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2022-09-04Auto merge of #100576 - joboet:movable_const_remutex, r=Mark-Simulacrumbors-25/+16
Make `ReentrantMutex` movable and `const` As `MovableMutex` is now `const`, it can be used to simplify the implementation and interface of the internal reentrant mutex type. Consequently, the standard error stream does not need to be wrapped in `OnceLock` and `OnceLock::get_or_init_pin()` can be removed.
2022-09-03std: make `ReentrantMutex` movable and `const`; simplify `Stdout` initializationjoboet-25/+16
2022-09-01Update outdated comment about output capturing in print_to.Mara Bos-4/+4
2022-08-29Rollup merge of #100819 - WaffleLapkin:use_ptr_byte_methods, r=scottmcmDylan DPC-2/+2
Make use of `[wrapping_]byte_{add,sub}` These new methods trivially replace old `.cast().wrapping_offset().cast()` & similar code. Note that [`arith_offset`](https://doc.rust-lang.org/std/intrinsics/fn.arith_offset.html) and `wrapping_offset` are the same thing. r? ``@scottmcm`` _split off from #100746_
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
2022-08-28Rollup merge of #100296 - BlackHoleFox:os-error-aliases, r=thomccMatthias Krüger-0/+2
Add standard C error function aliases to last_os_error This aids the discoverability of `io::Error::last_os_error()` by linking to commonly used error number functions from C/C++. I've seen a few people not realize this exists, so hopefully this helps draw attention to the API to encourage using it over integer error codes.
2022-08-28Rollup merge of #97015 - nrc:read-buf-cursor, r=Mark-SimulacrumMatthias Krüger-379/+438
std::io: migrate ReadBuf to BorrowBuf/BorrowCursor This PR replaces `ReadBuf` (used by the `Read::read_buf` family of methods) with `BorrowBuf` and `BorrowCursor`. The general idea is to split `ReadBuf` because its API is large and confusing. `BorrowBuf` represents a borrowed buffer which is mostly read-only and (other than for construction) deals only with filled vs unfilled segments. a `BorrowCursor` is a mostly write-only view of the unfilled part of a `BorrowBuf` which distinguishes between initialized and uninitialized segments. For `Read::read_buf`, the caller would create a `BorrowBuf`, then pass a `BorrowCursor` to `read_buf`. In addition to the major API split, I've made the following smaller changes: * Removed some methods entirely from the API (mostly the functionality can be replicated with two calls rather than a single one) * Unified naming, e.g., by replacing initialized with init and assume_init with set_init * Added an easy way to get the number of bytes written to a cursor (`written` method) As well as simplifying the API (IMO), this approach has the following advantages: * Since we pass the cursor by value, we remove the 'unsoundness footgun' where a malicious `read_buf` could swap out the `ReadBuf`. * Since `read_buf` cannot write into the filled part of the buffer, we prevent the filled part shrinking or changing which could cause underflow for the caller or unexpected behaviour. ## Outline ```rust pub struct BorrowBuf<'a> impl Debug for BorrowBuf<'_> impl<'a> From<&'a mut [u8]> for BorrowBuf<'a> impl<'a> From<&'a mut [MaybeUninit<u8>]> for BorrowBuf<'a> impl<'a> BorrowBuf<'a> { pub fn capacity(&self) -> usize pub fn len(&self) -> usize pub fn init_len(&self) -> usize pub fn filled(&self) -> &[u8] pub fn unfilled<'this>(&'this mut self) -> BorrowCursor<'this, 'a> pub fn clear(&mut self) -> &mut Self pub unsafe fn set_init(&mut self, n: usize) -> &mut Self } pub struct BorrowCursor<'buf, 'data> impl<'buf, 'data> BorrowCursor<'buf, 'data> { pub fn clone<'this>(&'this mut self) -> BorrowCursor<'this, 'data> pub fn capacity(&self) -> usize pub fn written(&self) -> usize pub fn init_ref(&self) -> &[u8] pub fn init_mut(&mut