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85aaf69f | 1 | // Copyright 2015 The Rust Project Developers. See the COPYRIGHT |
1a4d82fc JJ |
2 | // file at the top-level directory of this distribution and at |
3 | // http://rust-lang.org/COPYRIGHT. | |
4 | // | |
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. | |
1a4d82fc | 10 | |
85aaf69f | 11 | //! Traits, helpers, and type definitions for core I/O functionality. |
c1a9b12d SL |
12 | //! |
13 | //! The `std::io` module contains a number of common things you'll need | |
14 | //! when doing input and output. The most core part of this module is | |
15 | //! the [`Read`][read] and [`Write`][write] traits, which provide the | |
16 | //! most general interface for reading and writing input and output. | |
17 | //! | |
18 | //! [read]: trait.Read.html | |
19 | //! [write]: trait.Write.html | |
20 | //! | |
21 | //! # Read and Write | |
22 | //! | |
b039eaaf SL |
23 | //! Because they are traits, `Read` and `Write` are implemented by a number |
24 | //! of other types, and you can implement them for your types too. As such, | |
25 | //! you'll see a few different types of I/O throughout the documentation in | |
26 | //! this module: `File`s, `TcpStream`s, and sometimes even `Vec<T>`s. For | |
27 | //! example, `Read` adds a `read()` method, which we can use on `File`s: | |
c1a9b12d SL |
28 | //! |
29 | //! ``` | |
30 | //! use std::io; | |
31 | //! use std::io::prelude::*; | |
32 | //! use std::fs::File; | |
33 | //! | |
34 | //! # fn foo() -> io::Result<()> { | |
35 | //! let mut f = try!(File::open("foo.txt")); | |
36 | //! let mut buffer = [0; 10]; | |
37 | //! | |
38 | //! // read up to 10 bytes | |
39 | //! try!(f.read(&mut buffer)); | |
40 | //! | |
41 | //! println!("The bytes: {:?}", buffer); | |
42 | //! # Ok(()) | |
43 | //! # } | |
44 | //! ``` | |
45 | //! | |
46 | //! `Read` and `Write` are so important, implementors of the two traits have a | |
47 | //! nickname: readers and writers. So you'll sometimes see 'a reader' instead | |
48 | //! of 'a type that implements the `Read` trait'. Much easier! | |
49 | //! | |
50 | //! ## Seek and BufRead | |
51 | //! | |
52 | //! Beyond that, there are two important traits that are provided: [`Seek`][seek] | |
53 | //! and [`BufRead`][bufread]. Both of these build on top of a reader to control | |
54 | //! how the reading happens. `Seek` lets you control where the next byte is | |
55 | //! coming from: | |
56 | //! | |
57 | //! ``` | |
58 | //! use std::io; | |
59 | //! use std::io::prelude::*; | |
60 | //! use std::io::SeekFrom; | |
61 | //! use std::fs::File; | |
62 | //! | |
63 | //! # fn foo() -> io::Result<()> { | |
64 | //! let mut f = try!(File::open("foo.txt")); | |
65 | //! let mut buffer = [0; 10]; | |
66 | //! | |
67 | //! // skip to the last 10 bytes of the file | |
68 | //! try!(f.seek(SeekFrom::End(-10))); | |
69 | //! | |
70 | //! // read up to 10 bytes | |
71 | //! try!(f.read(&mut buffer)); | |
72 | //! | |
73 | //! println!("The bytes: {:?}", buffer); | |
74 | //! # Ok(()) | |
75 | //! # } | |
76 | //! ``` | |
77 | //! | |
78 | //! [seek]: trait.Seek.html | |
79 | //! [bufread]: trait.BufRead.html | |
80 | //! | |
81 | //! `BufRead` uses an internal buffer to provide a number of other ways to read, but | |
82 | //! to show it off, we'll need to talk about buffers in general. Keep reading! | |
83 | //! | |
84 | //! ## BufReader and BufWriter | |
85 | //! | |
86 | //! Byte-based interfaces are unwieldy and can be inefficient, as we'd need to be | |
87 | //! making near-constant calls to the operating system. To help with this, | |
88 | //! `std::io` comes with two structs, `BufReader` and `BufWriter`, which wrap | |
89 | //! readers and writers. The wrapper uses a buffer, reducing the number of | |
90 | //! calls and providing nicer methods for accessing exactly what you want. | |
91 | //! | |
92 | //! For example, `BufReader` works with the `BufRead` trait to add extra | |
93 | //! methods to any reader: | |
94 | //! | |
95 | //! ``` | |
96 | //! use std::io; | |
97 | //! use std::io::prelude::*; | |
98 | //! use std::io::BufReader; | |
99 | //! use std::fs::File; | |
100 | //! | |
101 | //! # fn foo() -> io::Result<()> { | |
102 | //! let f = try!(File::open("foo.txt")); | |
103 | //! let mut reader = BufReader::new(f); | |
104 | //! let mut buffer = String::new(); | |
105 | //! | |
106 | //! // read a line into buffer | |
107 | //! try!(reader.read_line(&mut buffer)); | |
108 | //! | |
109 | //! println!("{}", buffer); | |
110 | //! # Ok(()) | |
111 | //! # } | |
112 | //! ``` | |
113 | //! | |
b039eaaf | 114 | //! `BufWriter` doesn't add any new ways of writing; it just buffers every call |
9cc50fc6 | 115 | //! to [`write()`][write()]: |
c1a9b12d SL |
116 | //! |
117 | //! ``` | |
118 | //! use std::io; | |
119 | //! use std::io::prelude::*; | |
120 | //! use std::io::BufWriter; | |
121 | //! use std::fs::File; | |
122 | //! | |
123 | //! # fn foo() -> io::Result<()> { | |
124 | //! let f = try!(File::create("foo.txt")); | |
125 | //! { | |
126 | //! let mut writer = BufWriter::new(f); | |
127 | //! | |
128 | //! // write a byte to the buffer | |
129 | //! try!(writer.write(&[42])); | |
130 | //! | |
131 | //! } // the buffer is flushed once writer goes out of scope | |
132 | //! | |
133 | //! # Ok(()) | |
134 | //! # } | |
135 | //! ``` | |
136 | //! | |
9cc50fc6 | 137 | //! [write()]: trait.Write.html#tymethod.write |
c1a9b12d SL |
138 | //! |
139 | //! ## Standard input and output | |
140 | //! | |
141 | //! A very common source of input is standard input: | |
142 | //! | |
143 | //! ``` | |
144 | //! use std::io; | |
145 | //! | |
146 | //! # fn foo() -> io::Result<()> { | |
147 | //! let mut input = String::new(); | |
148 | //! | |
149 | //! try!(io::stdin().read_line(&mut input)); | |
150 | //! | |
151 | //! println!("You typed: {}", input.trim()); | |
152 | //! # Ok(()) | |
153 | //! # } | |
154 | //! ``` | |
155 | //! | |
156 | //! And a very common source of output is standard output: | |
157 | //! | |
158 | //! ``` | |
159 | //! use std::io; | |
160 | //! use std::io::prelude::*; | |
161 | //! | |
162 | //! # fn foo() -> io::Result<()> { | |
163 | //! try!(io::stdout().write(&[42])); | |
164 | //! # Ok(()) | |
165 | //! # } | |
166 | //! ``` | |
167 | //! | |
b039eaaf | 168 | //! Of course, using `io::stdout()` directly is less common than something like |
c1a9b12d SL |
169 | //! `println!`. |
170 | //! | |
171 | //! ## Iterator types | |
172 | //! | |
173 | //! A large number of the structures provided by `std::io` are for various | |
174 | //! ways of iterating over I/O. For example, `Lines` is used to split over | |
175 | //! lines: | |
176 | //! | |
177 | //! ``` | |
178 | //! use std::io; | |
179 | //! use std::io::prelude::*; | |
180 | //! use std::io::BufReader; | |
181 | //! use std::fs::File; | |
182 | //! | |
183 | //! # fn foo() -> io::Result<()> { | |
184 | //! let f = try!(File::open("foo.txt")); | |
a7813a04 | 185 | //! let reader = BufReader::new(f); |
c1a9b12d SL |
186 | //! |
187 | //! for line in reader.lines() { | |
a7813a04 | 188 | //! println!("{}", try!(line)); |
c1a9b12d SL |
189 | //! } |
190 | //! | |
191 | //! # Ok(()) | |
192 | //! # } | |
193 | //! ``` | |
194 | //! | |
195 | //! ## Functions | |
196 | //! | |
a7813a04 | 197 | //! There are a number of [functions][functions-list] that offer access to various |
c1a9b12d SL |
198 | //! features. For example, we can use three of these functions to copy everything |
199 | //! from standard input to standard output: | |
200 | //! | |
201 | //! ``` | |
202 | //! use std::io; | |
203 | //! | |
204 | //! # fn foo() -> io::Result<()> { | |
205 | //! try!(io::copy(&mut io::stdin(), &mut io::stdout())); | |
206 | //! # Ok(()) | |
207 | //! # } | |
208 | //! ``` | |
209 | //! | |
a7813a04 | 210 | //! [functions-list]: #functions-1 |
c1a9b12d SL |
211 | //! |
212 | //! ## io::Result | |
213 | //! | |
214 | //! Last, but certainly not least, is [`io::Result`][result]. This type is used | |
215 | //! as the return type of many `std::io` functions that can cause an error, and | |
216 | //! can be returned from your own functions as well. Many of the examples in this | |
217 | //! module use the [`try!`][try] macro: | |
218 | //! | |
219 | //! ``` | |
220 | //! use std::io; | |
221 | //! | |
222 | //! fn read_input() -> io::Result<()> { | |
223 | //! let mut input = String::new(); | |
224 | //! | |
225 | //! try!(io::stdin().read_line(&mut input)); | |
226 | //! | |
227 | //! println!("You typed: {}", input.trim()); | |
228 | //! | |
229 | //! Ok(()) | |
230 | //! } | |
231 | //! ``` | |
232 | //! | |
233 | //! The return type of `read_input()`, `io::Result<()>`, is a very common type | |
234 | //! for functions which don't have a 'real' return value, but do want to return | |
235 | //! errors if they happen. In this case, the only purpose of this function is | |
b039eaaf | 236 | //! to read the line and print it, so we use `()`. |
c1a9b12d SL |
237 | //! |
238 | //! [result]: type.Result.html | |
9e0c209e | 239 | //! [try]: ../macro.try.html |
9cc50fc6 SL |
240 | //! |
241 | //! ## Platform-specific behavior | |
242 | //! | |
243 | //! Many I/O functions throughout the standard library are documented to indicate | |
244 | //! what various library or syscalls they are delegated to. This is done to help | |
245 | //! applications both understand what's happening under the hood as well as investigate | |
246 | //! any possibly unclear semantics. Note, however, that this is informative, not a binding | |
247 | //! contract. The implementation of many of these functions are subject to change over | |
248 | //! time and may call fewer or more syscalls/library functions. | |
1a4d82fc | 249 | |
c34b1796 | 250 | #![stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc | 251 | |
85aaf69f | 252 | use cmp; |
d9579d0f | 253 | use rustc_unicode::str as core_str; |
c34b1796 | 254 | use error as std_error; |
1a4d82fc | 255 | use fmt; |
85aaf69f | 256 | use result; |
c34b1796 | 257 | use str; |
9cc50fc6 | 258 | use memchr; |
1a4d82fc | 259 | |
92a42be0 | 260 | #[stable(feature = "rust1", since = "1.0.0")] |
