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use cli::{clear_screen, Args};
use env_logger;
use error::Result;
use gitignore;
use log;
use notification_filter::NotificationFilter;
#[cfg(target_os = "linux")]
use notify;
use pathop::PathOp;
use process::{self, Process};
use signal::{self, Signal};
use std::{
collections::HashMap,
io::Write,
sync::{
mpsc::{channel, Receiver},
Arc, RwLock,
},
time::Duration,
};
use watcher::{Event, Watcher};
fn init_logger(debug: bool) {
let mut log_builder = env_logger::Builder::new();
let level = if debug {
log::LevelFilter::Debug
} else {
log::LevelFilter::Warn
};
log_builder
.format(|buf, r| writeln!(buf, "*** {}", r.args()))
.filter(None, level)
.init();
}
pub trait Handler {
fn new(args: Args) -> Result<Self>
where
Self: Sized;
fn on_manual(&mut self) -> Result<bool>;
fn on_update(&mut self, ops: &[PathOp]) -> Result<bool>;
}
pub fn watch<H>(args: Args) -> Result<()>
where
H: Handler,
{
init_logger(args.debug);
let mut handler = H::new(args.clone())?;
let gitignore = gitignore::load(if args.no_vcs_ignore { &[] } else { &args.paths });
let filter = NotificationFilter::new(&args.filters, &args.ignores, gitignore)?;
let (tx, rx) = channel();
let poll = args.poll.clone();
#[cfg(target_os = "linux")]
let poll_interval = args.poll_interval.clone();
let watcher = Watcher::new(tx.clone(), &args.paths, args.poll, args.poll_interval).or_else(|err| {
if poll {
return Err(err);
}
#[cfg(target_os = "linux")]
{
use nix::libc;
let mut fallback = false;
if let notify::Error::Io(ref e) = err {
if e.raw_os_error() == Some(libc::ENOSPC) {
warn!("System notification limit is too small, falling back to polling mode. For better performance increase system limit:\n\tsysctl fs.inotify.max_user_watches=524288");
fallback = true;
}
}
if fallback {
return Watcher::new(tx, &args.paths, true, poll_interval);
}
}
Err(err)
})?;
if watcher.is_polling() {
warn!("Polling for changes every {} ms", args.poll_interval);
}
if args.run_initially && !args.once {
if !handler.on_manual()? {
return Ok(());
}
}
loop {
debug!("Waiting for filesystem activity");
let paths = wait_fs(&rx, &filter, args.debounce);
debug!("Paths updated: {:?}", paths);
if !handler.on_update(&paths)? {
break;
}
}
Ok(())
}
pub struct ExecHandler {
args: Args,
signal: Option<Signal>,
child_process: Arc<RwLock<Option<Process>>>,
}
impl ExecHandler {
fn spawn(&mut self, ops: &[PathOp]) -> Result<()> {
if self.args.clear_screen {
clear_screen();
}
debug!("Launching child process");
let mut guard = self.child_process.write()?;
*guard = Some(process::spawn(&self.args.cmd, ops, self.args.no_shell)?);
Ok(())
}
}
impl Handler for ExecHandler {
fn new(args: Args) -> Result<Self> {
let child_process: Arc<RwLock<Option<Process>>> = Arc::new(RwLock::new(None));
let weak_child = Arc::downgrade(&child_process);
let signal = signal::new(args.signal.clone());
signal::install_handler(move |sig: Signal| {
if let Some(lock) = weak_child.upgrade() {
let strong = lock.read().unwrap();
if let Some(ref child) = *strong {
match sig {
Signal::SIGCHLD => child.reap(),
_ => child.signal(sig),
}
}
}
});
Ok(Self {
args,
signal,
child_process,
})
}
fn on_manual(&mut self) -> Result<bool> {
let cls = self.args.clear_screen;
self.args.clear_screen = false;
self.spawn(&[])?;
self.args.clear_screen = cls;
Ok(true)
}
fn on_update(&mut self, ops: &[PathOp]) -> Result<bool> {
let scenario = (self.args.restart, self.signal.is_some());
match scenario {
(true, true) => {
signal_process(&self.child_process, self.signal, true);
self.spawn(ops)?;
}
(true, false) => {
let sigterm = signal::new(Some("SIGTERM".into()));
signal_process(&self.child_process, sigterm, true);
self.spawn(ops)?;
}
(false, true) => signal_process(&self.child_process, self.signal, false),
(false, false) => {
signal_process(&self.child_process, None, true);
self.spawn(ops)?;
}
}
if self.args.once {
signal_process(&self.child_process, self.signal, false);
return Ok(false);
}
Ok(true)
}
}
pub fn run(args: Args) -> Result<()> {
watch::<ExecHandler>(args)
}
fn wait_fs(rx: &Receiver<Event>, filter: &NotificationFilter, debounce: u64) -> Vec<PathOp> {
let mut paths = Vec::new();
let mut cache = HashMap::new();
loop {
let e = rx.recv().expect("error when reading event");
if let Some(ref path) = e.path {
let pathop = PathOp::new(path, e.op.ok(), e.cookie);
let excluded = filter.is_excluded(path);
if !cache.contains_key(&pathop) {
cache.insert(pathop.clone(), excluded);
}
if !excluded {
paths.push(pathop);
break;
}
}
}
let timeout = Duration::from_millis(debounce);
while let Ok(e) = rx.recv_timeout(timeout) {
if let Some(ref path) = e.path {
let pathop = PathOp::new(path, e.op.ok(), e.cookie);
if cache.contains_key(&pathop) {
continue;
}
let excluded = filter.is_excluded(path);
cache.insert(pathop.clone(), excluded);
if !excluded {
paths.push(pathop);
}
}
}
paths
}
fn signal_process(process: &RwLock<Option<Process>>, signal: Option<Signal>, wait: bool) {
let guard = process.read().unwrap();
if let Some(ref child) = *guard {
if let Some(s) = signal {
child.signal(s);
}
if wait {
debug!("Waiting for process to exit...");
child.wait();
}
}
}