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Diffstat (limited to 'ctr-std/src/io/stdio.rs')
| -rw-r--r-- | ctr-std/src/io/stdio.rs | 722 |
1 files changed, 722 insertions, 0 deletions
diff --git a/ctr-std/src/io/stdio.rs b/ctr-std/src/io/stdio.rs new file mode 100644 index 0000000..e16e801 --- /dev/null +++ b/ctr-std/src/io/stdio.rs @@ -0,0 +1,722 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +use io::prelude::*; + +use cell::RefCell; +use fmt; +use io::lazy::Lazy; +use io::{self, BufReader, LineWriter}; +use sync::{Arc, Mutex, MutexGuard}; +use sys::stdio; +use sys_common::remutex::{ReentrantMutex, ReentrantMutexGuard}; +use thread::LocalKeyState; + +/// Stdout used by print! and println! macros +thread_local! { + static LOCAL_STDOUT: RefCell<Option<Box<Write + Send>>> = { + RefCell::new(None) + } +} + +/// A handle to a raw instance of the standard input stream of this process. +/// +/// This handle is not synchronized or buffered in any fashion. Constructed via +/// the `std::io::stdio::stdin_raw` function. +struct StdinRaw(stdio::Stdin); + +/// A handle to a raw instance of the standard output stream of this process. +/// +/// This handle is not synchronized or buffered in any fashion. Constructed via +/// the `std::io::stdio::stdout_raw` function. +struct StdoutRaw(stdio::Stdout); + +/// A handle to a raw instance of the standard output stream of this process. +/// +/// This handle is not synchronized or buffered in any fashion. Constructed via +/// the `std::io::stdio::stderr_raw` function. +struct StderrRaw(stdio::Stderr); + +/// Constructs a new raw handle to the standard input of this process. +/// +/// The returned handle does not interact with any other handles created nor +/// handles returned by `std::io::stdin`. Data buffered by the `std::io::stdin` +/// handles is **not** available to raw handles returned from this function. +/// +/// The returned handle has no external synchronization or buffering. +fn stdin_raw() -> io::Result<StdinRaw> { stdio::Stdin::new().map(StdinRaw) } + +/// Constructs a new raw handle to the standard output stream of this process. +/// +/// The returned handle does not interact with any other handles created nor +/// handles returned by `std::io::stdout`. Note that data is buffered by the +/// `std::io::stdout` handles so writes which happen via this raw handle may +/// appear before previous writes. +/// +/// The returned handle has no external synchronization or buffering layered on +/// top. +fn stdout_raw() -> io::Result<StdoutRaw> { stdio::Stdout::new().map(StdoutRaw) } + +/// Constructs a new raw handle to the standard error stream of this process. +/// +/// The returned handle does not interact with any other handles created nor +/// handles returned by `std::io::stderr`. +/// +/// The returned handle has no external synchronization or buffering layered on +/// top. +fn stderr_raw() -> io::Result<StderrRaw> { stdio::Stderr::new().map(StderrRaw) } + +impl Read for StdinRaw { + fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { self.0.read(buf) } + fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> { + self.0.read_to_end(buf) + } +} +impl Write for StdoutRaw { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { self.0.write(buf) } + fn flush(&mut self) -> io::Result<()> { self.0.flush() } +} +impl Write for StderrRaw { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { self.0.write(buf) } + fn flush(&mut self) -> io::Result<()> { self.0.flush() } +} + +enum Maybe<T> { + Real(T), + Fake, +} + +impl<W: io::Write> io::Write for Maybe<W> { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + match *self { + Maybe::Real(ref mut w) => handle_ebadf(w.write(buf), buf.len()), + Maybe::Fake => Ok(buf.len()) + } + } + + fn flush(&mut self) -> io::Result<()> { + match *self { + Maybe::Real(ref mut w) => handle_ebadf(w.flush(), ()), + Maybe::Fake => Ok(()) + } + } +} + +impl<R: io::Read> io::Read for Maybe<R> { + fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { + match *self { + Maybe::Real(ref mut r) => handle_ebadf(r.read(buf), 0), + Maybe::Fake => Ok(0) + } + } + fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> { + match *self { + Maybe::Real(ref mut r) => handle_ebadf(r.read_to_end(buf), 