e9174d1e | 261 | pub use self::buffered::{BufReader, BufWriter, LineWriter}; |
92a42be0 | 262 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 263 | pub use self::buffered::IntoInnerError; |
92a42be0 | 264 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 265 | pub use self::cursor::Cursor; |
92a42be0 | 266 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 267 | pub use self::error::{Result, Error, ErrorKind}; |
92a42be0 | 268 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 269 | pub use self::util::{copy, sink, Sink, empty, Empty, repeat, Repeat}; |
92a42be0 | 270 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 271 | pub use self::stdio::{stdin, stdout, stderr, _print, Stdin, Stdout, Stderr}; |
92a42be0 | 272 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 | 273 | pub use self::stdio::{StdoutLock, StderrLock, StdinLock}; |
92a42be0 | 274 | #[unstable(feature = "libstd_io_internals", issue = "0")] |
c34b1796 AL |
275 | #[doc(no_inline, hidden)] |
276 | pub use self::stdio::{set_panic, set_print}; | |
277 | ||
85aaf69f | 278 | pub mod prelude; |
1a4d82fc | 279 | mod buffered; |
85aaf69f SL |
280 | mod cursor; |
281 | mod error; | |
282 | mod impls; | |
62682a34 | 283 | mod lazy; |
85aaf69f | 284 | mod util; |
c34b1796 | 285 | mod stdio; |
1a4d82fc | 286 | |
54a0048b | 287 | const DEFAULT_BUF_SIZE: usize = 8 * 1024; |
1a4d82fc | 288 | |
85aaf69f SL |
289 | // A few methods below (read_to_string, read_line) will append data into a |
290 | // `String` buffer, but we need to be pretty careful when doing this. The | |
291 | // implementation will just call `.as_mut_vec()` and then delegate to a | |
292 | // byte-oriented reading method, but we must ensure that when returning we never | |
293 | // leave `buf` in a state such that it contains invalid UTF-8 in its bounds. | |
294 | // | |
295 | // To this end, we use an RAII guard (to protect against panics) which updates | |
296 | // the length of the string when it is dropped. This guard initially truncates | |
297 | // the string to the prior length and only after we've validated that the | |
298 | // new contents are valid UTF-8 do we allow it to set a longer length. | |
299 | // | |
300 | // The unsafety in this function is twofold: | |
301 | // | |
302 | // 1. We're looking at the raw bytes of `buf`, so we take on the burden of UTF-8 | |
303 | // checks. | |
304 | // 2. We're passing a raw buffer to the function `f`, and it is expected that | |
305 | // the function only *appends* bytes to the buffer. We'll get undefined | |
306 | // behavior if existing bytes are overwritten to have non-UTF-8 data. | |
c34b1796 AL |
307 | fn append_to_string<F>(buf: &mut String, f: F) -> Result<usize> |
308 | where F: FnOnce(&mut Vec<u8>) -> Result<usize> | |
85aaf69f SL |
309 | { |
310 | struct Guard<'a> { s: &'a mut Vec<u8>, len: usize } | |
d9579d0f | 311 | impl<'a> Drop for Guard<'a> { |
85aaf69f SL |
312 | fn drop(&mut self) { |
313 | unsafe { self.s.set_len(self.len); } | |
1a4d82fc JJ |
314 | } |
315 | } | |
1a4d82fc | 316 | |
85aaf69f SL |
317 | unsafe { |
318 | let mut g = Guard { len: buf.len(), s: buf.as_mut_vec() }; | |
319 | let ret = f(g.s); | |
320 | if str::from_utf8(&g.s[g.len..]).is_err() { | |
c34b1796 | 321 | ret.and_then(|_| { |
62682a34 | 322 | Err(Error::new(ErrorKind::InvalidData, |
c34b1796 | 323 | "stream did not contain valid UTF-8")) |
85aaf69f SL |
324 | }) |
325 | } else { | |
326 | g.len = g.s.len(); | |
327 | ret | |
328 | } | |
1a4d82fc JJ |
329 | } |
330 | } | |
331 | ||
c34b1796 AL |
332 | // This uses an adaptive system to extend the vector when it fills. We want to |
333 | // avoid paying to allocate and zero a huge chunk of memory if the reader only | |
334 | // has 4 bytes while still making large reads if the reader does have a ton | |
335 | // of data to return. Simply tacking on an extra DEFAULT_BUF_SIZE space every | |
336 | // time is 4,500 times (!) slower than this if the reader has a very small | |
337 | // amount of data to return. | |
338 | fn read_to_end<R: Read + ?Sized>(r: &mut R, buf: &mut Vec<u8>) -> Result<usize> { | |
339 | let start_len = buf.len(); | |
340 | let mut len = start_len; | |
341 | let mut new_write_size = 16; | |
342 | let ret; | |
85aaf69f | 343 | loop { |
c34b1796 AL |
344 | if len == buf.len() { |
345 | if new_write_size < DEFAULT_BUF_SIZE { | |
346 | new_write_size *= 2; | |
347 | } | |
c1a9b12d | 348 | buf.resize(len + new_write_size, 0); |
85aaf69f | 349 | } |
c34b1796 AL |
350 | |
351 | match r.read(&mut buf[len..]) { | |
352 | Ok(0) => { | |
353 | ret = Ok(len - start_len); | |
354 | break; | |
355 | } | |
356 | Ok(n) => len += n, | |
85aaf69f | 357 | Err(ref e) if e.kind() == ErrorKind::Interrupted => {} |
c34b1796 AL |
358 | Err(e) => { |
359 | ret = Err(e); | |
360 | break; | |
361 | } | |
85aaf69f | 362 | } |
1a4d82fc | 363 | } |
c34b1796 AL |
364 | |
365 | buf.truncate(len); | |
366 | ret | |
1a4d82fc JJ |
367 | } |
368 | ||
c1a9b12d | 369 | /// The `Read` trait allows for reading bytes from a source. |
85aaf69f | 370 | /// |
c1a9b12d | 371 | /// Implementors of the `Read` trait are sometimes called 'readers'. |
1a4d82fc | 372 | /// |
c1a9b12d SL |
373 | /// Readers are defined by one required method, `read()`. Each call to `read` |
374 | /// will attempt to pull bytes from this source into a provided buffer. A | |
375 | /// number of other methods are implemented in terms of `read()`, giving | |
376 | /// implementors a number of ways to read bytes while only needing to implement | |
377 | /// a single method. | |
378 | /// | |
379 | /// Readers are intended to be composable with one another. Many implementors | |
380 | /// throughout `std::io` take and provide types which implement the `Read` | |
381 | /// trait. | |
382 | /// | |
b039eaaf SL |
383 | /// Please note that each call to `read` may involve a system call, and |
384 | /// therefore, using something that implements [`BufRead`][bufread], such as | |
385 | /// [`BufReader`][bufreader], will be more efficient. | |
386 | /// | |
387 | /// [bufread]: trait.BufRead.html | |
388 | /// [bufreader]: struct.BufReader.html | |
389 | /// | |
c1a9b12d SL |
390 | /// # Examples |
391 | /// | |
392 | /// [`File`][file]s implement `Read`: | |
393 | /// | |
9cc50fc6 | 394 | /// [file]: ../fs/struct.File.html |
c1a9b12d SL |
395 | /// |
396 | /// ``` | |
397 | /// use std::io; | |
398 | /// use std::io::prelude::*; | |
399 | /// use std::fs::File; | |
400 | /// | |
401 | /// # fn foo() -> io::Result<()> { | |
402 | /// let mut f = try!(File::open("foo.txt")); | |
403 | /// let mut buffer = [0; 10]; | |
404 | /// | |
405 | /// // read up to 10 bytes | |
406 | /// try!(f.read(&mut buffer)); | |
407 | /// | |
408 | /// let mut buffer = vec![0; 10]; | |
409 | /// // read the whole file | |
410 | /// try!(f.read_to_end(&mut buffer)); | |
411 | /// | |
412 | /// // read into a String, so that you don't need to do the conversion. | |
413 | /// let mut buffer = String::new(); | |
414 | /// try!(f.read_to_string(&mut buffer)); | |
415 | /// | |
416 | /// // and more! See the other methods for more details. | |
417 | /// # Ok(()) | |
418 | /// # } | |
419 | /// ``` | |
c34b1796 | 420 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
421 | pub trait Read { |
422 | /// Pull some bytes from this source into the specified buffer, returning | |
423 | /// how many bytes were read. | |
424 | /// | |
425 | /// This function does not provide any guarantees about whether it blocks | |
426 | /// waiting for data, but if an object needs to block for a read but cannot | |
427 | /// it will typically signal this via an `Err` return value. | |
428 | /// | |
429 | /// If the return value of this method is `Ok(n)`, then it must be | |
430 | /// guaranteed that `0 <= n <= buf.len()`. A nonzero `n` value indicates | |
9346a6ac | 431 | /// that the buffer `buf` has been filled in with `n` bytes of data from this |
85aaf69f SL |
432 | /// source. If `n` is `0`, then it can indicate one of two scenarios: |
433 | /// | |
434 | /// 1. This reader has reached its "end of file" and will likely no longer | |
435 | /// be able to produce bytes. Note that this does not mean that the | |
436 | /// reader will *always* no longer be able to produce bytes. | |
437 | /// 2. The buffer specified was 0 bytes in length. | |
438 | /// | |
439 | /// No guarantees are provided about the contents of `buf` when this | |
440 | /// function is called, implementations cannot rely on any property of the | |
441 | /// contents of `buf` being true. It is recommended that implementations | |
442 | /// only write data to `buf` instead of reading its contents. | |
1a4d82fc | 443 | /// |
85aaf69f | 444 | /// # Errors |
1a4d82fc | 445 | /// |
85aaf69f SL |
446 | /// If this function encounters any form of I/O or other error, an error |
447 | /// variant will be returned. If an error is returned then it must be | |
448 | /// guaranteed that no bytes were read. | |
c1a9b12d SL |
449 | /// |
450 | /// # Examples | |
451 | /// | |
452 | /// [`File`][file]s implement `Read`: | |
453 | /// | |
9cc50fc6 | 454 | /// [file]: ../fs/struct.File.html |
c1a9b12d SL |
455 | /// |
456 | /// ``` | |
457 | /// use std::io; | |
458 | /// use std::io::prelude::*; | |
459 | /// use std::fs::File; | |
460 | /// | |
461 | /// # fn foo() -> io::Result<()> { | |
462 | /// let mut f = try!(File::open("foo.txt")); | |
463 | /// let mut buffer = [0; 10]; | |
464 | /// | |
465 | /// // read 10 bytes | |
466 | /// try!(f.read(&mut buffer[..])); | |
467 | /// # Ok(()) | |
468 | /// # } | |
469 | /// ``` | |
c34b1796 | 470 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 471 | fn read(&mut self, buf: &mut [u8]) -> Result<usize>; |
1a4d82fc | 472 | |
85aaf69f | 473 | /// Read all bytes until EOF in this source, placing them into `buf`. |
1a4d82fc | 474 | /// |
85aaf69f | 475 | /// All bytes read from this source will be appended to the specified buffer |
9346a6ac AL |
476 | /// `buf`. This function will continuously call `read` to append more data to |
477 | /// `buf` until `read` returns either `Ok(0)` or an error of | |
478 | /// non-`ErrorKind::Interrupted` kind. | |
1a4d82fc | 479 | /// |
9346a6ac | 480 | /// If successful, this function will return the total number of bytes read. |
