1
0
Fork 0
mirror of https://github.com/restic/restic.git synced 2024-12-23 16:26:11 +00:00
restic/checker/repacker.go
Alexander Neumann f53008d916 Allow saving duplicate blobs in the repacker
This adds code to the master index to allow saving duplicate blobs
within the repacker. In this mode, only the list of currently in flight
blobs is consulted, and not the index. This correct because while
repacking, a unique list of blobs is saved again to the index.
2016-01-17 21:14:55 +01:00

163 lines
4.2 KiB
Go

package checker
import (
"errors"
"github.com/restic/restic/backend"
"github.com/restic/restic/debug"
"github.com/restic/restic/repository"
)
// Repacker extracts still used blobs from packs with unused blobs and creates
// new packs.
type Repacker struct {
unusedBlobs backend.IDSet
repo *repository.Repository
}
// NewRepacker returns a new repacker that (when Repack() in run) cleans up the
// repository and creates new packs and indexs so that all blobs in unusedBlobs
// aren't used any more.
func NewRepacker(repo *repository.Repository, unusedBlobs backend.IDSet) *Repacker {
return &Repacker{
repo: repo,
unusedBlobs: unusedBlobs,
}
}
// Repack runs the process of finding still used blobs in packs with unused
// blobs, extracts them and creates new packs with just the still-in-use blobs.
func (r *Repacker) Repack() error {
debug.Log("Repacker.Repack", "searching packs for %v", r.unusedBlobs)
unneededPacks, err := FindPacksForBlobs(r.repo, r.unusedBlobs)
if err != nil {
return err
}
debug.Log("Repacker.Repack", "found packs: %v", unneededPacks)
blobs, err := FindBlobsForPacks(r.repo, unneededPacks)
if err != nil {
return err
}
debug.Log("Repacker.Repack", "found blobs: %v", blobs)
for id := range r.unusedBlobs {
debug.Log("Repacker.Repack", "remove unused blob %v", id.Str())
blobs.Delete(id)
}
debug.Log("Repacker.Repack", "need to repack blobs: %v", blobs)
err = RepackBlobs(r.repo, r.repo, blobs)
if err != nil {
return err
}
debug.Log("Repacker.Repack", "remove unneeded packs: %v", unneededPacks)
for packID := range unneededPacks {
err = r.repo.Backend().Remove(backend.Data, packID.String())
if err != nil {
return err
}
}
debug.Log("Repacker.Repack", "rebuild index, unneeded packs: %v", unneededPacks)
idx, err := r.repo.Index().RebuildIndex(unneededPacks)
newIndexID, err := repository.SaveIndex(r.repo, idx)
debug.Log("Repacker.Repack", "saved new index at %v, err %v", newIndexID.Str(), err)
if err != nil {
return err
}
debug.Log("Repacker.Repack", "remove old indexes: %v", idx.Supersedes())
for _, id := range idx.Supersedes() {
err = r.repo.Backend().Remove(backend.Index, id.String())
if err != nil {
debug.Log("Repacker.Repack", "error removing index %v: %v", id.Str(), err)
return err
}
debug.Log("Repacker.Repack", "removed index %v", id.Str())
}
return nil
}
// FindPacksForBlobs returns the set of packs that contain the blobs.
func FindPacksForBlobs(repo *repository.Repository, blobs backend.IDSet) (backend.IDSet, error) {
packs := backend.NewIDSet()
idx := repo.Index()
for id := range blobs {
blob, err := idx.Lookup(id)
if err != nil {
return nil, err
}
packs.Insert(blob.PackID)
}
return packs, nil
}
// FindBlobsForPacks returns the set of blobs contained in a pack of packs.
func FindBlobsForPacks(repo *repository.Repository, packs backend.IDSet) (backend.IDSet, error) {
blobs := backend.NewIDSet()
for packID := range packs {
for _, packedBlob := range repo.Index().ListPack(packID) {
blobs.Insert(packedBlob.ID)
}
}
return blobs, nil
}
// repackBlob loads a single blob from src and saves it in dst.
func repackBlob(src, dst *repository.Repository, id backend.ID) error {
blob, err := src.Index().Lookup(id)
if err != nil {
return err
}
debug.Log("RepackBlobs", "repacking blob %v, len %v", id.Str(), blob.PlaintextLength())
buf := make([]byte, 0, blob.PlaintextLength())
buf, err = src.LoadBlob(blob.Type, id, buf)
if err != nil {
return err
}
if uint(len(buf)) != blob.PlaintextLength() {
debug.Log("RepackBlobs", "repack blob %v: len(buf) isn't equal to length: %v = %v", id.Str(), len(buf), blob.PlaintextLength())
return errors.New("LoadBlob returned wrong data, len() doesn't match")
}
_, err = dst.SaveAndEncrypt(blob.Type, buf, &id, true)
if err != nil {
return err
}
return nil
}
// RepackBlobs reads all blobs in blobIDs from src and saves them into new pack
// files in dst. Source and destination repo may be the same.
func RepackBlobs(src, dst *repository.Repository, blobIDs backend.IDSet) (err error) {
for id := range blobIDs {
err = repackBlob(src, dst, id)
if err != nil {
return err
}
}
err = dst.Flush()
if err != nil {
return err
}
return nil
}