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go/internal/lsp/cache/watcher.go
Rebecca Stambler 0bbdf54eff internal/lsp: modify approach to watching changed files
This change modifies the invalidContent function to take a file change
type. This allows us to eliminate the separate invalidateMetadata
function. The logic of watching changed files is then further pushed
into the caching layer.

Updates golang/go#34218

Change-Id: Id31b3931c45ec408b6e7b4a362e00f9091ba4f70
Reviewed-on: https://go-review.googlesource.com/c/tools/+/201221
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
2019-10-22 21:33:45 +00:00

67 lines
1.5 KiB
Go

// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package cache
import (
"sync"
"golang.org/x/tools/internal/lsp/protocol"
)
type watcher struct {
id uint64
callback func(changeType protocol.FileChangeType) bool
}
type WatchMap struct {
mu sync.Mutex
nextID uint64
watchers map[interface{}][]watcher
}
func NewWatchMap() *WatchMap {
return &WatchMap{watchers: make(map[interface{}][]watcher)}
}
func (w *WatchMap) Watch(key interface{}, callback func(protocol.FileChangeType) bool) func() {
w.mu.Lock()
defer w.mu.Unlock()
id := w.nextID
w.nextID++
w.watchers[key] = append(w.watchers[key], watcher{
id: id,
callback: callback,
})
return func() {
// unwatch if invoked
w.mu.Lock()
defer w.mu.Unlock()
// find and delete the watcher entry
entries := w.watchers[key]
for i, entry := range entries {
if entry.id == id {
// found it
entries[i] = entries[len(entries)-1]
entries = entries[:len(entries)-1]
}
}
}
}
func (w *WatchMap) Notify(key interface{}, changeType protocol.FileChangeType) bool {
// Make a copy of the watcher callbacks so we don't need to hold
// the mutex during the callbacks (to avoid deadlocks).
w.mu.Lock()
entries := w.watchers[key]
entriesCopy := make([]watcher, len(entries))
copy(entriesCopy, entries)
w.mu.Unlock()
var result bool
for _, entry := range entriesCopy {
result = entry.callback(changeType) || result
}
return result
}