1a4d82fc | 481 | /// |
85aaf69f | 482 | /// # Errors |
1a4d82fc | 483 | /// |
85aaf69f SL |
484 | /// If this function encounters an error of the kind |
485 | /// `ErrorKind::Interrupted` then the error is ignored and the operation | |
486 | /// will continue. | |
1a4d82fc | 487 | /// |
85aaf69f SL |
488 | /// If any other read error is encountered then this function immediately |
489 | /// returns. Any bytes which have already been read will be appended to | |
490 | /// `buf`. | |
c1a9b12d SL |
491 | /// |
492 | /// # Examples | |
493 | /// | |
494 | /// [`File`][file]s implement `Read`: | |
495 | /// | |
9cc50fc6 | 496 | /// [file]: ../fs/struct.File.html |
c1a9b12d SL |
497 | /// |
498 | /// ``` | |
499 | /// use std::io; | |
500 | /// use std::io::prelude::*; | |
501 | /// use std::fs::File; | |
502 | /// | |
503 | /// # fn foo() -> io::Result<()> { | |
504 | /// let mut f = try!(File::open("foo.txt")); | |
505 | /// let mut buffer = Vec::new(); | |
506 | /// | |
507 | /// // read the whole file | |
508 | /// try!(f.read_to_end(&mut buffer)); | |
509 | /// # Ok(()) | |
510 | /// # } | |
511 | /// ``` | |
c34b1796 AL |
512 | #[stable(feature = "rust1", since = "1.0.0")] |
513 | fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize> { | |
85aaf69f | 514 | read_to_end(self, buf) |
1a4d82fc JJ |
515 | } |
516 | ||
85aaf69f | 517 | /// Read all bytes until EOF in this source, placing them into `buf`. |
1a4d82fc | 518 | /// |
c34b1796 AL |
519 | /// If successful, this function returns the number of bytes which were read |
520 | /// and appended to `buf`. | |
521 | /// | |
85aaf69f | 522 | /// # Errors |
1a4d82fc | 523 | /// |
85aaf69f SL |
524 | /// If the data in this stream is *not* valid UTF-8 then an error is |
525 | /// returned and `buf` is unchanged. | |
1a4d82fc | 526 | /// |
c1a9b12d SL |
527 | /// See [`read_to_end()`][readtoend] for other error semantics. |
528 | /// | |
529 | /// [readtoend]: #method.read_to_end | |
530 | /// | |
531 | /// # Examples | |
532 | /// | |
533 | /// [`File`][file]s implement `Read`: | |
534 | /// | |
9cc50fc6 | 535 | /// [file]: ../fs/struct.File.html |
c1a9b12d SL |
536 | /// |
537 | /// ``` | |
538 | /// use std::io; | |
539 | /// use std::io::prelude::*; | |
540 | /// use std::fs::File; | |
541 | /// | |
542 | /// # fn foo() -> io::Result<()> { | |
543 | /// let mut f = try!(File::open("foo.txt")); | |
544 | /// let mut buffer = String::new(); | |
545 | /// | |
546 | /// try!(f.read_to_string(&mut buffer)); | |
547 | /// # Ok(()) | |
548 | /// # } | |
549 | /// ``` | |
c34b1796 AL |
550 | #[stable(feature = "rust1", since = "1.0.0")] |
551 | fn read_to_string(&mut self, buf: &mut String) -> Result<usize> { | |
85aaf69f SL |
552 | // Note that we do *not* call `.read_to_end()` here. We are passing |
553 | // `&mut Vec<u8>` (the raw contents of `buf`) into the `read_to_end` | |
554 | // method to fill it up. An arbitrary implementation could overwrite the | |
555 | // entire contents of the vector, not just append to it (which is what | |
556 | // we are expecting). | |
557 | // | |
558 | // To prevent extraneously checking the UTF-8-ness of the entire buffer | |
559 | // we pass it to our hardcoded `read_to_end` implementation which we | |
560 | // know is guaranteed to only read data into the end of the buffer. | |
561 | append_to_string(buf, |b| read_to_end(self, b)) | |
1a4d82fc JJ |
562 | } |
563 | ||
e9174d1e SL |
564 | /// Read the exact number of bytes required to fill `buf`. |
565 | /// | |
566 | /// This function reads as many bytes as necessary to completely fill the | |
567 | /// specified buffer `buf`. | |
568 | /// | |
569 | /// No guarantees are provided about the contents of `buf` when this | |
570 | /// function is called, implementations cannot rely on any property of the | |
571 | /// contents of `buf` being true. It is recommended that implementations | |
572 | /// only write data to `buf` instead of reading its contents. | |
573 | /// | |
574 | /// # Errors | |
575 | /// | |
576 | /// If this function encounters an error of the kind | |
577 | /// `ErrorKind::Interrupted` then the error is ignored and the operation | |
578 | /// will continue. | |
579 | /// | |
580 | /// If this function encounters an "end of file" before completely filling | |
92a42be0 | 581 | /// the buffer, it returns an error of the kind `ErrorKind::UnexpectedEof`. |
e9174d1e SL |
582 | /// The contents of `buf` are unspecified in this case. |
583 | /// | |
584 | /// If any other read error is encountered then this function immediately | |
585 | /// returns. The contents of `buf` are unspecified in this case. | |
586 | /// | |
587 | /// If this function returns an error, it is unspecified how many bytes it | |
588 | /// has read, but it will never read more than would be necessary to | |
589 | /// completely fill the buffer. | |
590 | /// | |
591 | /// # Examples | |
592 | /// | |
593 | /// [`File`][file]s implement `Read`: | |
594 | /// | |
9cc50fc6 | 595 | /// [file]: ../fs/struct.File.html |
e9174d1e SL |
596 | /// |
597 | /// ``` | |
e9174d1e SL |
598 | /// use std::io; |
599 | /// use std::io::prelude::*; | |
600 | /// use std::fs::File; | |
601 | /// | |
602 | /// # fn foo() -> io::Result<()> { | |
603 | /// let mut f = try!(File::open("foo.txt")); | |
604 | /// let mut buffer = [0; 10]; | |
605 | /// | |
606 | /// // read exactly 10 bytes | |
607 | /// try!(f.read_exact(&mut buffer)); | |
608 | /// # Ok(()) | |
609 | /// # } | |
610 | /// ``` | |
92a42be0 | 611 | #[stable(feature = "read_exact", since = "1.6.0")] |
e9174d1e SL |
612 | fn read_exact(&mut self, mut buf: &mut [u8]) -> Result<()> { |
613 | while !buf.is_empty() { | |
614 | match self.read(buf) { | |
615 | Ok(0) => break, | |
616 | Ok(n) => { let tmp = buf; buf = &mut tmp[n..]; } | |
617 | Err(ref e) if e.kind() == ErrorKind::Interrupted => {} | |
618 | Err(e) => return Err(e), | |
619 | } | |
620 | } | |
621 | if !buf.is_empty() { | |
92a42be0 | 622 | Err(Error::new(ErrorKind::UnexpectedEof, |
e9174d1e SL |
623 | "failed to fill whole buffer")) |
624 | } else { | |
625 | Ok(()) | |
626 | } | |
627 | } | |
628 | ||
9346a6ac | 629 | /// Creates a "by reference" adaptor for this instance of `Read`. |
1a4d82fc | 630 | /// |
85aaf69f SL |
631 | /// The returned adaptor also implements `Read` and will simply borrow this |
632 | /// current reader. | |
c1a9b12d SL |
633 | /// |
634 | /// # Examples | |
635 | /// | |
636 | /// [`File`][file]s implement `Read`: | |
637 | /// | |
9cc50fc6 | 638 | /// [file]: ../fs/struct.File.html |
c1a9b12d SL |
639 | /// |
640 | /// ``` | |
641 | /// use std::io; | |
642 | /// use std::io::Read; | |
643 | /// use std::fs::File; | |
644 | /// | |
645 | /// # fn foo() -> io::Result<()> { | |
646 | /// let mut f = try!(File::open("foo.txt")); | |
647 | /// let mut buffer = Vec::new(); | |
648 | /// let mut other_buffer = Vec::new(); | |
649 | /// | |
650 | /// { | |
651 | /// let reference = f.by_ref(); | |
652 | /// | |
653 | /// // read at most 5 bytes | |
654 | /// try!(reference.take(5).read_to_end(&mut buffer)); | |
655 | /// | |
656 | /// } // drop our &mut reference so we can use f again | |
657 | /// | |
658 | /// // original file still usable, read the rest | |
659 | /// try!(f.read_to_end(&mut other_buffer)); | |
660 | /// # Ok(()) | |
661 | /// # } | |
662 | /// ``` | |
c34b1796 AL |
663 | #[stable(feature = "rust1", since = "1.0.0")] |
664 | fn by_ref(&mut self) -> &mut Self where Self: Sized { self } | |
1a4d82fc | 665 | |
9346a6ac | 666 | /// Transforms this `Read` instance to an `Iterator` over its bytes. |
1a4d82fc | 667 | /// |
85aaf69f SL |
668 | /// The returned type implements `Iterator` where the `Item` is `Result<u8, |
669 | /// R::Err>`. The yielded item is `Ok` if a byte was successfully read and | |
670 | /// `Err` otherwise for I/O errors. EOF is mapped to returning `None` from | |
671 | /// this iterator. | |
c1a9b12d SL |
672 | /// |
673 | /// # Examples | |
674 | /// | |
675 | /// [`File`][file]s implement `Read`: | |
676 | /// | |
9cc50fc6 | 677 | /// [file]: ../fs/struct.File.html |
c1a9b12d SL |
678 | /// |
679 | /// ``` | |
680 | /// use std::io; | |
681 | /// use std::io::prelude::*; | |
682 | /// use std::fs::File; | |
683 | /// | |
684 | /// # fn foo() -> io::Result<()> { | |
685 | /// let mut f = try!(File::open("foo.txt")); | |
686 | /// | |
687 | /// for byte in f.bytes() { | |
688 | /// println!("{}", byte.unwrap()); | |
689 | /// } | |
690 | /// # Ok(()) | |
691 | /// # } | |
692 | /// ``` | |
c34b1796 AL |
693 | #[stable(feature = "rust1", since = "1.0.0")] |
694 | fn bytes(self) -> Bytes<Self> where Self: Sized { | |
85aaf69f | 695 | Bytes { inner: self } |
1a4d82fc JJ |
696 | } |
697 | ||
9346a6ac | 698 | /// Transforms this `Read` instance to an `Iterator` over `char`s. |
1a4d82fc | 699 | /// |
d9579d0f | 700 | /// This adaptor will attempt to interpret this reader as a UTF-8 encoded |
85aaf69f SL |
701 | /// sequence of characters. The returned iterator will return `None` once |
702 | /// EOF is reached for this reader. Otherwise each element yielded will be a | |
703 | /// `Result<char, E>` where `E` may contain information about what I/O error | |
704 | /// occurred or where decoding failed. | |
1a4d82fc | 705 | /// |
85aaf69f SL |
706 | /// Currently this adaptor will discard intermediate data read, and should |
707 | /// be avoided if this is not desired. | |
c1a9b12d SL |
708 | /// |
709 | /// # Examples | |
710 | /// | |
711 | /// [`File`][file]s implement `Read`: | |
712 | /// | |
9cc50fc6 | 713 | /// [file]: ../fs/struct.File.html |
c1a9b12d SL |
714 | /// |
715 | /// ``` | |
716 | /// #![feature(io)] | |
717 | /// use std::io; | |
718 | /// use std::io::prelude::*; | |
719 | /// use std::fs::File; | |
720 | /// | |
721 | /// # fn foo() -> io::Result<()> { | |
722 | /// let mut f = try!(File::open("foo.txt")); | |
723 | /// | |
724 | /// for c in f.chars() { | |
725 | /// println!("{}", c.unwrap()); | |
726 | /// } | |
727 | /// # Ok(()) | |
728 | /// # } | |
729 | /// ``` | |
c34b1796 AL |
730 | #[unstable(feature = "io", reason = "the semantics of a partial read/write \ |
731 | of where errors happen is currently \ | |
e9174d1e SL |
