1 // Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Utility mixins that apply to all Readers and Writers
13 #![allow(missing_doc)]
15 // FIXME: Not sure how this should be structured
16 // FIXME: Iteration should probably be considered separately
18 use collections::{Collection, MutableSeq};
20 use option::{Option, Some, None};
21 use result::{Ok, Err};
23 use io::{IoError, IoResult, Reader};
24 use slice::{ImmutableVector, Vector};
27 /// An iterator that reads a single byte on each iteration,
28 /// until `.read_byte()` returns `EndOfFile`.
30 /// # Notes about the Iteration Protocol
32 /// The `Bytes` may yield `None` and thus terminate
33 /// an iteration, but continue to yield elements if iteration
34 /// is attempted again.
38 /// Any error other than `EndOfFile` that is produced by the underlying Reader
39 /// is returned by the iterator and should be handled by the caller.
40 pub struct Bytes<'r, T> {
44 impl<'r, R: Reader> Bytes<'r, R> {
45 /// Constructs a new byte iterator from the given Reader instance.
46 pub fn new(r: &'r mut R) -> Bytes<'r, R> {
53 impl<'r, R: Reader> Iterator<IoResult<u8>> for Bytes<'r, R> {
55 fn next(&mut self) -> Option<IoResult<u8>> {
56 match self.reader.read_byte() {
58 Err(IoError { kind: io::EndOfFile, .. }) => None,
59 Err(e) => Some(Err(e))
64 /// Converts an 8-bit to 64-bit unsigned value to a little-endian byte
65 /// representation of the given size. If the size is not big enough to
66 /// represent the value, then the high-order bytes are truncated.
70 /// * `n`: The value to convert.
71 /// * `size`: The size of the value, in bytes. This must be 8 or less, or task
72 /// failure occurs. If this is less than 8, then a value of that
73 /// many bytes is produced. For example, if `size` is 4, then a
74 /// 32-bit byte representation is produced.
75 /// * `f`: A callback that receives the value.
77 /// This function returns the value returned by the callback, for convenience.
78 pub fn u64_to_le_bytes<T>(n: u64, size: uint, f: |v: &[u8]| -> T) -> T {
79 use mem::{to_le16, to_le32, to_le64};
82 // LLVM fails to properly optimize this when using shifts instead of the to_le* intrinsics
86 2u => f(unsafe { transmute::<_, [u8, ..2]>(to_le16(n as u16)) }),
87 4u => f(unsafe { transmute::<_, [u8, ..4]>(to_le32(n as u32)) }),
88 8u => f(unsafe { transmute::<_, [u8, ..8]>(to_le64(n)) }),
91 let mut bytes = vec!();
95 bytes.push((n & 255_u64) as u8);
104 /// Converts an 8-bit to 64-bit unsigned value to a big-endian byte
105 /// representation of the given size. If the size is not big enough to
106 /// represent the value, then the high-order bytes are truncated.
110 /// * `n`: The value to convert.
111 /// * `size`: The size of the value, in bytes. This must be 8 or less, or task
112 /// failure occurs. If this is less than 8, then a value of that
113 /// many bytes is produced. For example, if `size` is 4, then a
114 /// 32-bit byte representation is produced.
115 /// * `f`: A callback that receives the value.
117 /// This function returns the value returned by the callback, for convenience.
118 pub fn u64_to_be_bytes<T>(n: u64, size: uint, f: |v: &[u8]| -> T) -> T {
119 use mem::{to_be16, to_be32, to_be64};
122 // LLVM fails to properly optimize this when using shifts instead of the to_be* intrinsics
126 2u => f(unsafe { transmute::<_, [u8, ..2]>(to_be16(n as u16)) }),
127 4u => f(unsafe { transmute::<_, [u8, ..4]>(to_be32(n as u32)) }),
128 8u => f(unsafe { transmute::<_, [u8, ..8]>(to_be64(n)) }),
130 let mut bytes = vec!();
133 let shift = (i - 1u) * 8u;
134 bytes.push((n >> shift) as u8);
142 /// Extracts an 8-bit to 64-bit unsigned big-endian value from the given byte
143 /// buffer and returns it as a 64-bit value.
147 /// * `data`: The buffer in which to extract the value.
148 /// * `start`: The offset at which to extract the value.
149 /// * `size`: The size of the value in bytes to extract. This must be 8 or
150 /// less, or task failure occurs. If this is less than 8, then only
151 /// that many bytes are parsed. For example, if `size` is 4, then a
152 /// 32-bit value is parsed.
