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Code Issues Releases Wiki Activity

prune: move logic into repository package

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This commit is contained in:
Michael Eischer 2024-04-06 19:21:21 +02:00
parent df9d4b455d
commit fc3b548625
4 changed files with 599 additions and 599 deletions
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576
cmd/restic/cmd_prune.go
View File

@ -4,14 +4,11 @@ import (
"context"
"math"
"runtime"
"sort"
"strconv"
"strings"
"github.com/restic/restic/internal/debug"
"github.com/restic/restic/internal/errors"
"github.com/restic/restic/internal/index"
"github.com/restic/restic/internal/pack"
"github.com/restic/restic/internal/repository"
"github.com/restic/restic/internal/restic"
"github.com/restic/restic/internal/ui"
@ -21,10 +18,6 @@ import (
"github.com/spf13/cobra"
)
var errorIndexIncomplete = errors.Fatal("index is not complete")
var errorPacksMissing = errors.Fatal("packs from index missing in repo")
var errorSizeNotMatching = errors.Fatal("pack size does not match calculated size from index")
var cmdPrune = &cobra.Command{
Use: "prune [flags]",
Short: "Remove unneeded data from the repository",
@ -194,14 +187,26 @@ func runPruneWithRepo(ctx context.Context, opts PruneOptions, gopts GlobalOption
return err
}
plan, stats, err := PlanPrune(ctx, opts, repo, func(ctx context.Context, repo restic.Repository) (usedBlobs restic.CountedBlobSet, err error) {
popts := repository.PruneOptions{
DryRun: opts.DryRun,
UnsafeRecovery: opts.unsafeRecovery,
MaxUnusedBytes: opts.maxUnusedBytes,
MaxRepackBytes: opts.MaxRepackBytes,
RepackCachableOnly: opts.RepackCachableOnly,
RepackSmall: opts.RepackSmall,
RepackUncompressed: opts.RepackUncompressed,
}
plan, stats, err := repository.PlanPrune(ctx, popts, repo, func(ctx context.Context, repo restic.Repository) (usedBlobs restic.CountedBlobSet, err error) {
return getUsedBlobs(ctx, repo, ignoreSnapshots, printer)
}, printer)
if err != nil {
return err
}
if opts.DryRun {
if popts.DryRun {
printer.P("\nWould have made the following changes:")
}
@ -213,459 +218,11 @@ func runPruneWithRepo(ctx context.Context, opts PruneOptions, gopts GlobalOption
// Trigger GC to reset garbage collection threshold
runtime.GC()
return DoPrune(ctx, opts, repo, plan, printer)
}
type PruneStats struct {
Blobs struct {
Used uint
Duplicate uint
Unused uint
Remove uint
Repack uint
Repackrm uint
}
Size struct {
Used uint64
Duplicate uint64
Unused uint64
Remove uint64
Repack uint64
Repackrm uint64
Unref uint64
Uncompressed uint64
}
Packs struct {
Used uint
Unused uint
PartlyUsed uint
Unref uint
Keep uint
Repack uint
Remove uint
}
}
type PrunePlan struct {
removePacksFirst restic.IDSet // packs to remove first (unreferenced packs)
repackPacks restic.IDSet // packs to repack
keepBlobs restic.CountedBlobSet // blobs to keep during repacking
removePacks restic.IDSet // packs to remove
ignorePacks restic.IDSet // packs to ignore when rebuilding the index
}
type packInfo struct {
usedBlobs uint
unusedBlobs uint
usedSize uint64
unusedSize uint64
tpe restic.BlobType
uncompressed bool
}
type packInfoWithID struct {
ID restic.ID
packInfo
mustCompress bool
}
// PlanPrune selects which files to rewrite and which to delete and which blobs to keep.
// Also some summary statistics are returned.
func PlanPrune(ctx context.Context, opts PruneOptions, repo restic.Repository, getUsedBlobs func(ctx context.Context, repo restic.Repository) (usedBlobs restic.CountedBlobSet, err error), printer progress.Printer) (PrunePlan, PruneStats, error) {
var stats PruneStats
usedBlobs, err := getUsedBlobs(ctx, repo)
if err != nil {
return PrunePlan{}, stats, err
}
printer.P("searching used packs...\n")
keepBlobs, indexPack, err := packInfoFromIndex(ctx, repo.Index(), usedBlobs, &stats, printer)
if err != nil {
return PrunePlan{}, stats, err
}
printer.P("collecting packs for deletion and repacking\n")
plan, err := decidePackAction(ctx, opts, repo, indexPack, &stats, printer)
if err != nil {
return PrunePlan{}, stats, err
}
if len(plan.repackPacks) != 0 {
blobCount := keepBlobs.Len()
// when repacking, we do not want to keep blobs which are
// already contained in kept packs, so delete them from keepBlobs
repo.Index().Each(ctx, func(blob restic.PackedBlob) {
if plan.removePacks.Has(blob.PackID) || plan.repackPacks.Has(blob.PackID) {
return
}
keepBlobs.Delete(blob.BlobHandle)
})
if keepBlobs.Len() < blobCount/2 {
// replace with copy to shrink map to necessary size if there's a chance to benefit
keepBlobs = keepBlobs.Copy()
}
} else {
// keepBlobs is only needed if packs are repacked
keepBlobs = nil
}
plan.keepBlobs = keepBlobs
return plan, stats, nil
}
func packInfoFromIndex(ctx context.Context, idx restic.MasterIndex, usedBlobs restic.CountedBlobSet, stats *PruneStats, printer progress.Printer) (restic.CountedBlobSet, map[restic.ID]packInfo, error) {
// iterate over all blobs in index to find out which blobs are duplicates