self) -> &mut [u8] pub fn uninit_mut(&mut self) -> &mut [MaybeUninit<u8>] pub unsafe fn as_mut(&mut self) -> &mut [MaybeUninit<u8>] pub unsafe fn advance(&mut self, n: usize) -> &mut Self pub fn ensure_init(&mut self) -> &mut Self pub unsafe fn set_init(&mut self, n: usize) -> &mut Self pub fn append(&mut self, buf: &[u8]) } ``` ## TODO * ~~Migrate non-unix libs and tests~~ * ~~Naming~~ * ~~`BorrowBuf` or `BorrowedBuf` or `SliceBuf`? (We might want an owned equivalent for the async IO traits)~~ * ~~Should we rename the `readbuf` module? We might keep the name indicate it includes both the buf and cursor variations and someday the owned version too. Or we could change it. It is not publicly exposed, so it is not that important~~. * ~~`read_buf` method: we read into the cursor now, so the `_buf` suffix is a bit weird.~~ * ~~Documentation~~ * Tests are incomplete (I adjusted existing tests, but did not add new ones). cc https://github.com/rust-lang/rust/issues/78485, https://github.com/rust-lang/rust/issues/94741 supersedes: https://github.com/rust-lang/rust/pull/95770, https://github.com/rust-lang/rust/pull/93359 fixes #93305
2022-08-23Make use of `[wrapping_]byte_{add,sub}`Maybe Waffle-2/+2
...replacing `.cast().wrapping_offset().cast()` & similar code.
2022-08-22Move error trait into coreJane Losare-Lusby-0/+9
2022-08-18make many std tests work in MiriRalf Jung-1/+2
2022-08-18Address reviewer commentsNick Cameron-45/+64
Signed-off-by: Nick Cameron <nrc@ncameron.org>
2022-08-14Add mention of `BufReader` in `Read::bytes` docsJakub Dąbek-1/+6
2022-08-08Add standard C error function aliasesBlackHoleFox-0/+2
Aids the discoverability of `io::Error::last_os_error()` by linking to commonly used error number functions from C/C++.
2022-08-05non-linux platformsNick Cameron-108/+177
Signed-off-by: Nick Cameron <nrc@ncameron.org>
2022-08-04Add some docs for BorrowBufNick Cameron-24/+60
Signed-off-by: Nick Cameron <nrc@ncameron.org>
2022-08-04std::io: migrate ReadBuf to BorrowBuf/BorrowCursorNick Cameron-376/+311
Signed-off-by: Nick Cameron <nrc@ncameron.org>
2022-07-27Auto merge of #98748 - saethlin:optimize-bufreader, r=Mark-Simulacrumbors-53/+134
Remove some redundant checks from BufReader The implementation of BufReader contains a lot of redundant checks. While any one of these checks is not particularly expensive to execute, especially when taken together they dramatically inhibit LLVM's ability to make subsequent optimizations by confusing data flow increasing the code size of anything that uses BufReader. In particular, these changes have a ~2x increase on the benchmark that this adds a `black_box` to. I'm adding that `black_box` here just in case LLVM gets clever enough to remove the reads entirely. Right now it can't, but these optimizations are really setting it up to do so. We get this optimization by factoring all the actual buffer management and bounds-checking logic into a new module inside `bufreader` with a new `Buffer` type. This makes it much easier to ensure that we have correctly encapsulated the management of the region of the buffer that we have read bytes into, and it lets us provide a new faster way to do small reads. `Buffer::consume_with` lets a caller do a read from the buffer with a single bounds check, instead of the double-check that's required to use `buffer` + `consume`. Unfortunately I'm not aware of a lot of open-source usage of `BufReader` in perf-critical environments. Some time ago I tweaked this code because I saw `BufReader` in a profile at work, and I contributed some benchmarks to the `bincode` crate which exercise `BufReader::buffer`. These changes appear to help those benchmarks at little, but all these sorts of benchmarks are kind of fragile so I'm wary of quoting anything specific.