732 | unclear and may change", |
733 | issue = "27802")] | |
c34b1796 | 734 | fn chars(self) -> Chars<Self> where Self: Sized { |
85aaf69f | 735 | Chars { inner: self } |
1a4d82fc JJ |
736 | } |
737 | ||
9346a6ac | 738 | /// Creates an adaptor which will chain this stream with another. |
1a4d82fc | 739 | /// |
85aaf69f SL |
740 | /// The returned `Read` instance will first read all bytes from this object |
741 | /// until EOF is encountered. Afterwards the output is equivalent to the | |
742 | /// output of `next`. | |
c1a9b12d SL |
743 | /// |
744 | /// # Examples | |
745 | /// | |
746 | /// [`File`][file]s implement `Read`: | |
747 | /// | |
9cc50fc6 | 748 | /// [file]: ../fs/struct.File.html |
c1a9b12d SL |
749 | /// |
750 | /// ``` | |
751 | /// use std::io; | |
752 | /// use std::io::prelude::*; | |
753 | /// use std::fs::File; | |
754 | /// | |
755 | /// # fn foo() -> io::Result<()> { | |
756 | /// let mut f1 = try!(File::open("foo.txt")); | |
757 | /// let mut f2 = try!(File::open("bar.txt")); | |
758 | /// | |
759 | /// let mut handle = f1.chain(f2); | |
760 | /// let mut buffer = String::new(); | |
761 | /// | |
762 | /// // read the value into a String. We could use any Read method here, | |
763 | /// // this is just one example. | |
764 | /// try!(handle.read_to_string(&mut buffer)); | |
765 | /// # Ok(()) | |
766 | /// # } | |
767 | /// ``` | |
c34b1796 AL |
768 | #[stable(feature = "rust1", since = "1.0.0")] |
769 | fn chain<R: Read>(self, next: R) -> Chain<Self, R> where Self: Sized { | |
85aaf69f | 770 | Chain { first: self, second: next, done_first: false } |
1a4d82fc JJ |
771 | } |
772 | ||
9346a6ac | 773 | /// Creates an adaptor which will read at most `limit` bytes from it. |
1a4d82fc | 774 | /// |
85aaf69f SL |
775 | /// This function returns a new instance of `Read` which will read at most |
776 | /// `limit` bytes, after which it will always return EOF (`Ok(0)`). Any | |
777 | /// read errors will not count towards the number of bytes read and future | |
778 | /// calls to `read` may succeed. | |
c1a9b12d SL |
779 | /// |
780 | /// # Examples | |
781 | /// | |
782 | /// [`File`][file]s implement `Read`: | |
783 | /// | |
9cc50fc6 | 784 | /// [file]: ../fs/struct.File.html |
c1a9b12d SL |
785 | /// |
786 | /// ``` | |
787 | /// use std::io; | |
788 | /// use std::io::prelude::*; | |
789 | /// use std::fs::File; | |
790 | /// | |
791 | /// # fn foo() -> io::Result<()> { | |
792 | /// let mut f = try!(File::open("foo.txt")); | |
793 | /// let mut buffer = [0; 5]; | |
794 | /// | |
795 | /// // read at most five bytes | |
796 | /// let mut handle = f.take(5); | |
797 | /// | |
798 | /// try!(handle.read(&mut buffer)); | |
799 | /// # Ok(()) | |
800 | /// # } | |
801 | /// ``` | |
c34b1796 AL |
802 | #[stable(feature = "rust1", since = "1.0.0")] |
803 | fn take(self, limit: u64) -> Take<Self> where Self: Sized { | |
85aaf69f | 804 | Take { inner: self, limit: limit } |
1a4d82fc | 805 | } |
85aaf69f | 806 | } |
1a4d82fc | 807 | |
85aaf69f SL |
808 | /// A trait for objects which are byte-oriented sinks. |
809 | /// | |
c1a9b12d SL |
810 | /// Implementors of the `Write` trait are sometimes called 'writers'. |
811 | /// | |
812 | /// Writers are defined by two required methods, `write()` and `flush()`: | |
813 | /// | |
814 | /// * The `write()` method will attempt to write some data into the object, | |
815 | /// returning how many bytes were successfully written. | |
816 | /// | |
817 | /// * The `flush()` method is useful for adaptors and explicit buffers | |
818 | /// themselves for ensuring that all buffered data has been pushed out to the | |
819 | /// 'true sink'. | |
820 | /// | |
821 | /// Writers are intended to be composable with one another. Many implementors | |
822 | /// throughout `std::io` take and provide types which implement the `Write` | |
823 | /// trait. | |
824 | /// | |
825 | /// # Examples | |
826 | /// | |
827 | /// ``` | |
828 | /// use std::io::prelude::*; | |
829 | /// use std::fs::File; | |
85aaf69f | 830 | /// |
c1a9b12d SL |
831 | /// # fn foo() -> std::io::Result<()> { |
832 | /// let mut buffer = try!(File::create("foo.txt")); | |
85aaf69f | 833 | /// |
c1a9b12d SL |
834 | /// try!(buffer.write(b"some bytes")); |
835 | /// # Ok(()) | |
836 | /// # } | |
837 | /// ``` | |
c34b1796 | 838 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
839 | pub trait Write { |
840 | /// Write a buffer into this object, returning how many bytes were written. | |
1a4d82fc | 841 | /// |
85aaf69f SL |
842 | /// This function will attempt to write the entire contents of `buf`, but |
843 | /// the entire write may not succeed, or the write may also generate an | |
844 | /// error. A call to `write` represents *at most one* attempt to write to | |
845 | /// any wrapped object. | |
1a4d82fc | 846 | /// |
85aaf69f | 847 | /// Calls to `write` are not guaranteed to block waiting for data to be |
62682a34 | 848 | /// written, and a write which would otherwise block can be indicated through |
85aaf69f | 849 | /// an `Err` variant. |
1a4d82fc | 850 | /// |
85aaf69f SL |
851 | /// If the return value is `Ok(n)` then it must be guaranteed that |
852 | /// `0 <= n <= buf.len()`. A return value of `0` typically means that the | |
853 | /// underlying object is no longer able to accept bytes and will likely not | |
854 | /// be able to in the future as well, or that the buffer provided is empty. | |
1a4d82fc | 855 | /// |
85aaf69f | 856 | /// # Errors |
1a4d82fc | 857 | /// |
85aaf69f SL |
858 | /// Each call to `write` may generate an I/O error indicating that the |
859 | /// operation could not be completed. If an error is returned then no bytes | |
860 | /// in the buffer were written to this writer. | |
1a4d82fc | 861 | /// |
85aaf69f SL |
862 | /// It is **not** considered an error if the entire buffer could not be |
863 | /// written to this writer. | |
c1a9b12d SL |
864 | /// |
865 | /// # Examples | |
866 | /// | |
867 | /// ``` | |
868 | /// use std::io::prelude::*; | |
869 | /// use std::fs::File; | |
870 | /// | |
871 | /// # fn foo() -> std::io::Result<()> { | |
872 | /// let mut buffer = try!(File::create("foo.txt")); | |
873 | /// | |
874 | /// try!(buffer.write(b"some bytes")); | |
875 | /// # Ok(()) | |
876 | /// # } | |
877 | /// ``` | |
c34b1796 | 878 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 879 | fn write(&mut self, buf: &[u8]) -> Result<usize>; |
1a4d82fc | 880 | |
85aaf69f SL |
881 | /// Flush this output stream, ensuring that all intermediately buffered |
882 | /// contents reach their destination. | |
1a4d82fc | 883 | /// |
85aaf69f | 884 | /// # Errors |
1a4d82fc | 885 | /// |
85aaf69f SL |
886 | /// It is considered an error if not all bytes could be written due to |
887 | /// I/O errors or EOF being reached. | |
c1a9b12d SL |
888 | /// |
889 | /// # Examples | |
890 | /// | |
891 | /// ``` | |
892 | /// use std::io::prelude::*; | |
893 | /// use std::io::BufWriter; | |
894 | /// use std::fs::File; | |
895 | /// | |
896 | /// # fn foo() -> std::io::Result<()> { | |
897 | /// let mut buffer = BufWriter::new(try!(File::create("foo.txt"))); | |
898 | /// | |
899 | /// try!(buffer.write(b"some bytes")); | |
900 | /// try!(buffer.flush()); | |
901 | /// # Ok(()) | |
902 | /// # } | |
903 | /// ``` | |
c34b1796 | 904 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 905 | fn flush(&mut self) -> Result<()>; |
1a4d82fc | 906 | |
85aaf69f | 907 | /// Attempts to write an entire buffer into this write. |
1a4d82fc | 908 | /// |
85aaf69f SL |
909 | /// This method will continuously call `write` while there is more data to |
910 | /// write. This method will not return until the entire buffer has been | |
911 | /// successfully written or an error occurs. The first error generated from | |
912 | /// this method will be returned. | |
1a4d82fc JJ |
913 | /// |
914 | /// # Errors | |
915 | /// | |
85aaf69f | 916 | /// This function will return the first error that `write` returns. |
c1a9b12d SL |
917 | /// |
918 | /// # Examples | |
919 | /// | |
920 | /// ``` | |
921 | /// use std::io::prelude::*; | |
922 | /// use std::fs::File; | |
923 | /// | |
924 | /// # fn foo() -> std::io::Result<()> { | |
925 | /// let mut buffer = try!(File::create("foo.txt")); | |
926 | /// | |
927 | /// try!(buffer.write_all(b"some bytes")); | |
928 | /// # Ok(()) | |
929 | /// # } | |
930 | /// ``` | |
c34b1796 | 931 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 932 | fn write_all(&mut self, mut buf: &[u8]) -> Result<()> { |
9346a6ac | 933 | while !buf.is_empty() { |
85aaf69f SL |
934 | match self.write(buf) { |
935 | Ok(0) => return Err(Error::new(ErrorKind::WriteZero, | |
c34b1796 | 936 | "failed to write whole buffer")), |
85aaf69f SL |
937 | Ok(n) => buf = &buf[n..], |
938 | Err(ref e) if e.kind() == ErrorKind::Interrupted => {} | |
939 | Err(e) => return Err(e), | |
940 | } | |
941 | } | |
942 | Ok(()) | |
943 | } | |
1a4d82fc JJ |
944 | |
945 | /// Writes a formatted string into this writer, returning any error | |
946 | /// encountered. | |
947 | /// | |
c1a9b12d SL |
948 | /// This method is primarily used to interface with the |
949 | /// [`format_args!`][formatargs] macro, but it is rare that this should | |
950 | /// explicitly be called. The [`write!`][write] macro should be favored to | |
951 | /// invoke this method instead. | |
952 | /// | |
9e0c209e SL |
953 | /// [formatargs]: ../macro.format_args.html |
954 | /// [write]: ../macro.write.html | |
1a4d82fc | 955 | /// |
c1a9b12d SL |
956 | /// This function internally uses the [`write_all`][writeall] method on |
957 | /// this trait and hence will continuously write data so long as no errors | |
958 | /// are received. This also means that partial writes are not indicated in | |
959 | /// this signature. | |
960 | /// | |
961 | /// [writeall]: #method.write_all | |
85aaf69f | 962 | /// |
1a4d82fc JJ |
963 | /// # Errors |
964 | /// | |
965 | /// This function will return any I/O error reported while formatting. | |
c1a9b12d SL |
966 | /// |
967 | /// # Examples | |
968 | /// | |
969 | /// ``` | |
970 | /// use std::io::prelude::*; | |
971 | /// use std::fs::File; | |
972 | /// | |
973 | /// # fn foo() -> std::io::Result<()> { | |