153 pub fn u64_from_be_bytes(data: &[u8], start: uint, size: uint) -> u64 {
154 use ptr::{copy_nonoverlapping_memory};
156 use slice::MutableVector;
160 if data.len() - start < size {
161 fail!("index out of bounds");
164 let mut buf = [0u8, ..8];
166 let ptr = data.as_ptr().offset(start as int);
167 let out = buf.as_mut_ptr();
168 copy_nonoverlapping_memory(out.offset((8 - size) as int), ptr, size);
169 from_be64(*(out as *const u64))
177 use io::{MemReader, MemWriter};
179 struct InitialZeroByteReader {
183 impl Reader for InitialZeroByteReader {
184 fn read(&mut self, buf: &mut [u8]) -> io::IoResult<uint> {
197 impl Reader for EofReader {
198 fn read(&mut self, _: &mut [u8]) -> io::IoResult<uint> {
199 Err(io::standard_error(io::EndOfFile))
203 struct ErroringReader;
205 impl Reader for ErroringReader {
206 fn read(&mut self, _: &mut [u8]) -> io::IoResult<uint> {
207 Err(io::standard_error(io::InvalidInput))
211 struct PartialReader {
215 impl Reader for PartialReader {
216 fn read(&mut self, buf: &mut [u8]) -> io::IoResult<uint> {
230 struct ErroringLaterReader {
234 impl Reader for ErroringLaterReader {
235 fn read(&mut self, buf: &mut [u8]) -> io::IoResult<uint> {
241 Err(io::standard_error(io::InvalidInput))
246 struct ThreeChunkReader {
250 impl Reader for ThreeChunkReader {
251 fn read(&mut self, buf: &mut [u8]) -> io::IoResult<uint> {
257 } else if self.count == 1 {
263 Err(io::standard_error(io::EndOfFile))
270 let mut reader = MemReader::new(vec!(10));
271 let byte = reader.read_byte();
272 assert!(byte == Ok(10));
276 fn read_byte_0_bytes() {
277 let mut reader = InitialZeroByteReader {
280 let byte = reader.read_byte();
281 assert!(byte == Ok(10));
286 let mut reader = EofReader;
287 let byte = reader.read_byte();
288 assert!(byte.is_err());
292 fn read_byte_error() {
293 let mut reader = ErroringReader;
294 let byte = reader.read_byte();
295 assert!(byte.is_err());
300 let mut reader = InitialZeroByteReader {
303 let byte = reader.bytes().next();
304 assert!(byte == Some(Ok(10)));
309 let mut reader = EofReader;
310 let byte = reader.bytes().next();
311 assert!(byte.is_none());
316 let mut reader = ErroringReader;
317 let mut it = reader.bytes();
318 let byte = it.next();
319 assert!(byte.unwrap().is_err());
324 let mut reader = MemReader::new(vec!(10, 11, 12, 13));
325 let bytes = reader.read_exact(4).unwrap();
326 assert!(bytes == vec!(10, 11, 12, 13));
330 fn read_bytes_partial() {
331 let mut reader = PartialReader {
334 let bytes = reader.read_exact(4).unwrap();
335 assert!(bytes == vec!(10, 11, 12, 13));
339 fn read_bytes_eof() {
340 let mut reader = MemReader::new(vec!(10, 11));
341 assert!(reader.read_exact(4).is_err());
346 let mut reader = MemReader::new(vec![10, 11, 12, 13]);
347 let mut buf = vec![8, 9];
348 assert!(reader.push_at_least(4, 4, &mut buf).is_ok());
349 assert!(buf == vec![8, 9, 10, 11, 12, 13]);
353 fn push_at_least_partial() {
354 let mut reader = PartialReader {
357 let mut buf = vec![8, 9];
358 assert!(reader.push_at_least(4, 4, &mut buf).is_ok());
359 assert!(buf == vec![8, 9, 10, 11, 12, 13]);
363 fn push_at_least_eof() {
364 let mut reader = MemReader::new(vec![10, 11]);
365 let mut buf = vec![8, 9];
366 assert!(reader.push_at_least(4, 4, &mut buf).is_err());
367 assert!(buf == vec![8, 9, 10, 11]);
371 fn push_at_least_error() {
372 let mut reader = ErroringLaterReader {
375 let mut buf = vec![8, 9];
376 assert!(reader.push_at_least(4, 4, &mut buf).is_err());
377 assert!(buf == vec![8, 9, 10]);
382 let mut reader = ThreeChunkReader {
385 let buf = reader.read_to_end().unwrap();
386 assert!(buf == vec!(10, 11, 12, 13));
391 fn read_to_end_error() {
392 let mut reader = ThreeChunkReader {
395 let buf = reader.read_to_end().unwrap();
396 assert!(buf == vec!(10, 11));
400 fn test_read_write_le_mem() {
401 let uints = [0, 1, 2, 42, 10_123, 100_123_456, ::u64::MAX];
