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
18 use option::Option::None;
19 use result::Result::{Err, Ok};
21 use io::{Reader, Writer, Seek, Buffer, IoError, SeekStyle, IoResult};
22 use slice::{mod, AsSlice, SliceExt};
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.slice_to_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 impl<'a> Reader for &'a [u8] {
211 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
212 if self.is_empty() { return Err(io::standard_error(io::EndOfFile)); }
214 let write_len = min(buf.len(), self.len());
216 let input = self[..write_len];
217 let output = buf.slice_to_mut(write_len);
218 slice::bytes::copy_memory(output, input);
221 *self = self.slice_from(write_len);
227 impl<'a> Buffer for &'a [u8] {
229 fn fill_buf(&mut self) -> IoResult<&[u8]> {
231 Err(io::standard_error(io::EndOfFile))
238 fn consume(&mut self, amt: uint) {
244 /// Writes to a fixed-size byte slice
246 /// If a write will not fit in the buffer, it returns an error and does not
252 /// # #![allow(unused_must_use)]
253 /// use std::io::BufWriter;
255 /// let mut buf = [0; 4];
257 /// let mut w = BufWriter::new(&mut buf);
258 /// w.write(&[0, 1, 2]);
260 /// assert!(buf == [0, 1, 2, 0]);
262 pub struct BufWriter<'a> {
267 impl<'a> BufWriter<'a> {
268 /// Creates a new `BufWriter` which will wrap the specified buffer. The
269 /// writer initially starts at position 0.
271 pub fn new(buf: &'a mut [u8]) -> BufWriter<'a> {
279 impl<'a> Writer for BufWriter<'a> {
281 fn write(&mut self, src: &[u8]) -> IoResult<()> {
282 let dst = self.buf.slice_from_mut(self.pos);
283 let dst_len = dst.len();
286 return Err(io::standard_error(io::EndOfFile));
289 let src_len = src.len();
291 if dst_len >= src_len {
292 slice::bytes::copy_memory(dst, src);
298 slice::bytes::copy_memory(dst, src[..dst_len]);
302 Err(io::standard_error(io::ShortWrite(dst_len)))
307 impl<'a> Seek for BufWriter<'a> {
309 fn tell(&self) -> IoResult<u64> { Ok(self.pos as u64) }
312 fn seek(&mut self, pos: i64, style: SeekStyle) -> IoResult<()> {
313 let new = try!(combine(style, self.pos, self.buf.len(), pos));
314 self.pos = min(new as uint, self.buf.len());
319 /// Reads from a fixed-size byte slice
324 /// # #![allow(unused_must_use)]
325 /// use std::io::BufReader;
327 /// let buf = [0, 1, 2, 3];
328 /// let mut r = BufReader::new(&buf);
330 /// assert_eq!(r.read_to_end().unwrap(), vec![0, 1, 2, 3]);
332 pub struct BufReader<'a> {
337 impl<'a> BufReader<'a> {
338 /// Creates a new buffered reader which will read the specified buffer
340 pub fn new(buf: &'a [u8]) -> BufReader<'a> {
347 /// Tests whether this reader has read all bytes in its buffer.
349 /// If `true`, then this will no longer return bytes from `read`.
351 pub fn eof(&self) -> bool { self.pos >= self.buf.len() }
354 impl<'a> Reader for BufReader<'a> {
356 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
357 if self.eof() { return Err(io::standard_error(io::EndOfFile)) }
359 let write_len = min(buf.len(), self.buf.len() - self.pos);
361 let input = self.buf[self.pos.. self.pos + write_len];
362 let output = buf.slice_to_mut(write_len);
363 assert_eq!(input.len(), output.len());
364 slice::bytes::copy_memory(output, input);
366 self.pos += write_len;
367 assert!(self.pos <= self.buf.len());
369 return Ok(write_len);
373 impl<'a> Seek for BufReader<'a> {
375 fn tell(&self) -> IoResult<u64> { Ok(self.pos as u64) }
378 fn seek(&mut self, pos: i64, style: SeekStyle) -> IoResult<()> {
379 let new = try!(combine(style, self.pos, self.buf.len(), pos));
380 self.pos = new as uint;