974 | /// let mut buffer = try!(File::create("foo.txt")); | |
975 | /// | |
976 | /// // this call | |
977 | /// try!(write!(buffer, "{:.*}", 2, 1.234567)); | |
978 | /// // turns into this: | |
979 | /// try!(buffer.write_fmt(format_args!("{:.*}", 2, 1.234567))); | |
980 | /// # Ok(()) | |
981 | /// # } | |
982 | /// ``` | |
c34b1796 | 983 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
984 | fn write_fmt(&mut self, fmt: fmt::Arguments) -> Result<()> { |
985 | // Create a shim which translates a Write to a fmt::Write and saves | |
1a4d82fc | 986 | // off I/O errors. instead of discarding them |
85aaf69f | 987 | struct Adaptor<'a, T: ?Sized + 'a> { |
1a4d82fc | 988 | inner: &'a mut T, |
85aaf69f | 989 | error: Result<()>, |
1a4d82fc JJ |
990 | } |
991 | ||
85aaf69f | 992 | impl<'a, T: Write + ?Sized> fmt::Write for Adaptor<'a, T> { |
1a4d82fc | 993 | fn write_str(&mut self, s: &str) -> fmt::Result { |
85aaf69f | 994 | match self.inner.write_all(s.as_bytes()) { |
1a4d82fc JJ |
995 | Ok(()) => Ok(()), |
996 | Err(e) => { | |
997 | self.error = Err(e); | |
998 | Err(fmt::Error) | |
999 | } | |
1000 | } | |
1001 | } | |
1002 | } | |
1003 | ||
1004 | let mut output = Adaptor { inner: self, error: Ok(()) }; | |
1005 | match fmt::write(&mut output, fmt) { | |
1006 | Ok(()) => Ok(()), | |
7453a54e SL |
1007 | Err(..) => { |
1008 | // check if the error came from the underlying `Write` or not | |
1009 | if output.error.is_err() { | |
1010 | output.error | |
1011 | } else { | |
1012 | Err(Error::new(ErrorKind::Other, "formatter error")) | |
1013 | } | |
1014 | } | |
1a4d82fc JJ |
1015 | } |
1016 | } | |
1a4d82fc | 1017 | |
9346a6ac | 1018 | /// Creates a "by reference" adaptor for this instance of `Write`. |
1a4d82fc | 1019 | /// |
85aaf69f SL |
1020 | /// The returned adaptor also implements `Write` and will simply borrow this |
1021 | /// current writer. | |
c1a9b12d SL |
1022 | /// |
1023 | /// # Examples | |
1024 | /// | |
1025 | /// ``` | |
1026 | /// use std::io::Write; | |
1027 | /// use std::fs::File; | |
1028 | /// | |
1029 | /// # fn foo() -> std::io::Result<()> { | |
1030 | /// let mut buffer = try!(File::create("foo.txt")); | |
1031 | /// | |
1032 | /// let reference = buffer.by_ref(); | |
1033 | /// | |
1034 | /// // we can use reference just like our original buffer | |
1035 | /// try!(reference.write_all(b"some bytes")); | |
1036 | /// # Ok(()) | |
1037 | /// # } | |
1038 | /// ``` | |
c34b1796 AL |
1039 | #[stable(feature = "rust1", since = "1.0.0")] |
1040 | fn by_ref(&mut self) -> &mut Self where Self: Sized { self } | |
1a4d82fc JJ |
1041 | } |
1042 | ||
c1a9b12d SL |
1043 | /// The `Seek` trait provides a cursor which can be moved within a stream of |
1044 | /// bytes. | |
1a4d82fc | 1045 | /// |
85aaf69f SL |
1046 | /// The stream typically has a fixed size, allowing seeking relative to either |
1047 | /// end or the current offset. | |
c1a9b12d SL |
1048 | /// |
1049 | /// # Examples | |
1050 | /// | |
1051 | /// [`File`][file]s implement `Seek`: | |
1052 | /// | |
9cc50fc6 | 1053 | /// [file]: ../fs/struct.File.html |
c1a9b12d SL |
1054 | /// |
1055 | /// ``` | |
1056 | /// use std::io; | |
1057 | /// use std::io::prelude::*; | |
1058 | /// use std::fs::File; | |
1059 | /// use std::io::SeekFrom; | |
1060 | /// | |
1061 | /// # fn foo() -> io::Result<()> { | |
1062 | /// let mut f = try!(File::open("foo.txt")); | |
1063 | /// | |
1064 | /// // move the cursor 42 bytes from the start of the file | |
1065 | /// try!(f.seek(SeekFrom::Start(42))); | |
1066 | /// # Ok(()) | |
1067 | /// # } | |
1068 | /// ``` | |
c34b1796 | 1069 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 1070 | pub trait Seek { |
c1a9b12d | 1071 | /// Seek to an offset, in bytes, in a stream. |
85aaf69f | 1072 | /// |
c1a9b12d SL |
1073 | /// A seek beyond the end of a stream is allowed, but implementation |
1074 | /// defined. | |
85aaf69f | 1075 | /// |
c1a9b12d SL |
1076 | /// If the seek operation completed successfully, |
1077 | /// this method returns the new position from the start of the stream. | |
5bcae85e | 1078 | /// That position can be used later with [`SeekFrom::Start`]. |
85aaf69f SL |
1079 | /// |
1080 | /// # Errors | |
1081 | /// | |
c1a9b12d | 1082 | /// Seeking to a negative offset is considered an error. |
5bcae85e SL |
1083 | /// |
1084 | /// [`SeekFrom::Start`]: enum.SeekFrom.html#variant.Start | |
c34b1796 | 1085 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 1086 | fn seek(&mut self, pos: SeekFrom) -> Result<u64>; |
1a4d82fc JJ |
1087 | } |
1088 | ||
85aaf69f | 1089 | /// Enumeration of possible methods to seek within an I/O object. |
5bcae85e SL |
1090 | /// |
1091 | /// It is used by the [`Seek`] trait. | |
1092 | /// | |
1093 | /// [`Seek`]: trait.Seek.html | |
85aaf69f | 1094 | #[derive(Copy, PartialEq, Eq, Clone, Debug)] |
c34b1796 | 1095 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
1096 | pub enum SeekFrom { |
1097 | /// Set the offset to the provided number of bytes. | |
c34b1796 | 1098 | #[stable(feature = "rust1", since = "1.0.0")] |
7453a54e | 1099 | Start(#[stable(feature = "rust1", since = "1.0.0")] u64), |
1a4d82fc | 1100 | |
85aaf69f SL |
1101 | /// Set the offset to the size of this object plus the specified number of |
1102 | /// bytes. | |
1103 | /// | |
9cc50fc6 | 1104 | /// It is possible to seek beyond the end of an object, but it's an error to |
85aaf69f | 1105 | /// seek before byte 0. |
c34b1796 | 1106 | #[stable(feature = "rust1", since = "1.0.0")] |
7453a54e | 1107 | End(#[stable(feature = "rust1", since = "1.0.0")] i64), |
1a4d82fc | 1108 | |
85aaf69f SL |
1109 | /// Set the offset to the current position plus the specified number of |
1110 | /// bytes. | |
1111 | /// | |
9cc50fc6 | 1112 | /// It is possible to seek beyond the end of an object, but it's an error to |
85aaf69f | 1113 | /// seek before byte 0. |
c34b1796 | 1114 | #[stable(feature = "rust1", since = "1.0.0")] |
7453a54e | 1115 | Current(#[stable(feature = "rust1", since = "1.0.0")] i64), |
1a4d82fc JJ |
1116 | } |
1117 | ||
85aaf69f | 1118 | fn read_until<R: BufRead + ?Sized>(r: &mut R, delim: u8, buf: &mut Vec<u8>) |
c34b1796 AL |
1119 | -> Result<usize> { |
1120 | let mut read = 0; | |
85aaf69f SL |
1121 | loop { |
1122 | let (done, used) = { | |
1123 | let available = match r.fill_buf() { | |
1124 | Ok(n) => n, | |
1125 | Err(ref e) if e.kind() == ErrorKind::Interrupted => continue, | |
1126 | Err(e) => return Err(e) | |
1127 | }; | |
9cc50fc6 | 1128 | match memchr::memchr(delim, available) { |
85aaf69f | 1129 | Some(i) => { |
92a42be0 | 1130 | buf.extend_from_slice(&available[..i + 1]); |
85aaf69f SL |
1131 | (true, i + 1) |
1132 | } | |
1133 | None => { | |
92a42be0 | 1134 | buf.extend_from_slice(available); |
85aaf69f SL |
1135 | (false, available.len()) |
1136 | } | |
1137 | } | |
1138 | }; | |
1139 | r.consume(used); | |
c34b1796 | 1140 | read += used; |
85aaf69f | 1141 | if done || used == 0 { |
c34b1796 | 1142 | return Ok(read); |
1a4d82fc JJ |
1143 | } |
1144 | } | |
1145 | } | |
1146 | ||
c1a9b12d SL |
1147 | /// A `BufRead` is a type of `Read`er which has an internal buffer, allowing it |
1148 | /// to perform extra ways of reading. | |
1149 | /// | |
1150 | /// For example, reading line-by-line is inefficient without using a buffer, so | |
1151 | /// if you want to read by line, you'll need `BufRead`, which includes a | |
1152 | /// [`read_line()`][readline] method as well as a [`lines()`][lines] iterator. | |
1153 | /// | |
1154 | /// [readline]: #method.read_line | |
1155 | /// [lines]: #method.lines | |
1156 | /// | |
1157 | /// # Examples | |
1158 | /// | |
1159 | /// A locked standard input implements `BufRead`: | |
1160 | /// | |
1161 | /// ``` | |
1162 | /// use std::io; | |
1163 | /// use std::io::prelude::*; | |
1164 | /// | |
1165 | /// let stdin = io::stdin(); | |
1166 | /// for line in stdin.lock().lines() { | |
1167 | /// println!("{}", line.unwrap()); | |
1168 | /// } | |
1169 | /// ``` | |
1170 | /// | |
1171 | /// If you have something that implements `Read`, you can use the [`BufReader` | |
1172 | /// type][bufreader] to turn it into a `BufRead`. | |
1173 | /// | |
1174 | /// For example, [`File`][file] implements `Read`, but not `BufRead`. | |
1175 | /// `BufReader` to the rescue! | |
85aaf69f | 1176 | /// |
c1a9b12d SL |
1177 | /// [bufreader]: struct.BufReader.html |
1178 | /// [file]: ../fs/struct.File.html | |
1179 | /// | |
1180 | /// ``` | |
1181 | /// use std::io::{self, BufReader}; | |
1182 | /// use std::io::prelude::*; | |
1183 | /// use std::fs::File; | |
1184 | /// | |
1185 | /// # fn foo() -> io::Result<()> { | |
1186 | /// let f = try!(File::open("foo.txt")); | |
1187 | /// let f = BufReader::new(f); | |
1188 | /// | |
1189 | /// for line in f.lines() { | |
1190 | /// println!("{}", line.unwrap()); | |
1191 | /// } | |
1192 | /// | |
1193 | /// # Ok(()) | |
1194 | /// # } | |
1195 | /// ``` | |
62682a34 | 1196 | /// |
c34b1796 | 1197 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 1198 | pub trait BufRead: Read { |
1a4d82fc | 1199 | /// Fills the internal buffer of this object, returning the buffer contents. |
85aaf69f | 1200 | /// |
c1a9b12d SL |
1201 | /// This function is a lower-level call. It needs to be paired with the |
1202 | /// [`consume`][consume] method to function properly. When calling this | |
1203 | /// method, none of the contents will be "read" in the sense that later | |
1204 | /// calling `read` may return the same contents. As such, `consume` must be | |
1205 | /// called with the number of bytes that are consumed from this buffer to | |
1206 | /// ensure that the bytes are never returned twice. | |
1a4d82fc | 1207 | /// |
c1a9b12d | 1208 | /// [consume]: #tymethod.consume |
1a4d82fc | 1209 | /// |
85aaf69f SL |
1210 | /// An empty buffer returned indicates that the stream has reached EOF. |
1211 | /// | |
1212 | /// # Errors | |
1a4d82fc JJ |
1213 | /// |
1214 | /// This function will return an I/O error if the underlying reader was | |
85aaf69f | 1215 | /// read, but returned an error. |
c1a9b12d SL |
1216 | /// |
1217 | /// # Examples | |
1218 | /// | |
1219 | /// A locked standard input implements `BufRead`: | |
1220 | /// | |
1221 | /// ``` | |
