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//! Alternative implementation of many functions found in [`std::io`], //! but suitable for blocking IO over networks. //! //! The main reason for this crate is the handling of [`ErrorKind`]`::Interrupted` in //! `std::io`. //! Except for [`std::io::Read::read`] and [`std::io::Write::write`], almost all functions //! will ignore interrupts and just retry. //! //! This crate provides alternative implementations using a similar API but allow for interrupts //! whithout losing any content. //! //! Most functions are based on buffered readers instead of plain readers to ensure that no //! content is lost on retry. //! //! [`std::io`]: https://doc.rust-lang.org/nightly/std/io/index.html //! [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html //! [`std::io::Read::read`]: https://doc.rust-lang.org/nightly/std/io/trait.Read.html#tymethod.read //! [`std::io::Write::write`]: //! https://doc.rust-lang.org/nightly/std/io/trait.Write.html#tymethod.write extern crate memchr; pub extern crate buf_redux; mod impls; mod adapt; mod iter; mod utf8; pub mod mock; use buf_redux as br; pub use adapt::{Retry, Take, Repeat, Chain, Compat}; pub use iter::{Bytes, Split, Collect}; pub use utf8::Utf8Reader; pub use std::io::{Result, Error, ErrorKind}; pub trait IoExt { fn compat(self) -> Compat<Self> where Self: Sized { Compat::new(self) } } impl<T> IoExt for T {} /// Alternative to `std::io::BufReader` pub type BufReader<R> = br::BufReader<R>; /// Copies the entire content of a buffered reader into a writer. /// /// Similar to [`std::io::copy`], this function will continuously read data from reader and /// then write it into writer in a streaming fashion until reader returns EOF. /// /// Errors /// ====== /// This function will return an error immediately if any call to [`fill_buf`] or /// [`write`] returns any kind of error. /// Instances of [`ErrorKind`]`::Interrupted` are *not* handled by this function. /// /// All bytes consumed from the buffered reader will be written to the specified writer and vice /// versa. /// It is guaranteed that no data is lost in case of error. /// /// Differences to `std::io::copy` /// ============================== /// - Does not retry on [`ErrorKind`]`::Interrupted`. /// - Uses [`BufRead`] instead of [`Read`]. /// - Does not return the number of bytes that are copied. /// /// Advantages /// ---------- /// - Allows for reliable retry on errors. /// - Function is interruptable, e.g. to allow graceful shutdown for server applications. /// - Avoids double buffering if the source already implements [`BufRead`]. /// - Allows different buffer sizes by using [`BufReader::with_capacity`]. /// /// Disadvantages /// ------------- /// The fact that it does not return the number of bytes copied stems from the fact that it cannot /// return this information in case of error. /// This would go against the goal of allowing reliable retry. /// /// [`fill_buf`]: ./trait.BufRead.html#tymethod.fill_buf /// [`write`]: ./trait.Write.html#tymethod.write /// [`Read`]: ./trait.Read.html /// [`BufRead`]: ./trait.BufRead.html /// [`BufReader::with_capacity`]: ./buf_redux_reexport/struct.BufReader.html#method.with_capacity /// [`std::io::copy`]: https://doc.rust-lang.org/nightly/std/io/fn.copy.html /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html pub fn copy<R: ?Sized, W: ?Sized>(reader: &mut R, writer: &mut W) -> Result<()> where R: BufRead, W: Write { loop { let written = { let buf = try!(reader.fill_buf()); if buf.len() == 0 { return Ok(()); } try!(writer.write(buf)) }; if written == 0 { return Err(Error::new(ErrorKind::WriteZero, "no bytes could be written")); } reader.consume(written); } } /// Copies the content of a buffered reader into a writer until a delimiter is reached. /// /// This function will continuously read data from reader and then write it into writer in a /// streaming fashion until until the delimiter or EOF is found. /// /// Errors /// ====== /// This function will return an error immediately if any call to [`fill_buf`] or /// [`write`] returns any kind of error. /// Instances of [`ErrorKind`]`::Interrupted` are *not* handled by this function. /// /// All bytes consumed from the buffered reader will be written to the specified writer and vice /// versa. /// It is guaranteed that no data is lost in case of error. /// /// [`fill_buf`]: ./trait.BufRead.html#tymethod.fill_buf /// [`write`]: ./trait.Write.html#tymethod.write /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html pub fn copy_until<R: ?Sized, W: ?Sized>(reader: &mut R, writer: &mut W, delim: u8) -> Result<()> where R: BufRead, W: Write { loop { let (found, used) = { let buf = try!