// The counter in usedBlobs describes how many instances of the blob exist in the repository index
// Thus 0 == blob is missing, 1 == blob exists once, >= 2 == duplicates exist
idx.Each(ctx, func(blob restic.PackedBlob) {
bh := blob.BlobHandle
count, ok := usedBlobs[bh]
if ok {
if count < math.MaxUint8 {
// don't overflow, but saturate count at 255
// this can lead to a non-optimal pack selection, but won't cause
// problems otherwise
count++
}
usedBlobs[bh] = count
}
})
// Check if all used blobs have been found in index
missingBlobs := restic.NewBlobSet()
for bh, count := range usedBlobs {
if count == 0 {
// blob does not exist in any pack files
missingBlobs.Insert(bh)
}
}
if len(missingBlobs) != 0 {
printer.E("%v not found in the index\n\n"+
"Integrity check failed: Data seems to be missing.\n"+
"Will not start prune to prevent (additional) data loss!\n"+
"Please report this error (along with the output of the 'prune' run) at\n"+
"https://github.com/restic/restic/issues/new/choose\n", missingBlobs)
return nil, nil, errorIndexIncomplete
}
indexPack := make(map[restic.ID]packInfo)
// save computed pack header size
for pid, hdrSize := range pack.Size(ctx, idx, true) {
// initialize tpe with NumBlobTypes to indicate it's not set
indexPack[pid] = packInfo{tpe: restic.NumBlobTypes, usedSize: uint64(hdrSize)}
}
hasDuplicates := false
// iterate over all blobs in index to generate packInfo
idx.Each(ctx, func(blob restic.PackedBlob) {
ip := indexPack[blob.PackID]
// Set blob type if not yet set
if ip.tpe == restic.NumBlobTypes {
ip.tpe = blob.Type
}
// mark mixed packs with "Invalid blob type"
if ip.tpe != blob.Type {
ip.tpe = restic.InvalidBlob
}
bh := blob.BlobHandle
size := uint64(blob.Length)
dupCount := usedBlobs[bh]
switch {
case dupCount >= 2:
hasDuplicates = true
// mark as unused for now, we will later on select one copy
ip.unusedSize += size
ip.unusedBlobs++
// count as duplicate, will later on change one copy to be counted as used
stats.Size.Duplicate += size
stats.Blobs.Duplicate++
case dupCount == 1: // used blob, not duplicate
ip.usedSize += size
ip.usedBlobs++
stats.Size.Used += size
stats.Blobs.Used++
default: // unused blob
ip.unusedSize += size
ip.unusedBlobs++
stats.Size.Unused += size
stats.Blobs.Unused++
}
if !blob.IsCompressed() {
ip.uncompressed = true
}
// update indexPack
indexPack[blob.PackID] = ip
})
// if duplicate blobs exist, those will be set to either "used" or "unused":
// - mark only one occurrence of duplicate blobs as used
// - if there are already some used blobs in a pack, possibly mark duplicates in this pack as "used"
// - if there are no used blobs in a pack, possibly mark duplicates as "unused"
if hasDuplicates {
// iterate again over all blobs in index (this is pretty cheap, all in-mem)
idx.Each(ctx, func(blob restic.PackedBlob) {
bh := blob.BlobHandle
count, ok := usedBlobs[bh]
// skip non-duplicate, aka. normal blobs
// count == 0 is used to mark that this was a duplicate blob with only a single occurrence remaining
if !ok || count == 1 {
return
}
ip := indexPack[blob.PackID]
size := uint64(blob.Length)
switch {
case ip.usedBlobs > 0, count == 0:
// other used blobs in pack or "last" occurrence -> transition to used
ip.usedSize += size
ip.usedBlobs++
ip.unusedSize -= size
ip.unusedBlobs--
// same for the global statistics
stats.Size.Used += size
stats.Blobs.Used++
stats.Size.Duplicate -= size
stats.Blobs.Duplicate--
// let other occurrences remain marked as unused
usedBlobs[bh] = 1
default:
// remain unused and decrease counter
count--
if count == 1 {
// setting count to 1 would lead to forgetting that this blob had duplicates
// thus use the special value zero. This will select the last instance of the blob for keeping.
count = 0
}
usedBlobs[bh] = count
}
// update indexPack
indexPack[blob.PackID] = ip
})
}
// Sanity check. If no duplicates exist, all blobs have value 1. After handling
// duplicates, this also applies to duplicates.
for _, count := range usedBlobs {
if count != 1 {
panic("internal error during blob selection")
}
}
return usedBlobs, indexPack, nil
}
func decidePackAction(ctx context.Context, opts PruneOptions, repo restic.Repository, indexPack map[restic.ID]packInfo, stats *PruneStats, printer progress.Printer) (PrunePlan, error) {
removePacksFirst := restic.NewIDSet()
removePacks := restic.NewIDSet()
repackPacks := restic.NewIDSet()
var repackCandidates []packInfoWithID
var repackSmallCandidates []packInfoWithID
repoVersion := repo.Config().Version
// only repack very small files by default
targetPackSize := repo.PackSize() / 25
if opts.RepackSmall {
// consider files with at least 80% of the target size as large enough
targetPackSize = repo.PackSize() / 5 * 4
}
// loop over all packs and decide what to do
bar := printer.NewCounter("packs processed")
bar.SetMax(uint64(len(indexPack)))
err := repo.List(ctx, restic.PackFile, func(id restic.ID, packSize int64) error {
p, ok := indexPack[id]
if !ok {
// Pack was not referenced in index and is not used => immediately remove!
