cloudflared/vendor/github.com/nxadm/tail/watch/filechanges.go
Sudarsan Reddy 414cb12f02 TUN-4961: Update quic-go to latest
- Updates fips-go to be the latest on cfsetup.yaml
- Updates sumtype's x/tools to be latest to avoid Internal: nil pkg
  errors with fips.
2021-08-27 12:26:00 +01:00

38 lines
1.0 KiB
Go

// Copyright (c) 2019 FOSS contributors of https://github.com/nxadm/tail
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:
}
}