*: Support variable length plumbing.Hash

The variable length for plumbing.Hash is defined at build time, blocked by
tag sha256.

This approach was a trade-off between keeping backwards compatibility while
making progress towards supporting SHA256 with a small amount of changes.

Relates to the SHA256 implementation, defined in #706.

Signed-off-by: Paulo Gomes <pjbgf@linux.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/plumbing/format/commitgraph/encoder.go b/plumbing/format/commitgraph/encoder.go
index bcf7d03..f61025b 100644
--- a/plumbing/format/commitgraph/encoder.go
+++ b/plumbing/format/commitgraph/encoder.go
@@ -1,7 +1,6 @@
 package commitgraph

 

 import (

-	"crypto"

 	"io"

 

 	"github.com/go-git/go-git/v5/plumbing"

@@ -17,7 +16,7 @@ type Encoder struct {
 

 // NewEncoder returns a new stream encoder that writes to w.

 func NewEncoder(w io.Writer) *Encoder {

-	h := hash.New(crypto.SHA1)

+	h := hash.New(hash.CryptoType)

 	mw := io.MultiWriter(w, h)

 	return &Encoder{mw, h}

 }

@@ -31,7 +30,7 @@ func (e *Encoder) Encode(idx Index) error {
 	hashToIndex, fanout, extraEdgesCount := e.prepare(idx, hashes)

 

 	chunkSignatures := [][]byte{oidFanoutSignature, oidLookupSignature, commitDataSignature}

-	chunkSizes := []uint64{4 * 256, uint64(len(hashes)) * 20, uint64(len(hashes)) * 36}

+	chunkSizes := []uint64{4 * 256, uint64(len(hashes)) * hash.Size, uint64(len(hashes)) * 36}

 	if extraEdgesCount > 0 {

 		chunkSignatures = append(chunkSignatures, extraEdgeListSignature)

 		chunkSizes = append(chunkSizes, uint64(extraEdgesCount)*4)

@@ -183,6 +182,6 @@ func (e *Encoder) encodeExtraEdges(extraEdges []uint32) (err error) {
 }

 

 func (e *Encoder) encodeChecksum() error {

-	_, err := e.Write(e.hash.Sum(nil)[:20])

+	_, err := e.Write(e.hash.Sum(nil)[:hash.Size])

 	return err

 }