(reader.fill_buf()); if buf.len() == 0 { return Err(Error::new(ErrorKind::UnexpectedEof, "Stream did not contain the delimiter")); } match memchr::memchr(delim, buf) { Some(i) => { let written = try!(writer.write(&buf[..i + 1])); (written == i + 1, written) } None => (false, try!(writer.write(buf))), } }; if used == 0 { return Err(Error::new(ErrorKind::WriteZero, "no bytes could be written")); } reader.consume(used); if found { return Ok(()); } } } /// Base trait for generic stream operations /// /// Most of these function are generalizations of functions already present in [`std::io::Read`] /// and/or [`std::io::Write`]: /// /// - `by_ref` ← [`std::io::Read::by_ref`] and [`std::io::Write::by_ref`] /// - `take` ← [`std::io::Read::take`] /// /// New methods without counterpart in `std::io` /// /// - `retry` /// /// [`std::io::Read`]: https://doc.rust-lang.org/nightly/std/io/trait.Read.html /// [`std::io::Write`]: https://doc.rust-lang.org/nightly/std/io/trait.Write.html /// [`std::io::Read::by_ref`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.by_ref /// [`std::io::Read::take`]: https://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.take /// [`std::io::Write::by_ref`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Write.html#method.by_ref pub trait Stream { /// Creates a "by reference" adaptor for this stream. /// /// This method is equivalent to [`std::io::Read::by_ref`] and [`std::io::Write::by_ref`] /// /// [`std::io::Read::by_ref`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.by_ref /// [`std::io::Write::by_ref`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Write.html#method.by_ref #[inline] fn by_ref(&mut self) -> &mut Self where Self: Sized { self } /// Creates an adapter which will limits the total number of bytes of this stream. /// /// This function returns a new stream instance of which will read write at most /// `limit` bytes, after which it will always return EOF (`Ok(0)`). Any /// errors will not count towards the number of bytes read and future /// calls to `read` or `write` may succeed. /// /// Differences to `std::io::Read::take` /// ==================================== /// This function is equivalent to [`std::io::Read::take`] except that the returned /// adapter implements [`BufReadGrow`] and [`std::io::Write`] if possible. /// /// [`BufReadGrow`]: ./trait.BufReadGrow.html /// [`std::io::Read::take`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.take /// [`std::io::Write`]: https://doc.rust-lang.org/nightly/std/io/trait.Write.html #[inline] fn take(self, limit: u64) -> Take<Self> where Self: Sized { Take::new(self, limit) } /// Transforms this stream into a stream that automatically retries on interrupts /// /// The returned adapter will behave identically to the original stream, except that it retries /// all operations automatically if an error of kind /// [`ErrorKind`]`::Interrupted` occurs. /// /// Note /// ---- /// Methods that are already expected to retry are forwarded directly to the underlying reader. /// /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html #[inline] fn retry(self) -> Retry<Self> where Self: Sized { Retry::new(self) } } impl<R: ?Sized> Stream for R {} /// Alternative to `std::io::Read` /// /// This trait is automatically implemented for all types that implement [`std::io::Read`]. /// /// Diffrerences to `std::io::Read` /// =============================== /// Methods that are just wrappers around the equivalent methods of `std::io::Read`: /// /// - `read` /// - `chain` /// /// New methods that have no counterpart in `std::io::Read`: /// /// - `buffer` /// - `repeat` /// /// Functions that were removed or moved to a different place, /// because they cannot be implemented with providing all desired guarantees: /// /// - `read_to_end` → [`BufRead::read_to_end`] /// - `read_to_string` → [`Utf8Reader::read_to_string`] /// - `read_exact` → [`BufRead::read_exact`] /// - `bytes` → [`BufRead::bytes`] /// - `chars` → [`Utf8Reader::chars`] /// /// [`BufRead::read_to_end`]: trait.BufRead.html#method.read_to_end /// [`BufRead::read_exact`]: trait.BufRead.html#method.read_exact /// [`BufRead::bytes`]: trait.BufRead.html#method.bytes /// [`Utf8Reader::read_to_string`]: struct.Utf8Reader.html#method.read_to_string /// [`Utf8Reader::chars`]: struct.Utf8Reader.html#method.chars /// [`std::io::Read`]: https://doc.rust-lang.org/nightly/std/io/trait.Read.html