0), + Maybe::Fake => Ok(0) + } + } +} + +fn handle_ebadf<T>(r: io::Result<T>, default: T) -> io::Result<T> { + use sys::stdio::EBADF_ERR; + + match r { + Err(ref e) if e.raw_os_error() == Some(EBADF_ERR) => Ok(default), + r => r + } +} + +/// A handle to the standard input stream of a process. +/// +/// Each handle is a shared reference to a global buffer of input data to this +/// process. A handle can be `lock`'d to gain full access to [`BufRead`] methods +/// (e.g. `.lines()`). Reads to this handle are otherwise locked with respect +/// to other reads. +/// +/// This handle implements the `Read` trait, but beware that concurrent reads +/// of `Stdin` must be executed with care. +/// +/// Created by the [`io::stdin`] method. +/// +/// [`io::stdin`]: fn.stdin.html +/// [`BufRead`]: trait.BufRead.html +#[stable(feature = "rust1", since = "1.0.0")] +pub struct Stdin { + inner: Arc<Mutex<BufReader<Maybe<StdinRaw>>>>, +} + +/// A locked reference to the `Stdin` handle. +/// +/// This handle implements both the [`Read`] and [`BufRead`] traits, and +/// is constructed via the [`Stdin::lock`] method. +/// +/// [`Read`]: trait.Read.html +/// [`BufRead`]: trait.BufRead.html +/// [`Stdin::lock`]: struct.Stdin.html#method.lock +#[stable(feature = "rust1", since = "1.0.0")] +pub struct StdinLock<'a> { + inner: MutexGuard<'a, BufReader<Maybe<StdinRaw>>>, +} + +/// Constructs a new handle to the standard input of the current process. +/// +/// Each handle returned is a reference to a shared global buffer whose access +/// is synchronized via a mutex. If you need more explicit control over +/// locking, see the [`lock() method`][lock]. +/// +/// [lock]: struct.Stdin.html#method.lock +/// +/// # Examples +/// +/// Using implicit synchronization: +/// +/// ``` +/// use std::io::{self, Read}; +/// +/// # fn foo() -> io::Result<String> { +/// let mut buffer = String::new(); +/// io::stdin().read_to_string(&mut buffer)?; +/// # Ok(buffer) +/// # } +/// ``` +/// +/// Using explicit synchronization: +/// +/// ``` +/// use std::io::{self, Read}; +/// +/// # fn foo() -> io::Result<String> { +/// let mut buffer = String::new(); +/// let stdin = io::stdin(); +/// let mut handle = stdin.lock(); +/// +/// handle.read_to_string(&mut buffer)?; +/// # Ok(buffer) +/// # } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub fn stdin() -> Stdin { + static INSTANCE: Lazy<Mutex<BufReader<Maybe<StdinRaw>>>> = Lazy::new(stdin_init); + return Stdin { + inner: INSTANCE.get().expect("cannot access stdin during shutdown"), + }; + + fn stdin_init() -> Arc<Mutex<BufReader<Maybe<StdinRaw>>>> { + let stdin = match stdin_raw() { + Ok(stdin) => Maybe::Real(stdin), + _ => Maybe::Fake + }; + + Arc::new(Mutex::new(BufReader::with_capacity(stdio::STDIN_BUF_SIZE, stdin))) + } +} + +impl Stdin { + /// Locks this handle to the standard input stream, returning a readable + /// guard. + /// + /// The lock is released when the returned lock goes out of scope. The + /// returned guard also implements the [`Read`] and [`BufRead`] traits for + /// accessing the underlying data. + /// + /// [`Read`]: trait.Read.html + /// [`BufRead`]: trait.BufRead.html + /// + /// # Examples + /// + /// ``` + /// use std::io::{self, Read}; + /// + /// # fn foo() -> io::Result<String> { + /// let mut buffer = String::new(); + /// let stdin = io::stdin(); + /// let mut handle = stdin.lock(); + /// + /// handle.read_to_string(&mut buffer)?; + /// # Ok(buffer) + /// # } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn lock(&self) -> StdinLock { + StdinLock { inner: self.inner.lock().unwrap_or_else(|e| e.into_inner()) } + } + + /// Locks this handle and reads a line of input into the specified buffer. + /// + /// For detailed semantics of this method, see the documentation on + /// [`BufRead::read_line`]. + /// + /// [`BufRead::read_line`]: trait.BufRead.html#method.read_line + /// + /// # Examples + /// + /// ```no_run + /// use std::io; + /// + /// let mut input = String::new(); + /// match io::stdin().read_line(&mut input) { + /// Ok(n) => { + /// println!("{} bytes read", n); + /// println!("{}", input); + /// } + /// Err(error) => println!