printer.V("will remove pack %v as it is unused and not indexed\n", id.Str())
removePacksFirst.Insert(id)
stats.Size.Unref += uint64(packSize)
return nil
}
if p.unusedSize+p.usedSize != uint64(packSize) && p.usedBlobs != 0 {
// Pack size does not fit and pack is needed => error
// If the pack is not needed, this is no error, the pack can
// and will be simply removed, see below.
printer.E("pack %s: calculated size %d does not match real size %d\nRun 'restic repair index'.\n",
id.Str(), p.unusedSize+p.usedSize, packSize)
return errorSizeNotMatching
}
// statistics
switch {
case p.usedBlobs == 0:
stats.Packs.Unused++
case p.unusedBlobs == 0:
stats.Packs.Used++
default:
stats.Packs.PartlyUsed++
}
if p.uncompressed {
stats.Size.Uncompressed += p.unusedSize + p.usedSize
}
mustCompress := false
if repoVersion >= 2 {
// repo v2: always repack tree blobs if uncompressed
// compress data blobs if requested
mustCompress = (p.tpe == restic.TreeBlob || opts.RepackUncompressed) && p.uncompressed
}
// decide what to do
switch {
case p.usedBlobs == 0:
// All blobs in pack are no longer used => remove pack!
removePacks.Insert(id)
stats.Blobs.Remove += p.unusedBlobs
stats.Size.Remove += p.unusedSize
case opts.RepackCachableOnly && p.tpe == restic.DataBlob:
// if this is a data pack and --repack-cacheable-only is set => keep pack!
stats.Packs.Keep++
case p.unusedBlobs == 0 && p.tpe != restic.InvalidBlob && !mustCompress:
if packSize >= int64(targetPackSize) {
// All blobs in pack are used and not mixed => keep pack!
stats.Packs.Keep++
} else {
repackSmallCandidates = append(repackSmallCandidates, packInfoWithID{ID: id, packInfo: p, mustCompress: mustCompress})
}
default:
// all other packs are candidates for repacking
repackCandidates = append(repackCandidates, packInfoWithID{ID: id, packInfo: p, mustCompress: mustCompress})
}
delete(indexPack, id)
bar.Add(1)
return nil
})
bar.Done()
if err != nil {
return PrunePlan{}, err
}
// At this point indexPacks contains only missing packs!
// missing packs that are not needed can be ignored
ignorePacks := restic.NewIDSet()
for id, p := range indexPack {
if p.usedBlobs == 0 {
ignorePacks.Insert(id)
stats.Blobs.Remove += p.unusedBlobs
stats.Size.Remove += p.unusedSize
delete(indexPack, id)
}
}
if len(indexPack) != 0 {
printer.E("The index references %d needed pack files which are missing from the repository:\n", len(indexPack))
for id := range indexPack {
printer.E(" %v\n", id)
}
return PrunePlan{}, errorPacksMissing
}
if len(ignorePacks) != 0 {
printer.E("Missing but unneeded pack files are referenced in the index, will be repaired\n")
for id := range ignorePacks {
printer.E("will forget missing pack file %v\n", id)
}
}
if len(repackSmallCandidates) < 10 {
// too few small files to be worth the trouble, this also prevents endlessly repacking
// if there is just a single pack file below the target size
stats.Packs.Keep += uint(len(repackSmallCandidates))
} else {
repackCandidates = append(repackCandidates, repackSmallCandidates...)
}
// Sort repackCandidates such that packs with highest ratio unused/used space are picked first.
// This is equivalent to sorting by unused / total space.
// Instead of unused[i] / used[i] > unused[j] / used[j] we use
// unused[i] * used[j] > unused[j] * used[i] as uint32*uint32 < uint64
// Moreover packs containing trees and too small packs are sorted to the beginning
sort.Slice(repackCandidates, func(i, j int) bool {
pi := repackCandidates[i].packInfo
pj := repackCandidates[j].packInfo
switch {
case pi.tpe != restic.DataBlob && pj.tpe == restic.DataBlob:
return true
case pj.tpe != restic.DataBlob && pi.tpe == restic.DataBlob:
return false
case pi.unusedSize+pi.usedSize < uint64(targetPackSize) && pj.unusedSize+pj.usedSize >= uint64(targetPackSize):
return true
case pj.unusedSize+pj.usedSize < uint64(targetPackSize) && pi.unusedSize+pi.usedSize >= uint64(targetPackSize):
return false
}
return pi.unusedSize*pj.usedSize > pj.unusedSize*pi.usedSize
})
repack := func(id restic.ID, p packInfo) {
repackPacks.Insert(id)
stats.Blobs.Repack += p.unusedBlobs + p.usedBlobs
stats.Size.Repack += p.unusedSize + p.usedSize
stats.Blobs.Repackrm += p.unusedBlobs
stats.Size.Repackrm += p.unusedSize
if p.uncompressed {
stats.Size.Uncompressed -= p.unusedSize + p.usedSize
}
}
// calculate limit for number of unused bytes in the repo after repacking
maxUnusedSizeAfter := opts.maxUnusedBytes(stats.Size.Used)
for _, p := range repackCandidates {
reachedUnusedSizeAfter := (stats.Size.Unused-stats.Size.Remove-stats.Size.Repackrm < maxUnusedSizeAfter)
reachedRepackSize := stats.Size.Repack+p.unusedSize+p.usedSize >= opts.MaxRepackBytes
packIsLargeEnough := p.unusedSize+p.usedSize >= uint64(targetPackSize)
switch {
case reachedRepackSize:
stats.Packs.Keep++
case p.tpe != restic.DataBlob, p.mustCompress:
// repacking non-data packs / uncompressed-trees is only limited by repackSize
repack(p.ID, p.packInfo)
case reachedUnusedSizeAfter && packIsLargeEnough:
// for all other packs stop repacking if tolerated unused size is reached.
