# HG changeset patch
# User Yuya Nishihara <y...@tcha.org>
# Date 1538824244 -32400
# Sat Oct 06 20:10:44 2018 +0900
# Node ID 389e082b48ba5a543a2c0497963cca4231e22504
# Parent 83ae46b307d87085a0a0f8224f021adf7788050d
rust-chg: spawn server process if not running
This is the minimal reimplementation of gethgcmd(), execcmdserver(),
retryconnectcmdserver(), and connectcmdserver() in chg.c.
No config validation is yet implemented.
diff --git a/rust/chg/src/lib.rs b/rust/chg/src/lib.rs
--- a/rust/chg/src/lib.rs
+++ b/rust/chg/src/lib.rs
@@ -7,9 +7,12 @@ extern crate bytes;
#[macro_use]
extern crate futures;
extern crate libc;
+#[macro_use]
+extern crate log;
extern crate tokio;
extern crate tokio_hglib;
extern crate tokio_process;
+extern crate tokio_timer;
mod attachio;
mod clientext;
diff --git a/rust/chg/src/locator.rs b/rust/chg/src/locator.rs
--- a/rust/chg/src/locator.rs
+++ b/rust/chg/src/locator.rs
@@ -5,6 +5,7 @@
//! Utility for locating command-server process.
+use futures::future::{self, Either, Loop};
use std::env;
use std::ffi::{OsStr, OsString};
use std::fs::{self, DirBuilder};
@@ -12,8 +13,12 @@ use std::io;
use std::os::unix::ffi::{OsStrExt, OsStringExt};
use std::os::unix::fs::{DirBuilderExt, MetadataExt};
use std::path::{Path, PathBuf};
-use std::process;
+use std::process::{self, Command};
use std::time::Duration;
+use tokio::prelude::*;
+use tokio_hglib::UnixClient;
+use tokio_process::{Child, CommandExt};
+use tokio_timer;
use super::procutil;
@@ -52,13 +57,106 @@ impl Locator {
buf.extend_from_slice(format!(".{}", self.process_id).as_bytes());
OsString::from_vec(buf).into()
}
+
+ /// Connects to the server.
+ ///
+ /// The server process will be spawned if not running.
+ pub fn connect(self) -> impl Future<Item = (Self, UnixClient), Error =
io::Error> {
+ self.try_connect()
+ }
+
+ /// Tries to connect to the existing server, or spawns new if not running.
+ fn try_connect(self) -> impl Future<Item = (Self, UnixClient), Error =
io::Error> {
+ debug!("try connect to {}", self.base_sock_path.display());
+ UnixClient::connect(self.base_sock_path.clone())
+ .then(|res| {
+ match res {
+ Ok(client) => Either::A(future::ok((self, client))),
+ Err(_) => Either::B(self.spawn_connect()),
+ }
+ })
+ }
+
+ /// Spawns new server process and connects to it.
+ ///
+ /// The server will be spawned at the current working directory, then
+ /// chdir to "/", so that the server will load configs from the target
+ /// repository.
+ fn spawn_connect(self) -> impl Future<Item = (Self, UnixClient), Error =
io::Error> {
+ let sock_path = self.temp_sock_path();
+ debug!("start cmdserver at {}", sock_path.display());
+ Command::new(&self.hg_command)
+ .arg("serve")
+ .arg("--cmdserver").arg("chgunix")
+ .arg("--address").arg(&sock_path)
+ .arg("--daemon-postexec").arg("chdir:/")
+ .current_dir(&self.current_dir)
+ .env_clear()
+ .envs(self.env_vars.iter().cloned())
+ .env("CHGINTERNALMARK", "")
+ .spawn_async()
+ .into_future()
+ .and_then(|server| self.connect_spawned(server, sock_path))
+ .and_then(|(loc, client, sock_path)| {
+ debug!("rename {} to {}", sock_path.display(),
loc.base_sock_path.display());
+ fs::rename(&sock_path, &loc.base_sock_path)?;
+ Ok((loc, client))
+ })
+ }
+
+ /// Tries to connect to the just spawned server repeatedly until timeout
+ /// exceeded.
+ fn connect_spawned(self, server: Child, sock_path: PathBuf)
+ -> impl Future<Item = (Self, UnixClient, PathBuf),
Error = io::Error> {
+ debug!("try connect to {} repeatedly", sock_path.display());
+ let connect = future::loop_fn(sock_path, |sock_path| {
+ UnixClient::connect(sock_path.clone())
+ .then(|res| {
+ match res {
+ Ok(client) => {
+ Either::A(future::ok(Loop::Break((client,
sock_path))))
+ }
+ Err(_) => {
+ // try again with slight delay
+ let fut =
tokio_timer::sleep(Duration::from_millis(10))
+ .map(|()| Loop::Continue(sock_path))
+ .map_err(|err|
io::Error::new(io::ErrorKind::Other, err));
+ Either::B(fut)
+ }
+ }
+ })
+ });
+
+ // waits for either connection established or server failed to start
+ connect.select2(server)
+ .map_err(|res| res.split().0)
+ .timeout(self.timeout)
+ .map_err(|err| {
+ err.into_inner().unwrap_or_else(|| {
+ io::Error::new(io::ErrorKind::TimedOut,
+ "timed out while connecting to server")
+ })
+ })
+ .and_then(|res| {
+ match res {
+ Either::A(((client, sock_path), server)) => {
+ server.forget(); // continue to run in background
+ Ok((self, client, sock_path))
+ }
+ Either::B((st, _)) => {
+ Err(io::Error::new(io::ErrorKind::Other,
+ format!("server exited too early:
{}", st)))
+ }
+ }
+ })
+ }
}
/// Determines the server socket to connect to.
///
/// If no `$CHGSOCKNAME` is specified, the socket directory will be created
/// as necessary.
-pub fn prepare_server_socket_path() -> io::Result<PathBuf> {
+fn prepare_server_socket_path() -> io::Result<PathBuf> {
if let Some(s) = env::var_os("CHGSOCKNAME") {
Ok(PathBuf::from(s))
} else {
diff --git a/rust/chg/src/main.rs b/rust/chg/src/main.rs
--- a/rust/chg/src/main.rs
+++ b/rust/chg/src/main.rs
@@ -10,7 +10,7 @@ extern crate tokio;
extern crate tokio_hglib;
use chg::{ChgClientExt, ChgUiHandler};
-use chg::locator;
+use chg::locator::Locator;
use chg::procutil;
use futures::sync::oneshot;
use std::env;
@@ -18,7 +18,6 @@ use std::io;
use std::process;
use std::time::Instant;
use tokio::prelude::*;
-use tokio_hglib::UnixClient;
struct DebugLogger {
start: Instant,
@@ -58,6 +57,8 @@ fn main() {
log::set_max_level(log::LevelFilter::Debug);
}
+ // TODO: add loop detection by $CHGINTERNALMARK
+
let code = run().unwrap_or_else(|err| {
writeln!(io::stderr(), "chg: abort: {}", err).unwrap_or(());
255
@@ -67,11 +68,11 @@ fn main() {
fn run() -> io::Result<i32> {
let current_dir = env::current_dir()?;
- let sock_path = locator::prepare_server_socket_path()?;
+ let loc = Locator::prepare_from_env()?;
let handler = ChgUiHandler::new();
let (result_tx, result_rx) = oneshot::channel();
- let fut = UnixClient::connect(sock_path)
- .and_then(|client| {
+ let fut = loc.connect()
+ .and_then(|(_, client)| {
client.set_current_dir(current_dir)
})
.and_then(|client| {
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