+
+struct GapThenFull<K, V, M> {
+ gap: EmptyBucket<K, V, ()>,
+ full: FullBucket<K, V, M>
+}
+
+impl<K, V, M: Deref<RawTable<K,V>>> GapThenFull<K, V, M> {
+ pub fn full<'a>(&'a self) -> &'a FullBucket<K, V, M> {
+ &self.full
+ }
+
+ pub fn shift(mut self) -> Option<GapThenFull<K, V, M>> {
+ unsafe {
+ *self.gap.raw.hash = mem::replace(&mut *self.full.raw.hash, EMPTY_BUCKET);
+ mem::overwrite(self.gap.raw.key, ptr::read(self.full.raw.key as *const K));
+ mem::overwrite(self.gap.raw.val, ptr::read(self.full.raw.val as *const V));
+ }
+
+ let FullBucket { raw, idx, .. } = self.full;
+
+ match self.full.next().peek() {
+ Empty(_) => None,
+ Full(bucket) => {
+ self.gap.raw = raw;
+ self.gap.idx = idx;
+
+ self.full = bucket;
+ self.full.idx &= self.full.table.capacity - 1;
+
+ Some(self)
+ }
+ }
+ }
+}
+
+impl<K, V> RawPtr<u64> for RawBucket<K, V> {
+ unsafe fn offset(self, count: int) -> RawBucket<K, V> {
+ RawBucket {
+ hash: self.hash.offset(count),
+ key: self.key.offset(count),
+ val: self.val.offset(count),
+ }
+ }
+
+ fn null() -> RawBucket<K, V> {
+ RawBucket {
+ hash: RawPtr::null(),
+ key: RawPtr::null(),
+ val: RawPtr::null()
+ }
+ }
+
+ fn is_null(&self) -> bool {
+ self.hash.is_null()
+ }
+
+ fn to_uint(&self) -> uint {
+ self.hash.to_uint()
+ }
+
+ unsafe fn to_option(&self) -> Option<&u64> {
+ self.hash.to_option()
+ }
+}
+
+impl<K, V, M: Deref<RawTable<K,V>>> EmptyBucket<K, V, M> {
+ pub fn next(self) -> Bucket<K, V, M> {
+ let mut bucket = self.into_bucket();
+ bucket.next();
+ bucket
+ }
+
+ pub fn into_bucket(self) -> Bucket<K, V, M> {
+ Bucket {
+ raw: self.raw,
+ idx: self.idx,
+ table: self.table
+ }
+ }
+
+ pub fn gap_peek(self) -> Option<GapThenFull<K, V, M>> {
+ let gap = EmptyBucket {
+ raw: self.raw,
+ idx: self.idx,
+ table: ()
+ };
+
+ match self.next().peek() {
+ Empty(_) => None,
+ Full(bucket) => {
+ Some(GapThenFull {
+ gap: gap,
+ full: bucket
+ })
+ }
+ }
+ }
+}
+
+impl<K, V, M: DerefMut<RawTable<K,V>>> EmptyBucket<K, V, M> {
+ pub fn put(mut self, hash: SafeHash, key: K, value: V)
+ -> FullBucket<K, V, M> {
+ unsafe {
+ *self.raw.hash = hash.inspect();
+ write(self.raw.key, key);
+ write(self.raw.val, value);
+ }
+
+ self.table.size += 1;
+
+ FullBucket { raw: self.raw, idx: self.idx, table: self.table }
+ }
+}
+
+impl<K, V, M: Deref<RawTable<K,V>>> FullBucket<K, V, M> {
+ pub fn next(self) -> Bucket<K, V, M> {
+ let mut bucket = self.into_bucket();
+ bucket.next();
+ bucket
+ }
+
+ pub fn into_bucket(self) -> Bucket<K, V, M> {
+ Bucket {
+ raw: self.raw,
+ idx: self.idx,
+ table: self.table
+ }
+ }
+
+ pub fn distance(&self) -> uint {