385 impl<'a> Buffer for BufReader<'a> {
387 fn fill_buf(&mut self) -> IoResult<&[u8]> {
388 if self.pos < self.buf.len() {
389 Ok(self.buf[self.pos..])
391 Err(io::standard_error(io::EndOfFile))
396 fn consume(&mut self, amt: uint) { self.pos += amt; }
401 extern crate "test" as test_crate;
405 use io::{SeekSet, SeekCur, SeekEnd};
407 use self::test_crate::Bencher;
410 fn test_vec_writer() {
411 let mut writer = Vec::new();
412 writer.write(&[0]).unwrap();
413 writer.write(&[1, 2, 3]).unwrap();
414 writer.write(&[4, 5, 6, 7]).unwrap();
415 let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7];
416 assert_eq!(writer.as_slice(), b);
420 fn test_mem_writer() {
421 let mut writer = MemWriter::new();
422 writer.write(&[0]).unwrap();
423 writer.write(&[1, 2, 3]).unwrap();
424 writer.write(&[4, 5, 6, 7]).unwrap();
425 let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7];
426 assert_eq!(writer.get_ref(), b);
430 fn test_buf_writer() {
431 let mut buf = [0 as u8; 9];
433 let mut writer = BufWriter::new(&mut buf);
434 assert_eq!(writer.tell(), Ok(0));
435 writer.write(&[0]).unwrap();
436 assert_eq!(writer.tell(), Ok(1));
437 writer.write(&[1, 2, 3]).unwrap();
438 writer.write(&[4, 5, 6, 7]).unwrap();
439 assert_eq!(writer.tell(), Ok(8));
440 writer.write(&[]).unwrap();
441 assert_eq!(writer.tell(), Ok(8));
443 assert_eq!(writer.write(&[8, 9]).unwrap_err().kind, io::ShortWrite(1));
444 assert_eq!(writer.write(&[10]).unwrap_err().kind, io::EndOfFile);
446 let b: &[_] = &[0, 1, 2, 3, 4, 5, 6, 7, 8];
451 fn test_buf_writer_seek() {
452 let mut buf = [0 as u8; 8];
454 let mut writer = BufWriter::new(&mut buf);
455 assert_eq!(writer.tell(), Ok(0));
456 writer.write(&[1]).unwrap();
457 assert_eq!(writer.tell(), Ok(1));
459 writer.seek(2, SeekSet).unwrap();
460 assert_eq!(writer.tell(), Ok(2));
461 writer.write(&[2]).unwrap();
462 assert_eq!(writer.tell(), Ok(3));
464 writer.seek(-2, SeekCur).unwrap();
465 assert_eq!(writer.tell(), Ok(1));
466 writer.write(&[3]).unwrap();
467 assert_eq!(writer.tell(), Ok(2));
469 writer.seek(-1, SeekEnd).unwrap();
470 assert_eq!(writer.tell(), Ok(7));
471 writer.write(&[4]).unwrap();
472 assert_eq!(writer.tell(), Ok(8));
475 let b: &[_] = &[1, 3, 2, 0, 0, 0, 0, 4];
480 fn test_buf_writer_error() {
481 let mut buf = [0 as u8; 2];
482 let mut writer = BufWriter::new(&mut buf);
483 writer.write(&[0]).unwrap();
485 match writer.write(&[0, 0]) {
487 Err(e) => assert_eq!(e.kind, io::ShortWrite(1)),
492 fn test_mem_reader() {
493 let mut reader = MemReader::new(vec!(0, 1, 2, 3, 4, 5, 6, 7));
495 assert_eq!(reader.read(&mut buf), Ok(0));
496 assert_eq!(reader.tell(), Ok(0));
498 assert_eq!(reader.read(&mut buf), Ok(1));
499 assert_eq!(reader.tell(), Ok(1));
502 let mut buf = [0; 4];
503 assert_eq!(reader.read(&mut buf), Ok(4));
504 assert_eq!(reader.tell(), Ok(5));
505 let b: &[_] = &[1, 2, 3, 4];
507 assert_eq!(reader.read(&mut buf), Ok(3));
508 let b: &[_] = &[5, 6, 7];