stats.Packs.Keep++
default:
repack(p.ID, p.packInfo)
}
}
stats.Packs.Unref = uint(len(removePacksFirst))
stats.Packs.Repack = uint(len(repackPacks))
stats.Packs.Remove = uint(len(removePacks))
if repo.Config().Version < 2 {
// compression not supported for repository format version 1
stats.Size.Uncompressed = 0
}
return PrunePlan{removePacksFirst: removePacksFirst,
removePacks: removePacks,
repackPacks: repackPacks,
ignorePacks: ignorePacks,
}, nil
return repository.DoPrune(ctx, popts, repo, plan, printer)
}
// printPruneStats prints out the statistics
func printPruneStats(printer progress.Printer, stats PruneStats) error {
func printPruneStats(printer progress.Printer, stats repository.PruneStats) error {
printer.V("\nused: %10d blobs / %s\n", stats.Blobs.Used, ui.FormatBytes(stats.Size.Used))
if stats.Blobs.Duplicate > 0 {
printer.V("duplicates: %10d blobs / %s\n", stats.Blobs.Duplicate, ui.FormatBytes(stats.Size.Duplicate))
@ -706,107 +263,6 @@ func printPruneStats(printer progress.Printer, stats PruneStats) error {
return nil
}
// DoPrune does the actual pruning:
// - remove unreferenced packs first
// - repack given pack files while keeping the given blobs
// - rebuild the index while ignoring all files that will be deleted
// - delete the files
// plan.removePacks and plan.ignorePacks are modified in this function.
func DoPrune(ctx context.Context, opts PruneOptions, repo restic.Repository, plan PrunePlan, printer progress.Printer) (err error) {
if opts.DryRun {
printer.V("Repeated prune dry-runs can report slightly different amounts of data to keep or repack. This is expected behavior.\n\n")
if len(plan.removePacksFirst) > 0 {
printer.V("Would have removed the following unreferenced packs:\n%v\n\n", plan.removePacksFirst)
}
printer.V("Would have repacked and removed the following packs:\n%v\n\n", plan.repackPacks)
printer.V("Would have removed the following no longer used packs:\n%v\n\n", plan.removePacks)
// Always quit here if DryRun was set!
return nil
}
// unreferenced packs can be safely deleted first
if len(plan.removePacksFirst) != 0 {
printer.P("deleting unreferenced packs\n")
DeleteFiles(ctx, repo, plan.removePacksFirst, restic.PackFile, printer)
}
if len(plan.repackPacks) != 0 {
printer.P("repacking packs\n")
bar := printer.NewCounter("packs repacked")
bar.SetMax(uint64(len(plan.repackPacks)))
_, err := repository.Repack(ctx, repo, repo, plan.repackPacks, plan.keepBlobs, bar)
bar.Done()
if err != nil {
return errors.Fatal(err.Error())
}
// Also remove repacked packs
plan.removePacks.Merge(plan.repackPacks)
if len(plan.keepBlobs) != 0 {
printer.E("%v was not repacked\n\n"+
"Integrity check failed.\n"+
"Please report this error (along with the output of the 'prune' run) at\n"+
"https://github.com/restic/restic/issues/new/choose\n", plan.keepBlobs)
return errors.Fatal("internal error: blobs were not repacked")
}
// allow GC of the blob set
plan.keepBlobs = nil
}
if len(plan.ignorePacks) == 0 {
plan.ignorePacks = plan.removePacks
} else {
plan.ignorePacks.Merge(plan.removePacks)
}
if opts.unsafeRecovery {
printer.P("deleting index files\n")
indexFiles := repo.Index().(*index.MasterIndex).IDs()
err = DeleteFilesChecked(ctx, repo, indexFiles, restic.IndexFile, printer)
if err != nil {
return errors.Fatalf("%s", err)
}
} else if len(plan.ignorePacks) != 0 {
err = rebuildIndexFiles(ctx, repo, plan.ignorePacks, nil, false, printer)
if err != nil {
return errors.Fatalf("%s", err)
}
}
if len(plan.removePacks) != 0 {
printer.P("removing %d old packs\n", len(plan.removePacks))
DeleteFiles(ctx, repo, plan.removePacks, restic.PackFile, printer)
}
if opts.unsafeRecovery {
err = rebuildIndexFiles(ctx, repo, plan.ignorePacks, nil, true, printer)
if err != nil {
return errors.Fatalf("%s", err)
}
}
printer.P("done\n")
return nil
}
func rebuildIndexFiles(ctx context.Context, repo restic.Repository, removePacks restic.IDSet, extraObsolete restic.IDs, skipDeletion bool, printer progress.Printer) error {
printer.P("rebuilding index\n")
bar := printer.NewCounter("packs processed")
return repo.Index().Save(ctx, repo, removePacks, extraObsolete, restic.MasterIndexSaveOpts{
SaveProgress: bar,
DeleteProgress: func() *progress.Counter {
return printer.NewCounter("old indexes deleted")
},
DeleteReport: func(id restic.ID, _ error) {
printer.VV("removed index %v\n", id.String())
},
SkipDeletion: skipDeletion,
})
