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authorMáximo Cuadros <mcuadros@gmail.com>2019-04-22 13:35:45 +0200
committerGitHub <noreply@github.com>2019-04-22 13:35:45 +0200
commit78092a2843dc534d6f5ee2048f608d84c407bf46 (patch)
tree71fa29bba0c05b9757a92643b75cd3fb035413fb /plumbing/format
parente5268e9c3c94f60e3c2008dc2ab4762c75352bfc (diff)
parent74ae8aab9157e2a661efb3c9beafac626f73672b (diff)
downloadgo-git-78092a2843dc534d6f5ee2048f608d84c407bf46.tar.gz
Merge pull request #1119 from filipnavara/idxfile-reverse-index
plumbing: idxfile, avoid unnecessary building of reverse offset/hash map
Diffstat (limited to 'plumbing/format')
-rw-r--r--plumbing/format/idxfile/idxfile.go30
1 files changed, 26 insertions, 4 deletions
diff --git a/plumbing/format/idxfile/idxfile.go b/plumbing/format/idxfile/idxfile.go
index 5fed278..26cca59 100644
--- a/plumbing/format/idxfile/idxfile.go
+++ b/plumbing/format/idxfile/idxfile.go
@@ -55,7 +55,8 @@ type MemoryIndex struct {
PackfileChecksum [20]byte
IdxChecksum [20]byte
- offsetHash map[int64]plumbing.Hash
+ offsetHash map[int64]plumbing.Hash
+ offsetHashIsFull bool
}
var _ Index = (*MemoryIndex)(nil)
@@ -121,7 +122,17 @@ func (idx *MemoryIndex) FindOffset(h plumbing.Hash) (int64, error) {
return 0, plumbing.ErrObjectNotFound
}
- return idx.getOffset(k, i)
+ offset, err := idx.getOffset(k, i)
+
+ if !idx.offsetHashIsFull {
+ // Save the offset for reverse lookup
+ if idx.offsetHash == nil {
+ idx.offsetHash = make(map[int64]plumbing.Hash)
+ }
+ idx.offsetHash[offset] = h
+ }
+
+ return offset, err
}
const isO64Mask = uint64(1) << 31
@@ -167,14 +178,24 @@ func (idx *MemoryIndex) getCRC32(firstLevel, secondLevel int) (uint32, error) {
// FindHash implements the Index interface.
func (idx *MemoryIndex) FindHash(o int64) (plumbing.Hash, error) {
+ var hash plumbing.Hash
+ var ok bool
+
+ if idx.offsetHash != nil {
+ if hash, ok = idx.offsetHash[o]; ok {
+ return hash, nil
+ }
+ }
+
// Lazily generate the reverse offset/hash map if required.
- if idx.offsetHash == nil {
+ if !idx.offsetHashIsFull || idx.offsetHash == nil {
if err := idx.genOffsetHash(); err != nil {
return plumbing.ZeroHash, err
}
+
+ hash, ok = idx.offsetHash[o]
}
- hash, ok := idx.offsetHash[o]
if !ok {
return plumbing.ZeroHash, plumbing.ErrObjectNotFound
}
@@ -190,6 +211,7 @@ func (idx *MemoryIndex) genOffsetHash() error {
}
idx.offsetHash = make(map[int64]plumbing.Hash, count)
+ idx.offsetHashIsFull = true
iter, err := idx.Entries()
if err != nil {