509 assert_eq!(buf[0..3], b);
510 assert!(reader.read(&mut buf).is_err());
511 let mut reader = MemReader::new(vec!(0, 1, 2, 3, 4, 5, 6, 7));
512 assert_eq!(reader.read_until(3).unwrap(), vec!(0, 1, 2, 3));
513 assert_eq!(reader.read_until(3).unwrap(), vec!(4, 5, 6, 7));
514 assert!(reader.read(&mut buf).is_err());
518 fn test_slice_reader() {
519 let in_buf = vec![0, 1, 2, 3, 4, 5, 6, 7];
520 let mut reader = &mut in_buf.as_slice();
522 assert_eq!(reader.read(&mut buf), Ok(0));
524 assert_eq!(reader.read(&mut buf), Ok(1));
525 assert_eq!(reader.len(), 7);
527 assert_eq!(buf.as_slice(), b);
528 let mut buf = [0; 4];
529 assert_eq!(reader.read(&mut buf), Ok(4));
530 assert_eq!(reader.len(), 3);
531 let b: &[_] = &[1, 2, 3, 4];
532 assert_eq!(buf.as_slice(), b);
533 assert_eq!(reader.read(&mut buf), Ok(3));
534 let b: &[_] = &[5, 6, 7];
535 assert_eq!(buf[0..3], b);
536 assert!(reader.read(&mut buf).is_err());
537 let mut reader = &mut in_buf.as_slice();
538 assert_eq!(reader.read_until(3).unwrap(), vec!(0, 1, 2, 3));
539 assert_eq!(reader.read_until(3).unwrap(), vec!(4, 5, 6, 7));
540 assert!(reader.read(&mut buf).is_err());
544 fn test_buf_reader() {
545 let in_buf = vec![0, 1, 2, 3, 4, 5, 6, 7];
546 let mut reader = BufReader::new(in_buf.as_slice());
548 assert_eq!(reader.read(&mut buf), Ok(0));
549 assert_eq!(reader.tell(), Ok(0));
551 assert_eq!(reader.read(&mut buf), Ok(1));
552 assert_eq!(reader.tell(), Ok(1));
555 let mut buf = [0; 4];
556 assert_eq!(reader.read(&mut buf), Ok(4));
557 assert_eq!(reader.tell(), Ok(5));
558 let b: &[_] = &[1, 2, 3, 4];
560 assert_eq!(reader.read(&mut buf), Ok(3));
561 let b: &[_] = &[5, 6, 7];
562 assert_eq!(buf[0..3], b);
563 assert!(reader.read(&mut buf).is_err());
564 let mut reader = BufReader::new(in_buf.as_slice());
565 assert_eq!(reader.read_until(3).unwrap(), vec!(0, 1, 2, 3));
566 assert_eq!(reader.read_until(3).unwrap(), vec!(4, 5, 6, 7));
567 assert!(reader.read(&mut buf).is_err());
571 fn test_read_char() {
572 let b = b"Vi\xE1\xBB\x87t";
573 let mut r = BufReader::new(b);
574 assert_eq!(r.read_char(), Ok('V'));
575 assert_eq!(r.read_char(), Ok('i'));
576 assert_eq!(r.read_char(), Ok('ệ'));
577 assert_eq!(r.read_char(), Ok('t'));
578 assert!(r.read_char().is_err());
582 fn test_read_bad_char() {
584 let mut r = BufReader::new(b);
585 assert!(r.read_char().is_err());
589 fn test_write_strings() {
590 let mut writer = MemWriter::new();
591 writer.write_str("testing").unwrap();
592 writer.write_line("testing").unwrap();
593 writer.write_str("testing").unwrap();
594 let mut r = BufReader::new(writer.get_ref());
595 assert_eq!(r.read_to_string().unwrap(), "testingtesting\ntesting");
599 fn test_write_char() {
600 let mut writer = MemWriter::new();
601 writer.write_char('a').unwrap();
602 writer.write_char('\n').unwrap();
603 writer.write_char('ệ').unwrap();
604 let mut r = BufReader::new(writer.get_ref());
605 assert_eq!(r.read_to_string().unwrap(), "a\nệ");