2022-07-26Add Buffer::consume_with to enable direct buffer access with one checkBen Kimock-3/+18
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/+20
protect `std::io::Take::limit` from overflow in `read` Resolves #94981
2022-07-25remove useless mut from examplessourcelliu-4/+4
2022-07-24Rename and document the new BufReader internalsBen Kimock-29/+33
2022-07-24Allow Buffer methods to inlineBen Kimock-0/+9
2022-07-24Remove some redundant checks from BufReaderBen Kimock-53/+106
The implementation of BufReader contains a lot of redundant checks. While any one of these checks is not particularly expensive to execute, especially when taken together they dramatically inhibit LLVM's ability to make subsequent optimizations.
2022-07-23Remove `mut`Phosra-1/+1
2022-07-16Rollup merge of #98387 - NobodyXu:feature/std_io_Error_try_downgrade_inner, ↵Yuki Okushi-1/+127
r=yaahc Add new unstable API `downcast` to `std::io::Error` https://github.com/rust-lang/libs-team/issues/57 Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>
2022-07-15Apply suggestions from code reviewJane Losare-Lusby-1/+1
2022-07-15Improve example of `downcast`Jiahao XU-3/+4
Co-authored-by: Jane Losare-Lusby <jlusby42@gmail.com>
2022-07-14Rename `std::io::Error::try_downcast_inner` to `downcast`Jiahao XU-11/+11
Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>
2022-07-11Add Read Impl for &StdinAïssata-0/+23
2022-07-05Add `BufRead::skip_until`William Venner-0/+84
2022-06-28Follow C-RW-VALUE in std::io::Cursor exampleMatt Fellenz-1/+1
2022-06-28Auto merge of #98324 - conradludgate:write-vectored-vec, r=Mark-Simulacrumbors-25/+149
attempt to optimise vectored write benchmarked: old: ``` test io::cursor::tests::bench_write_vec ... bench: 68 ns/iter (+/- 2) test io::cursor::tests::bench_write_vec_vectored ... bench: 913 ns/iter (+/- 31) ``` new: ``` test io::cursor::tests::bench_write_vec ... bench: 64 ns/iter (+/- 0) test io::cursor::tests::bench_write_vec_vectored ... bench: 747 ns/iter (+/- 27) ``` More unsafe than I wanted (and less gains) in the end, but it still does the job
2022-06-26attempt to optimise vectored writeConrad Ludgate-25/+149
2022-06-23Rollup merge of #96173 - jmaargh:jmaargh/with-capacity-doc-fix, r=Dylan-DPCMichael Goulet-4/+4
Fix documentation for `with_capacity` and `reserve` families of methods Fixes #95614 Documentation for the following methods - `with_capacity` - `with_capacity_in` - `with_capacity_and_hasher` - `reserve` - `reserve_exact` - `try_reserve` - `try_reserve_exact` was inconsistent and often not entirely correct where they existed on the following types - `Vec` - `VecDeque` - `String` - `OsString` - `PathBuf` - `BinaryHeap` - `HashSet` - `HashMap` - `BufWriter` - `LineWriter` since the allocator is allowed to allocate more than the requested capacity in all such cases, and will frequently "allocate" much more in the case of zero-sized types (I also checked `BufReader`, but there the docs appear to be accurate as it appears to actually allocate the exact capacity). Some effort was made to make the documentation more consistent between types as well.