}
func getUsedBlobs(ctx context.Context, repo restic.Repository, ignoreSnapshots restic.IDSet, printer progress.Printer) (usedBlobs restic.CountedBlobSet, err error) {
var snapshotTrees restic.IDs
printer.P("loading all snapshots...\n")

3
cmd/restic/cmd_prune_integration_test.go
View File

@ -7,6 +7,7 @@ import (
"testing"
"github.com/restic/restic/internal/backend"
"github.com/restic/restic/internal/repository"
rtest "github.com/restic/restic/internal/test"
"github.com/restic/restic/internal/ui/termstatus"
)
@ -145,7 +146,7 @@ func TestPruneWithDamagedRepository(t *testing.T) {
// prune should fail
rtest.Assert(t, withTermStatus(env.gopts, func(ctx context.Context, term *termstatus.Terminal) error {
return runPrune(context.TODO(), pruneDefaultOptions, env.gopts, term)
}) == errorPacksMissing,
}) == repository.ErrPacksMissing,
"prune should have reported index not complete error")
}

38
cmd/restic/delete.go
View File

@ -1,38 +0,0 @@
package main
import (
"context"
"github.com/restic/restic/internal/restic"
"github.com/restic/restic/internal/ui/progress"
)
// DeleteFiles deletes the given fileList of fileType in parallel
// it will print a warning if there is an error, but continue deleting the remaining files
func DeleteFiles(ctx context.Context, repo restic.Repository, fileList restic.IDSet, fileType restic.FileType, printer progress.Printer) {
_ = deleteFiles(ctx, true, repo, fileList, fileType, printer)
}
// DeleteFilesChecked deletes the given fileList of fileType in parallel
// if an error occurs, it will cancel and return this error
func DeleteFilesChecked(ctx context.Context, repo restic.Repository, fileList restic.IDSet, fileType restic.FileType, printer progress.Printer) error {
return deleteFiles(ctx, false, repo, fileList, fileType, printer)
}
// deleteFiles deletes the given fileList of fileType in parallel
// if ignoreError=true, it will print a warning if there was an error, else it will abort.
func deleteFiles(ctx context.Context, ignoreError bool, repo restic.Repository, fileList restic.IDSet, fileType restic.FileType, printer progress.Printer) error {
bar := printer.NewCounter("files deleted")
defer bar.Done()
return restic.ParallelRemove(ctx, repo, fileList, fileType, func(id restic.ID, err error) error {
if err != nil {
printer.E("unable to remove %v/%v from the repository\n", fileType, id)
if !ignoreError {
return err
}
}
printer.VV("removed %v/%v\n", fileType, id)
return nil
}, bar)
}

581
internal/repository/prune.go Normal file
View File

@ -0,0 +1,581 @@
package repository
import (
"context"
"math"
"sort"
"github.com/restic/restic/internal/errors"
"github.com/restic/restic/internal/index"
"github.com/restic/restic/internal/pack"
"github.com/restic/restic/internal/restic"
"github.com/restic/restic/internal/ui/progress"
)
var ErrIndexIncomplete = errors.Fatal("index is not complete")
var ErrPacksMissing = errors.Fatal("packs from index missing in repo")
var ErrSizeNotMatching = errors.Fatal("pack size does not match calculated size from index")
// PruneOptions collects all options for the cleanup command.
type PruneOptions struct {
DryRun bool
UnsafeRecovery bool
MaxUnusedBytes func(used uint64) (unused uint64) // calculates the number of unused bytes after repacking, according to MaxUnused
MaxRepackBytes uint64
RepackCachableOnly bool
RepackSmall bool
RepackUncompressed bool
}
type PruneStats struct {
Blobs struct {
Used uint
Duplicate uint
Unused uint
Remove uint
Repack uint
Repackrm uint
}
Size struct {
Used uint64
Duplicate uint64
Unused uint64
Remove uint64
Repack uint64
Repackrm uint64
Unref uint64
Uncompressed uint64
}
Packs struct {
Used uint
Unused uint
PartlyUsed uint
Unref uint
Keep uint
Repack uint
Remove uint
}
}
type PrunePlan struct {
removePacksFirst restic.IDSet // packs to remove first (unreferenced packs)
repackPacks restic.IDSet // packs to repack
keepBlobs restic.CountedBlobSet // blobs to keep during repacking
removePacks restic.IDSet // packs to remove
ignorePacks restic.IDSet // packs to ignore when rebuilding the index
}
type packInfo struct {
usedBlobs uint
unusedBlobs uint
usedSize uint64
unusedSize uint64
tpe restic.BlobType
uncompressed bool
}
type packInfoWithID struct {
ID restic.ID
packInfo
mustCompress bool
}
// PlanPrune selects which files to rewrite and which to delete and which blobs to keep.
// Also some summary statistics are returned.