+ (self.idx - self.hash().inspect() as uint) & (self.table.capacity() - 1)
+ }
+
+ pub fn hash(&self) -> SafeHash {
+ unsafe {
+ SafeHash {
+ hash: *self.raw.hash
+ }
+ }
+ }
+
+ pub fn read<'a>(&'a self) -> (&'a K, &'a V) {
+ unsafe {
+ (&*self.raw.key,
+ &*self.raw.val)
+ }
+ }
+
+ pub fn into_refs(self) -> (&K, &V) {
+ unsafe {
+ // debug_assert!(*self.raw.hash != EMPTY_BUCKET);
+ (&*self.raw.key,
+ &*self.raw.val)
+ }
+ }
+}
+
+impl<K, V, M: DerefMut<RawTable<K,V>>> FullBucket<K, V, M> {
+ pub fn take(mut self) -> (EmptyBucket<K, V, M>, K, V) {
+ let key = self.raw.key as *const K;
+ let val = self.raw.val as *const V;
+
+ self.table.size -= 1;
+
+ unsafe {
+ *self.raw.hash = EMPTY_BUCKET;
+ (
+ EmptyBucket {
+ raw: self.raw,
+ idx: self.idx,
+ table: self.table
+ },
+ ptr::read(key),
+ ptr::read(val)
+ )
+ }
+ }
+
+ pub fn replace(&mut self, h: SafeHash, k: K, v: V) -> (SafeHash, K, V) {
+ unsafe {
+ let old_hash = ptr::replace(self.raw.hash as *mut SafeHash, h);
+ let old_key = ptr::replace(self.raw.key, k);
+ let old_val = ptr::replace(self.raw.val, v);
+
+ (old_hash, old_key, old_val)
+ }
+ }
+
+ pub fn read_mut<'a>(&'a self) -> (&'a mut K, &'a mut V) {
+ unsafe {
+ // debug_assert!(*self.raw.hash != EMPTY_BUCKET);
+ (&mut *self.raw.key,
+ &mut *self.raw.val)
+ }
+ }
+
+ pub fn into_mut_refs(self) -> (&mut K, &mut V) {
+ unsafe {
+ // debug_assert!(*self.raw.hash != EMPTY_BUCKET);
+ (&mut *self.raw.key,
+ &mut *self.raw.val)
+ }
+ }
+}
+
+impl<K, V, M: Deref<RawTable<K,V>>> Bucket<K, V, M> {
+ pub fn new(table: M, hash: &SafeHash) -> Bucket<K, V, M> {
+ let ib_index = (hash.inspect() as uint) & (table.capacity() - 1);
+ Bucket {
+ raw: unsafe {
+ table.as_mut_ptrs().offset(ib_index as int)
+ },
+ idx: ib_index,
+ table: table
+ }
+ }
+
+ pub fn at_index(table: M, ib_index: uint) -> Bucket<K, V, M> {
+ let ib_index = ib_index & (table.capacity() - 1);
+ Bucket {
+ raw: unsafe {
+ table.as_mut_ptrs().offset(ib_index as int)
+ },
+ idx: ib_index,
+ table: table
+ }
+ }
+
+ pub fn first(table: M) -> Bucket<K, V, M> {
+ Bucket {
+ raw: table.as_mut_ptrs(),
+ idx: 0,
+ table: table
+ }
+ }
+
+ pub fn peek(self) -> BucketState<K, V, M> {
+ match unsafe { *self.raw.hash } {
+ EMPTY_BUCKET =>
+ Empty(EmptyBucket {
+ raw: self.raw,
+ idx: self.idx,
+ table: self.table
+ }),
+ _ =>
+ Full(FullBucket {
+ raw: self.raw,
+ idx: self.idx,
+ table: self.table
+ })
+ }
+ }
+
+ pub fn next(&mut self) {
+ self.idx += 1;
+
+ let dist = if self.idx == self.table.capacity() {
+ -(self.table.capacity() as int - 1)
+ } else {
+ 1i
+ };
+
+ unsafe {
+ self.raw = self.raw.offset(dist);
