1 // Copyright 2013 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 // ignore-lexer-test FIXME #15679
13 //! Readers and Writers for in-memory buffers
19 use result::{Err, Ok};
21 use io::{Reader, Writer, Seek, Buffer, IoError, SeekStyle, IoResult};
22 use slice::{mod, AsSlice, SlicePrelude};
25 const BUF_CAPACITY: uint = 128;
27 fn combine(seek: SeekStyle, cur: uint, end: uint, offset: i64) -> IoResult<u64> {
28 // compute offset as signed and clamp to prevent overflow
29 let pos = match seek {
37 kind: io::InvalidInput,
38 desc: "invalid seek to a negative offset",
42 Ok((offset + pos) as u64)
46 impl Writer for Vec<u8> {
48 fn write(&mut self, buf: &[u8]) -> IoResult<()> {
54 /// Writes to an owned, growable byte vector
59 /// # #![allow(unused_must_use)]
60 /// use std::io::MemWriter;
62 /// let mut w = MemWriter::new();
63 /// w.write(&[0, 1, 2]);
65 /// assert_eq!(w.into_inner(), vec!(0, 1, 2));
67 #[deprecated = "use the Vec<u8> Writer implementation directly"]
69 pub struct MemWriter {
74 /// Create a new `MemWriter`.
76 pub fn new() -> MemWriter {
77 MemWriter::with_capacity(BUF_CAPACITY)
79 /// Create a new `MemWriter`, allocating at least `n` bytes for
80 /// the internal buffer.
82 pub fn with_capacity(n: uint) -> MemWriter {
83 MemWriter::from_vec(Vec::with_capacity(n))
85 /// Create a new `MemWriter` that will append to an existing `Vec`.
87 pub fn from_vec(buf: Vec<u8>) -> MemWriter {
88 MemWriter { buf: buf }
91 /// Acquires an immutable reference to the underlying buffer of this
94 pub fn get_ref<'a>(&'a self) -> &'a [u8] { self.buf.as_slice() }
96 /// Unwraps this `MemWriter`, returning the underlying buffer
98 pub fn into_inner(self) -> Vec<u8> { self.buf }
100 /// Deprecated, use into_inner() instead
101 #[deprecated = "renamed to into_inner()"]
102 pub fn unwrap(self) -> Vec<u8> { self.into_inner() }
105 impl Writer for MemWriter {
107 fn write(&mut self, buf: &[u8]) -> IoResult<()> {
108 self.buf.push_all(buf);
113 /// Reads from an owned byte vector
118 /// # #![allow(unused_must_use)]
119 /// use std::io::MemReader;
121 /// let mut r = MemReader::new(vec!(0, 1, 2));
123 /// assert_eq!(r.read_to_end().unwrap(), vec!(0, 1, 2));
125 pub struct MemReader {
131 /// Creates a new `MemReader` which will read the buffer given. The buffer
132 /// can be re-acquired through `unwrap`
134 pub fn new(buf: Vec<u8>) -> MemReader {
141 /// Tests whether this reader has read all bytes in its buffer.
143 /// If `true`, then this will no longer return bytes from `read`.
145 pub fn eof(&self) -> bool { self.pos >= self.buf.len() }
147 /// Acquires an immutable reference to the underlying buffer of this
150 /// No method is exposed for acquiring a mutable reference to the buffer
151 /// because it could corrupt the state of this `MemReader`.
