syncthing/lib/scanner/blockqueue.go
2015-11-17 21:23:17 +01:00

92 lines
2.1 KiB
Go

// Copyright (C) 2014 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at http://mozilla.org/MPL/2.0/.
package scanner
import (
"os"
"path/filepath"
"github.com/syncthing/syncthing/lib/protocol"
"github.com/syncthing/syncthing/lib/sync"
)
// The parallell hasher reads FileInfo structures from the inbox, hashes the
// file to populate the Blocks element and sends it to the outbox. A number of
// workers are used in parallel. The outbox will become closed when the inbox
// is closed and all items handled.
func newParallelHasher(dir string, blockSize, workers int, outbox, inbox chan protocol.FileInfo, counter Counter, done, cancel chan struct{}) {
wg := sync.NewWaitGroup()
wg.Add(workers)
for i := 0; i < workers; i++ {
go func() {
hashFiles(dir, blockSize, outbox, inbox, counter, cancel)
wg.Done()
}()
}
go func() {
wg.Wait()
if done != nil {
close(done)
}
close(outbox)
}()
}
func HashFile(path string, blockSize int, sizeHint int64, counter Counter) ([]protocol.BlockInfo, error) {
fd, err := os.Open(path)
if err != nil {
l.Debugln("open:", err)
return []protocol.BlockInfo{}, err
}
defer fd.Close()
if sizeHint == 0 {
fi, err := fd.Stat()
if err != nil {
l.Debugln("stat:", err)
return []protocol.BlockInfo{}, err
}
sizeHint = fi.Size()
}
return Blocks(fd, blockSize, sizeHint, counter)
}
func hashFiles(dir string, blockSize int, outbox, inbox chan protocol.FileInfo, counter Counter, cancel chan struct{}) {
for {
select {
case f, ok := <-inbox:
if !ok {
return
}
if f.IsDirectory() || f.IsDeleted() {
panic("Bug. Asked to hash a directory or a deleted file.")
}
blocks, err := HashFile(filepath.Join(dir, f.Name), blockSize, f.CachedSize, counter)
if err != nil {
l.Debugln("hash error:", f.Name, err)
continue
}
f.Blocks = blocks
select {
case outbox <- f:
case <-cancel:
return
}
case <-cancel:
return
}
}
}