+ }
+ }
+}
+
+impl<K, V, M> BucketWithTable<M> for FullBucket<K, V, M> {
+ fn table<'a>(&'a self) -> &'a M {
+ &self.table
+ }
+
+ fn into_table(self) -> M {
+ self.table
+ }
+
+ fn index(&self) -> uint {
+ self.idx
+ }
+}
+
+impl<K, V, M> BucketWithTable<M> for EmptyBucket<K, V, M> {
+ fn table<'a>(&'a self) -> &'a M {
+ &self.table
+ }
+
+ fn into_table(self) -> M {
+ self.table
+ }
+
+ fn index(&self) -> uint {
+ self.idx
+ }
+}
+
+impl<K, V, M> BucketWithTable<M> for Bucket<K, V, M> {
+ fn table<'a>(&'a self) -> &'a M {
+ &self.table
+ }
+
+ fn into_table(self) -> M {
+ self.table
+ }
+
+ fn index(&self) -> uint {
+ self.idx
+ }
+}
+
+impl<'table,K,V> Deref<RawTable<K,V>> for &'table RawTable<K,V> {
+ fn deref<'a>(&'a self) -> &'a RawTable<K,V> {
+ &**self
+ }
+}
+
+impl<'table,K,V> Deref<RawTable<K,V>> for &'table mut RawTable<K,V> {
+ fn deref<'a>(&'a self) -> &'a RawTable<K,V> {
+ &**self
+ }
+}
+
+impl<'table,K,V> DerefMut<RawTable<K,V>> for &'table mut RawTable<K,V> {
+ fn deref_mut<'a>(&'a mut self) -> &'a mut RawTable<K,V> {
+ &mut **self
+ }
+}
+
+pub enum BucketState<K, V, M> {
+ Empty(EmptyBucket<K, V, M>),
+ Full(FullBucket<K, V, M>),
+}
+
+/// A hash that is not zero, since we use a hash of zero to represent empty
+/// buckets.
+#[deriving(PartialEq)]
+pub struct SafeHash {
+ hash: u64,
+}
+
+impl SafeHash {
+ /// Peek at the hash value, which is guaranteed to be non-zero.
+ #[inline(always)]
+ pub fn inspect(&self) -> u64 { self.hash }
+}
+
+/// We need to remove hashes of 0. That's reserved for empty buckets.
+/// This function wraps up `hash_keyed` to be the only way outside this
+/// module to generate a SafeHash.
+pub fn make_hash<T: Hash<S>, S, H: Hasher<S>>(hasher: &H, t: &T) -> SafeHash {
+ match hasher.hash(t) {
+ // This constant is exceedingly likely to hash to the same
+ // bucket, but it won't be counted as empty!
+ EMPTY_BUCKET => SafeHash { hash: 0x8000_0000_0000_0000 },
+ h => SafeHash { hash: h },
+ }
+}
+
+fn round_up_to_next(unrounded: uint, target_alignment: uint) -> uint {
+ assert!(is_power_of_two(target_alignment));
+ (unrounded + target_alignment - 1) & !(target_alignment - 1)
+}
+
+#[test]
+fn test_rounding() {
+ assert_eq!(round_up_to_next(0, 4), 0);
+ assert_eq!(round_up_to_next(1, 4), 4);
+ assert_eq!(round_up_to_next(2, 4), 4);
+ assert_eq!(round_up_to_next(3, 4), 4);
+ assert_eq!(round_up_to_next(4, 4), 4);
+ assert_eq!(round_up_to_next(5, 4), 8);
+}
+
+// Returns a tuple of (minimum required malloc alignment, hash_offset,
+// key_offset, val_offset, array_size), from the start of a mallocated array.
