Merge pull request #578 from erizocosmico/perf/reduce-gc-press
packfile: improve performance a little by reducing gc pressure
diff --git a/plumbing/format/packfile/common.go b/plumbing/format/packfile/common.go
index 728cb16..7dad1f6 100644
--- a/plumbing/format/packfile/common.go
+++ b/plumbing/format/packfile/common.go
@@ -1,7 +1,9 @@
package packfile
import (
+ "bytes"
"io"
+ "sync"
"gopkg.in/src-d/go-git.v4/plumbing/storer"
"gopkg.in/src-d/go-git.v4/utils/ioutil"
@@ -49,3 +51,9 @@
_, err = io.Copy(w, packfile)
return err
}
+
+var bufPool = sync.Pool{
+ New: func() interface{} {
+ return bytes.NewBuffer(nil)
+ },
+}
diff --git a/plumbing/format/packfile/decoder.go b/plumbing/format/packfile/decoder.go
index e49de51..3d475b2 100644
--- a/plumbing/format/packfile/decoder.go
+++ b/plumbing/format/packfile/decoder.go
@@ -347,7 +347,8 @@
}
func (d *Decoder) fillREFDeltaObjectContent(obj plumbing.EncodedObject, ref plumbing.Hash) (uint32, error) {
- buf := bytes.NewBuffer(nil)
+ buf := bufPool.Get().(*bytes.Buffer)
+ buf.Reset()
_, crc, err := d.s.NextObject(buf)
if err != nil {
return 0, err
@@ -364,6 +365,7 @@
obj.SetType(base.Type())
err = ApplyDelta(obj, base, buf.Bytes())
d.cachePut(obj)
+ bufPool.Put(buf)
return crc, err
}
diff --git a/plumbing/format/packfile/diff_delta.go b/plumbing/format/packfile/diff_delta.go
index 60a04d9..7e9f822 100644
--- a/plumbing/format/packfile/diff_delta.go
+++ b/plumbing/format/packfile/diff_delta.go
@@ -60,13 +60,15 @@
// DiffDelta returns the delta that transforms src into tgt.
func DiffDelta(src []byte, tgt []byte) []byte {
- buf := bytes.NewBuffer(nil)
+ buf := bufPool.Get().(*bytes.Buffer)
+ buf.Reset()
buf.Write(deltaEncodeSize(len(src)))
buf.Write(deltaEncodeSize(len(tgt)))
sindex := initMatch(src)
- ibuf := bytes.NewBuffer(nil)
+ ibuf := bufPool.Get().(*bytes.Buffer)
+ ibuf.Reset()
for i := 0; i < len(tgt); i++ {
offset, l := findMatch(src, tgt, sindex, i)
@@ -93,8 +95,12 @@
}
encodeInsertOperation(ibuf, buf)
+ bytes := buf.Bytes()
- return buf.Bytes()
+ bufPool.Put(buf)
+ bufPool.Put(ibuf)
+
+ return bytes
}
func encodeInsertOperation(ibuf, buf *bytes.Buffer) {
diff --git a/plumbing/format/packfile/scanner.go b/plumbing/format/packfile/scanner.go
index 1dab2f2..d2d776f 100644
--- a/plumbing/format/packfile/scanner.go
+++ b/plumbing/format/packfile/scanner.go
@@ -9,6 +9,7 @@
"hash/crc32"
"io"
stdioutil "io/ioutil"
+ "sync"
"gopkg.in/src-d/go-git.v4/plumbing"
"gopkg.in/src-d/go-git.v4/utils/binary"
@@ -291,10 +292,18 @@
}
defer ioutil.CheckClose(s.zr, &err)
- n, err = io.Copy(w, s.zr)
+ buf := byteSlicePool.Get().([]byte)
+ n, err = io.CopyBuffer(w, s.zr, buf)
+ byteSlicePool.Put(buf)
return
}
+var byteSlicePool = sync.Pool{
+ New: func() interface{} {
+ return make([]byte, 32*1024)
+ },
+}
+
// SeekFromStart sets a new offset from start, returns the old position before
// the change.
func (s *Scanner) SeekFromStart(offset int64) (previous int64, err error) {
@@ -324,7 +333,9 @@
// Close reads the reader until io.EOF
func (s *Scanner) Close() error {
- _, err := io.Copy(stdioutil.Discard, s.r)
+ buf := byteSlicePool.Get().([]byte)
+ _, err := io.CopyBuffer(stdioutil.Discard, s.r, buf)
+ byteSlicePool.Put(buf)
return err
}