153 pub fn get_ref<'a>(&'a self) -> &'a [u8] { self.buf.as_slice() }
155 /// Unwraps this `MemReader`, returning the underlying buffer
157 pub fn into_inner(self) -> Vec<u8> { self.buf }
159 /// Deprecated, use into_inner() instead
160 #[deprecated = "renamed to into_inner()"]
161 pub fn unwrap(self) -> Vec<u8> { self.into_inner() }
164 impl Reader for MemReader {
166 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
167 if self.eof() { return Err(io::standard_error(io::EndOfFile)) }
169 let write_len = min(buf.len(), self.buf.len() - self.pos);
171 let input = self.buf[self.pos.. self.pos + write_len];
172 let output = buf[mut ..write_len];
173 assert_eq!(input.len(), output.len());
174 slice::bytes::copy_memory(output, input);
176 self.pos += write_len;
177 assert!(self.pos <= self.buf.len());
179 return Ok(write_len);
183 impl Seek for MemReader {
185 fn tell(&self) -> IoResult<u64> { Ok(self.pos as u64) }
188 fn seek(&mut self, pos: i64, style: SeekStyle) -> IoResult<()> {
189 let new = try!(combine(style, self.pos, self.buf.len(), pos));
190 self.pos = new as uint;
195 impl Buffer for MemReader {
197 fn fill_buf<'a>(&'a mut self) -> IoResult<&'a [u8]> {
198 if self.pos < self.buf.len() {
199 Ok(self.buf[self.pos..])
201 Err(io::standard_error(io::EndOfFile))
206 fn consume(&mut self, amt: uint) { self.pos += amt; }
209 /// Writes to a fixed-size byte slice
211 /// If a write will not fit in the buffer, it returns an error and does not
217 /// # #![allow(unused_must_use)]
218 /// use std::io::BufWriter;
220 /// let mut buf = [0, ..4];
222 /// let mut w = BufWriter::new(&mut buf);
223 /// w.write(&[0, 1, 2]);
225 /// assert!(buf == [0, 1, 2, 0]);
227 pub struct BufWriter<'a> {
232 impl<'a> BufWriter<'a> {
233 /// Creates a new `BufWriter` which will wrap the specified buffer. The
234 /// writer initially starts at position 0.
236 pub fn new<'a>(buf: &'a mut [u8]) -> BufWriter<'a> {
244 impl<'a> Writer for BufWriter<'a> {
246 fn write(&mut self, buf: &[u8]) -> IoResult<()> {
247 // return an error if the entire write does not fit in the buffer
248 let cap = if self.pos >= self.buf.len() { 0 } else { self.buf.len() - self.pos };
251 kind: io::OtherIoError,
252 desc: "Trying to write past end of buffer",
257 slice::bytes::copy_memory(self.buf[mut self.pos..], buf);
258 self.pos += buf.len();
263 impl<'a> Seek for BufWriter<'a> {
265 fn tell(&self) -> IoResult<u64> { Ok(self.pos as u64) }
268 fn seek(&mut self, pos: i64, style: SeekStyle) -> IoResult<()> {
269 let new = try!(combine(style, self.pos, self.buf.len(), pos));
270 self.pos = new as uint;
275 /// Reads from a fixed-size byte slice
280 /// # #![allow(unused_must_use)]
281 /// use std::io::BufReader;
283 /// let mut buf = [0, 1, 2, 3];
284 /// let mut r = BufReader::new(&mut buf);
286 /// assert_eq!(r.read_to_end().unwrap(), vec!(0, 1, 2, 3));
288 pub struct BufReader<'a> {
293 impl<'a> BufReader<'a> {
294 /// Creates a new buffered reader which will read the specified buffer
296 pub fn new<'a>(buf: &'a [u8]) -> BufReader<'a> {
303 /// Tests whether this reader has read all bytes in its buffer.
305 /// If `true`, then this will no longer return bytes from `read`.