+fn calculate_offsets(
+ hash_size: uint, hash_align: uint,
+ keys_size: uint, keys_align: uint,
+ vals_size: uint, vals_align: uint) -> (uint, uint, uint, uint, uint) {
+
+ let hash_offset = 0;
+ let end_of_hashes = hash_offset + hash_size;
+
+ let keys_offset = round_up_to_next(end_of_hashes, keys_align);
+ let end_of_keys = keys_offset + keys_size;
+
+ let vals_offset = round_up_to_next(end_of_keys, vals_align);
+ let end_of_vals = vals_offset + vals_size;
+
+ let min_align = cmp::max(hash_align, cmp::max(keys_align, vals_align));
+
+ (min_align, hash_offset, keys_offset, vals_offset, end_of_vals)
+}
+
+#[test]
+fn test_offset_calculation() {
+ assert_eq!(calculate_offsets(128, 8, 15, 1, 4, 4 ), (8, 0, 128, 144, 148));
+ assert_eq!(calculate_offsets(3, 1, 2, 1, 1, 1 ), (1, 0, 3, 5, 6));
+ assert_eq!(calculate_offsets(6, 2, 12, 4, 24, 8), (8, 0, 8, 24, 48));
+}
+
+impl<K, V> RawTable<K, V> {
+
+ /// Does not initialize the buckets. The caller should ensure they,
+ /// at the very least, set every hash to EMPTY_BUCKET.
+ unsafe fn new_uninitialized(capacity: uint) -> RawTable<K, V> {
+ if capacity == 0 {
+ return RawTable {
+ size: 0,
+ capacity: 0,
+ hashes: 0 as *mut u64,
+ };
+ }
+ let hashes_size = capacity.checked_mul(&size_of::<u64>())
+ .expect("capacity overflow");
+ let keys_size = capacity.checked_mul(&size_of::< K >())
+ .expect("capacity overflow");
+ let vals_size = capacity.checked_mul(&size_of::< V >())
+ .expect("capacity overflow");
+
+ // Allocating hashmaps is a little tricky. We need to allocate three
+ // arrays, but since we know their sizes and alignments up front,
+ // we just allocate a single array, and then have the subarrays
+ // point into it.
+ //
+ // This is great in theory, but in practice getting the alignment
+ // right is a little subtle. Therefore, calculating offsets has been
+ // factored out into a different function.
+ let (malloc_alignment, hash_offset, _, _, size) =
+ calculate_offsets(
+ hashes_size, min_align_of::<u64>(),
+ keys_size, min_align_of::< K >(),
+ vals_size, min_align_of::< V >());
+
+ let buffer = allocate(size, malloc_alignment);
+
+ let hashes = buffer.offset(hash_offset as int) as *mut u64;
+
+ RawTable {
+ capacity: capacity,
+ size: 0,
+ hashes: hashes,
+ }
+ }
+
+ fn as_mut_ptrs(&self) -> RawBucket<K, V> {
+ let hashes_size = self.capacity * size_of::<u64>();
+ let keys_size = self.capacity * size_of::<K>();
+
+ let keys_offset = (hashes_size + min_align_of::< K >() - 1) & !(min_align_of::< K >() - 1);
+ let end_of_keys = keys_offset + keys_size;
+
+ let vals_offset = (end_of_keys + min_align_of::< V >() - 1) & !(min_align_of::< V >() - 1);
+
+ let buffer = self.hashes as *mut u8;
+
+ unsafe {
+ RawBucket {
+ hash: self.hashes,
+ key: buffer.offset(keys_offset as int) as *mut K,
+ val: buffer.offset(vals_offset as int) as *mut V
+ }
+ }
+ }
+
+ /// Creates a new raw table from a given capacity. All buckets are
+ /// initially empty.
+ #[allow(experimental)]
+ pub fn new(capacity: uint) -> RawTable<K, V> {
+ unsafe {
+ let ret = RawTable::new_uninitialized(capacity);
+ set_memory(ret.hashes, 0u8, capacity);
+ ret
+ }
+ }
+
+ /// The hashtable's capacity, similar to a vector's.
+ pub fn capacity(&self) -> uint {
+ self.capacity
+ }
+
+ /// The number of elements ever `put` in the hashtable, minus the number
+ /// of elements ever `take`n.
