diff options
| -rw-r--r-- | packfile/reader.go | 36 |
1 files changed, 24 insertions, 12 deletions
diff --git a/packfile/reader.go b/packfile/reader.go index 3725822..4c110b4 100644 --- a/packfile/reader.go +++ b/packfile/reader.go @@ -123,7 +123,13 @@ func (p *PackfileReader) readInt32() (uint32, error) { } func (p *PackfileReader) readObjects(packfile *Packfile) error { + // This code has 50-80 µs of overhead per object not counting zlib inflation. + // Together with zlib inflation, it's 400-410 µs for small objects. + // That's 1 sec for ~2450 objects, ~4.20 MB, or ~250 ms per MB, + // of which 12-20 % is _not_ zlib inflation (ie. is our code). + p.startedGivingBack = true + var unknownForBytes [4]byte offset := 12 for i := 0; i < packfile.ObjectCount; i++ { @@ -135,8 +141,7 @@ func (p *PackfileReader) readObjects(packfile *Packfile) error { p.offsets[offset] = r.hash offset += r.counter + 4 - unknownForBytes := make([]byte, 4) - p.r.Read(unknownForBytes) + p.r.Read(unknownForBytes[:]) if err == io.EOF { break @@ -195,8 +200,8 @@ func (p *PackfileReader) readObject(packfile *Packfile, offset int) (*objectRead func newObjectReader(pr *PackfileReader, pf *Packfile, offset int) (*objectReader, error) { o := &objectReader{pr: pr, pf: pf, offset: offset} - buf := make([]byte, 1) - if _, err := o.Read(buf); err != nil { + var buf [1]byte + if _, err := o.Read(buf[:]); err != nil { return nil, err } @@ -205,7 +210,7 @@ func newObjectReader(pr *PackfileReader, pf *Packfile, offset int) (*objectReade var shift uint = 4 for buf[0]&0x80 == 0x80 { - if _, err := o.Read(buf); err != nil { + if _, err := o.Read(buf[:]); err != nil { return nil, err } @@ -217,8 +222,8 @@ func newObjectReader(pr *PackfileReader, pf *Packfile, offset int) (*objectReade } func (o *objectReader) readREFDelta() error { - ref := make([]byte, 20) - o.Read(ref) + var ref [20]byte + o.Read(ref[:]) buf, err := o.inflate() if err != nil { @@ -228,9 +233,9 @@ func (o *objectReader) readREFDelta() error { refhash := fmt.Sprintf("%x", ref) referenced, ok := o.pr.objects[refhash] if !ok { - o.pr.deltas = append(o.pr.deltas, packfileDelta{hash: refhash, delta: buf}) + o.pr.deltas = append(o.pr.deltas, packfileDelta{hash: refhash, delta: buf[:]}) } else { - patched := PatchDelta(referenced.bytes, buf) + patched := PatchDelta(referenced.bytes, buf[:]) if patched == nil { return NewError("error while patching %x", ref) } @@ -329,8 +334,8 @@ func (o *objectReader) addObject(bytes []byte) error { func (o *objectReader) inflate() ([]byte, error) { //Quick fix "Invalid git object tag '\x00'" when the length of a object is 0 if o.size == 0 { - buf := make([]byte, 4) - if _, err := o.Read(buf); err != nil { + var buf [4]byte + if _, err := o.Read(buf[:]); err != nil { return nil, err } @@ -352,7 +357,14 @@ func (o *objectReader) inflate() ([]byte, error) { return nil, NewError("the object size exceeed the allowed limit: %d", o.size) } - buf := make([]byte, o.size) + var arrbuf [4096]byte // Stack-allocated for <4 KB objects. + var buf []byte + if uint64(len(arrbuf)) >= o.size { + buf = arrbuf[:o.size] + } else { + buf = make([]byte, o.size) + } + read := 0 for read < int(o.size) { n, err := zr.Read(buf[read:]) |