func PlanPrune(ctx context.Context, opts PruneOptions, repo restic.Repository, getUsedBlobs func(ctx context.Context, repo restic.Repository) (usedBlobs restic.CountedBlobSet, err error), printer progress.Printer) (PrunePlan, PruneStats, error) {
var stats PruneStats
usedBlobs, err := getUsedBlobs(ctx, repo)
if err != nil {
return PrunePlan{}, stats, err
}
printer.P("searching used packs...\n")
keepBlobs, indexPack, err := packInfoFromIndex(ctx, repo.Index(), usedBlobs, &stats, printer)
if err != nil {
return PrunePlan{}, stats, err
}
printer.P("collecting packs for deletion and repacking\n")
plan, err := decidePackAction(ctx, opts, repo, indexPack, &stats, printer)
if err != nil {
return PrunePlan{}, stats, err
}
if len(plan.repackPacks) != 0 {
blobCount := keepBlobs.Len()
// when repacking, we do not want to keep blobs which are
// already contained in kept packs, so delete them from keepBlobs
repo.Index().Each(ctx, func(blob restic.PackedBlob) {
if plan.removePacks.Has(blob.PackID) || plan.repackPacks.Has(blob.PackID) {
return
}
keepBlobs.Delete(blob.BlobHandle)
})
if keepBlobs.Len() < blobCount/2 {
// replace with copy to shrink map to necessary size if there's a chance to benefit
keepBlobs = keepBlobs.Copy()
}
} else {
// keepBlobs is only needed if packs are repacked
keepBlobs = nil
}
plan.keepBlobs = keepBlobs
return plan, stats, nil
}
func packInfoFromIndex(ctx context.Context, idx restic.MasterIndex, usedBlobs restic.CountedBlobSet, stats *PruneStats, printer progress.Printer) (restic.CountedBlobSet, map[restic.ID]packInfo, error) {
// iterate over all blobs in index to find out which blobs are duplicates
// The counter in usedBlobs describes how many instances of the blob exist in the repository index
// Thus 0 == blob is missing, 1 == blob exists once, >= 2 == duplicates exist
idx.Each(ctx, func(blob restic.PackedBlob) {
bh := blob.BlobHandle
count, ok := usedBlobs[bh]
if ok {
if count < math.MaxUint8 {
// don't overflow, but saturate count at 255
// this can lead to a non-optimal pack selection, but won't cause
// problems otherwise
count++
}
usedBlobs[bh] = count
}
})
// Check if all used blobs have been found in index
missingBlobs := restic.NewBlobSet()
for bh, count := range usedBlobs {
if count == 0 {
// blob does not exist in any pack files
missingBlobs.Insert(bh)
}
}
if len(missingBlobs) != 0 {
printer.E("%v not found in the index\n\n"+
"Integrity check failed: Data seems to be missing.\n"+
"Will not start prune to prevent (additional) data loss!\n"+
"Please report this error (along with the output of the 'prune' run) at\n"+
"https://github.com/restic/restic/issues/new/choose\n", missingBlobs)
return nil, nil, ErrIndexIncomplete
}
indexPack := make(map[restic.ID]packInfo)
// save computed pack header size
for pid, hdrSize := range pack.Size(ctx, idx, true) {
// initialize tpe with NumBlobTypes to indicate it's not set
indexPack[pid] = packInfo{tpe: restic.NumBlobTypes, usedSize: uint64(hdrSize)}
}
hasDuplicates := false
// iterate over all blobs in index to generate packInfo
idx.Each(ctx, func(blob restic.PackedBlob) {
ip := indexPack[blob.PackID]
// Set blob type if not yet set
if ip.tpe == restic.NumBlobTypes {
ip.tpe = blob.Type
}
// mark mixed packs with "Invalid blob type"
if ip.tpe != blob.Type {
ip.tpe = restic.InvalidBlob
}
bh := blob.BlobHandle
size := uint64(blob.Length)
dupCount := usedBlobs[bh]
switch {
case dupCount >= 2:
hasDuplicates = true
// mark as unused for now, we will later on select one copy
ip.unusedSize += size
ip.unusedBlobs++
// count as duplicate, will later on change one copy to be counted as used
stats.Size.Duplicate += size
stats.Blobs.Duplicate++
case dupCount == 1: // used blob, not duplicate
ip.usedSize += size
ip.usedBlobs++
stats.Size.Used += size
stats.Blobs.Used++
default: // unused blob
ip.unusedSize += size
ip.unusedBlobs++
stats.Size.Unused += size
stats.Blobs.Unused++
}
if !blob.IsCompressed() {
ip.uncompressed = true
}
// update indexPack
indexPack[blob.PackID] = ip
})
// if duplicate blobs exist, those will be set to either "used" or "unused":
// - mark only one occurrence of duplicate blobs as used
// - if there are already some used blobs in a pack, possibly mark duplicates in this pack as "used"
// - if there are no used blobs in a pack, possibly mark duplicates as "unused"
if hasDuplicates {
// iterate again over all blobs in index (this is pretty cheap, all in-mem)
idx.Each(ctx, func(blob restic.PackedBlob) {
bh := blob.BlobHandle
count, ok := usedBlobs[bh]
// skip non-duplicate, aka. normal blobs
// count == 0 is used to mark that this was a duplicate blob with only a single occurrence remaining
if !ok || count == 1 {
return
}
ip := indexPack[blob.PackID]
size := uint64(blob.Length)
switch {
case ip.usedBlobs > 0, count == 0:
// other used blobs in pack or "last" occurrence -> transition to used
ip.usedSize += size
ip.usedBlobs++
ip.unusedSize -= size
ip.unusedBlobs--
// same for the global statistics
stats.Size.Used += size
stats.Blobs.Used++
stats.Size.Duplicate -= size
stats.Blobs.Duplicate--
// let other occurrences remain marked as unused
usedBlobs[bh] = 1
default:
// remain unused and decrease counter
count--
if count == 1 {
// setting count to 1 would lead to forgetting that this blob had duplicates
// thus use the special value zero. This will select the last instance of the blob for keeping.
count = 0
}
usedBlobs[bh] = count
}
// update indexPack
indexPack[blob.PackID] = ip
})
}
// Sanity check. If no duplicates exist, all blobs have value 1. After handling
// duplicates, this also applies to duplicates.