+ pub fn size(&self) -> uint {
+ self.size
+ }
+
+ fn ptrs<'a>(&'a self) -> RawBuckets<'a, K, V> {
+ RawBuckets {
+ raw: self.as_mut_ptrs(),
+ hashes_end: unsafe {
+ self.hashes.offset(self.capacity as int)
+ }
+ }
+ }
+
+ pub fn iter<'a>(&'a self) -> Entries<'a, K, V> {
+ Entries {
+ iter: self.ptrs(),
+ elems_left: self.size(),
+ }
+ }
+
+ pub fn mut_iter<'a>(&'a mut self) -> MutEntries<'a, K, V> {
+ MutEntries {
+ iter: self.ptrs(),
+ elems_left: self.size(),
+ }
+ }
+
+ pub fn move_iter(self) -> MoveEntries<K, V> {
+ MoveEntries {
+ iter: self.ptrs(),
+ table: self,
+ }
+ }
+
+ pub fn rev_move_buckets<'a>(&'a mut self) -> RevMoveBuckets<'a, K, V> {
+ let raw_bucket = self.as_mut_ptrs();
+ unsafe {
+ RevMoveBuckets {
+ raw: raw_bucket.offset(self.capacity as int),
+ hashes_end: raw_bucket.hash,
+ elems_left: self.size
+ }
+ }
+ }
+}
+
+pub struct RawBuckets<'a, K, V> {
+ raw: RawBucket<K, V>,
+ hashes_end: *mut u64
+}
+
+impl<'a, K, V> Iterator<RawBucket<K, V>> for RawBuckets<'a, K, V> {
+ fn next(&mut self) -> Option<RawBucket<K, V>> {
+ while self.raw.hash != self.hashes_end {
+ unsafe {
+ let prev = ptr::replace(&mut self.raw, self.raw.offset(1));
+ if *prev.hash != EMPTY_BUCKET {
+ return Some(prev);
+ }
+ }
+ }
+
+ None
+ }
+}
+
+pub struct RevMoveBuckets<'a, K, V> {
+ raw: RawBucket<K, V>,
+ hashes_end: *mut u64,
+ elems_left: uint
+}
+
+impl<'a, K, V> Iterator<(K, V)> for RevMoveBuckets<'a, K, V> {
+ fn next(&mut self) -> Option<(K, V)> {
+ if self.elems_left == 0 {
+ return None;
+ }
+
+ loop {
+ debug_assert!(self.raw.hash != self.hashes_end);
+
+ unsafe {
+ self.raw = self.raw.offset(-1);
+
+ if *self.raw.hash != EMPTY_BUCKET {
+ self.elems_left -= 1;
+ return Some((
+ ptr::read(self.raw.key as *const K),
+ ptr::read(self.raw.val as *const V)
+ ));
+ }
+ }
+ }
+ }
+}
+
+// `read_all_mut` casts a `*u64` to a `*SafeHash`. Since we statically
+// ensure that a `FullIndex` points to an index with a non-zero hash,
+// and a `SafeHash` is just a `u64` with a different name, this is
+// safe.
+//
+// This test ensures that a `SafeHash` really IS the same size as a
+// `u64`. If you need to change the size of `SafeHash` (and
+// consequently made this test fail), `read_all_mut` needs to be
+// modified to no longer assume this.
+#[test]
+fn can_alias_safehash_as_u64() {
+ assert_eq!(size_of::<SafeHash>(), size_of::<u64>())
+}
+
+/// Note: stage0-specific version that lacks bound.
+#[cfg(stage0)]
+pub struct Entries<'a, K, V> {
+ iter: RawBuckets<'a, K, V>,
+ elems_left: uint,
+}
+
+/// Iterator over shared references to entries in a table.
+#[cfg(not(stage0))]
+pub struct Entries<'a, K: 'a, V: 'a> {
+ iter: RawBuckets<'a, K, V>,
+ elems_left: uint,
+}
+
+/// Note: stage0-specific version that lacks bound.
+#[cfg(stage0)]
+pub struct MutEntries<'a, K, V> {
+ iter: RawBuckets<'a, K, V>,
+ elems_left: uint,
+}
+
+/// Iterator over mutable references to entries in a table.
+#[cfg(not(stage0))]
+pub struct MutEntries<'a, K: 'a, V: 'a> {
+ iter: RawBuckets<'a, K, V>,
+ elems_left: uint,
+}
+
+/// Iterator over the entries in a table, consuming the table.
