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2023-03-11read_buf_exact: on error, all read bytes are appended to the bufferTomasz Miąsko-2/+16
Guarantee that when `read_buf_exact` returns, all bytes read will be appended to the buffer. Including the case when the operations fails. The motivating use case are operations on a non-blocking reader. When `read_buf_exact` fails with `ErrorKind::WouldBlock` error, the operation can be resumed at a later time.
2023-02-08std: add tracking issue for `RawOsError`joboet-1/+1
2023-01-31std: add type alias for raw OS errorsjoboet-0/+2
Implement rust-lang/libs-team#173.
2023-01-01Document a way to limit read_line lengthKornel-2/+3
2023-01-01Document read_line gotchaKornel-2/+5
2022-10-24Fix grammar in docs for std::io::ReadJesse Ruderman-2/+2
2022-10-15Add `IsTerminal` trait to determine if a descriptor or handle is a terminalJosh Triplett-0/+2
The UNIX and WASI implementations use `isatty`. The Windows implementation uses the same logic the `atty` crate uses, including the hack needed to detect msys terminals. Implement this trait for `File` and for `Stdin`/`Stdout`/`Stderr` and their locked counterparts on all platforms. On UNIX and WASI, implement it for `BorrowedFd`/`OwnedFd`. On Windows, implement it for `BorrowedHandle`/`OwnedHandle`. Based on https://github.com/rust-lang/rust/pull/91121 Co-authored-by: Matt Wilkinson <mattwilki17@gmail.com>
2022-10-07Make tests capture the error printed by a Result returnDavid Tolnay-0/+1
2022-09-26replace stabilization placeholdersPietro Albini-1/+1
2022-08-28Stabilize `std::io::read_to_string`Noah Lev-3/+1
2022-08-28Rollup merge of #100520 - jakubdabek:patch-1, r=thomccMatthias Krüger-1/+6
Add mention of `BufReader` in `Read::bytes` docs There is a general paragraph about `BufRead` in the `Read` trait's docs, however using `bytes` without `BufRead` *always* has a large impact, due to reads of size 1. `@rustbot` label +A-docs
2022-08-18Address reviewer commentsNick Cameron-8/+8
Signed-off-by: Nick Cameron <nrc@ncameron.org>
2022-08-14Add mention of `BufReader` in `Read::bytes` docsJakub Dąbek-1/+6
2022-08-05non-linux platformsNick Cameron-11/+10
Signed-off-by: Nick Cameron <nrc@ncameron.org>
2022-08-04std::io: migrate ReadBuf to BorrowBuf/BorrowCursorNick Cameron-40/+43
Signed-off-by: Nick Cameron <nrc@ncameron.org>
2022-07-26Rollup merge of #99716 - sourcelliu:iomut, r=Mark-SimulacrumMatthias Krüger-4/+4
remove useless mut from examples remove useless mut from examples
2022-07-25Rollup merge of #95040 - frank-king:fix/94981, r=Mark-SimulacrumYuki Okushi-0/+1
protect `std::io::Take::limit` from overflow in `read` Resolves #94981
2022-07-25remove useless mut from examplessourcelliu-4/+4
2022-06-21update ioslice docs to use shared slicesConrad Ludgate-6/+6
2022-06-20Rollup merge of #94855 - m-ou-se:advance-slice-panic-docs, r=kennytmDylan DPC-16/+34
Panic when advance_slices()'ing too far and update docs. This updates advance_slices() to panic when advancing too far, like advance() already does. And updates the docs to say so. See https://github.com/rust-lang/rust/issues/62726#issuecomment-1065253213
2022-05-29protect `std::io::Take::limit` from overflow in `read`Frank King-0/+1
fixs #94981
2022-05-09Use Rust 2021 prelude in std itself.Mara Bos-1/+0
2022-03-16changed wordingDylan DPC-1/+2
2022-03-15Improve the explanation about the behaviour of read_linezed.zy-1/+1
2022-03-11Update advance and advance_slices docs.Mara Bos-14/+28
2022-03-11Panic when advance_slices()'ing too far.Mara Bos-2/+6
2022-03-10Use implicit capture syntax in format_argsT-O-R-U-S-6/+6
This updates the standard library's documentation to use the new syntax. The documentation is worthwhile to update as it should be more idiomatic (particularly for features like this, which are nice for users to get acquainted with). The general codebase is likely more hassle than benefit to update: it'll hurt git blame, and generally updates can be done by folks updating the code if (and when) that makes things more readable with the new format. A few places in the compiler and library code are updated (mostly just due to already having been done when this commit was first authored).
