mirror of
https://github.com/octoleo/syncthing.git
synced 2024-11-09 14:50:56 +00:00
125 lines
3.0 KiB
Go
125 lines
3.0 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 (
|
|
"errors"
|
|
"os"
|
|
"path/filepath"
|
|
|
|
"github.com/syncthing/syncthing/lib/protocol"
|
|
"github.com/syncthing/syncthing/lib/sync"
|
|
)
|
|
|
|
// The parallel 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{}, useWeakHashes bool) {
|
|
wg := sync.NewWaitGroup()
|
|
wg.Add(workers)
|
|
|
|
for i := 0; i < workers; i++ {
|
|
go func() {
|
|
hashFiles(dir, blockSize, outbox, inbox, counter, cancel, useWeakHashes)
|
|
wg.Done()
|
|
}()
|
|
}
|
|
|
|
go func() {
|
|
wg.Wait()
|
|
if done != nil {
|
|
close(done)
|
|
}
|
|
close(outbox)
|
|
}()
|
|
}
|
|
|
|
// HashFile hashes the files and returns a list of blocks representing the file.
|
|
func HashFile(path string, blockSize int, counter Counter, useWeakHashes bool) ([]protocol.BlockInfo, error) {
|
|
fd, err := os.Open(path)
|
|
if err != nil {
|
|
l.Debugln("open:", err)
|
|
return nil, err
|
|
}
|
|
defer fd.Close()
|
|
|
|
// Get the size and modtime of the file before we start hashing it.
|
|
|
|
fi, err := fd.Stat()
|
|
if err != nil {
|
|
l.Debugln("stat before:", err)
|
|
return nil, err
|
|
}
|
|
size := fi.Size()
|
|
modTime := fi.ModTime()
|
|
|
|
// Hash the file. This may take a while for large files.
|
|
|
|
blocks, err := Blocks(fd, blockSize, size, counter, useWeakHashes)
|
|
if err != nil {
|
|
l.Debugln("blocks:", err)
|
|
return nil, err
|
|
}
|
|
|
|
// Recheck the size and modtime again. If they differ, the file changed
|
|
// while we were reading it and our hash results are invalid.
|
|
|
|
fi, err = fd.Stat()
|
|
if err != nil {
|
|
l.Debugln("stat after:", err)
|
|
return nil, err
|
|
}
|
|
if size != fi.Size() || !modTime.Equal(fi.ModTime()) {
|
|
return nil, errors.New("file changed during hashing")
|
|
}
|
|
|
|
return blocks, nil
|
|
}
|
|
|
|
func hashFiles(dir string, blockSize int, outbox, inbox chan protocol.FileInfo, counter Counter, cancel chan struct{}, useWeakHashes bool) {
|
|
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, counter, useWeakHashes)
|
|
if err != nil {
|
|
l.Debugln("hash error:", f.Name, err)
|
|
continue
|
|
}
|
|
|
|
f.Blocks = blocks
|
|
|
|
// The size we saw when initially deciding to hash the file
|
|
// might not have been the size it actually had when we hashed
|
|
// it. Update the size from the block list.
|
|
|
|
f.Size = 0
|
|
for _, b := range blocks {
|
|
f.Size += int64(b.Size)
|
|
}
|
|
|
|
select {
|
|
case outbox <- f:
|
|
case <-cancel:
|
|
return
|
|
}
|
|
|
|
case <-cancel:
|
|
return
|
|
}
|
|
}
|
|
}
|