609 fn test_read_whole_string_bad() {
611 let mut r = BufReader::new(&buf);
612 match r.read_to_string() {
621 let mut r = BufReader::new(&buf);
622 r.seek(10, SeekSet).unwrap();
623 assert!(r.read(&mut []).is_err());
625 let mut r = MemReader::new(vec!(10));
626 r.seek(10, SeekSet).unwrap();
627 assert!(r.read(&mut []).is_err());
630 let mut r = BufWriter::new(&mut buf);
631 r.seek(10, SeekSet).unwrap();
632 assert!(r.write(&[3]).is_err());
638 let mut r = BufReader::new(&buf);
639 assert!(r.seek(-1, SeekSet).is_err());
641 let mut r = MemReader::new(vec!(10));
642 assert!(r.seek(-1, SeekSet).is_err());
645 let mut r = BufWriter::new(&mut buf);
646 assert!(r.seek(-1, SeekSet).is_err());
650 fn io_read_at_least() {
651 let mut r = MemReader::new(vec![1, 2, 3, 4, 5, 6, 7, 8]);
652 let mut buf = [0; 3];
653 assert!(r.read_at_least(buf.len(), &mut buf).is_ok());
654 let b: &[_] = &[1, 2, 3];
656 assert!(r.read_at_least(0, buf.slice_to_mut(0)).is_ok());
658 assert!(r.read_at_least(buf.len(), &mut buf).is_ok());
659 let b: &[_] = &[4, 5, 6];
661 assert!(r.read_at_least(buf.len(), &mut buf).is_err());
662 let b: &[_] = &[7, 8, 6];
666 fn do_bench_mem_writer(b: &mut Bencher, times: uint, len: uint) {
667 let src: Vec<u8> = Vec::from_elem(len, 5);
669 b.bytes = (times * len) as u64;
671 let mut wr = MemWriter::new();
672 for _ in range(0, times) {
673 wr.write(src.as_slice()).unwrap();
677 assert_eq!(v.len(), times * len);
678 assert!(v.iter().all(|x| *x == 5));
683 fn bench_mem_writer_001_0000(b: &mut Bencher) {
684 do_bench_mem_writer(b, 1, 0)
688 fn bench_mem_writer_001_0010(b: &mut Bencher) {
689 do_bench_mem_writer(b, 1, 10)
693 fn bench_mem_writer_001_0100(b: &mut Bencher) {
694 do_bench_mem_writer(b, 1, 100)
698 fn bench_mem_writer_001_1000(b: &mut Bencher) {
699 do_bench_mem_writer(b, 1, 1000)
703 fn bench_mem_writer_100_0000(b: &mut Bencher) {
704 do_bench_mem_writer(b, 100, 0)
708 fn bench_mem_writer_100_0010(b: &mut Bencher) {
709 do_bench_mem_writer(b, 100, 10)
713 fn bench_mem_writer_100_0100(b: &mut Bencher) {
714 do_bench_mem_writer(b, 100, 100)
718 fn bench_mem_writer_100_1000(b: &mut Bencher) {
719 do_bench_mem_writer(b, 100, 1000)
723 fn bench_mem_reader(b: &mut Bencher) {
725 let buf = [5 as u8; 100].to_vec();
727 let mut rdr = MemReader::new(buf);
728 for _i in range(0u, 10) {
729 let mut buf = [0 as u8; 10];
730 rdr.read(&mut buf).unwrap();
731 assert_eq!(buf.as_slice(), [5; 10].as_slice());
738 fn bench_buf_writer(b: &mut Bencher) {
740 let mut buf = [0 as u8; 100];
742 let mut wr = BufWriter::new(&mut buf);
743 for _i in range(0u, 10) {
744 wr.write(&[5; 10]).unwrap();
747 assert_eq!(buf.as_slice(), [5; 100].as_slice());
752 fn bench_buf_reader(b: &mut Bencher) {
754 let buf = [5 as u8; 100];
756 let mut rdr = BufReader::new(&buf);
757 for _i in range(0u, 10) {
758 let mut buf = [0 as u8; 10];
759 rdr.read(&mut buf).unwrap();
760 assert_eq!(buf, [5; 10]);