+pub struct MoveEntries<K, V> {
+ table: RawTable<K, V>,
+ iter: RawBuckets<'static, K, V>
+}
+
+impl<'a, K, V> Iterator<(&'a K, &'a V)> for Entries<'a, K, V> {
+ fn next(&mut self) -> Option<(&'a K, &'a V)> {
+ self.iter.next().map(|bucket| {
+ self.elems_left -= 1;
+ unsafe {
+ (&*bucket.key,
+ &*bucket.val)
+ }
+ })
+ }
+
+ fn size_hint(&self) -> (uint, Option<uint>) {
+ (self.elems_left, Some(self.elems_left))
+ }
+}
+
+impl<'a, K, V> Iterator<(&'a K, &'a mut V)> for MutEntries<'a, K, V> {
+ fn next(&mut self) -> Option<(&'a K, &'a mut V)> {
+ self.iter.next().map(|bucket| {
+ self.elems_left -= 1;
+ unsafe {
+ (&*bucket.key,
+ &mut *bucket.val)
+ }
+ })
+ }
+
+ fn size_hint(&self) -> (uint, Option<uint>) {
+ (self.elems_left, Some(self.elems_left))
+ }
+}
+
+impl<K, V> Iterator<(SafeHash, K, V)> for MoveEntries<K, V> {
+ fn next(&mut self) -> Option<(SafeHash, K, V)> {
+ self.iter.next().map(|bucket| {
+ self.table.size -= 1;
+ unsafe {
+ (
+ SafeHash {
+ hash: *bucket.hash,
+ },
+ ptr::read(bucket.key as *const K),
+ ptr::read(bucket.val as *const V)
+ )
+ }
+ })
+ }
+
+ fn size_hint(&self) -> (uint, Option<uint>) {
+ let size = self.table.size();
+ (size, Some(size))
+ }
+}
+
+impl<K: Clone, V: Clone> Clone for RawTable<K, V> {
+ fn clone(&self) -> RawTable<K, V> {
+ unsafe {
+ let mut new_ht = RawTable::new_uninitialized(self.capacity());
+
+ {
+ let cap = self.capacity();
+ let mut new_buckets = Bucket::first(&mut new_ht);
+ let mut buckets = Bucket::first(self);
+ while buckets.index() != cap {
+ match buckets.peek() {
+ Full(full) => {
+ let (h, k, v) = {
+ let (k, v) = full.read();
+ (full.hash(), k.clone(), v.clone())
+ };
+ *new_buckets.raw.hash = h.inspect();
+ mem::overwrite(new_buckets.raw.key, k);
+ mem::overwrite(new_buckets.raw.val, v);
+ }
+ _ => {
+ *new_buckets.raw.hash = EMPTY_BUCKET;
+ }
+ }
+ new_buckets.next();
+ buckets.next();
+ }
+ }
+
+ new_ht.size = self.size();
+
+ new_ht
+ }
+ }
+}
+
+#[unsafe_destructor]
+impl<K, V> Drop for RawTable<K, V> {
+ fn drop(&mut self) {
+ if self.hashes.is_null() {
+ return;
+ }
+ // This is in reverse because we're likely to have partially taken
+ // some elements out with `.move_iter()` from the front.
+ // Check if the size is 0, so we don't do a useless scan when
+ // dropping empty tables such as on resize.
+ // Avoid double free of elements already moved out.
+ for _ in self.rev_move_buckets() {}
+
+ let hashes_size = self.capacity * size_of::<u64>();
+ let keys_size = self.capacity * size_of::<K>();
+ let vals_size = self.capacity * size_of::<V>();
+ let (align, _, _, _, size) = calculate_offsets(hashes_size, min_align_of::<u64>(),
+ keys_size, min_align_of::<K>(),
+ vals_size, min_align_of::<V>());
+
+ unsafe {
+ deallocate(self.hashes as *mut u8, size, align);
+ // Remember how everything was allocated out of one buffer
+ // during initialization? We only need one call to free here.
+ }
+
+ self.hashes = RawPtr::null();
+ }
+}
projects / rust.git / commitdiff