1222 | /// use std::io; | |
1223 | /// use std::io::prelude::*; | |
1224 | /// | |
1225 | /// let stdin = io::stdin(); | |
1226 | /// let mut stdin = stdin.lock(); | |
1227 | /// | |
1228 | /// // we can't have two `&mut` references to `stdin`, so use a block | |
1229 | /// // to end the borrow early. | |
1230 | /// let length = { | |
1231 | /// let buffer = stdin.fill_buf().unwrap(); | |
1232 | /// | |
1233 | /// // work with buffer | |
1234 | /// println!("{:?}", buffer); | |
1235 | /// | |
1236 | /// buffer.len() | |
1237 | /// }; | |
1238 | /// | |
1239 | /// // ensure the bytes we worked with aren't returned again later | |
1240 | /// stdin.consume(length); | |
1241 | /// ``` | |
c34b1796 | 1242 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 1243 | fn fill_buf(&mut self) -> Result<&[u8]>; |
1a4d82fc JJ |
1244 | |
1245 | /// Tells this buffer that `amt` bytes have been consumed from the buffer, | |
1246 | /// so they should no longer be returned in calls to `read`. | |
c34b1796 | 1247 | /// |
c1a9b12d SL |
1248 | /// This function is a lower-level call. It needs to be paired with the |
1249 | /// [`fill_buf`][fillbuf] method to function properly. This function does | |
1250 | /// not perform any I/O, it simply informs this object that some amount of | |
1251 | /// its buffer, returned from `fill_buf`, has been consumed and should no | |
1252 | /// longer be returned. As such, this function may do odd things if | |
1253 | /// `fill_buf` isn't called before calling it. | |
1254 | /// | |
54a0048b | 1255 | /// [fillbuf]: #tymethod.fill_buf |
c1a9b12d SL |
1256 | /// |
1257 | /// The `amt` must be `<=` the number of bytes in the buffer returned by | |
1258 | /// `fill_buf`. | |
c34b1796 | 1259 | /// |
c1a9b12d | 1260 | /// # Examples |
c34b1796 | 1261 | /// |
c1a9b12d SL |
1262 | /// Since `consume()` is meant to be used with [`fill_buf()`][fillbuf], |
1263 | /// that method's example includes an example of `consume()`. | |
c34b1796 | 1264 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 1265 | fn consume(&mut self, amt: usize); |
1a4d82fc | 1266 | |
c1a9b12d | 1267 | /// Read all bytes into `buf` until the delimiter `byte` is reached. |
1a4d82fc | 1268 | /// |
c1a9b12d SL |
1269 | /// This function will read bytes from the underlying stream until the |
1270 | /// delimiter or EOF is found. Once found, all bytes up to, and including, | |
1271 | /// the delimiter (if found) will be appended to `buf`. | |
1a4d82fc | 1272 | /// |
c1a9b12d SL |
1273 | /// If this reader is currently at EOF then this function will not modify |
1274 | /// `buf` and will return `Ok(n)` where `n` is the number of bytes which | |
1275 | /// were read. | |
1a4d82fc | 1276 | /// |
85aaf69f | 1277 | /// # Errors |
1a4d82fc | 1278 | /// |
85aaf69f SL |
1279 | /// This function will ignore all instances of `ErrorKind::Interrupted` and |
1280 | /// will otherwise return any errors returned by `fill_buf`. | |
1a4d82fc | 1281 | /// |
85aaf69f SL |
1282 | /// If an I/O error is encountered then all bytes read so far will be |
1283 | /// present in `buf` and its length will have been adjusted appropriately. | |
c1a9b12d SL |
1284 | /// |
1285 | /// # Examples | |
1286 | /// | |
1287 | /// A locked standard input implements `BufRead`. In this example, we'll | |
1288 | /// read from standard input until we see an `a` byte. | |
1289 | /// | |
1290 | /// ``` | |
1291 | /// use std::io; | |
1292 | /// use std::io::prelude::*; | |
1293 | /// | |
1294 | /// fn foo() -> io::Result<()> { | |
1295 | /// let stdin = io::stdin(); | |
1296 | /// let mut stdin = stdin.lock(); | |
1297 | /// let mut buffer = Vec::new(); | |
1298 | /// | |
1299 | /// try!(stdin.read_until(b'a', &mut buffer)); | |
1300 | /// | |
1301 | /// println!("{:?}", buffer); | |
1302 | /// # Ok(()) | |
1303 | /// # } | |
1304 | /// ``` | |
c34b1796 AL |
1305 | #[stable(feature = "rust1", since = "1.0.0")] |
1306 | fn read_until(&mut self, byte: u8, buf: &mut Vec<u8>) -> Result<usize> { | |
85aaf69f | 1307 | read_until(self, byte, buf) |
1a4d82fc JJ |
1308 | } |
1309 | ||
c1a9b12d SL |
1310 | /// Read all bytes until a newline (the 0xA byte) is reached, and append |
1311 | /// them to the provided buffer. | |
1a4d82fc | 1312 | /// |
c1a9b12d SL |
1313 | /// This function will read bytes from the underlying stream until the |
1314 | /// newline delimiter (the 0xA byte) or EOF is found. Once found, all bytes | |
1315 | /// up to, and including, the delimiter (if found) will be appended to | |
1316 | /// `buf`. | |
1a4d82fc | 1317 | /// |
85aaf69f | 1318 | /// If this reader is currently at EOF then this function will not modify |
c34b1796 AL |
1319 | /// `buf` and will return `Ok(n)` where `n` is the number of bytes which |
1320 | /// were read. | |
85aaf69f SL |
1321 | /// |
1322 | /// # Errors | |
1323 | /// | |
1324 | /// This function has the same error semantics as `read_until` and will also | |
1325 | /// return an error if the read bytes are not valid UTF-8. If an I/O error | |
1326 | /// is encountered then `buf` may contain some bytes already read in the | |
1327 | /// event that all data read so far was valid UTF-8. | |
c1a9b12d SL |
1328 | /// |
1329 | /// # Examples | |
1330 | /// | |
1331 | /// A locked standard input implements `BufRead`. In this example, we'll | |
1332 | /// read all of the lines from standard input. If we were to do this in | |
1333 | /// an actual project, the [`lines()`][lines] method would be easier, of | |
1334 | /// course. | |
1335 | /// | |
1336 | /// [lines]: #method.lines | |
1337 | /// | |
1338 | /// ``` | |
1339 | /// use std::io; | |
1340 | /// use std::io::prelude::*; | |
1341 | /// | |
1342 | /// let stdin = io::stdin(); | |
1343 | /// let mut stdin = stdin.lock(); | |
1344 | /// let mut buffer = String::new(); | |
1345 | /// | |
1346 | /// while stdin.read_line(&mut buffer).unwrap() > 0 { | |
1347 | /// // work with buffer | |
1348 | /// println!("{:?}", buffer); | |
1349 | /// | |
1350 | /// buffer.clear(); | |
1351 | /// } | |
1352 | /// ``` | |
c34b1796 AL |
1353 | #[stable(feature = "rust1", since = "1.0.0")] |
1354 | fn read_line(&mut self, buf: &mut String) -> Result<usize> { | |
85aaf69f SL |
1355 | // Note that we are not calling the `.read_until` method here, but |
1356 | // rather our hardcoded implementation. For more details as to why, see | |
1357 | // the comments in `read_to_end`. | |
1358 | append_to_string(buf, |b| read_until(self, b'\n', b)) | |
1a4d82fc | 1359 | } |
1a4d82fc | 1360 | |
85aaf69f SL |
1361 | /// Returns an iterator over the contents of this reader split on the byte |
1362 | /// `byte`. | |
1a4d82fc | 1363 | /// |
85aaf69f SL |
1364 | /// The iterator returned from this function will return instances of |
1365 | /// `io::Result<Vec<u8>>`. Each vector returned will *not* have the | |
1366 | /// delimiter byte at the end. | |
1a4d82fc | 1367 | /// |
85aaf69f SL |
1368 | /// This function will yield errors whenever `read_until` would have also |
1369 | /// yielded an error. | |
c1a9b12d SL |
1370 | /// |
1371 | /// # Examples | |
1372 | /// | |
1373 | /// A locked standard input implements `BufRead`. In this example, we'll | |
1374 | /// read some input from standard input, splitting on commas. | |
1375 | /// | |
1376 | /// ``` | |
1377 | /// use std::io; | |
1378 | /// use std::io::prelude::*; | |
1379 | /// | |
1380 | /// let stdin = io::stdin(); | |
1381 | /// | |
1382 | /// for content in stdin.lock().split(b',') { | |
1383 | /// println!("{:?}", content.unwrap()); | |
1384 | /// } | |
1385 | /// ``` | |
c34b1796 AL |
1386 | #[stable(feature = "rust1", since = "1.0.0")] |
1387 | fn split(self, byte: u8) -> Split<Self> where Self: Sized { | |
85aaf69f SL |
1388 | Split { buf: self, delim: byte } |
1389 | } | |
1a4d82fc | 1390 | |
85aaf69f | 1391 | /// Returns an iterator over the lines of this reader. |
1a4d82fc | 1392 | /// |
85aaf69f SL |
1393 | /// The iterator returned from this function will yield instances of |
1394 | /// `io::Result<String>`. Each string returned will *not* have a newline | |
e9174d1e | 1395 | /// byte (the 0xA byte) or CRLF (0xD, 0xA bytes) at the end. |
c1a9b12d SL |
1396 | /// |
1397 | /// # Examples | |
1398 | /// | |
1399 | /// A locked standard input implements `BufRead`: | |
1400 | /// | |
1401 | /// ``` | |
1402 | /// use std::io; | |
1403 | /// use std::io::prelude::*; | |
1404 | /// | |
1405 | /// let stdin = io::stdin(); | |
1406 | /// | |
1407 | /// for line in stdin.lock().lines() { | |
1408 | /// println!("{}", line.unwrap()); | |
1409 | /// } | |
1410 | /// ``` | |
c34b1796 AL |
1411 | #[stable(feature = "rust1", since = "1.0.0")] |
1412 | fn lines(self) -> Lines<Self> where Self: Sized { | |
85aaf69f SL |
1413 | Lines { buf: self } |
1414 | } | |
1415 | } | |
1416 | ||
c1a9b12d SL |
1417 | /// Adaptor to chain together two readers. |
1418 | /// | |
1419 | /// This struct is generally created by calling [`chain()`][chain] on a reader. | |
1420 | /// Please see the documentation of `chain()` for more details. | |
85aaf69f | 1421 | /// |
c1a9b12d | 1422 | /// [chain]: trait.Read.html#method.chain |
c34b1796 | 1423 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
1424 | pub struct Chain<T, U> { |
1425 | first: T, | |
1426 | second: U, | |
1427 | done_first: bool, | |
1a4d82fc JJ |
1428 | } |
1429 | ||
c34b1796 | 1430 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
1431 | impl<T: Read, U: Read> Read for Chain<T, U> { |
1432 | fn read(&mut self, buf: &mut [u8]) -> Result<usize> { | |
1433 | if !self.done_first { | |
54a0048b | 1434 | match self.first.read(buf)? { |
85aaf69f SL |
1435 | 0 => { self.done_first = true; } |
1436 | n => return Ok(n), | |
1437 | } | |
1438 | } | |
1439 | self.second.read(buf) | |
1440 | } | |
1a4d82fc JJ |
1441 | } |
1442 | ||
54a0048b SL |
1443 | #[stable(feature = "chain_bufread", since = "1.9.0")] |
1444 | impl<T: BufRead, U: BufRead> BufRead for Chain<T, U> { | |
1445 | fn fill_buf(&mut self) -> Result<&[u8]> { | |
1446 | if !self.done_first { | |
1447 | match self.first.fill_buf()? { | |
1448 | buf if buf.len() == 0 => { self.done_first = true; } | |
1449 | buf => return Ok(buf), | |
1450 | } | |
1451 | } | |
1452 | self.second.fill_buf() | |
