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package watch
type FileChanges struct {
Modified chan bool // Channel to get notified of modifications
Truncated chan bool // Channel to get notified of truncations
Deleted chan bool // Channel to get notified of deletions/renames
}
func NewFileChanges() *FileChanges {
return &FileChanges{
make(chan bool, 1), make(chan bool, 1), make(chan bool, 1)}
}
func (fc *FileChanges) NotifyModified() {
sendOnlyIfEmpty(fc.Modified)
}
func (fc *FileChanges) NotifyTruncated() {
sendOnlyIfEmpty(fc.Truncated)
}
func (fc *FileChanges) NotifyDeleted() {
sendOnlyIfEmpty(fc.Deleted)
}
// sendOnlyIfEmpty sends on a bool channel only if the channel has no
// backlog to be read by other goroutines. This concurrency pattern
// can be used to notify other goroutines if and only if they are
// looking for it (i.e., subsequent notifications can be compressed
// into one).
func sendOnlyIfEmpty(ch chan bool) {
select {
case ch <- true:
default:
}
}
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