for _, count := range usedBlobs {
if count != 1 {
panic("internal error during blob selection")
}
}
return usedBlobs, indexPack, nil
}
func decidePackAction(ctx context.Context, opts PruneOptions, repo restic.Repository, indexPack map[restic.ID]packInfo, stats *PruneStats, printer progress.Printer) (PrunePlan, error) {
removePacksFirst := restic.NewIDSet()
removePacks := restic.NewIDSet()
repackPacks := restic.NewIDSet()
var repackCandidates []packInfoWithID
var repackSmallCandidates []packInfoWithID
repoVersion := repo.Config().Version
// only repack very small files by default
targetPackSize := repo.PackSize() / 25
if opts.RepackSmall {
// consider files with at least 80% of the target size as large enough
targetPackSize = repo.PackSize() / 5 * 4
}
// loop over all packs and decide what to do
bar := printer.NewCounter("packs processed")
bar.SetMax(uint64(len(indexPack)))
err := repo.List(ctx, restic.PackFile, func(id restic.ID, packSize int64) error {
p, ok := indexPack[id]
if !ok {
// Pack was not referenced in index and is not used => immediately remove!
printer.V("will remove pack %v as it is unused and not indexed\n", id.Str())
removePacksFirst.Insert(id)
stats.Size.Unref += uint64(packSize)
return nil
}
if p.unusedSize+p.usedSize != uint64(packSize) && p.usedBlobs != 0 {
// Pack size does not fit and pack is needed => error
// If the pack is not needed, this is no error, the pack can
// and will be simply removed, see below.
printer.E("pack %s: calculated size %d does not match real size %d\nRun 'restic repair index'.\n",
id.Str(), p.unusedSize+p.usedSize, packSize)
return ErrSizeNotMatching
}
// statistics
switch {
case p.usedBlobs == 0:
stats.Packs.Unused++
case p.unusedBlobs == 0:
stats.Packs.Used++
default:
stats.Packs.PartlyUsed++
}
if p.uncompressed {
stats.Size.Uncompressed += p.unusedSize + p.usedSize
}
mustCompress := false
if repoVersion >= 2 {
// repo v2: always repack tree blobs if uncompressed
// compress data blobs if requested
mustCompress = (p.tpe == restic.TreeBlob || opts.RepackUncompressed) && p.uncompressed
}
// decide what to do
switch {
case p.usedBlobs == 0:
// All blobs in pack are no longer used => remove pack!
removePacks.Insert(id)
stats.Blobs.Remove += p.unusedBlobs
stats.Size.Remove += p.unusedSize
case opts.RepackCachableOnly && p.tpe == restic.DataBlob:
// if this is a data pack and --repack-cacheable-only is set => keep pack!
stats.Packs.Keep++
case p.unusedBlobs == 0 && p.tpe != restic.InvalidBlob && !mustCompress:
if packSize >= int64(targetPackSize) {
// All blobs in pack are used and not mixed => keep pack!
stats.Packs.Keep++
} else {
repackSmallCandidates = append(repackSmallCandidates, packInfoWithID{ID: id, packInfo: p, mustCompress: mustCompress})
}
default:
// all other packs are candidates for repacking
repackCandidates = append(repackCandidates, packInfoWithID{ID: id, packInfo: p, mustCompress: mustCompress})
}
delete(indexPack, id)
bar.Add(1)
return nil
})
bar.Done()
if err != nil {
return PrunePlan{}, err
}
// At this point indexPacks contains only missing packs!
// missing packs that are not needed can be ignored
ignorePacks := restic.NewIDSet()
for id, p := range indexPack {
if p.usedBlobs == 0 {
ignorePacks.Insert(id)
stats.Blobs.Remove += p.unusedBlobs
stats.Size.Remove += p.unusedSize
delete(indexPack, id)
}
}
if len(indexPack) != 0 {
printer.E("The index references %d needed pack files which are missing from the repository:\n", len(indexPack))
for id := range indexPack {
printer.E(" %v\n", id)
}
return PrunePlan{}, ErrPacksMissing
}
if len(ignorePacks) != 0 {
printer.E("Missing but unneeded pack files are referenced in the index, will be repaired\n")
for id := range ignorePacks {
printer.E("will forget missing pack file %v\n", id)
}
}
if len(repackSmallCandidates) < 10 {
// too few small files to be worth the trouble, this also prevents endlessly repacking
// if there is just a single pack file below the target size
stats.Packs.Keep += uint(len(repackSmallCandidates))
} else {
repackCandidates = append(repackCandidates, repackSmallCandidates...)
}
// Sort repackCandidates such that packs with highest ratio unused/used space are picked first.
// This is equivalent to sorting by unused / total space.
// Instead of unused[i] / used[i] > unused[j] / used[j] we use
// unused[i] * used[j] > unused[j] * used[i] as uint32*uint32 < uint64
// Moreover packs containing trees and too small packs are sorted to the beginning
sort.Slice(repackCandidates, func(i, j int) bool {
pi := repackCandidates[i].packInfo
pj := repackCandidates[j].packInfo
switch {
case pi.tpe != restic.DataBlob && pj.tpe == restic.DataBlob:
return true
case pj.tpe != restic.DataBlob && pi.tpe == restic.DataBlob:
return false
case pi.unusedSize+pi.usedSize < uint64(targetPackSize) && pj.unusedSize+pj.usedSize >= uint64(targetPackSize):
return true
case pj.unusedSize+pj.usedSize < uint64(targetPackSize) && pi.unusedSize+pi.usedSize >= uint64(targetPackSize):
return false
}
return pi.unusedSize*pj.usedSize > pj.unusedSize*pi.usedSize
})
repack := func(id restic.ID, p packInfo) {
repackPacks.Insert(id)
stats.Blobs.Repack += p.unusedBlobs + p.usedBlobs
stats.Size.Repack += p.unusedSize + p.usedSize
stats.Blobs.Repackrm += p.unusedBlobs
stats.Size.Repackrm += p.unusedSize
if p.uncompressed {
stats.Size.Uncompressed -= p.unusedSize + p.usedSize
}
}
// calculate limit for number of unused bytes in the repo after repacking
maxUnusedSizeAfter := opts.MaxUnusedBytes(stats.Size.Used)
for _, p := range repackCandidates {
reachedUnusedSizeAfter := (stats.Size.Unused-stats.Size.Remove-stats.Size.Repackrm < maxUnusedSizeAfter)
reachedRepackSize := stats.Size.Repack+p.unusedSize+p.usedSize >= opts.MaxRepackBytes
packIsLargeEnough := p.unusedSize+p.usedSize >= uint64(targetPackSize)
switch {
case reachedRepackSize:
stats.Packs.Keep++
case p.tpe != restic.DataBlob, p.mustCompress:
// repacking non-data packs / uncompressed-trees is only limited by repackSize
repack(p.ID, p.packInfo)
case reachedUnusedSizeAfter && packIsLargeEnough:
// for all other packs stop repacking if tolerated unused size is reached.
