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forgejo/modules/watcher/watcher.go
zeripath bb0ff77e46
Share HTML template renderers and create a watcher framework (#20218)
The recovery, API, Web and package frameworks all create their own HTML
Renderers. This increases the memory requirements of Gitea
unnecessarily with duplicate templates being kept in memory.

Further the reloading framework in dev mode for these involves locking
and recompiling all of the templates on each load. This will potentially
hide concurrency issues and it is inefficient.

This PR stores the templates renderer in the context and stores this
context in the NormalRoutes, it then creates a fsnotify.Watcher
framework to watch files.

The watching framework is then extended to the mailer templates which
were previously not being reloaded in dev.

Then the locales are simplified to a similar structure.

Fix #20210 
Fix #20211
Fix #20217

Signed-off-by: Andrew Thornton <art27@cantab.net>
2022-08-28 10:43:25 +01:00

115 lines
3.1 KiB
Go

// Copyright 2022 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package watcher
import (
"context"
"io/fs"
"os"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/process"
"github.com/fsnotify/fsnotify"
)
// CreateWatcherOpts are options to configure the watcher
type CreateWatcherOpts struct {
// PathsCallback is used to set the required paths to watch
PathsCallback func(func(path, name string, d fs.DirEntry, err error) error) error
// BeforeCallback is called before any files are watched
BeforeCallback func()
// Between Callback is called between after a watched event has occurred
BetweenCallback func()
// AfterCallback is called as this watcher ends
AfterCallback func()
}
// CreateWatcher creates a watcher labelled with the provided description and running with the provided options.
// The created watcher will create a subcontext from the provided ctx and register it with the process manager.
func CreateWatcher(ctx context.Context, desc string, opts *CreateWatcherOpts) {
go run(ctx, desc, opts)
}
func run(ctx context.Context, desc string, opts *CreateWatcherOpts) {
if opts.BeforeCallback != nil {
opts.BeforeCallback()
}
if opts.AfterCallback != nil {
defer opts.AfterCallback()
}
ctx, _, finished := process.GetManager().AddTypedContext(ctx, "Watcher: "+desc, process.SystemProcessType, true)
defer finished()
log.Trace("Watcher loop starting for %s", desc)
defer log.Trace("Watcher loop ended for %s", desc)
watcher, err := fsnotify.NewWatcher()
if err != nil {
log.Error("Unable to create watcher for %s: %v", desc, err)
return
}
if err := opts.PathsCallback(func(path, _ string, d fs.DirEntry, err error) error {
if err != nil && !os.IsNotExist(err) {
return err
}
log.Trace("Watcher: %s watching %q", desc, path)
_ = watcher.Add(path)
return nil
}); err != nil {
log.Error("Unable to create watcher for %s: %v", desc, err)
_ = watcher.Close()
return
}
// Note we don't call the BetweenCallback here
for {
select {
case event, ok := <-watcher.Events:
if !ok {
_ = watcher.Close()
return
}
log.Debug("Watched file for %s had event: %v", desc, event)
case err, ok := <-watcher.Errors:
if !ok {
_ = watcher.Close()
return
}
log.Error("Error whilst watching files for %s: %v", desc, err)
case <-ctx.Done():
_ = watcher.Close()
return
}
// Recreate the watcher - only call the BetweenCallback after the new watcher is set-up
_ = watcher.Close()
watcher, err = fsnotify.NewWatcher()
if err != nil {
log.Error("Unable to create watcher for %s: %v", desc, err)
return
}
if err := opts.PathsCallback(func(path, _ string, _ fs.DirEntry, err error) error {
if err != nil {
return err
}
_ = watcher.Add(path)
return nil
}); err != nil {
log.Error("Unable to create watcher for %s: %v", desc, err)
_ = watcher.Close()
return
}
// Inform our BetweenCallback that there has been an event
if opts.BetweenCallback != nil {
opts.BetweenCallback()
}
}
}