2022-02-13Make default stdio lock() return 'static handlesMark Rousskov-2/+0
This also deletes the unstable API surface area previously added to expose this functionality on new methods rather than built into the current set.
2022-02-04Hide Repr details from io::Error, and rework `io::Error::new_const`.Thom Chiovoloni-7/+11
2022-01-13Remove `&mut` from `io::read_to_string` signatureNoah Lev-2/+2
`@m-ou-se` [realized][1] that because `Read` is implemented for `&mut impl Read`, there's no need to take `&mut` in `io::read_to_string`. Removing the `&mut` from the signature allows users to remove the `&mut` from their calls (and thus pass an owned reader) if they don't use the reader later. [1]: https://github.com/rust-lang/rust/issues/80218#issuecomment-874322129
2022-01-09Compute most of Public/Exported access level in rustc_resolveLamb-17/+10
Mak DefId to AccessLevel map in resolve for export hir_id to accesslevel in resolve and applied in privacy using local def id removing tracing probes making function not recursive and adding comments Move most of Exported/Public res to rustc_resolve moving public/export res to resolve fix missing stability attributes in core, std and alloc move code to access_levels.rs return for some kinds instead of going through them Export correctness, macro changes, comments add comment for import binding add comment for import binding renmae to access level visitor, remove comments, move fn as closure, remove new_key fmt fix rebase fix rebase fmt fmt fix: move macro def to rustc_resolve fix: reachable AccessLevel for enum variants fmt fix: missing stability attributes for other architectures allow unreachable pub in rustfmt fix: missing impl access level + renaming export to reexport Missing impl access level was found thanks to a test in clippy
2021-12-14Fix a bunch of typosFrank Steffahn-2/+2
2021-11-02formattingDrMeepster-1/+1
2021-11-02fix change clobbered by rebaseDrMeepster-7/+23
2021-11-02implement review suggestionsDrMeepster-3/+13
2021-11-02more efficent File::read_buf impl for windows and unixDrMeepster-3/+10
2021-11-02read_bufDrMeepster-133/+103
2021-10-31Rollup merge of #90430 - jkugelman:must-use-std-a-through-n, r=joshtriplettMatthias Krüger-0/+3
Add #[must_use] to remaining std functions (A-N) I've run out of compelling reasons to group functions together across crates so I'm just going to go module-by-module. This is half of the remaining items from the `std` crate, from A-N. I added these functions myself. Clippy predictably ignored the `mut` ones, but I don't know why the rest weren't flagged. Check them closely, please? Maybe I overlooked good reasons. ```rust std::backtrace::Backtrace const fn disabled() -> Backtrace; std::backtrace::Backtrace<'a> fn frames(&'a self) -> &'a [BacktraceFrame]; std::collections::hash_map::RawOccupiedEntryMut<'a, K, V> fn key_mut(&mut self) -> &mut K; std::collections::hash_map::RawOccupiedEntryMut<'a, K, V> fn get_mut(&mut self) -> &mut V; std::collections::hash_map::RawOccupiedEntryMut<'a, K, V> fn get_key_value(&mut self) -> (&K, &V); std::collections::hash_map::RawOccupiedEntryMut<'a, K, V> fn get_key_value_mut(&mut self) -> (&mut K, &mut V); std::env fn var_os<K: AsRef<OsStr>>(key: K) -> Option<OsString>; std::env fn split_paths<T: AsRef<OsStr> + ?Sized>(unparsed: &T) -> SplitPaths<'_>; std::io::Error fn get_mut(&mut self) -> Option<&mut (dyn error::Error + Send + Sync + 'static)>; ``` Parent issue: #89692 r? `@joshtriplett`
2021-10-31Rollup merge of #89068 - bjorn3:restructure_rt2, r=joshtriplettMatthias Krüger-3/+1
Restructure std::rt (part 2) A couple more cleanups on top of https://github.com/rust-lang/rust/pull/89011 Blocked on #89011
2021-10-30Add #[must_use] to remaining std functions (A-N)John Kugelman-0/+3
2021-10-10Add #[must_use] to core and std constructorsJohn Kugelman-0/+1