307 pub fn eof(&self) -> bool { self.pos >= self.buf.len() }
310 impl<'a> Reader for BufReader<'a> {
312 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
313 if self.eof() { return Err(io::standard_error(io::EndOfFile)) }
315 let write_len = min(buf.len(), self.buf.len() - self.pos);
317 let input = self.buf[self.pos.. self.pos + write_len];
318 let output = buf[mut ..write_len];
319 assert_eq!(input.len(), output.len());
320 slice::bytes::copy_memory(output, input);
322 self.pos += write_len;
323 assert!(self.pos <= self.buf.len());
325 return Ok(write_len);
329 impl<'a> Seek for BufReader<'a> {
331 fn tell(&self) -> IoResult<u64> { Ok(self.pos as u64) }
334 fn seek(&mut self, pos: i64, style: SeekStyle) -> IoResult<()> {
335 let new = try!(combine(style, self.pos, self.buf.len(), pos));
336 self.pos = new as uint;
341 impl<'a> Buffer for BufReader<'a> {
343 fn fill_buf<'a>(&'a mut self) -> IoResult<&'a [u8]> {
344 if self.pos < self.buf.len() {
345 Ok(self.buf[self.pos..])
347 Err(io::standard_error(io::EndOfFile))
352 fn consume(&mut self, amt: uint) { self.pos += amt; }
362 use self::test::Bencher;
366 fn test_mem_writer() {
367 let mut writer = MemWriter::new();
368 writer.write(&[0]).unwrap();
369 writer.write(&[1, 2, 3]).unwrap();
370 writer.write(&[4, 5, 6, 7]).unwrap();
371 let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7];
372 assert_eq!(writer.get_ref(), b);
376 fn test_buf_writer() {
377 let mut buf = [0 as u8, ..8];
379 let mut writer = BufWriter::new(&mut buf);
380 assert_eq!(writer.tell(), Ok(0));
381 writer.write(&[0]).unwrap();
382 assert_eq!(writer.tell(), Ok(1));
383 writer.write(&[1, 2, 3]).unwrap();
384 writer.write(&[4, 5, 6, 7]).unwrap();
385 assert_eq!(writer.tell(), Ok(8));
386 writer.write(&[]).unwrap();
387 assert_eq!(writer.tell(), Ok(8));
389 let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7];
390 assert_eq!(buf.as_slice(), b);
394 fn test_buf_writer_seek() {
395 let mut buf = [0 as u8, ..8];
397 let mut writer = BufWriter::new(&mut buf);
398 assert_eq!(writer.tell(), Ok(0));
399 writer.write(&[1]).unwrap();
400 assert_eq!(writer.tell(), Ok(1));
402 writer.seek(2, SeekSet).unwrap();
403 assert_eq!(writer.tell(), Ok(2));
404 writer.write(&[2]).unwrap();
405 assert_eq!(writer.tell(), Ok(3));
407 writer.seek(-2, SeekCur).unwrap();
408 assert_eq!(writer.tell(), Ok(1));
409 writer.write(&[3]).unwrap();
410 assert_eq!(writer.tell(), Ok(2));
412 writer.seek(-1, SeekEnd).unwrap();
413 assert_eq!(writer.tell(), Ok(7));
414 writer.write(&[4]).unwrap();
415 assert_eq!(writer.tell(), Ok(8));
418 let b: &[_] = &[1, 3, 2, 0, 0, 0, 0, 4];
419 assert_eq!(buf.as_slice(), b);
423 fn test_buf_writer_error() {
424 let mut buf = [0 as u8, ..2];
425 let mut writer = BufWriter::new(&mut buf);
426 writer.write(&[0]).unwrap();
428 match writer.write(&[0, 0]) {
430 Err(e) => assert_eq!(e.kind, io::OtherIoError),
435 fn test_mem_reader() {