1453 | } | |
1454 | ||
1455 | fn consume(&mut self, amt: usize) { | |
1456 | if !self.done_first { | |
1457 | self.first.consume(amt) | |
1458 | } else { | |
1459 | self.second.consume(amt) | |
1460 | } | |
1461 | } | |
1462 | } | |
1463 | ||
85aaf69f | 1464 | /// Reader adaptor which limits the bytes read from an underlying reader. |
1a4d82fc | 1465 | /// |
c1a9b12d SL |
1466 | /// This struct is generally created by calling [`take()`][take] on a reader. |
1467 | /// Please see the documentation of `take()` for more details. | |
1468 | /// | |
1469 | /// [take]: trait.Read.html#method.take | |
c34b1796 | 1470 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
1471 | pub struct Take<T> { |
1472 | inner: T, | |
1473 | limit: u64, | |
1a4d82fc JJ |
1474 | } |
1475 | ||
85aaf69f SL |
1476 | impl<T> Take<T> { |
1477 | /// Returns the number of bytes that can be read before this instance will | |
1478 | /// return EOF. | |
1a4d82fc | 1479 | /// |
85aaf69f | 1480 | /// # Note |
1a4d82fc | 1481 | /// |
85aaf69f SL |
1482 | /// This instance may reach EOF after reading fewer bytes than indicated by |
1483 | /// this method if the underlying `Read` instance reaches EOF. | |
5bcae85e SL |
1484 | /// |
1485 | /// # Examples | |
1486 | /// | |
1487 | /// ``` | |
1488 | /// use std::io; | |
1489 | /// use std::io::prelude::*; | |
1490 | /// use std::fs::File; | |
1491 | /// | |
1492 | /// # fn foo() -> io::Result<()> { | |
1493 | /// let f = try!(File::open("foo.txt")); | |
1494 | /// | |
1495 | /// // read at most five bytes | |
1496 | /// let handle = f.take(5); | |
1497 | /// | |
1498 | /// println!("limit: {}", handle.limit()); | |
1499 | /// # Ok(()) | |
1500 | /// # } | |
1501 | /// ``` | |
c34b1796 | 1502 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f | 1503 | pub fn limit(&self) -> u64 { self.limit } |
9e0c209e SL |
1504 | |
1505 | /// Consumes the `Take`, returning the wrapped reader. | |
1506 | /// | |
1507 | /// # Examples | |
1508 | /// | |
1509 | /// ``` | |
1510 | /// #![feature(io_take_into_inner)] | |
1511 | /// | |
1512 | /// use std::io; | |
1513 | /// use std::io::prelude::*; | |
1514 | /// use std::fs::File; | |
1515 | /// | |
1516 | /// # fn foo() -> io::Result<()> { | |
1517 | /// let mut file = try!(File::open("foo.txt")); | |
1518 | /// | |
1519 | /// let mut buffer = [0; 5]; | |
1520 | /// let mut handle = file.take(5); | |
1521 | /// try!(handle.read(&mut buffer)); | |
1522 | /// | |
1523 | /// let file = handle.into_inner(); | |
1524 | /// # Ok(()) | |
1525 | /// # } | |
1526 | /// ``` | |
1527 | #[unstable(feature = "io_take_into_inner", issue = "0")] | |
1528 | pub fn into_inner(self) -> T { | |
1529 | self.inner | |
1530 | } | |
85aaf69f | 1531 | } |
1a4d82fc | 1532 | |
c34b1796 | 1533 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
1534 | impl<T: Read> Read for Take<T> { |
1535 | fn read(&mut self, buf: &mut [u8]) -> Result<usize> { | |
c34b1796 AL |
1536 | // Don't call into inner reader at all at EOF because it may still block |
1537 | if self.limit == 0 { | |
1538 | return Ok(0); | |
1539 | } | |
1540 | ||
85aaf69f | 1541 | let max = cmp::min(buf.len() as u64, self.limit) as usize; |
54a0048b | 1542 | let n = self.inner.read(&mut buf[..max])?; |
85aaf69f SL |
1543 | self.limit -= n as u64; |
1544 | Ok(n) | |
1a4d82fc JJ |
1545 | } |
1546 | } | |
1547 | ||
c34b1796 AL |
1548 | #[stable(feature = "rust1", since = "1.0.0")] |
1549 | impl<T: BufRead> BufRead for Take<T> { | |
1550 | fn fill_buf(&mut self) -> Result<&[u8]> { | |
a7813a04 XL |
1551 | // Don't call into inner reader at all at EOF because it may still block |
1552 | if self.limit == 0 { | |
1553 | return Ok(&[]); | |
1554 | } | |
1555 | ||
54a0048b | 1556 | let buf = self.inner.fill_buf()?; |
c34b1796 AL |
1557 | let cap = cmp::min(buf.len() as u64, self.limit) as usize; |
1558 | Ok(&buf[..cap]) | |
1559 | } | |
1560 | ||
1561 | fn consume(&mut self, amt: usize) { | |
1562 | // Don't let callers reset the limit by passing an overlarge value | |
1563 | let amt = cmp::min(amt as u64, self.limit) as usize; | |
1564 | self.limit -= amt as u64; | |
1565 | self.inner.consume(amt); | |
1566 | } | |
1567 | } | |
1568 | ||
5bcae85e SL |
1569 | fn read_one_byte(reader: &mut Read) -> Option<Result<u8>> { |
1570 | let mut buf = [0]; | |
1571 | loop { | |
1572 | return match reader.read(&mut buf) { | |
1573 | Ok(0) => None, | |
1574 | Ok(..) => Some(Ok(buf[0])), | |
1575 | Err(ref e) if e.kind() == ErrorKind::Interrupted => continue, | |
1576 | Err(e) => Some(Err(e)), | |
1577 | }; | |
1578 | } | |
1579 | } | |
1580 | ||
c1a9b12d SL |
1581 | /// An iterator over `u8` values of a reader. |
1582 | /// | |
1583 | /// This struct is generally created by calling [`bytes()`][bytes] on a reader. | |
1584 | /// Please see the documentation of `bytes()` for more details. | |
1a4d82fc | 1585 | /// |
c1a9b12d | 1586 | /// [bytes]: trait.Read.html#method.bytes |
c34b1796 | 1587 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
1588 | pub struct Bytes<R> { |
1589 | inner: R, | |
1a4d82fc JJ |
1590 | } |
1591 | ||
c34b1796 | 1592 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
1593 | impl<R: Read> Iterator for Bytes<R> { |
1594 | type Item = Result<u8>; | |
1a4d82fc | 1595 | |
85aaf69f | 1596 | fn next(&mut self) -> Option<Result<u8>> { |
5bcae85e | 1597 | read_one_byte(&mut self.inner) |
85aaf69f | 1598 | } |
1a4d82fc JJ |
1599 | } |
1600 | ||
c1a9b12d | 1601 | /// An iterator over the `char`s of a reader. |
1a4d82fc | 1602 | /// |
c1a9b12d SL |
1603 | /// This struct is generally created by calling [`chars()`][chars] on a reader. |
1604 | /// Please see the documentation of `chars()` for more details. | |
1605 | /// | |
1606 | /// [chars]: trait.Read.html#method.chars | |
e9174d1e SL |
1607 | #[unstable(feature = "io", reason = "awaiting stability of Read::chars", |
1608 | issue = "27802")] | |
85aaf69f SL |
1609 | pub struct Chars<R> { |
1610 | inner: R, | |
1a4d82fc JJ |
1611 | } |
1612 | ||
85aaf69f SL |
1613 | /// An enumeration of possible errors that can be generated from the `Chars` |
1614 | /// adapter. | |
c34b1796 | 1615 | #[derive(Debug)] |
e9174d1e SL |
1616 | #[unstable(feature = "io", reason = "awaiting stability of Read::chars", |
1617 | issue = "27802")] | |
85aaf69f SL |
1618 | pub enum CharsError { |
1619 | /// Variant representing that the underlying stream was read successfully | |
1620 | /// but it did not contain valid utf8 data. | |
1621 | NotUtf8, | |
1a4d82fc | 1622 | |
85aaf69f SL |
1623 | /// Variant representing that an I/O error occurred. |
1624 | Other(Error), | |
1a4d82fc JJ |
1625 | } |
1626 | ||
e9174d1e SL |
1627 | #[unstable(feature = "io", reason = "awaiting stability of Read::chars", |
1628 | issue = "27802")] | |
85aaf69f SL |
1629 | impl<R: Read> Iterator for Chars<R> { |
1630 | type Item = result::Result<char, CharsError>; | |
1a4d82fc | 1631 | |
85aaf69f | 1632 | fn next(&mut self) -> Option<result::Result<char, CharsError>> { |
5bcae85e SL |
1633 | let first_byte = match read_one_byte(&mut self.inner) { |
1634 | None => return None, | |
1635 | Some(Ok(b)) => b, | |
1636 | Some(Err(e)) => return Some(Err(CharsError::Other(e))), | |
85aaf69f SL |
1637 | }; |
1638 | let width = core_str::utf8_char_width(first_byte); | |
1639 | if width == 1 { return Some(Ok(first_byte as char)) } | |
1640 | if width == 0 { return Some(Err(CharsError::NotUtf8)) } | |
1641 | let mut buf = [first_byte, 0, 0, 0]; | |
1642 | { | |
1643 | let mut start = 1; | |
1644 | while start < width { | |
1645 | match self.inner.read(&mut buf[start..width]) { | |
1646 | Ok(0) => return Some(Err(CharsError::NotUtf8)), | |
1647 | Ok(n) => start += n, | |
5bcae85e | 1648 | Err(ref e) if e.kind() == ErrorKind::Interrupted => continue, |
85aaf69f SL |
1649 | Err(e) => return Some(Err(CharsError::Other(e))), |
1650 | } | |
1651 | } | |
1652 | } | |
1653 | Some(match str::from_utf8(&buf[..width]).ok() { | |
54a0048b | 1654 | Some(s) => Ok(s.chars().next().unwrap()), |
85aaf69f SL |
1655 | None => Err(CharsError::NotUtf8), |
1656 | }) | |
1657 | } | |
1a4d82fc JJ |
1658 | } |
1659 | ||
e9174d1e SL |
1660 | #[unstable(feature = "io", reason = "awaiting stability of Read::chars", |
1661 | issue = "27802")] | |
c34b1796 | 1662 | impl std_error::Error for CharsError { |
85aaf69f SL |
1663 | fn description(&self) -> &str { |
1664 | match *self { | |
1665 | CharsError::NotUtf8 => "invalid utf8 encoding", | |
c34b1796 | 1666 | CharsError::Other(ref e) => std_error::Error::description(e), |
85aaf69f SL |
1667 | } |
1668 | } | |
c34b1796 | 1669 | fn cause(&self) -> Option<&std_error::Error> { |
85aaf69f SL |
1670 | match *self { |
1671 | CharsError::NotUtf8 => None, | |
1672 | CharsError::Other(ref e) => e.cause(), | |
1673 | } | |
1a4d82fc JJ |
1674 | } |
1675 | } | |
1676 | ||
e9174d1e SL |
1677 | #[unstable(feature = "io", reason = "awaiting stability of Read::chars", |
1678 | issue = "27802")] | |
85aaf69f | 1679 | impl fmt::Display for CharsError { |
1a4d82fc | 1680 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
85aaf69f SL |
1681 | match *self { |
1682 | CharsError::NotUtf8 => { | |
1683 | "byte stream did not contain valid utf8".fmt(f) | |
1684 | } | |
1685 | CharsError::Other(ref e) => e.fmt(f), | |
1686 | } | |
1a4d82fc JJ |
1687 | } |
1688 | } | |
1689 | ||
85aaf69f SL |
1690 | /// An iterator over the contents of an instance of `BufRead` split on a |
1691 | /// particular byte. | |
1692 | /// | |
c1a9b12d SL |
1693 | /// This struct is generally created by calling [`split()`][split] on a |
1694 | /// `BufRead`. Please see the documentation of `split()` for more details. | |
1695 | /// | |
1696 | /// [split]: trait.BufRead.html#method.split | |
c34b1796 | 1697 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
1698 | pub struct Split<B> { |
1699 | buf: B, | |
1700 | delim: u8, | |
1701 | } | |
1a4d82fc | 1702 | |
c34b1796 | 1703 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
1704 | impl<B: BufRead> Iterator for Split<B> { |
1705 | type Item = Result<Vec<u8>>; | |
1a4d82fc | 1706 | |
85aaf69f SL |
1707 | fn next(&mut self) -> Option<Result<Vec<u8>>> { |
1708 | let mut buf = Vec::new(); | |
1709 | match self.buf.read_until(self.delim, &mut buf) { | |