("error: {}", error), + /// } + /// ``` + /// + /// You can run the example one of two ways: + /// + /// - Pipe some text to it, e.g. `printf foo | path/to/executable` + /// - Give it text interactively by running the executable directly, + /// in which case it will wait for the Enter key to be pressed before + /// continuing + #[stable(feature = "rust1", since = "1.0.0")] + pub fn read_line(&self, buf: &mut String) -> io::Result<usize> { + self.lock().read_line(buf) + } +} + +#[stable(feature = "std_debug", since = "1.16.0")] +impl fmt::Debug for Stdin { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + f.pad("Stdin { .. }") + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Read for Stdin { + fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { + self.lock().read(buf) + } + fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> { + self.lock().read_to_end(buf) + } + fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> { + self.lock().read_to_string(buf) + } + fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> { + self.lock().read_exact(buf) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<'a> Read for StdinLock<'a> { + fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { + self.inner.read(buf) + } + fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> { + self.inner.read_to_end(buf) + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl<'a> BufRead for StdinLock<'a> { + fn fill_buf(&mut self) -> io::Result<&[u8]> { self.inner.fill_buf() } + fn consume(&mut self, n: usize) { self.inner.consume(n) } +} + +#[stable(feature = "std_debug", since = "1.16.0")] +impl<'a> fmt::Debug for StdinLock<'a> { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + f.pad("StdinLock { .. }") + } +} + +/// A handle to the global standard output stream of the current process. +/// +/// Each handle shares a global buffer of data to be written to the standard +/// output stream. Access is also synchronized via a lock and explicit control +/// over locking is available via the [`lock()`] method. +/// +/// Created by the [`io::stdout`] method. +/// +/// [`lock()`]: #method.lock +/// [`io::stdout`]: fn.stdout.html +#[stable(feature = "rust1", since = "1.0.0")] +pub struct Stdout { + // FIXME: this should be LineWriter or BufWriter depending on the state of + // stdout (tty or not). Note that if this is not line buffered it + // should also flush-on-panic or some form of flush-on-abort. + inner: Arc<ReentrantMutex<RefCell<LineWriter<Maybe<StdoutRaw>>>>>, +} + +/// A locked reference to the `Stdout` handle. +/// +/// This handle implements the [`Write`] trait, and is constructed via +/// the [`Stdout::lock`] method. +/// +/// [`Write`]: trait.Write.html +/// [`Stdout::lock`]: struct.Stdout.html#method.lock +#[stable(feature = "rust1", since = "1.0.0")] +pub struct StdoutLock<'a> { + inner: ReentrantMutexGuard<'a, RefCell<LineWriter<Maybe<StdoutRaw>>>>, +} + +/// Constructs a new handle to the standard output of the current process. +/// +/// Each handle returned is a reference to a shared global buffer whose access +/// is synchronized via a mutex. If you need more explicit control over +/// locking, see the [Stdout::lock] method. +/// +/// [Stdout::lock]: struct.Stdout.html#method.lock +/// +/// # Examples +/// +/// Using implicit synchronization: +/// +/// ``` +/// use std::io::{self, Write}; +/// +/// # fn foo() -> io::Result<()> { +/// io::stdout().write(b"hello world")?; +/// +/// # Ok(()) +/// # } +/// ``` +/// +/// Using explicit synchronization: +/// +/// ``` +/// use std::io::{self, Write}; +/// +/// # fn foo() -> io::Result<()> { +/// let stdout = io::stdout(); +/// let mut handle = stdout.lock(); +/// +/// handle.write(b"hello world")?; +/// +/// # Ok(()) +/// # } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub fn stdout() -> Stdout { + static INSTANCE: Lazy<ReentrantMutex<RefCell<LineWriter<Maybe<StdoutRaw>>>>> + = Lazy::new(stdout_init); + return Stdout { + inner: INSTANCE.get().expect("cannot access stdout during shutdown"), + }; + + fn stdout_init() -> Arc<ReentrantMutex<RefCell<LineWriter<Maybe<StdoutRaw>>>>> { + let stdout = match stdout_raw() { + Ok(stdout) => Maybe::Real(stdout), + _ => Maybe::Fake, + }; + Arc::new(ReentrantMutex::new(RefCell::new(LineWriter::new(stdout)))) + } +} + +impl Stdout { + /// Locks this handle to the standard output