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Reuse byte buffer in WriteChunks and writeHash (#653) 

* Re-use byte buffer in WriteChunks and writeHash

Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>

* Add CHANGELOG entry

Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>

* Fix review comments

Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>

* Remove old comment

Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
This commit is contained in:
Ganesh Vernekar 2019-07-12 18:42:34 +05:30 committed by GitHub
parent 45ee02add5
commit 3bc1ea3d75
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 11 additions and 12 deletions
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23
chunks/chunks.go
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@ -57,8 +57,9 @@ type Meta struct {
} }
// writeHash writes the chunk encoding and raw data into the provided hash. // writeHash writes the chunk encoding and raw data into the provided hash.
func (cm *Meta) writeHash(h hash.Hash) error { func (cm *Meta) writeHash(h hash.Hash, buf []byte) error {
if _, err := h.Write([]byte{byte(cm.Chunk.Encoding())}); err != nil { buf = append(buf[:0], byte(cm.Chunk.Encoding()))
if _, err := h.Write(buf[:1]); err != nil {
return err return err
} }
if _, err := h.Write(cm.Chunk.Bytes()); err != nil { if _, err := h.Write(cm.Chunk.Bytes()); err != nil {
@ -97,6 +98,7 @@ type Writer struct {
wbuf *bufio.Writer wbuf *bufio.Writer
n int64 n int64
crc32 hash.Hash crc32 hash.Hash
buf [binary.MaxVarintLen32]byte
segmentSize int64 segmentSize int64
} }
@ -299,22 +301,19 @@ func (w *Writer) WriteChunks(chks ...Meta) error {
} }
} }
var ( var seq = uint64(w.seq()) << 32
b = [binary.MaxVarintLen32]byte{}
seq = uint64(w.seq()) << 32
)
for i := range chks { for i := range chks {
chk := &chks[i] chk := &chks[i]
chk.Ref = seq | uint64(w.n) chk.Ref = seq | uint64(w.n)
n := binary.PutUvarint(b[:], uint64(len(chk.Chunk.Bytes()))) n := binary.PutUvarint(w.buf[:], uint64(len(chk.Chunk.Bytes())))
if err := w.write(b[:n]); err != nil { if err := w.write(w.buf[:n]); err != nil {
return err return err
} }
b[0] = byte(chk.Chunk.Encoding()) w.buf[0] = byte(chk.Chunk.Encoding())
if err := w.write(b[:1]); err != nil { if err := w.write(w.buf[:1]); err != nil {
return err return err
} }
if err := w.write(chk.Chunk.Bytes()); err != nil { if err := w.write(chk.Chunk.Bytes()); err != nil {
@ -322,10 +321,10 @@ func (w *Writer) WriteChunks(chks ...Meta) error {
} }
w.crc32.Reset() w.crc32.Reset()
if err := chk.writeHash(w.crc32); err != nil { if err := chk.writeHash(w.crc32, w.buf[:]); err != nil {
return err return err
} }
if err := w.write(w.crc32.Sum(b[:0])); err != nil { if err := w.write(w.crc32.Sum(w.buf[:0])); err != nil {
return err return err
} }
} }