c34b1796 AL |
1710 | Ok(0) => None, |
1711 | Ok(_n) => { | |
85aaf69f SL |
1712 | if buf[buf.len() - 1] == self.delim { |
1713 | buf.pop(); | |
1714 | } | |
1715 | Some(Ok(buf)) | |
1716 | } | |
1717 | Err(e) => Some(Err(e)) | |
1a4d82fc JJ |
1718 | } |
1719 | } | |
85aaf69f SL |
1720 | } |
1721 | ||
c1a9b12d | 1722 | /// An iterator over the lines of an instance of `BufRead`. |
85aaf69f | 1723 | /// |
c1a9b12d SL |
1724 | /// This struct is generally created by calling [`lines()`][lines] on a |
1725 | /// `BufRead`. Please see the documentation of `lines()` for more details. | |
1726 | /// | |
1727 | /// [lines]: trait.BufRead.html#method.lines | |
c34b1796 | 1728 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
1729 | pub struct Lines<B> { |
1730 | buf: B, | |
1731 | } | |
1732 | ||
c34b1796 | 1733 | #[stable(feature = "rust1", since = "1.0.0")] |
85aaf69f SL |
1734 | impl<B: BufRead> Iterator for Lines<B> { |
1735 | type Item = Result<String>; | |
1a4d82fc | 1736 | |
85aaf69f SL |
1737 | fn next(&mut self) -> Option<Result<String>> { |
1738 | let mut buf = String::new(); | |
1739 | match self.buf.read_line(&mut buf) { | |
c34b1796 AL |
1740 | Ok(0) => None, |
1741 | Ok(_n) => { | |
85aaf69f SL |
1742 | if buf.ends_with("\n") { |
1743 | buf.pop(); | |
e9174d1e SL |
1744 | if buf.ends_with("\r") { |
1745 | buf.pop(); | |
1746 | } | |
1a4d82fc | 1747 | } |
85aaf69f | 1748 | Some(Ok(buf)) |
1a4d82fc | 1749 | } |
85aaf69f | 1750 | Err(e) => Some(Err(e)) |
1a4d82fc JJ |
1751 | } |
1752 | } | |
85aaf69f SL |
1753 | } |
1754 | ||
1755 | #[cfg(test)] | |
1756 | mod tests { | |
85aaf69f | 1757 | use io::prelude::*; |
c34b1796 | 1758 | use io; |
85aaf69f | 1759 | use super::Cursor; |
c1a9b12d SL |
1760 | use test; |
1761 | use super::repeat; | |
1a4d82fc JJ |
1762 | |
1763 | #[test] | |
85aaf69f | 1764 | fn read_until() { |
c34b1796 | 1765 | let mut buf = Cursor::new(&b"12"[..]); |
85aaf69f | 1766 | let mut v = Vec::new(); |
c34b1796 | 1767 | assert_eq!(buf.read_until(b'3', &mut v).unwrap(), 2); |
85aaf69f SL |
1768 | assert_eq!(v, b"12"); |
1769 | ||
c34b1796 | 1770 | let mut buf = Cursor::new(&b"1233"[..]); |
85aaf69f | 1771 | let mut v = Vec::new(); |
c34b1796 | 1772 | assert_eq!(buf.read_until(b'3', &mut v).unwrap(), 3); |
85aaf69f SL |
1773 | assert_eq!(v, b"123"); |
1774 | v.truncate(0); | |
c34b1796 | 1775 | assert_eq!(buf.read_until(b'3', &mut v).unwrap(), 1); |
85aaf69f SL |
1776 | assert_eq!(v, b"3"); |
1777 | v.truncate(0); | |
c34b1796 | 1778 | assert_eq!(buf.read_until(b'3', &mut v).unwrap(), 0); |
85aaf69f | 1779 | assert_eq!(v, []); |
1a4d82fc JJ |
1780 | } |
1781 | ||
1782 | #[test] | |
85aaf69f | 1783 | fn split() { |
c34b1796 | 1784 | let buf = Cursor::new(&b"12"[..]); |
85aaf69f | 1785 | let mut s = buf.split(b'3'); |
c34b1796 AL |
1786 | assert_eq!(s.next().unwrap().unwrap(), vec![b'1', b'2']); |
1787 | assert!(s.next().is_none()); | |
1a4d82fc | 1788 | |
c34b1796 | 1789 | let buf = Cursor::new(&b"1233"[..]); |
85aaf69f | 1790 | let mut s = buf.split(b'3'); |
c34b1796 AL |
1791 | assert_eq!(s.next().unwrap().unwrap(), vec![b'1', b'2']); |
1792 | assert_eq!(s.next().unwrap().unwrap(), vec![]); | |
1793 | assert!(s.next().is_none()); | |
85aaf69f | 1794 | } |
1a4d82fc | 1795 | |
85aaf69f SL |
1796 | #[test] |
1797 | fn read_line() { | |
c34b1796 | 1798 | let mut buf = Cursor::new(&b"12"[..]); |
85aaf69f | 1799 | let mut v = String::new(); |
c34b1796 | 1800 | assert_eq!(buf.read_line(&mut v).unwrap(), 2); |
85aaf69f SL |
1801 | assert_eq!(v, "12"); |
1802 | ||
c34b1796 | 1803 | let mut buf = Cursor::new(&b"12\n\n"[..]); |
85aaf69f | 1804 | let mut v = String::new(); |
c34b1796 | 1805 | assert_eq!(buf.read_line(&mut v).unwrap(), 3); |
85aaf69f SL |
1806 | assert_eq!(v, "12\n"); |
1807 | v.truncate(0); | |
c34b1796 | 1808 | assert_eq!(buf.read_line(&mut v).unwrap(), 1); |
85aaf69f SL |
1809 | assert_eq!(v, "\n"); |
1810 | v.truncate(0); | |
c34b1796 | 1811 | assert_eq!(buf.read_line(&mut v).unwrap(), 0); |
85aaf69f SL |
1812 | assert_eq!(v, ""); |
1813 | } | |
1a4d82fc | 1814 | |
85aaf69f SL |
1815 | #[test] |
1816 | fn lines() { | |
e9174d1e | 1817 | let buf = Cursor::new(&b"12\r"[..]); |
85aaf69f | 1818 | let mut s = buf.lines(); |
e9174d1e | 1819 | assert_eq!(s.next().unwrap().unwrap(), "12\r".to_string()); |
c34b1796 | 1820 | assert!(s.next().is_none()); |
1a4d82fc | 1821 | |
e9174d1e | 1822 | let buf = Cursor::new(&b"12\r\n\n"[..]); |
85aaf69f | 1823 | let mut s = buf.lines(); |
c34b1796 AL |
1824 | assert_eq!(s.next().unwrap().unwrap(), "12".to_string()); |
1825 | assert_eq!(s.next().unwrap().unwrap(), "".to_string()); | |
1826 | assert!(s.next().is_none()); | |
1a4d82fc JJ |
1827 | } |
1828 | ||
1829 | #[test] | |
85aaf69f | 1830 | fn read_to_end() { |
c34b1796 | 1831 | let mut c = Cursor::new(&b""[..]); |
85aaf69f | 1832 | let mut v = Vec::new(); |
c34b1796 | 1833 | assert_eq!(c.read_to_end(&mut v).unwrap(), 0); |
85aaf69f SL |
1834 | assert_eq!(v, []); |
1835 | ||
c34b1796 | 1836 | let mut c = Cursor::new(&b"1"[..]); |
85aaf69f | 1837 | let mut v = Vec::new(); |
c34b1796 | 1838 | assert_eq!(c.read_to_end(&mut v).unwrap(), 1); |
85aaf69f | 1839 | assert_eq!(v, b"1"); |
c1a9b12d SL |
1840 | |
1841 | let cap = 1024 * 1024; | |
1842 | let data = (0..cap).map(|i| (i / 3) as u8).collect::<Vec<_>>(); | |
1843 | let mut v = Vec::new(); | |
1844 | let (a, b) = data.split_at(data.len() / 2); | |
1845 | assert_eq!(Cursor::new(a).read_to_end(&mut v).unwrap(), a.len()); | |
1846 | assert_eq!(Cursor::new(b).read_to_end(&mut v).unwrap(), b.len()); | |
1847 | assert_eq!(v, data); | |
1a4d82fc JJ |
1848 | } |
1849 | ||
85aaf69f SL |
1850 | #[test] |
1851 | fn read_to_string() { | |
c34b1796 | 1852 | let mut c = Cursor::new(&b""[..]); |
85aaf69f | 1853 | let mut v = String::new(); |
c34b1796 | 1854 | assert_eq!(c.read_to_string(&mut v).unwrap(), 0); |
85aaf69f SL |
1855 | assert_eq!(v, ""); |
1856 | ||
c34b1796 | 1857 | let mut c = Cursor::new(&b"1"[..]); |
85aaf69f | 1858 | let mut v = String::new(); |
c34b1796 | 1859 | assert_eq!(c.read_to_string(&mut v).unwrap(), 1); |
85aaf69f SL |
1860 | assert_eq!(v, "1"); |
1861 | ||
c34b1796 | 1862 | let mut c = Cursor::new(&b"\xff"[..]); |
85aaf69f SL |
1863 | let mut v = String::new(); |
1864 | assert!(c.read_to_string(&mut v).is_err()); | |
1a4d82fc | 1865 | } |
c34b1796 | 1866 | |
e9174d1e SL |
1867 | #[test] |
1868 | fn read_exact() { | |
1869 | let mut buf = [0; 4]; | |
1870 | ||
1871 | let mut c = Cursor::new(&b""[..]); | |
1872 | assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), | |
92a42be0 | 1873 | io::ErrorKind::UnexpectedEof); |
e9174d1e SL |
1874 | |
1875 | let mut c = Cursor::new(&b"123"[..]).chain(Cursor::new(&b"456789"[..])); | |
1876 | c.read_exact(&mut buf).unwrap(); | |
1877 | assert_eq!(&buf, b"1234"); | |
1878 | c.read_exact(&mut buf).unwrap(); | |
1879 | assert_eq!(&buf, b"5678"); | |
1880 | assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), | |
92a42be0 | 1881 | io::ErrorKind::UnexpectedEof); |
e9174d1e SL |
1882 | } |
1883 | ||
1884 | #[test] | |
1885 | fn read_exact_slice() { | |
1886 | let mut buf = [0; 4]; | |
1887 | ||
1888 | let mut c = &b""[..]; | |
1889 | assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), | |
92a42be0 | 1890 | io::ErrorKind::UnexpectedEof); |
e9174d1e SL |
1891 | |
1892 | let mut c = &b"123"[..]; | |
1893 | assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), | |
92a42be0 | 1894 | io::ErrorKind::UnexpectedEof); |
e9174d1e SL |
1895 | // make sure the optimized (early returning) method is being used |
1896 | assert_eq!(&buf, &[0; 4]); | |
1897 | ||
1898 | let mut c = &b"1234"[..]; | |
1899 | c.read_exact(&mut buf).unwrap(); | |
1900 | assert_eq!(&buf, b"1234"); | |
1901 | ||
1902 | let mut c = &b"56789"[..]; | |
1903 | c.read_exact(&mut buf).unwrap(); | |
1904 | assert_eq!(&buf, b"5678"); | |
1905 | assert_eq!(c, b"9"); | |
1906 | } | |
1907 | ||
c34b1796 AL |
1908 | #[test] |
1909 | fn take_eof() { | |
1910 | struct R; | |
1911 | ||
1912 | impl Read for R { | |
1913 | fn read(&mut self, _: &mut [u8]) -> io::Result<usize> { | |
1914 | Err(io::Error::new(io::ErrorKind::Other, "")) | |
1915 | } | |
1916 | } | |
a7813a04 XL |
1917 | impl BufRead for R { |
1918 | fn fill_buf(&mut self) -> io::Result<&[u8]> { | |
1919 | Err(io::Error::new(io::ErrorKind::Other, "")) | |
1920 | } | |
1921 | fn consume(&mut self, _amt: usize) { } | |
1922 | } | |
c34b1796 AL |
1923 | |
1924 | let mut buf = [0; 1]; | |
1925 | assert_eq!(0, R.take(0).read(&mut buf).unwrap()); | |
a7813a04 | 1926 | assert_eq!(b"", R.take(0).fill_buf().unwrap()); |
c34b1796 | 1927 | } |
c1a9b12d | 1928 | |
54a0048b SL |
1929 | fn cmp_bufread<Br1: BufRead, Br2: BufRead>(mut br1: Br1, mut br2: Br2, exp: &[u8]) { |
1930 | let mut cat = Vec::new(); | |
1931 | loop { | |
1932 | let consume = { | |
1933 | let buf1 = br1.fill_buf().unwrap(); | |
1934 | let buf2 = br2.fill_buf().unwrap(); | |
1935 | let minlen = if buf1.len() < buf2.len() { buf1.len() } else { buf2.len() }; | |
1936 | assert_eq!(buf1[..minlen], buf2[..minlen]); | |
1937 | cat.extend_from_slice(&buf1[..minlen]); | |
1938 | minlen | |
1939 | }; | |
1940 | if consume == 0 { | |
1941 | break; | |
1942 | } | |
1943 | br1.consume(consume); | |
1944 | br2.consume(consume); | |
1945 | } | |
1946 | assert_eq!(br1.fill_buf().unwrap().len(), 0); | |
1947 | assert_eq!(br2.fill_buf().unwrap().len(), 0); | |
1948 | assert_eq!(&cat[..], &exp[..]) | |
1949 | } | |
1950 | ||
1951 | #[test] | |
1952 | fn chain_bufread() { | |
1953 | let testdata = b"ABCDEFGHIJKL"; | |
1954 | let chain1 = (&testdata[..3]).chain(&testdata[3..6]) | |
1955 | .chain(&testdata[6..9]) | |
1956 | .chain(&testdata[9..]); | |
1957 | let chain2 = (&testdata[..4]).chain(&testdata[4..8]) | |
1958 | .chain(&testdata[8..]); | |
1959 | cmp_bufread(chain1, chain2, &testdata[..]); | |
1960 | } | |
1961 | ||
c1a9b12d SL |
1962 | #[bench] |
1963 | fn bench_read_to_end(b: &mut test::Bencher) { | |
1964 | b.iter(|| { | |
1965 | let mut lr = repeat(1).take(10000000); | |
1966 | let mut vec = Vec::with_capacity(1024); | |
9cc50fc6 | 1967 | super::read_to_end(&mut lr, &mut vec) |
c1a9b12d SL |
1968 | }); |
1969 | } | |
1a4d82fc | 1970 | } |