2021-10-07Optimize File::read_to_end and read_to_stringJohn Kugelman-30/+41
Reading a file into an empty vector or string buffer can incur unnecessary `read` syscalls and memory re-allocations as the buffer "warms up" and grows to its final size. This is perhaps a necessary evil with generic readers, but files can be read in smarter by checking the file size and reserving that much capacity. `std::fs::read` and `read_to_string` already perform this optimization: they open the file, reads its metadata, and call `with_capacity` with the file size. This ensures that the buffer does not need to be resized and an initial string of small `read` syscalls. However, if a user opens the `File` themselves and calls `file.read_to_end` or `file.read_to_string` they do not get this optimization. ```rust let mut buf = Vec::new(); file.read_to_end(&mut buf)?; ``` I searched through this project's codebase and even here are a *lot* of examples of this. They're found all over in unit tests, which isn't a big deal, but there are also several real instances in the compiler and in Cargo. I've documented the ones I found in a comment here: https://github.com/rust-lang/rust/issues/89516#issuecomment-934423999 Most telling, the `Read` trait and the `read_to_end` method both show this exact pattern as examples of how to use readers. What this says to me is that this shouldn't be solved by simply fixing the instances of it in this codebase. If it's here it's certain to be prevalent in the wider Rust ecosystem. To that end, this commit adds specializations of `read_to_end` and `read_to_string` directly on `File`. This way it's no longer a minor footgun to start with an empty buffer when reading a file in. A nice side effect of this change is that code that accesses a `File` as a bare `Read` constraint or via a `dyn Read` trait object will benefit. For example, this code from `compiler/rustc_serialize/src/json.rs`: ```rust pub fn from_reader(rdr: &mut dyn Read) -> Result<Json, BuilderError> { let mut contents = Vec::new(); match rdr.read_to_end(&mut contents) { ``` Related changes: - I also added specializations to `BufReader` to delegate to `self.inner`'s methods. That way it can call `File`'s optimized implementations if the inner reader is a file. - The private `std::io::append_to_string` function is now marked `unsafe`. - `File::read_to_string` being more efficient means that the performance note for `io::read_to_string` can be softened. I've added @camelid's suggested wording from: https://github.com/rust-lang/rust/issues/80218#issuecomment-936806502
2021-10-04Auto merge of #89165 - jkugelman:read-to-end-overallocation, r=joshtriplettbors-22/+31
Fix read_to_end to not grow an exact size buffer If you know how much data to expect and use `Vec::with_capacity` to pre-allocate a buffer of that capacity, `Read::read_to_end` will still double its capacity. It needs some space to perform a read, even though that read ends up returning `0`. It's a bummer to carefully pre-allocate 1GB to read a 1GB file into memory and end up using 2GB. This fixes that behavior by special casing a full buffer and reading into a small "probe" buffer instead. If that read returns `0` then it's confirmed that the buffer was the perfect size. If it doesn't, the probe buffer is appended to the normal buffer and the read loop continues. Fixing this allows several workarounds in the standard library to be removed: - `Take` no longer needs to override `Read::read_to_end`. - The `reservation_size` callback that allowed `Take` to inhibit the previous over-allocation behavior isn't needed. - `fs::read` doesn't need to reserve an extra byte in `initial_buffer_size`. Curiously, there was a unit test that specifically checked that `Read::read_to_end` *does* over-allocate. I removed that test, too.