stream, returning a writable + /// guard. + /// + /// The lock is released when the returned lock goes out of scope. The + /// returned guard also implements the `Write` trait for writing data. + /// + /// # Examples + /// + /// ``` + /// use std::io::{self, Write}; + /// + /// # fn foo() -> io::Result<()> { + /// let stdout = io::stdout(); + /// let mut handle = stdout.lock(); + /// + /// handle.write(b"hello world")?; + /// + /// # Ok(()) + /// # } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn lock(&self) -> StdoutLock { + StdoutLock { inner: self.inner.lock().unwrap_or_else(|e| e.into_inner()) } + } +} + +#[stable(feature = "std_debug", since = "1.16.0")] +impl fmt::Debug for Stdout { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + f.pad("Stdout { .. }") + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Write for Stdout { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + self.lock().write(buf) + } + fn flush(&mut self) -> io::Result<()> { + self.lock().flush() + } + fn write_all(&mut self, buf: &[u8]) -> io::Result<()> { + self.lock().write_all(buf) + } + fn write_fmt(&mut self, args: fmt::Arguments) -> io::Result<()> { + self.lock().write_fmt(args) + } +} +#[stable(feature = "rust1", since = "1.0.0")] +impl<'a> Write for StdoutLock<'a> { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + self.inner.borrow_mut().write(buf) + } + fn flush(&mut self) -> io::Result<()> { + self.inner.borrow_mut().flush() + } +} + +#[stable(feature = "std_debug", since = "1.16.0")] +impl<'a> fmt::Debug for StdoutLock<'a> { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + f.pad("StdoutLock { .. }") + } +} + +/// A handle to the standard error stream of a process. +/// +/// For more information, see the [`io::stderr`] method. +/// +/// [`io::stderr`]: fn.stderr.html +#[stable(feature = "rust1", since = "1.0.0")] +pub struct Stderr { + inner: Arc<ReentrantMutex<RefCell<Maybe<StderrRaw>>>>, +} + +/// A locked reference to the `Stderr` handle. +/// +/// This handle implements the `Write` trait and is constructed via +/// the [`Stderr::lock`] method. +/// +/// [`Stderr::lock`]: struct.Stderr.html#method.lock +#[stable(feature = "rust1", since = "1.0.0")] +pub struct StderrLock<'a> { + inner: ReentrantMutexGuard<'a, RefCell<Maybe<StderrRaw>>>, +} + +/// Constructs a new handle to the standard error of the current process. +/// +/// This handle is not buffered. +/// +/// # Examples +/// +/// Using implicit synchronization: +/// +/// ``` +/// use std::io::{self, Write}; +/// +/// # fn foo() -> io::Result<()> { +/// io::stderr().write(b"hello world")?; +/// +/// # Ok(()) +/// # } +/// ``` +/// +/// Using explicit synchronization: +/// +/// ``` +/// use std::io::{self, Write}; +/// +/// # fn foo() -> io::Result<()> { +/// let stderr = io::stderr(); +/// let mut handle = stderr.lock(); +/// +/// handle.write(b"hello world")?; +/// +/// # Ok(()) +/// # } +/// ``` +#[stable(feature = "rust1", since = "1.0.0")] +pub fn stderr() -> Stderr { + static INSTANCE: Lazy<ReentrantMutex<RefCell<Maybe<StderrRaw>>>> = Lazy::new(stderr_init); + return Stderr { + inner: INSTANCE.get().expect("cannot access stderr during shutdown"), + }; + + fn stderr_init() -> Arc<ReentrantMutex<RefCell<Maybe<StderrRaw>>>> { + let stderr = match stderr_raw() { + Ok(stderr) => Maybe::Real(stderr), + _ => Maybe::Fake, + }; + Arc::new(ReentrantMutex::new(RefCell::new(stderr))) + } +} + +impl Stderr { + /// Locks this handle to the standard error stream, returning a writable + /// guard. + /// + /// The lock is released when the returned lock goes out of scope. The + /// returned guard also implements the `Write` trait for writing data. + /// + /// # Examples + /// + /// ``` + /// use std::io::{self, Write}; + /// + /// fn foo() -> io::Result<()> { + /// let stderr = io::stderr(); + /// let mut handle = stderr.lock(); + /// + /// handle.write(b"hello world")?; + /// + /// Ok(()) + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn lock(&self) -> StderrLock { + StderrLock { inner: self.inner.lock().unwrap_or_else(|e| e.into_inner()) } + } +} + +#[stable(feature = "std_debug", since = "1.16.0")] +impl fmt::Debug for Stderr { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + f.pad("Stderr { .. }") + } +} + +#[stable(feature = "rust1", since = "1.0.0")] +impl Write for Stderr { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + self.lock().write(buf) + } + fn flush(&mut self) -> io::Result<()> { + self.lock().flush() + } + fn write_all(&mut self, buf: &[u8]) -> io::Result<()> { + self.lock().write_all(buf) + } + fn write_fmt(&mut self, args: fmt::Arguments) -> io::Result<()> { + self.lock().write_fmt(args) + } +} +#[stable(feature = "rust1", since = "1.0.0")] +impl<'a> Write for StderrLock<'a> { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + self.inner.borrow_mut().write(buf) + } + fn flush(&mut self) -> io::Result<()> { + self.inner.borrow_mut().flush() + } +} + +#[stable(feature = "std_debug", since = "1.16.0")] +impl<'a> fmt::Debug for StderrLock<'a> { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + f.pad("StderrLock { .. }") + } +} + +/// Resets the thread-local stderr handle to the specified writer +/// +/// This will replace the current thread's stderr handle, returning the old +/// handle. All future calls to `panic!` and friends will emit their output to +/// this specified handle. +/// +/// Note that this does not need to be called for all new threads; the default +/// output handle is to the process's stderr stream. +#[unstable(feature = "set_stdio", + reason = "this function may disappear completely or be replaced \ + with a more general mechanism", + issue = "0")] +#[doc(hidden)] +pub fn set_panic(sink: Option<Box<Write + Send>>) -> Option<Box<Write + Send>> { + use panicking::LOCAL_STDERR; + use mem; + LOCAL_STDERR.with(move |slot| { + mem::replace(&mut *slot.borrow_mut(), sink) + }).and_then(|mut s| { + let _ = s.flush(); + Some(s) + }) +} + +/// Resets the thread-local stdout handle to the specified writer +/// +/// This will replace the current thread's stdout handle, returning the old +/// handle. All future calls to `print!` and friends will emit their output to +/// this specified handle. +/// +/// Note that this does not need to be called for all new threads; the default +/// output handle is to the process's stdout stream. +#[unstable(feature = "set_stdio", + reason = "this function may disappear completely or be replaced \ + with a more general mechanism", + issue = "0")] +#[doc(hidden)] +pub fn set_print(sink: Option<Box<Write + Send>>) -> Option<Box<Write + Send>> { + use mem; + LOCAL_STDOUT.with(move |slot| { + mem::replace(&mut *slot.borrow_mut(), sink) + }).and_then(|mut s| { + let _ = s.flush(); + Some(s) + }) +} + +#[unstable(feature = "print", + reason = "implementation detail which may disappear or be replaced at any time", + issue = "0")] +#[doc(hidden)] +pub fn _print(args: fmt::Arguments) { + // As an implementation of the `println!` macro, we want to try our best to + // not panic wherever possible and get the output somewhere. There are + // currently two possible vectors for panics we take care of here: + // + // 1. If the TLS key for the local stdout has been destroyed, accessing it + // would cause a panic. Note that we just lump in the uninitialized case + // here for convenience, we're not trying to avoid a panic. + // 2. If the local stdout is currently in use (e.g. we're in the middle of + // already printing) then accessing again would cause a panic. + // + // If, however, the actual I/O causes an error, we do indeed panic. + let result = match LOCAL_STDOUT.state() { + LocalKeyState::Uninitialized | + LocalKeyState::Destroyed => stdout().write_fmt(args), + LocalKeyState::Valid => { + LOCAL_STDOUT.with(|s| { + if let Ok(mut borrowed) = s.try_borrow_mut() { + if let Some(w) = borrowed.as_mut() { + return w.write_fmt(args); + } + } + stdout().write_fmt(args) + }) + } + }; + if let Err(e) = result { + panic!("failed printing to stdout: {}", e); + } +} + +#[cfg(test)] +mod tests { + use thread; + use super::*; + + #[test] + #[cfg_attr(target_os = "emscripten", ignore)] + fn panic_doesnt_poison() { + thread::spawn(|| { + let _a = stdin(); + let _a = _a.lock(); + let _a = stdout(); + let _a = _a.lock(); + let _a = stderr(); + let _a = _a.lock(); + panic!(); + }).join().unwrap_err(); + + let _a = stdin(); + let _a = _a.lock(); + let _a = stdout(); + let _a = _a.lock(); + let _a = stderr(); + let _a = _a.lock(); + } +} |