436 let mut reader = MemReader::new(vec!(0, 1, 2, 3, 4, 5, 6, 7));
438 assert_eq!(reader.read(&mut buf), Ok(0));
439 assert_eq!(reader.tell(), Ok(0));
441 assert_eq!(reader.read(&mut buf), Ok(1));
442 assert_eq!(reader.tell(), Ok(1));
444 assert_eq!(buf.as_slice(), b);
445 let mut buf = [0, ..4];
446 assert_eq!(reader.read(&mut buf), Ok(4));
447 assert_eq!(reader.tell(), Ok(5));
448 let b: &[_] = &[1, 2, 3, 4];
449 assert_eq!(buf.as_slice(), b);
450 assert_eq!(reader.read(&mut buf), Ok(3));
451 let b: &[_] = &[5, 6, 7];
452 assert_eq!(buf[0..3], b);
453 assert!(reader.read(&mut buf).is_err());
454 let mut reader = MemReader::new(vec!(0, 1, 2, 3, 4, 5, 6, 7));
455 assert_eq!(reader.read_until(3).unwrap(), vec!(0, 1, 2, 3));
456 assert_eq!(reader.read_until(3).unwrap(), vec!(4, 5, 6, 7));
457 assert!(reader.read(&mut buf).is_err());
461 fn test_buf_reader() {
462 let in_buf = vec![0, 1, 2, 3, 4, 5, 6, 7];
463 let mut reader = BufReader::new(in_buf.as_slice());
465 assert_eq!(reader.read(&mut buf), Ok(0));
466 assert_eq!(reader.tell(), Ok(0));
468 assert_eq!(reader.read(&mut buf), Ok(1));
469 assert_eq!(reader.tell(), Ok(1));
471 assert_eq!(buf.as_slice(), b);
472 let mut buf = [0, ..4];
473 assert_eq!(reader.read(&mut buf), Ok(4));
474 assert_eq!(reader.tell(), Ok(5));
475 let b: &[_] = &[1, 2, 3, 4];
476 assert_eq!(buf.as_slice(), b);
477 assert_eq!(reader.read(&mut buf), Ok(3));
478 let b: &[_] = &[5, 6, 7];
479 assert_eq!(buf[0..3], b);
480 assert!(reader.read(&mut buf).is_err());
481 let mut reader = BufReader::new(in_buf.as_slice());
482 assert_eq!(reader.read_until(3).unwrap(), vec!(0, 1, 2, 3));
483 assert_eq!(reader.read_until(3).unwrap(), vec!(4, 5, 6, 7));
484 assert!(reader.read(&mut buf).is_err());
488 fn test_read_char() {
489 let b = b"Vi\xE1\xBB\x87t";
490 let mut r = BufReader::new(b);
491 assert_eq!(r.read_char(), Ok('V'));
492 assert_eq!(r.read_char(), Ok('i'));
493 assert_eq!(r.read_char(), Ok('ệ'));
494 assert_eq!(r.read_char(), Ok('t'));
495 assert!(r.read_char().is_err());
499 fn test_read_bad_char() {
501 let mut r = BufReader::new(b);
502 assert!(r.read_char().is_err());
506 fn test_write_strings() {
507 let mut writer = MemWriter::new();
508 writer.write_str("testing").unwrap();
509 writer.write_line("testing").unwrap();
510 writer.write_str("testing").unwrap();
511 let mut r = BufReader::new(writer.get_ref());
512 assert_eq!(r.read_to_string().unwrap(), "testingtesting\ntesting".to_string());
516 fn test_write_char() {
517 let mut writer = MemWriter::new();
518 writer.write_char('a').unwrap();
519 writer.write_char('\n').unwrap();
520 writer.write_char('ệ').unwrap();
521 let mut r = BufReader::new(writer.get_ref());
522 assert_eq!(r.read_to_string().unwrap(), "a\nệ".to_string());
526 fn test_read_whole_string_bad() {
528 let mut r = BufReader::new(&buf);
529 match r.read_to_string() {
538 let mut r = BufReader::new(&buf);
539 r.seek(10, SeekSet).unwrap();