403 let mut writer = MemWriter::new();
404 for i in uints.iter() {
405 writer.write_le_u64(*i).unwrap();
408 let mut reader = MemReader::new(writer.unwrap());
409 for i in uints.iter() {
410 assert!(reader.read_le_u64().unwrap() == *i);
416 fn test_read_write_be() {
417 let uints = [0, 1, 2, 42, 10_123, 100_123_456, ::u64::MAX];
419 let mut writer = MemWriter::new();
420 for i in uints.iter() {
421 writer.write_be_u64(*i).unwrap();
424 let mut reader = MemReader::new(writer.unwrap());
425 for i in uints.iter() {
426 assert!(reader.read_be_u64().unwrap() == *i);
431 fn test_read_be_int_n() {
432 let ints = [::i32::MIN, -123456, -42, -5, 0, 1, ::i32::MAX];
434 let mut writer = MemWriter::new();
435 for i in ints.iter() {
436 writer.write_be_i32(*i).unwrap();
439 let mut reader = MemReader::new(writer.unwrap());
440 for i in ints.iter() {
441 // this tests that the sign extension is working
442 // (comparing the values as i32 would not test this)
443 assert!(reader.read_be_int_n(4).unwrap() == *i as i64);
449 //big-endian floating-point 8.1250
450 let buf = vec![0x41, 0x02, 0x00, 0x00];
452 let mut writer = MemWriter::new();
453 writer.write(buf.as_slice()).unwrap();
455 let mut reader = MemReader::new(writer.unwrap());
456 let f = reader.read_be_f32().unwrap();
457 assert!(f == 8.1250);
461 fn test_read_write_f32() {
464 let mut writer = MemWriter::new();
465 writer.write_be_f32(f).unwrap();
466 writer.write_le_f32(f).unwrap();
468 let mut reader = MemReader::new(writer.unwrap());
469 assert!(reader.read_be_f32().unwrap() == 8.1250);
470 assert!(reader.read_le_f32().unwrap() == 8.1250);
474 fn test_u64_from_be_bytes() {
475 use super::u64_from_be_bytes;
477 let buf = [0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09];
480 assert_eq!(u64_from_be_bytes(buf, 0, 0), 0);
481 assert_eq!(u64_from_be_bytes(buf, 0, 1), 0x01);
482 assert_eq!(u64_from_be_bytes(buf, 0, 2), 0x0102);
483 assert_eq!(u64_from_be_bytes(buf, 0, 3), 0x010203);
484 assert_eq!(u64_from_be_bytes(buf, 0, 4), 0x01020304);
485 assert_eq!(u64_from_be_bytes(buf, 0, 5), 0x0102030405);
486 assert_eq!(u64_from_be_bytes(buf, 0, 6), 0x010203040506);
487 assert_eq!(u64_from_be_bytes(buf, 0, 7), 0x01020304050607);
488 assert_eq!(u64_from_be_bytes(buf, 0, 8), 0x0102030405060708);
491 assert_eq!(u64_from_be_bytes(buf, 1, 0), 0);
492 assert_eq!(u64_from_be_bytes(buf, 1, 1), 0x02);
493 assert_eq!(u64_from_be_bytes(buf, 1, 2), 0x0203);
494 assert_eq!(u64_from_be_bytes(buf, 1, 3), 0x020304);
495 assert_eq!(u64_from_be_bytes(buf, 1, 4), 0x02030405);
496 assert_eq!(u64_from_be_bytes(buf, 1, 5), 0x0203040506);
497 assert_eq!(u64_from_be_bytes(buf, 1, 6), 0x020304050607);
498 assert_eq!(u64_from_be_bytes(buf, 1, 7), 0x02030405060708);
499 assert_eq!(u64_from_be_bytes(buf, 1, 8), 0x0203040506070809);
507 use collections::Collection;
509 use self::test::Bencher;
511 // why is this a macro? wouldn't an inlined function work just as well?
512 macro_rules! u64_from_be_bytes_bench_impl(
513 ($b:expr, $size:expr, $stride:expr, $start_index:expr) =>
515 use super::u64_from_be_bytes;
517 let data = Vec::from_fn($stride*100+$start_index, |i| i as u8);
520 let mut i = $start_index;
521 while i < data.len() {
522 sum += u64_from_be_bytes(data.as_slice(), i, $size);
530 fn u64_from_be_bytes_4_aligned(b: &mut Bencher) {
531 u64_from_be_bytes_bench_impl!(b, 4, 4, 0);
535 fn u64_from_be_bytes_4_unaligned(b: &mut Bencher) {
536 u64_from_be_bytes_bench_impl!(b, 4, 4, 1);
540 fn u64_from_be_bytes_7_aligned(b: &mut Bencher) {
541 u64_from_be_bytes_bench_impl!(b, 7, 8, 0);
545 fn u64_from_be_bytes_7_unaligned(b: &mut Bencher) {
546 u64_from_be_bytes_bench_impl!(b, 7, 8, 1);
550 fn u64_from_be_bytes_8_aligned(b: &mut Bencher) {
551 u64_from_be_bytes_bench_impl!(b, 8, 8, 0);
555 fn u64_from_be_bytes_8_unaligned(b: &mut Bencher) {
556 u64_from_be_bytes_bench_impl!(b, 8, 8, 1);