2022-06-23Use `unwrap` instead of `unwrap_unchecked`Jiahao XU-3/+7
Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>
2022-06-22Add new unit test `test_try_downcast_inner`Jiahao XU-1/+52
Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>
2022-06-22Add new unstable API `Error::try_downgrade_inner`Jiahao XU-0/+57
Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>
2022-06-22Impl `io::error::repr_bitpacked::Repr::new`Jiahao XU-0/+9
that accepts `ErrorData<Box<Custom>>` Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>
2022-06-22Impl `io::error::repr_unpacked::Repr::new`Jiahao XU-0/+4
that accepts `ErrorData<Box<Custom>>` Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>
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-20/+38
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
2022-06-19Fix documentation for with_capacity and reserve families of methodsjmaargh-4/+4
Documentation for the following methods with_capacity with_capacity_in with_capacity_and_hasher reserve reserve_exact try_reserve try_reserve_exact was inconsistent and often not entirely correct where they existed on the following types Vec VecDeque String OsString PathBuf BinaryHeap HashSet HashMap BufWriter LineWriter since the allocator is allowed to allocate more than the requested capacity in all such cases, and will frequently "allocate" much more in the case of zero-sized types (I also checked BufReader, but there the docs appear to be accurate as it appears to actually allocate the exact capacity). Some effort was made to make the documentation more consistent between types as well. Fix with_capacity* methods for Vec Fix *reserve* methods for Vec Fix docs for *reserve* methods of VecDeque Fix docs for String::with_capacity Fix docs for *reserve* methods of String Fix docs for OsString::with_capacity Fix docs for *reserve* methods on OsString Fix docs for with_capacity* methods on HashSet Fix docs for *reserve methods of HashSet Fix docs for with_capacity* methods of HashMap Fix docs for *reserve methods on HashMap Fix expect messages about OOM in doctests Fix docs for BinaryHeap::with_capacity Fix docs for *reserve* methods of BinaryHeap Fix typos Fix docs for with_capacity on BufWriter and LineWriter Fix consistent use of `hasher` between `HashMap` and `HashSet` Fix warning in doc test Add test for capacity of vec with ZST Fix doc test error
2022-06-16Move/rename `lazy::Sync{OnceCell,Lazy}` to `sync::{Once,Lazy}Lock`Maybe Waffle-5/+4
2022-06-10Rollup merge of #97922 - paolobarbolini:no-vecdeque-extra-reserve, r=the8472Yuki Okushi-2/+0
Remove redundant calls to reserve in impl Write for VecDeque Removes the reserve calls made redundant by #95904 (as discussed in https://github.com/rust-lang/rust/pull/95632#discussion_r846850293)
2022-06-10Auto merge of #95770 - nrc:read-buf-builder, r=joshtriplettbors-7/+11
std::io: Modify some ReadBuf method signatures to return `&mut Self` This allows using `ReadBuf` in a builder-like style and to setup a `ReadBuf` and pass it to `read_buf` in a single expression, e.g., ``` // With this PR: reader.read_buf(ReadBuf::uninit(buf).assume_init(init_len))?; // Previously: let mut buf = ReadBuf::uninit(buf); buf.assume_init(init_len); reader.read_buf(&mut buf)?; ``` r? `@sfackler` cc https://github.com/rust-lang/rust/issues/78485, https://github.com/rust-lang/rust/issues/94741
2022-06-09Remove redundant calls to reserve in impl Write for VecDequePaolo Barbolini-2/+0
2022-06-09Rollup merge of #95632 - evanrichter:master, r=joshtriplettYuki Okushi-0/+48
impl Read and Write for VecDeque<u8> Implementing `Read` and `Write` for `VecDeque<u8>` fills in the VecDeque api surface where `Vec<u8>` and `Cursor<Vec<u8>>` already impl Read and Write. Not only for completeness, but VecDeque in particular is a very handy mock interface for a TCP echo service, if only it supported Read/Write. Since this PR is just an impl trait, I don't think there is a way to limit it behind a feature flag, so it's "insta-stable". Please correct me if I'm wrong here, not trying to rush stability.
2022-05-29protect `std::io::Take::limit` from overflow in `read`Frank King-0/+20
fixs #94981
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