pub trait Read: Stream { /// Pull some bytes from this source into the specified buffer, returning /// how many bytes were read. /// /// This methode is equivalent to [`std::io::Read::read`]. /// /// [`std::io::Read::read`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Read.html#tymethod.read fn read(&mut self, buf: &mut [u8]) -> Result<usize>; /// Creates an adaptor which will chain this stream with another. /// /// This method is equivalent to [`std::io::Read::chain`]. /// /// [`std::io::Read::chain`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.chain #[inline] fn chain<R>(self, next: R) -> Chain<Self, R> where Self: Sized, R: Read { Chain::new(self, next) } /// Creates a buffered reader with default capacity and default strategies /// /// Please see the documentation of [`BufReader`] for more details /// /// [`BufReader`]: ./buf_redux_reexport/struct.BufReader.html #[inline] fn buffer(self) -> BufReader<Self> where Self: Sized { BufReader::new(self) } /// Transforms this reader into a reader that automatically restarts from the beginning after /// EOF is reached #[inline] fn repeat(self) -> Repeat<Self> where Self: Sized { Repeat::new(self) } } /// Alternative to `std::io::Write` /// /// This trait is automatically implemented for all types that implement `std::io::Write`. /// /// Differences to `std::io::Write` /// =============================== /// Methods that are just wrappers around the equivalent methods of `std::io::Write`: /// /// - `write` /// - `flush` /// /// Methods that provide a slightly different functionality than their counterparts in /// `std::io::Write`: /// /// - `write_all` /// /// Functions that were removed or moved to a different trait, /// because they cannot be implemented with providing all desired guarantees: /// /// - `write_fmt` → removed pub trait Write: Stream { /// Write a buffer into this object, returning how many bytes were written. /// /// This method is equivalent to [`std::io::Write::write`]. /// /// [`std::io::Write::write`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Write.html#tymethod.write fn write(&mut self, buf: &[u8]) -> Result<usize>; /// Flush this output stream, ensuring that all intermediately buffered /// contents reach their destination. /// /// This method is equivalent to [`std::io::Write::flush`]. /// /// [`std::io::Write::flush`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Write.html#tymethod.flush fn flush(&mut self) -> Result<()>; /// Attempts to write an entire buffer into this write. /// /// Similarly to [`std::io::Write::write_all`], /// this method will continuously call `write` while there is more data to write. /// This method will not return until the entire buffer has been /// successfully written or an error occurs. The first error generated from /// this method will be returned. /// /// The supplied buffer will be consumed by the writing operation. /// /// Errors /// ====== /// This function will return an error immediately if any call to [`write`] returns /// any kind of error. /// Instances of [`ErrorKind`]`::Interrupted` are *not* handled by this function. /// /// All bytes consumed from the buffer will be written to the the writer and vice versa. /// It is guaranteed that no data is lost in case of error. /// /// Differences to `std::io::Write::write_all` /// ========================================== /// - Does not retry on [`ErrorKind`]`::Interrupted`. /// - Takes a `BufRead` instance instead of just a plain `&[u8]`. /// /// Advantages /// ---------- /// - Function is interruptable, e.g. to allow graceful shutdown for server applications. /// - In case of error, it is always clear how much data was already written. No data is lost. /// /// [`write`]: ./trait.Write.html#tymethod.write /// [`std::io::Write::write_all`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Write.html#method.write_all /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html #[inline] fn write_all<R: ?Sized>(&mut self, buf: &mut R) -> Result<()> where Self: Sized, R: BufRead { copy(buf, self) } } /// Alternative to `std::io::BufRead` /// /// This trait is automatically implemented for all types that implement `std::io::BufRead`. /// /// Differences to [`std::io::BufRead`] /// =================================== /// Methods that are just wrappers around the equivalent methods of [`std::io::BufRead`]: /// /// - `fill_buf` /// - `consume` /// /// Methods that provide a slightly different functionality than their counterparts in /// [`std::io::BufRead`]: /// /// - `read_until` /// - `split` /// /// Methods originally implemented in a different place: /// /// - `read_to_end` ← [`std::io::Read::read_to_end`] /// - `read_exact` ← [`std::io::Read::read_exact`] /// - `bytes` ← [`std::io::Read::bytes`] /// /// New methods that have no counterpart in `std::io`: /// /// - `skip_to_end` /// - `skip_until` /// /// Functions that were removed or moved to a different trait, /// because they cannot be implemented with providing all desired guarantees: /// /// - `read_line` → [`Utf8Reader::read_line`] /// /// [`Utf8Reader::read_line`]: ./struct.Utf8Reader.html#method.read_line /// [`std::io::Read::read_to_end`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.read_to_end /// [`std::io::Read::read_exact`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.read_exact /// [`std::io::Read::bytes`]: https://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.bytes /// [`std::io::Read`]: https://doc.rust-lang.org/nightly/std/io/trait.Read.html pub trait BufRead: Read { /// Fills the internal buffer of this object, returning the buffer contents. /// /// This method is equivalent to [`std::io::BufRead::fill_buf`]. /// /// [`std::io::BufRead::fill_buf`]: /// https://doc.rust-lang.org/nightly/std/io/trait.BufRead.html#tymethod.fill_buf fn fill_buf(&mut self) -> Result<&[u8]>; /// Tells this buffer that `amt` bytes have been consumed from the buffer, /// so they should no longer be returned in calls to `read`. /// /// This method is equivalent to [`std::io::BufRead::consume`]. /// /// [`std::io::BufRead::consume`]: /// https://doc.rust-lang.org/nightly/std/io/trait.BufRead.html#tymethod.consume #[inline] fn consume(&mut self, amt: usize); /// Read all bytes until EOF in this source, placing them into `buf`. /// /// Similar to [`std::io::Read::read_to_end`], all bytes read from this source will /// be appended to the specified buffer `buf`. /// /// This function will continuously call [`fill_buf`] and [`consume`] to /// append more data to `buf` until [`fill_buf`] returns either `Ok(&[])` or any kind of error. /// /// Errors /// ====== /// This function will return an error immediately if any call to [`fill_buf`] returns /// any kind of error. /// Instances of [`ErrorKind`]`::Interrupted` are *not* handled by this function. /// /// All bytes consumed from the reader will be written to the buffer and vice versa. /// It is guaranteed that no data is lost in case of error. /// /// Differences to `std::io::Read::read_to_end` /// =========================================== /// - Does not retry on [`ErrorKind`]`::Interrupted`. /// - Uses [`BufRead`] instead of [`Read`]. /// - Does not return the number of bytes that are copied. /// - Works with all kind of writers, not just `Vec<u8>` /// /// Advantages /// ---------- /// - Function is interruptable, e.g. to allow graceful shutdown for server applications. /// - Avoids double buffering if the source already implements [`BufRead`]. /// - Allows different buffer sizes by using [`BufReader::with_capacity`]. /// /// Disadvantages /// ------------- /// The fact that it does not return the number of bytes copied stems from the fact that it /// cannot return this information in case of error. /// This would go against the goal of allowing reliable retry. /// /// [`fill_buf`]: ./trait.BufRead.html#tymethod.fill_buf /// [`consume`]: ./trait.BufRead.html#tymethod.consume /// [`BufRead`]: ./trait.BufRead.html /// [`Read`]: ./trait.Read.html /// [`BufReader::with_capacity`]: /// ./buf_redux_reexport/struct.BufReader.html#method.with_capacity /// [`std::io::Read::read_to_end`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.read_to_end /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html #[inline] fn read_to_end<B: ?Sized>(&mut self, buf: &mut B) -> Result<()> where Self: Sized, B: Write { copy(self, buf) } /// Skip all bytes until EOF in this source. /// /// Acts like [`read_to_end`], but all bytes read from this source are /// discarded. /// /// This function will continuously call [`fill_buf`] and [`consume`] until /// [`fill_buf`] returns either `Ok(&[])` or any kind of error. /// /// Errors /// ====== /// This function will return an error immediately if any call to [`fill_buf`] returns /// any kind of error. /// Instances of [`ErrorKind`]`::Interrupted` are *not* handled by this function. /// /// [`read_to_end`]: #method.read_to_end /// [`fill_buf`]: ./trait.BufRead.html#tymethod.fill_buf /// [`consume`]: ./trait.BufRead.html#tymethod.consume /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html #[inline] fn skip_to_end(&mut self) -> Result<()> { copy(self, &mut std::io::sink()) } /// Read the exact number of bytes required to fill `buf`. /// /// Similarliy to [`std::io::Read::read_exact`], this function reads as many bytes /// as necessary to completely fill the specified buffer `buf`. /// /// No guarantees are provided about the contents of `buf` when this /// function is called, implementations cannot rely on any property of the /// contents of `buf` being true. It is recommended that implementations /// only write data to `buf` instead of reading its contents. /// /// Errors /// ====== /// This function will return an error immediately if any call to [`fill_buf`] returns /// any kind of error. /// Instances of [`ErrorKind`]`::Interrupted` are *not* handled by this function. /// /// If this function encounters an "end of file" before completely filling /// the buffer, it returns an error of the kind [`ErrorKind`]`::UnexpectedEof`. /// /// If this function returns an error, the buffer will contain all bytes read up to that point. /// The position of the cursor will point one byte past the last read byte. /// /// All bytes consumed from the reader will be written to the buffer and vice versa. /// It is guaranteed that no data is lost in case of error. /// /// Differences to `std::io::Read::read_exact` /// ========================================== /// - Does not retry on [`ErrorKind`]`::Interrupted`. /// - Uses [`BufRead`] instead of [`Read`]. /// - In case of error the buffer contains all bytes read up to that point. /// - Takes a [`Cursor`] instead of plain buffer to track the current position. /// /// Advantages /// ---------- /// - Function is interruptable, e.g. to allow graceful shutdown for server applications. /// - No data ist lost on error. /// /// Disadvantages /// ------------- /// The function is slightly less ergonomic to use. /// /// [`fill_buf`]: ./trait.BufRead.html#tymethod.fill_buf /// [`BufRead`]: ./trait.BufRead.html /// [`Read`]: ./trait.Read.html /// [`Cursor`]: https://doc.rust-lang.org/nightly/std/io/struct.Cursor.html /// [`std::io::Read::read_exact`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.read_exact /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html fn read_exact(&mut self, buf: &mut std::io::Cursor<&mut [u8]>) -> Result<()> { let mut remaining = buf.get_ref().len() - buf.position() as usize; while remaining > 0 { let written = { let available = try!(BufRead::fill_buf(self)); if available.len() == 0 { return Err(Error::new(ErrorKind::UnexpectedEof, "Stream is already at EOF")); } try!(buf.write(available)) }; remaining -= written; BufRead::consume(self, written); } Ok(()) } /// Transforms this buffered reader into an iterator over its bytes. /// /// This method is approximately equivalent to [`std::io::Read::bytes`]. /// /// The returned type implements [`std::iter::Iterator`] /// where the `Item` is `Result<u8, R::Err>`. /// The yielded item is `Ok` if a byte was successfully read and /// `Err` otherwise for I/O errors. EOF is mapped to returning `None` from /// this iterator. /// /// Errors /// ====== /// If fill_buf returns any kind of error, the iterator yields `Some(Err)`. In case of error /// it is safe to iterate further to retry the reading operation. /// Instances of [`ErrorKind`]`::Interrupted` are *not* handled by the iterator. /// /// Differences to `std::io::Read::bytes` /// ===================================== /// - Uses [`BufRead`] instead of [`Read`]. /// /// Advantages /// ---------- /// - No accidentialy unbuffered reading of single bytes /// /// [`Read`]: ./trait.Read.html /// [`BufRead`]: ./trait.BufRead.html /// [`std::io::Read::bytes`]: /// https://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.bytes /// [`std::iter::Iterator`]: https://doc.rust-lang.org/nightly/std/iter/trait.Iterator.html /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html #[inline] fn bytes(self) -> Bytes<Self> where Self: Sized { Bytes::new(self) } /// Read all bytes into a buffer until a delimiter is reached. /// /// Similar to [`std::io::BufRead::read_until`] ,this function will read bytes from /// the underlying stream and push them to the specified buffer `buf`, until the delimiter /// `delim` is found. If the delimiter is found, it is also part of the result. /// /// Errors /// ====== /// This function will return an error immediately if any call to [`fill_buf`] returns /// any kind of error. /// Instances of [`ErrorKind`]`::Interrupted` are *not* handled by this function. /// /// If this