TheArchive/restic
1
0
Fork 0
mirror of https://github.com/restic/restic.git synced 2025-12-10 01:12:31 +00:00
Code Issues Packages Projects Releases Wiki Activity

repository/master_index: Optimize Index.Lookup()

Browse Source 
When looking up a blob in the master index, with several
indexes present in the master index, a significant amount of time
is spent generating errors for each failed lookup.  However, these
errors are often used to check if a blob is present, but the contents
are not inspected making the overhead of the error not useful.

Instead, change Index.Lookup (and Index.LookupSize) to instead return
a boolean denoting if the blob was found instead of an error.  Also change
all the calls to these functions to handle the new function signature.

benchmark                                            old ns/op     new ns/op     delta
BenchmarkMasterIndexLookupSingleIndex-6              820           897           +9.39%
BenchmarkMasterIndexLookupMultipleIndex-6            12821         2001          -84.39%
BenchmarkMasterIndexLookupSingleIndexUnknown-6       5378          492           -90.85%
BenchmarkMasterIndexLookupMultipleIndexUnknown-6     17026         1649          -90.31%

benchmark                                            old allocs     new allocs     delta
BenchmarkMasterIndexLookupSingleIndex-6              9              9              +0.00%
BenchmarkMasterIndexLookupMultipleIndex-6            59             19             -67.80%
BenchmarkMasterIndexLookupSingleIndexUnknown-6       22             6              -72.73%
BenchmarkMasterIndexLookupMultipleIndexUnknown-6     72             16             -77.78%

benchmark                                            old bytes     new bytes     delta
BenchmarkMasterIndexLookupSingleIndex-6              160           160           +0.00%
BenchmarkMasterIndexLookupMultipleIndex-6            3200          240           -92.50%
BenchmarkMasterIndexLookupSingleIndexUnknown-6       1232          48            -96.10%
BenchmarkMasterIndexLookupMultipleIndexUnknown-6     4272          128           -97.00%
This commit is contained in:
Matthew Dawson
2018-01-12 01:20:12 -05:00
parent ebce4b2581
commit df2c03a6a4
15 changed files with 192 additions and 68 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
cmd/restic/cmd_cat.go
View File

@@ -165,8 +165,8 @@ func runCat(gopts GlobalOptions, args []string) error {
case "blob":
for _, t := range []restic.BlobType{restic.DataBlob, restic.TreeBlob} {
list, err := repo.Index().Lookup(id, t)
if err != nil {
list, found := repo.Index().Lookup(id, t)
if !found {
continue
}
blob := list[0]

6
cmd/restic/cmd_diff.go
View File

@@ -135,9 +135,9 @@ func updateBlobs(repo restic.Repository, blobs restic.BlobSet, stats *DiffStat)
stats.TreeBlobs++
}
size, err := repo.LookupBlobSize(h.ID, h.Type)
if err != nil {
Warnf("unable to find blob size for %v: %v\n", h, err)
size, found := repo.LookupBlobSize(h.ID, h.Type)
if !found {
Warnf("unable to find blob size for %v\n", h)
continue
}

6
cmd/restic/cmd_dump.go
View File

@@ -59,9 +59,9 @@ func splitPath(path string) []string {
func dumpNode(ctx context.Context, repo restic.Repository, node *restic.Node) error {
var buf []byte
for _, id := range node.Content {
size, err := repo.LookupBlobSize(id, restic.DataBlob)
if err != nil {
return err
size, found := repo.LookupBlobSize(id, restic.DataBlob)
if !found {
return errors.Errorf("id %v not found in repository", id)
}
buf = buf[:cap(buf)]