Remove CommandTicket to avoid Vec allocation

This commit is contained in:
Matthias Reitinger 2017-11-15 01:56:32 +01:00 committed by David Peter
parent bc88b8f80e
commit c18caaa6f6
4 changed files with 114 additions and 142 deletions

98
src/exec/command.rs Normal file
View file

@ -0,0 +1,98 @@
// Copyright (c) 2017 fd developers
// 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. All files in the project carrying such
// notice may not be copied, modified, or distributed except
// according to those terms.
use std::process::Command;
use std::sync::{Arc, Mutex};
use std::io;
/// Executes a command.
#[cfg(not(unix))]
pub fn execute_command(mut cmd: Command, out_perm: Arc<Mutex<()>>) {
use std::process::Stdio;
use std::io::Write;
// Spawn the supplied command.
let output = cmd.stdout(Stdio::piped()).stderr(Stdio::piped()).output();
// Then wait for the command to exit, if it was spawned.
match output {
Ok(output) => {
// While this lock is active, this thread will be the only thread allowed
// to write it's outputs.
let _lock = out_perm.lock().unwrap();
let stdout = io::stdout();
let stderr = io::stderr();
let _ = stdout.lock().write_all(&output.stdout);
let _ = stderr.lock().write_all(&output.stderr);
}
Err(why) => eprintln!("fd: exec error: {}", why),
}
}
/// Executes a command.
#[cfg(all(unix))]
pub fn execute_command(mut cmd: Command, out_perm: Arc<Mutex<()>>) {
use libc::{close, dup2, pipe, STDERR_FILENO, STDOUT_FILENO};
use std::fs::File;
use std::os::unix::process::CommandExt;
use std::os::unix::io::FromRawFd;
// Initial a pair of pipes that will be used to
// pipe the std{out,err} of the spawned process.
let mut stdout_fds = [0; 2];
let mut stderr_fds = [0; 2];
unsafe {
pipe(stdout_fds.as_mut_ptr());
pipe(stderr_fds.as_mut_ptr());
}
// Configure the pipes accordingly in the child.
let child = cmd.before_exec(move || unsafe {
// Redirect the child's std{out,err} to the write ends of our pipe.
dup2(stdout_fds[1], STDOUT_FILENO);
dup2(stderr_fds[1], STDERR_FILENO);
// Close all the fds we created here, so EOF will be sent when the program exits.
close(stdout_fds[0]);
close(stdout_fds[1]);
close(stderr_fds[0]);
close(stderr_fds[1]);
Ok(())
}).spawn();
// Open the read end of the pipes as `File`s.
let (mut pout, mut perr) = unsafe {
// Close the write ends of the pipes in the parent
close(stdout_fds[1]);
close(stderr_fds[1]);
(
// But create files from the read ends.
File::from_raw_fd(stdout_fds[0]),
File::from_raw_fd(stderr_fds[0]),
)
};
match child {
Ok(mut child) => {
let _ = child.wait();
// Create a lock to ensure that this thread has exclusive access to writing.
let _lock = self.out_perm.lock().unwrap();
// And then write the outputs of the process until EOF is sent to each file.
let stdout = io::stdout();
let stderr = io::stderr();
let _ = io::copy(&mut pout, &mut stdout.lock());
let _ = io::copy(&mut perr, &mut stderr.lock());
}
Err(why) => eprintln!("fd: exec error: {}", why),
}
}

View file

@ -34,6 +34,6 @@ pub fn job(
// Drop the lock so that other threads can read from the the receiver.
drop(lock);
// Generate a command and execute it.
cmd.generate(&value, Arc::clone(&out_perm)).then_execute();
cmd.generate_and_execute(&value, Arc::clone(&out_perm));
}
}