reader has reached EOF then this function will return /// [`ErrorKind`]`::UnexpectedEof`. /// /// All bytes consumed from the buffered reader will be written to the specified buffer and /// vice versa. /// It is guaranteed that no data is lost in case of error. /// /// Differences to `std::io::BufRead::read_until` /// ============================================= /// - Does not retry on [`ErrorKind`]`::Interrupted`. /// - Does not return the number of bytes that are read. /// - Returns an error on EOF instead of success. /// - Works with all kind of writers, not just `Vec<u8>` /// /// Advantages /// ---------- /// - Function is interruptable, e.g. to allow graceful shutdown for server applications. /// /// Disadvantages /// ------------- /// The fact that it does not return the number of bytes copied stems from the fact that it /// cannot return this information in case of error. /// This would go against the goal of allowing reliable retry. /// /// [`fill_buf`]: ./trait.BufRead.html#tymethod.fill_buf /// [`std::io::BufRead::read_until`]: /// http://doc.rust-lang.org/nightly/std/io/trait.BufRead.html#method.read_until /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html #[inline] fn read_until<W: ?Sized>(&mut self, delim: u8, buf: &mut W) -> Result<()> where Self: Sized, W: Write { copy_until(self, buf, delim) } /// Skips all bytes until a delimiter is reached. /// /// This function will discard bytes from the underlying stream until the delimiter `delim` is /// found. /// /// Acts like [`read_until`], but all bytes read from this source are /// discarded. /// /// Errors /// ====== /// This function will return an error immediately if any call to [`fill_buf`] returns /// any kind of error. /// Instances of [`ErrorKind`]`::Interrupted` are *not* handled by this function. /// /// If this reader has reached EOF then this function will return /// [`ErrorKind`]`::UnexpectedEof`. /// /// [`read_until`]: #method.read_until /// [`fill_buf`]: ./trait.BufRead.html#tymethod.fill_buf /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html #[inline] fn skip_until(&mut self, delim: u8) -> Result<()> { copy_until(self, &mut std::io::sink(), delim) } /// Returns an iterator over the contents of this reader split on a delimiter. /// /// The iterator returned from this function will return instances of /// `io::Result<Vec<u8>>`. Each vector returned will *not* have the /// delimiter byte at the end. /// /// Errors /// ====== /// The iterator will yield an error whenever [`read_until`] would have also /// returned an error. /// /// [`read_until`]: #method.read_until #[inline] fn split(self, byte: u8) -> Split<Self> where Self: Sized { Split::new(self, byte) } } fn find2(delims: (u8, u8), buf: &[u8]) -> usize { let mut start = 0; while let Some(i) = memchr::memchr(delims.0, &buf[start..]) { let current = start + i; if (current == buf.len() - 1) || (buf[current + 1] == delims.1) { return current; } start = current + 1; } buf.len() } /// A `BufReadGrow` is a `BufRead`er that has the ability to read additional data even if the /// buffer is not empty. /// /// A `BufRead` guarantees an internal buffer of at only one byte with no possibility to read /// additional data without consuming the already read data first. /// With this limitation it is not possible to implement many functions in an interrupt-safe way. /// /// Interrupt-safe function require that - when the function returns - all data is either left in /// the stream or appended to the buffer. /// But for example when read UTF-8 with a `BufRead`er, /// this requirement can only be met by appending incomplete UTF-8 to the buffer which is also /// unacceptable by itself. /// /// For that reason, the `BufReadGrow` trait is introduced which extends `BufRead` by a method to /// grow the internal buffer. /// This requires the buffer to be able to relocate the data in the internal buffer. pub trait BufReadGrow: BufRead { /// Grows the internal buffer of this object by at least one byte, /// returning the buffer contents. /// /// Like [`fill_buf`], this function is a lower-level call. /// It needs to be paired with the [`consume`] method to function properly. /// When calling this method, none of the contents will be "read" in the sense that later /// calling `read` may return the same contents. As such, `consume` must be /// called with the number of bytes that are consumed from this buffer to /// ensure that the bytes are never returned twice. /// /// Errors /// ====== /// - Any error returned by the underlying call to `read` will be returned immediately. /// - If the stream has already reached EOF, an error of kind /// [`ErrorKind`]`::UnexpectedEof` is returned. /// - If the internal buffer of is full, an appropriate error is returned. /// Since there is no specific `ErrorKind` for this, [`ErrorKind`]`::Other` /// should be used. /// /// [`fill_buf`]: trait.BufRead.html#tymethod.fill_buf /// [`consume`]: trait.BufRead.html#tymethod.consume /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html fn grow_buf(&mut self) -> Result<&[u8]>; /// Fills the internal buffer to at least the specified amount, /// returning the buffer contents. /// /// Like [`BufRead::fill_buf`][`fill_buf`] and [`grow_buf`], this function is a lower-level call. /// It needs to be paired with the [`consume`] method to function properly. /// When calling this method, none of the contents will be "read" in the sense that later /// calling `read` may return the same contents. As such, `consume` must be /// called with the number of bytes that are consumed from this buffer to /// ensure that the bytes are never returned twice. /// /// Errors /// ====== /// - Any I/O error will be returned immediately. /// - If the stream has already reached EOF, an error of kind /// [`ErrorKind`]`::UnexpectedEof` is returned. /// - If the internal buffer of is full, an appropriate error is returned. /// See [`grow_buf`] for more details. /// /// [`grow_buf`]: #tymethod.grow_buf /// [`fill_buf`]: trait.BufRead.html#tymethod.fill_buf /// [`consume`]: trait.BufRead.html#tymethod.consume /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html fn fill_buf_min(&mut self, size: usize) -> Result<&[u8]> { let len = try!(self.fill_buf()).len(); match len { 0 => Err(Error::new(ErrorKind::UnexpectedEof, "Unexpected end of stream")), n if n == size - 1 => self.grow_buf(), n if n < size => { while try!(self.grow_buf()).len() < size {} self.fill_buf() } _ => self.fill_buf(), } } /// Read all bytes into a buffer until two consecutive delimiters are reached. /// /// This function will read bytes from the underlying stream and push them to the specified /// buffer `buf`, until the two consecutive delimiters `delims` are found. /// If the delimiters are found, they also part of the result. /// /// Errors /// ====== /// This function will return an error immediately if a call to [`fill_buf`] returns /// any kind of error. /// Instances of [`ErrorKind`]`::Interrupted` are *not* handled by this function. /// /// If this reader has reached EOF then this function will return /// [`ErrorKind`]`::UnexpectedEof`. /// /// In case of an error, all bytes read up to that point are appended to the buffer and /// consumed from this buffered reader. /// There's one notable exception to that rule: If the last byte in the buffer would be the /// first delimiter, it is left in the buffered reader. /// Otherwise retrying on error would not work reliably. /// /// In any case, all bytes consumed from the buffered reader will be written to the specified /// buffer and vice versa. /// It is guaranteed that no data is lost in case of error. /// /// [`fill_buf`]: ./trait.BufRead.html#tymethod.fill_buf /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html fn read_until2(&mut self, delims: (u8, u8), buf: &mut Vec<u8>) -> Result<()> { let mut extend = false; loop { let (done, used) = { let available = if extend { try!(self.grow_buf()) } else { try!(self.fill_buf()) }; if available.len() == 0 { return Err(Error::new(ErrorKind::UnexpectedEof, "Stream did not contain the delimiters")); } extend = false; let found = find2(delims, available); let (done, used) = if found == available.len() { (false, found) } else if found == available.len() - 1 { extend = true; (false, found) } else { (true, found + 2) }; buf.extend_from_slice(&available[..used]); (done, used) }; self.consume(used); if done { return Ok(()); } } } /// Skip all bytes until two consecutive delimiters are reached. /// /// This function will discard bytes from the underlying stream until the two consecutive /// delimiters `delims` are found. /// /// Errors /// ====== /// This function will return an error immediately if a call to [`fill_buf`] returns /// any kind of error. /// Instances of [`ErrorKind`]`::Interrupted` are *not* handled by this function. /// /// If this reader has reached EOF then this function will return /// [`ErrorKind`]`::UnexpectedEof`. /// /// [`fill_buf`]: ./trait.BufRead.html#tymethod.fill_buf /// [`ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html fn skip_until2(&mut self, delims: (u8, u8)) -> Result<()> { let mut extend = false; loop { let (done, used) = { let available = if extend { try!