stats.Packs.Keep++
default:
repack(p.ID, p.packInfo)
}
}
stats.Packs.Unref = uint(len(removePacksFirst))
stats.Packs.Repack = uint(len(repackPacks))
stats.Packs.Remove = uint(len(removePacks))
if repo.Config().Version < 2 {
// compression not supported for repository format version 1
stats.Size.Uncompressed = 0
}
return PrunePlan{removePacksFirst: removePacksFirst,
removePacks: removePacks,
repackPacks: repackPacks,
ignorePacks: ignorePacks,
}, nil
}
// DoPrune does the actual pruning:
// - remove unreferenced packs first
// - repack given pack files while keeping the given blobs
// - rebuild the index while ignoring all files that will be deleted
// - delete the files
// plan.removePacks and plan.ignorePacks are modified in this function.
func DoPrune(ctx context.Context, opts PruneOptions, repo restic.Repository, plan PrunePlan, printer progress.Printer) (err error) {
if opts.DryRun {
printer.V("Repeated prune dry-runs can report slightly different amounts of data to keep or repack. This is expected behavior.\n\n")
if len(plan.removePacksFirst) > 0 {
printer.V("Would have removed the following unreferenced packs:\n%v\n\n", plan.removePacksFirst)
}
printer.V("Would have repacked and removed the following packs:\n%v\n\n", plan.repackPacks)
printer.V("Would have removed the following no longer used packs:\n%v\n\n", plan.removePacks)
// Always quit here if DryRun was set!
return nil
}
// unreferenced packs can be safely deleted first
if len(plan.removePacksFirst) != 0 {
printer.P("deleting unreferenced packs\n")
_ = deleteFiles(ctx, true, repo, plan.removePacksFirst, restic.PackFile, printer)
}
if len(plan.repackPacks) != 0 {
printer.P("repacking packs\n")
bar := printer.NewCounter("packs repacked")
bar.SetMax(uint64(len(plan.repackPacks)))
_, err := Repack(ctx, repo, repo, plan.repackPacks, plan.keepBlobs, bar)
bar.Done()
if err != nil {
return errors.Fatal(err.Error())
}
// Also remove repacked packs
plan.removePacks.Merge(plan.repackPacks)
if len(plan.keepBlobs) != 0 {
printer.E("%v was not repacked\n\n"+
"Integrity check failed.\n"+
"Please report this error (along with the output of the 'prune' run) at\n"+
"https://github.com/restic/restic/issues/new/choose\n", plan.keepBlobs)
return errors.Fatal("internal error: blobs were not repacked")
}
// allow GC of the blob set
plan.keepBlobs = nil
}
if len(plan.ignorePacks) == 0 {
plan.ignorePacks = plan.removePacks
} else {
plan.ignorePacks.Merge(plan.removePacks)
}
if opts.UnsafeRecovery {
printer.P("deleting index files\n")
indexFiles := repo.Index().(*index.MasterIndex).IDs()
err = deleteFiles(ctx, false, repo, indexFiles, restic.IndexFile, printer)
if err != nil {
return errors.Fatalf("%s", err)
}
} else if len(plan.ignorePacks) != 0 {
err = rebuildIndexFiles(ctx, repo, plan.ignorePacks, nil, false, printer)
if err != nil {
return errors.Fatalf("%s", err)
}
}
if len(plan.removePacks) != 0 {
printer.P("removing %d old packs\n", len(plan.removePacks))
_ = deleteFiles(ctx, true, repo, plan.removePacks, restic.PackFile, printer)
}
if opts.UnsafeRecovery {
err = rebuildIndexFiles(ctx, repo, plan.ignorePacks, nil, true, printer)
if err != nil {
return errors.Fatalf("%s", err)
}
}
printer.P("done\n")
return nil
}
// deleteFiles deletes the given fileList of fileType in parallel
// if ignoreError=true, it will print a warning if there was an error, else it will abort.
func deleteFiles(ctx context.Context, ignoreError bool, repo restic.Repository, fileList restic.IDSet, fileType restic.FileType, printer progress.Printer) error {
bar := printer.NewCounter("files deleted")
defer bar.Done()
return restic.ParallelRemove(ctx, repo, fileList, fileType, func(id restic.ID, err error) error {
if err != nil {
printer.E("unable to remove %v/%v from the repository\n", fileType, id)
if !ignoreError {
return err
}
}
printer.VV("removed %v/%v\n", fileType, id)
return nil
}, bar)
}