forked from TrueCloudLab/restic
83 lines
2.1 KiB
Go
83 lines
2.1 KiB
Go
package index
|
|
|
|
import (
|
|
"context"
|
|
"runtime"
|
|
"sync"
|
|
|
|
"github.com/restic/restic/internal/debug"
|
|
"github.com/restic/restic/internal/restic"
|
|
"golang.org/x/sync/errgroup"
|
|
)
|
|
|
|
// ForAllIndexes loads all index files in parallel and calls the given callback.
|
|
// It is guaranteed that the function is not run concurrently. If the callback
|
|
// returns an error, this function is cancelled and also returns that error.
|
|
func ForAllIndexes(ctx context.Context, repo restic.Repository,
|
|
fn func(id restic.ID, index *Index, oldFormat bool, err error) error) error {
|
|
|
|
debug.Log("Start")
|
|
|
|
type FileInfo struct {
|
|
restic.ID
|
|
Size int64
|
|
}
|
|
|
|
var m sync.Mutex
|
|
|
|
// track spawned goroutines using wg, create a new context which is
|
|
// cancelled as soon as an error occurs.
|
|
wg, ctx := errgroup.WithContext(ctx)
|
|
|
|
ch := make(chan FileInfo)
|
|
// send list of index files through ch, which is closed afterwards
|
|
wg.Go(func() error {
|
|
defer close(ch)
|
|
return repo.List(ctx, restic.IndexFile, func(id restic.ID, size int64) error {
|
|
select {
|
|
case <-ctx.Done():
|
|
return ctx.Err()
|
|
case ch <- FileInfo{id, size}:
|
|
}
|
|
return nil
|
|
})
|
|
})
|
|
|
|
// a worker receives an index ID from ch, loads the index, and sends it to indexCh
|
|
worker := func() error {
|
|
var buf []byte
|
|
for fi := range ch {
|
|
debug.Log("worker got file %v", fi.ID.Str())
|
|
var err error
|
|
var idx *Index
|
|
oldFormat := false
|
|
|
|
if cap(buf) < int(fi.Size) {
|
|
// overallocate a bit
|
|
buf = make([]byte, fi.Size+128*1024)
|
|
}
|
|
buf, err = repo.LoadUnpacked(ctx, restic.IndexFile, fi.ID, buf[:0])
|
|
if err == nil {
|
|
idx, oldFormat, err = DecodeIndex(buf, fi.ID)
|
|
}
|
|
|
|
m.Lock()
|
|
err = fn(fi.ID, idx, oldFormat, err)
|
|
m.Unlock()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// decoding an index can take quite some time such that this can be both CPU- or IO-bound
|
|
// as the whole index is kept in memory anyways, a few workers too much don't matter
|
|
workerCount := int(repo.Connections()) + runtime.GOMAXPROCS(0)
|
|
// run workers on ch
|
|
for i := 0; i < workerCount; i++ {
|
|
wg.Go(worker)
|
|
}
|
|
|
|
return wg.Wait()
|
|
}
|