540 assert!(r.read(&mut []).is_err());
542 let mut r = MemReader::new(vec!(10));
543 r.seek(10, SeekSet).unwrap();
544 assert!(r.read(&mut []).is_err());
547 let mut r = BufWriter::new(&mut buf);
548 r.seek(10, SeekSet).unwrap();
549 assert!(r.write(&[3]).is_err());
555 let mut r = BufReader::new(&buf);
556 assert!(r.seek(-1, SeekSet).is_err());
558 let mut r = MemReader::new(vec!(10));
559 assert!(r.seek(-1, SeekSet).is_err());
562 let mut r = BufWriter::new(&mut buf);
563 assert!(r.seek(-1, SeekSet).is_err());
567 fn io_read_at_least() {
568 let mut r = MemReader::new(vec![1, 2, 3, 4, 5, 6, 7, 8]);
569 let mut buf = [0, ..3];
570 assert!(r.read_at_least(buf.len(), &mut buf).is_ok());
571 let b: &[_] = &[1, 2, 3];
572 assert_eq!(buf.as_slice(), b);
573 assert!(r.read_at_least(0, buf[mut ..0]).is_ok());
574 assert_eq!(buf.as_slice(), b);
575 assert!(r.read_at_least(buf.len(), &mut buf).is_ok());
576 let b: &[_] = &[4, 5, 6];
577 assert_eq!(buf.as_slice(), b);
578 assert!(r.read_at_least(buf.len(), &mut buf).is_err());
579 let b: &[_] = &[7, 8, 6];
580 assert_eq!(buf.as_slice(), b);
583 fn do_bench_mem_writer(b: &mut Bencher, times: uint, len: uint) {
584 let src: Vec<u8> = Vec::from_elem(len, 5);
586 b.bytes = (times * len) as u64;
588 let mut wr = MemWriter::new();
589 for _ in range(0, times) {
590 wr.write(src.as_slice()).unwrap();
594 assert_eq!(v.len(), times * len);
595 assert!(v.iter().all(|x| *x == 5));
600 fn bench_mem_writer_001_0000(b: &mut Bencher) {
601 do_bench_mem_writer(b, 1, 0)
605 fn bench_mem_writer_001_0010(b: &mut Bencher) {
606 do_bench_mem_writer(b, 1, 10)
610 fn bench_mem_writer_001_0100(b: &mut Bencher) {
611 do_bench_mem_writer(b, 1, 100)
615 fn bench_mem_writer_001_1000(b: &mut Bencher) {
616 do_bench_mem_writer(b, 1, 1000)
620 fn bench_mem_writer_100_0000(b: &mut Bencher) {
621 do_bench_mem_writer(b, 100, 0)
625 fn bench_mem_writer_100_0010(b: &mut Bencher) {
626 do_bench_mem_writer(b, 100, 10)
630 fn bench_mem_writer_100_0100(b: &mut Bencher) {
631 do_bench_mem_writer(b, 100, 100)
635 fn bench_mem_writer_100_1000(b: &mut Bencher) {
636 do_bench_mem_writer(b, 100, 1000)
640 fn bench_mem_reader(b: &mut Bencher) {
642 let buf = [5 as u8, ..100].to_vec();
644 let mut rdr = MemReader::new(buf);
645 for _i in range(0u, 10) {
646 let mut buf = [0 as u8, .. 10];
647 rdr.read(&mut buf).unwrap();
648 assert_eq!(buf.as_slice(), [5, .. 10].as_slice());
655 fn bench_buf_writer(b: &mut Bencher) {
657 let mut buf = [0 as u8, ..100];
659 let mut wr = BufWriter::new(&mut buf);
660 for _i in range(0u, 10) {
661 wr.write(&[5, .. 10]).unwrap();
664 assert_eq!(buf.as_slice(), [5, .. 100].as_slice());
669 fn bench_buf_reader(b: &mut Bencher) {
671 let buf = [5 as u8, ..100];
673 let mut rdr = BufReader::new(&buf);
674 for _i in range(0u, 10) {
675 let mut buf = [0 as u8, .. 10];
676 rdr.read(&mut buf).unwrap();
677 assert_eq!(buf.as_slice(), [5, .. 10].as_slice());