2021-10-03Re-export io::stdio::cleanup instead of wrap itbjorn3-3/+1
2021-09-25Auto merge of #88343 - steffahn:fix_code_spacing, r=jyn514bors-9/+10
Fix spacing of links in inline code. Similar to #80733, but the focus is different. This PR eliminates all occurrences of pieced-together inline code blocks like [`Box`]`<`[`Option`]`<T>>` and replaces them with good-looking ones (using HTML-syntax), like <code>[Box]<[Option]\<T>></code>. As far as I can tell, I should’ve found all of these in the standard library (regex search with `` r"`\]`|`\[`" ``) \[except for in `core::convert` where I’ve noticed other things in the docs that I want to fix in a separate PR]. In particular, unlike #80733, I’ve added almost no new instance of inline code that’s broken up into multiple links (or some link and some link-free part). I also added tooltips (the stuff in quotes for the markdown link listings) in places that caught my eye, but that’s by no means systematic, just opportunistic. [Box]: https://doc.rust-lang.org/std/boxed/struct.Box.html "Box" [`Box`]: https://doc.rust-lang.org/std/boxed/struct.Box.html "Box" [Option]: https://doc.rust-lang.org/std/option/enum.Option.html "Option" [`Option`]: https://doc.rust-lang.org/std/option/enum.Option.html "Option" Context: I got annoyed by repeatedly running into new misformatted inline code while reading the standard library docs. I know that once issue #83997 (and/or related ones) are resolved, these changes become somewhat obsolete, but I fail to notice much progress on that end right now. r? `@jyn514`
2021-09-25Apply 16 commits (squashed)Frank Steffahn-9/+10
---------- Fix spacing for links inside code blocks, and improve link tooltips in alloc::fmt ---------- Fix spacing for links inside code blocks, and improve link tooltips in alloc::{rc, sync} ---------- Fix spacing for links inside code blocks, and improve link tooltips in alloc::string ---------- Fix spacing for links inside code blocks in alloc::vec ---------- Fix spacing for links inside code blocks in core::option ---------- Fix spacing for links inside code blocks, and improve a few link tooltips in core::result ---------- Fix spacing for links inside code blocks in core::{iter::{self, iterator}, stream::stream, poll} ---------- Fix spacing for links inside code blocks, and improve a few link tooltips in std::{fs, path} ---------- Fix spacing for links inside code blocks in std::{collections, time} ---------- Fix spacing for links inside code blocks in and make formatting of `&str`-like types consistent in std::ffi::{c_str, os_str} ---------- Fix spacing for links inside code blocks, and improve link tooltips in std::ffi ---------- Fix spacing for links inside code blocks, and improve a few link tooltips in std::{io::{self, buffered::{bufreader, bufwriter}, cursor, util}, net::{self, addr}} ---------- Fix typo in link to `into` for `OsString` docs ---------- Remove tooltips that will probably become redundant in the future ---------- Apply suggestions from code review Replacing `…std/primitive.reference.html` paths with just `reference` Co-authored-by: Joshua Nelson <github@jyn.dev> ---------- Also replace `…std/primitive.reference.html` paths with just `reference` in `core::pin`
2021-09-22Fix read_to_end to not grow an exact size bufferJohn Kugelman-22/+31
If you know how much data to expect and use `Vec::with_capacity` to pre-allocate a buffer of that capacity, `Read::read_to_end` will still double its capacity. It needs some space to perform a read, even though that read ends up returning `0`. It's a bummer to carefully pre-allocate 1GB to read a 1GB file into memory and end up using 2GB. This fixes that behavior by special casing a full buffer and reading into a small "probe" buffer instead. If that read returns `0` then it's confirmed that the buffer was the perfect size. If it doesn't, the probe buffer is appended to the normal buffer and the read loop continues. Fixing this allows several workarounds in the standard library to be removed: - `Take` no longer needs to override `Read::read_to_end`. - The `reservation_size` callback that allowed `Take` to inhibit the previous over-allocation behavior isn't needed. - `fs::read` doesn't need to reserve an extra byte in `initial_buffer_size`. Curiously, there was a unit test that specifically checked that `Read::read_to_end` *does* over-allocate. I removed that test, too.
2021-09-05Tweak `write_fmt` doc.kraktus-1/+1
Previous version wrongly used `but` while the two parts of the sentence are not contradicting but completing with each other.
2021-08-24Stabilise BufWriter::into_partsIan Jackson-1/+1
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
2021-08-22Fix typos “an”→“a” and a few different ones that appeared in the ↵Frank Steffahn-1/+1
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