// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// +build darwin,!ios freebsd linux,!arm64 netbsd solaris windows
package accounts
import (
"time"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/rjeczalik/notify"
)
type watcher struct {
ac *addrCache
starting bool
running bool
ev chan notify.EventInfo
quit chan struct{}
}
func newWatcher(ac *addrCache) *watcher {
return &watcher{
ac: ac,
ev: make(chan notify.EventInfo, 10),
quit: make(chan struct{}),
}
}
// starts the watcher loop in the background.
// Start a watcher in the background if that's not already in progress.
// The caller must hold w.ac.mu.
func (w *watcher) start() {
if w.starting || w.running {
return
}
w.starting = true
go w.loop()
}
func (w *watcher) close() {
close(w.quit)
}
func (w *watcher) loop() {
defer func() {
w.ac.mu.Lock()
w.running = false
w.starting = false
w.ac.mu.Unlock()
}()
err := notify.Watch(w.ac.keydir, w.ev, notify.All)
if err != nil {
glog.V(logger.Detail).Infof("can't watch %s: %v", w.ac.keydir, err)
return
}
defer notify.Stop(w.ev)
glog.V(logger.Detail).Infof("now watching %s", w.ac.keydir)
defer glog.V(logger.Detail).Infof("no longer watching %s", w.ac.keydir)
w.ac.mu.Lock()
w.running = true
w.ac.mu.Unlock()
// Wait for file system events and reload.
// When an event occurs, the reload call is delayed a bit so that
// multiple events arriving quickly only cause a single reload.
var (
debounce = time.NewTimer(0)
debounceDuration = 500 * time.Millisecond
inCycle, hadEvent bool
)
defer debounce.Stop()
for {
select {
case <-w.quit:
return
case <-w.ev:
if !inCycle {
debounce.Reset(debounceDuration)
inCycle = true
} else {
hadEvent = true
}
case <-debounce.C:
w.ac.mu.Lock()
w.ac.reload()
w.ac.mu.Unlock()
if hadEvent {
debounce.Reset(debounceDuration)
inCycle, hadEvent = true, false
} else {
inCycle, hadEvent = false, false
}
}
}
}