View file

@ -7,27 +7,28 @@
// according to those terms.
// TODO: Possible optimization could avoid pushing characters on a buffer.
mod ticket;
mod command;
mod token;
mod job;
mod input;
use std::borrow::Cow;
use std::path::Path;
use std::process::Command;
use std::sync::{Arc, Mutex};
use regex::Regex;
use self::input::{basename, dirname, remove_extension};
use self::ticket::CommandTicket;
use self::command::execute_command;
use self::token::Token;
pub use self::job::job;
/// Contains a collection of `TokenizedArgument`s that are utilized to generate command strings.
///
/// The arguments are a representation of the supplied command template, and are meant to be coupled
/// with an input in order to generate a command. The `generate()` method will be used to generate
/// a command and obtain a ticket for executing that command.
/// with an input in order to generate a command. The `generate_and_execute()` method will be used
/// to generate a command and execute it.
#[derive(Debug, Clone, PartialEq)]
pub struct TokenizedCommand {
args: Vec<TokenizedArgument>,
@ -74,7 +75,7 @@ impl TokenizedCommand {
S: AsRef<str>,
{
lazy_static! {
static ref PLACEHOLDER: Regex = Regex::new(r"\{(/?\.?|//)\}").unwrap();
static ref PLACEHOLDER_PATTERN: Regex = Regex::new(r"\{(/?\.?|//)\}").unwrap();
}
let mut args = Vec::new();
@ -86,7 +87,7 @@ impl TokenizedCommand {
let mut tokens = Vec::new();
let mut start = 0;
for placeholder in PLACEHOLDER.find_iter(arg) {
for placeholder in PLACEHOLDER_PATTERN.find_iter(arg) {
// Leading text before the placeholder.
if placeholder.start() > start {
tokens.push(Token::Text(arg[start..placeholder.start()].to_owned()));
@ -128,24 +129,23 @@ impl TokenizedCommand {
TokenizedCommand { args: args }
}
/// Generates a ticket that is required to execute the generated command.
/// Generates and executes a command.
///
/// Using the internal `args` field, and a supplied `input` variable, arguments will be
/// collected in a Vec. Once all arguments have been processed, the Vec will be wrapped
/// within a `CommandTicket`, which will be responsible for executing the command.
pub fn generate(&self, input: &Path, out_perm: Arc<Mutex<()>>) -> CommandTicket {
/// Using the internal `args` field, and a supplied `input` variable, a `Command` will be
/// build. Once all arguments have been processed, the command is executed.
pub fn generate_and_execute(&self, input: &Path, out_perm: Arc<Mutex<()>>) {
let input = input
.strip_prefix(".")
.unwrap_or(input)
.to_string_lossy()
.into_owned();
let mut args = Vec::with_capacity(self.args.len());
for arg in &self.args {
args.push(arg.generate(&input));
let mut cmd = Command::new(self.args[0].generate(&input).as_ref());
for arg in &self.args[1..] {
cmd.arg(arg.generate(&input).as_ref());
}
CommandTicket::new(args, out_perm)
execute_command(cmd, out_perm)
}
}

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@ -1,126 +0,0 @@
// Copyright (c) 2017 fd developers
// 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. All files in the project carrying such
// notice may not be copied, modified, or distributed except
// according to those terms.
use std::process::Command;
use std::sync::{Arc, Mutex};
use std::io;
/// A state that offers access to executing a generated command.
///
/// The ticket holds the collection of arguments of a command to be executed.
pub struct CommandTicket {
args: Vec<String>,
out_perm: Arc<Mutex<()>>,
}
impl CommandTicket {
pub fn new<I, S>(args: I, out_perm: Arc<Mutex<()>>) -> CommandTicket
where
I: IntoIterator<Item = S>,
S: AsRef<str>,
{
CommandTicket {
args: args.into_iter().map(|x| x.as_ref().to_owned()).collect(),
out_perm: out_perm,
}
}
/// Executes the command stored within the ticket.
#[cfg(not(unix))]
pub fn then_execute(self) {
use std::process::Stdio;
use std::io::Write;
// Spawn the supplied command.
let cmd = Command::new(&self.args[0])
.args(&self.args[1..])
.stdout(Stdio::piped())
.stderr(Stdio::piped())
.output();
// Then wait for the command to exit, if it was spawned.
match cmd {
Ok(output) => {
// While this lock is active, this thread will be the only thread allowed
// to write it's outputs.
let _lock = self.out_perm.lock().unwrap();
let stdout = io::stdout();
let stderr = io::stderr();
let _ = stdout.lock().write_all(&output.stdout);
let _ = stderr.lock().write_all(&output.stderr);
}
Err(why) => eprintln!("fd: exec error: {}", why),
}
}
#[cfg(all(unix))]
pub fn then_execute(self) {
use libc::{close, dup2, pipe, STDERR_FILENO, STDOUT_FILENO};
use std::fs::File;
use std::os::unix::process::CommandExt;
use std::os::unix::io::FromRawFd;
// Initial a pair of pipes that will be used to
// pipe the std{out,err} of the spawned process.
let mut stdout_fds = [0; 2];
let mut stderr_fds = [0; 2];
unsafe {
pipe(stdout_fds.as_mut_ptr());
pipe(stderr_fds.as_mut_ptr());
}
// Spawn the supplied command.
let cmd = Command::new(&self.args[0])
.args(&self.args[1..])
// Configure the pipes accordingly in the child.
.before_exec(move || unsafe {
// Redirect the child's std{out,err} to the write ends of our pipe.
dup2(stdout_fds[1], STDOUT_FILENO);
dup2(stderr_fds[1], STDERR_FILENO);
// Close all the fds we created here, so EOF will be sent when the program exits.
close(stdout_fds[0]);
close(stdout_fds[1]);
close(stderr_fds[0]);
close(stderr_fds[1]);
Ok(())
})
.spawn();
// Open the read end of the pipes as `File`s.
let (mut pout, mut perr) = unsafe {
// Close the write ends of the pipes in the parent
close(stdout_fds[1]);
close(stderr_fds[1]);
(
// But create files from the read ends.
File::from_raw_fd(stdout_fds[0]),
File::from_raw_fd(stderr_fds[0]),
)
};
match cmd {
Ok(mut child) => {
let _ = child.wait();
// Create a lock to ensure that this thread has exclusive access to writing.
let _lock = self.out_perm.lock().unwrap();
// And then write the outputs of the process until EOF is sent to each file.
let stdout = io::stdout();
let stderr = io::stderr();
let _ = io::copy(&mut pout, &mut stdout.lock());
let _ = io::copy(&mut perr, &mut stderr.lock());
}
Err(why) => eprintln!("fd: exec error: {}", why),
}
}
}