(self.grow_buf()) } else { try!(self.fill_buf()) }; if available.len() == 0 { return Err(Error::new(ErrorKind::UnexpectedEof, "Stream did not contain the delimiters")); } extend = false; let found = find2(delims, available); let (done, used) = if found == available.len() { (false, found) } else if found == available.len() - 1 { extend = true; (false, found) } else { (true, found + 2) }; (done, used) }; self.consume(used); if done { return Ok(()); } } } fn decode_utf8(self) -> utf8::Utf8Reader<Self> where Self: Sized { utf8::Utf8Reader::new(self) } } #[cfg(test)] mod tests { use std::io; use buf_redux as br; use {Read, BufRead, BufReadGrow}; #[test] fn read_until() { let mut buf = io::Cursor::new(&b"12"[..]); let mut v = Vec::new(); assert_eq!(buf.read_until(b'3', &mut v).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); assert_eq!(v, b"12"); let mut buf = io::Cursor::new(&b"1233"[..]); let mut v = Vec::new(); buf.read_until(b'3', &mut v).unwrap(); assert_eq!(v, b"123"); v.truncate(0); buf.read_until(b'3', &mut v).unwrap(); assert_eq!(v, b"3"); v.truncate(0); assert_eq!(buf.read_until(b'3', &mut v).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); assert_eq!(v, b""); } #[test] fn read_to_end() { let mut c = io::Cursor::new(&b""[..]); let mut v = Vec::new(); c.read_to_end(&mut v).unwrap(); assert_eq!(v, b""); let mut c = io::Cursor::new(&b"1"[..]); let mut v = Vec::new(); c.read_to_end(&mut v).unwrap(); assert_eq!(v, b"1"); let cap = 1024 * 1024; let data = (0..cap).map(|i| (i / 3) as u8).collect::<Vec<_>>(); let mut v = Vec::new(); let (a, b) = data.split_at(data.len() / 2); io::Cursor::new(a).read_to_end(&mut v).unwrap(); io::Cursor::new(b).read_to_end(&mut v).unwrap(); assert_eq!(v, data); } #[test] fn read_exact() { let mut buf = [0; 4]; let mut buf = io::Cursor::new(&mut buf[..]); let mut c = io::Cursor::new(&b""[..]); assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); assert_eq!(buf.position(), 0); let mut c = io::Cursor::new(&b"123"[..]).chain(io::Cursor::new(&b"456789"[..])); buf.set_position(0); c.read_exact(&mut buf).unwrap(); assert_eq!(buf.position(), 4); assert_eq!(buf.get_ref(), b"1234"); buf.set_position(0); c.read_exact(&mut buf).unwrap(); assert_eq!(buf.position(), 4); assert_eq!(buf.get_ref(), b"5678"); buf.set_position(0); assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); assert_eq!(buf.position(), 1); } #[test] fn read_exact_slice() { let mut buf = [0; 4]; let mut buf = io::Cursor::new(&mut buf[..]); let mut c = &b""[..]; assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); let mut c = &b"123"[..]; buf.set_position(0); assert_eq!(c.read_exact(&mut buf).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); assert_eq!(buf.position(), 3); assert_eq!(buf.get_ref(), b"123\0"); let mut c = &b"1234"[..]; buf.set_position(0); c.read_exact(&mut buf).unwrap(); assert_eq!(buf.position(), 4); assert_eq!(buf.get_ref(), b"1234"); let mut c = &b"56789"[..]; buf.set_position(0); c.read_exact(&mut buf).unwrap(); assert_eq!(buf.position(), 4); assert_eq!(buf.get_ref(), b"5678"); assert_eq!(c, b"9"); } #[test] fn read_until2() { let mut buf = io::Cursor::new(&b"1234321234554"[..]); let mut v = Vec::new(); assert_eq!(buf.read_until2((b'3', b'5'), &mut v).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); assert_eq!(v, b"1234321234554"); let mut buf = io::Cursor::new(&b"1234321234554"[..]); let mut v = Vec::new(); buf.read_until2((b'3', b'4'), &mut v).unwrap(); assert_eq!(v, b"1234"); v.truncate(0); buf.read_until2((b'3', b'4'), &mut v).unwrap(); assert_eq!(v, b"321234"); v.truncate(0); assert_eq!(buf.read_until2((b'3', b'4'), &mut v).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); assert_eq!(v, b"554"); } #[test] fn read_until2_smallbuffer() { let mut buf = br::BufReader::with_capacity(3, io::Cursor::new(&b"12343212334554"[..])); let mut v = Vec::new(); assert_eq!(buf.read_until2((b'3', b'5'), &mut v).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); assert_eq!(v, b"12343212334554"); let mut buf = br::BufReader::with_capacity(3, io::Cursor::new(&b"12343212334554"[..])); let mut v = Vec::new(); buf.read_until2((b'3', b'4'), &mut v).unwrap(); assert_eq!(v, b"1234"); v.truncate(0); buf.read_until2((b'3', b'4'), &mut v).unwrap(); assert_eq!(v, b"3212334"); v.truncate(0); assert_eq!(buf.read_until2((b'3', b'4'), &mut v).unwrap_err().kind(), io::ErrorKind::UnexpectedEof); assert_eq!(v, b"554"); } }