Merge pull request #68 from libgit2/cmn/oid-revamp

Oid revamp

git.go

@@ -8,6 +8,7 @@ package git
 import "C"
 import (
 	"bytes"
+	"encoding/hex"
 	"errors"
 	"runtime"
 	"strings"
@@ -28,10 +29,8 @@ func init() {
 	C.git_threads_init()
 }
 
-// Oid
-type Oid struct {
-	bytes [20]byte
-}
+// Oid represents the id for a Git object.
+type Oid [20]byte
 
 func newOidFromC(coid *C.git_oid) *Oid {
 	if coid == nil {
@@ -39,62 +38,57 @@ func newOidFromC(coid *C.git_oid) *Oid {
 	}
 
 	oid := new(Oid)
-	copy(oid.bytes[0:20], C.GoBytes(unsafe.Pointer(coid), 20))
+	copy(oid[0:20], C.GoBytes(unsafe.Pointer(coid), 20))
 	return oid
 }
 
-func NewOid(b []byte) *Oid {
+func NewOidFromBytes(b []byte) *Oid {
 	oid := new(Oid)
-	copy(oid.bytes[0:20], b[0:20])
+	copy(oid[0:20], b[0:20])
 	return oid
 }
 
 func (oid *Oid) toC() *C.git_oid {
-	return (*C.git_oid)(unsafe.Pointer(&oid.bytes))
+	return (*C.git_oid)(unsafe.Pointer(oid))
 }
 
-func NewOidFromString(s string) (*Oid, error) {
-	o := new(Oid)
-	cs := C.CString(s)
-	defer C.free(unsafe.Pointer(cs))
-
-	runtime.LockOSThread()
-	defer runtime.UnlockOSThread()
-
-	if ret := C.git_oid_fromstr(o.toC(), cs); ret < 0 {
-		return nil, MakeGitError(ret)
+func NewOid(s string) (*Oid, error) {
+	if len(s) > C.GIT_OID_HEXSZ {
+		return nil, errors.New("string is too long for oid")
 	}
 
+	o := new(Oid)
+
+	slice, error := hex.DecodeString(s)
+	if error != nil {
+		return nil, error
+	}
+
+	copy(o[:], slice[:20])
 	return o, nil
 }
 
 func (oid *Oid) String() string {
-	buf := make([]byte, 40)
-	C.git_oid_fmt((*C.char)(unsafe.Pointer(&buf[0])), oid.toC())
-	return string(buf)
-}
-
-func (oid *Oid) Bytes() []byte {
-	return oid.bytes[0:]
+	return hex.EncodeToString(oid[:])
 }
 
 func (oid *Oid) Cmp(oid2 *Oid) int {
-	return bytes.Compare(oid.bytes[:], oid2.bytes[:])
+	return bytes.Compare(oid[:], oid2[:])
 }
 
 func (oid *Oid) Copy() *Oid {
 	ret := new(Oid)
-	copy(ret.bytes[:], oid.bytes[:])
+	copy(ret[:], oid[:])
 	return ret
 }
 
 func (oid *Oid) Equal(oid2 *Oid) bool {
-	return bytes.Equal(oid.bytes[:], oid2.bytes[:])
+	return bytes.Equal(oid[:], oid2[:])
 }
 
 func (oid *Oid) IsZero() bool {
-	for _, a := range oid.bytes {
-		if a != '0' {
+	for _, a := range oid {
+		if a != 0 {
 			return false
 		}
 	}
@@ -102,7 +96,7 @@ func (oid *Oid) IsZero() bool {
 }
 
 func (oid *Oid) NCmp(oid2 *Oid, n uint) int {
-	return bytes.Compare(oid.bytes[:n], oid2.bytes[:n])
+	return bytes.Compare(oid[:n], oid2[:n])
 }
 
 func ShortenOids(ids []*Oid, minlen int) (int, error) {

git_test.go

@@ -54,3 +54,11 @@ func seedTestRepo(t *testing.T, repo *Repository) (*Oid, *Oid) {
 
 	return commitId, treeId
 }
+
+func TestOidZero(t *testing.T) {
+	var zeroId Oid
+
+	if !zeroId.IsZero() {
+		t.Error("Zero Oid is not zero")
+	}
+}

odb_test.go

@@ -27,7 +27,7 @@ func TestOdbStream(t *testing.T) {
 	error = stream.Close()
 	checkFatal(t, error)
 
-	expectedId, error := NewOidFromString("30f51a3fba5274d53522d0f19748456974647b4f")
+	expectedId, error := NewOid("30f51a3fba5274d53522d0f19748456974647b4f")
 	checkFatal(t, error)
 	if stream.Id.Cmp(expectedId) != 0 {
 		t.Fatal("Wrong data written")