split out alpha pointer decoder

metafile/metafile.go

@@ -8,18 +8,23 @@ import (
 )
 
 var (
-	MediaWarning = []byte("# git-media\n")
-	alpha        = "http://git-media.io/v/1"
+	MediaWarning  = []byte("# git-media\n")
+	alpha         = "http://git-media.io/v/1"
+	latest        = "http://git-media.io/v/2"
+	oidType       = "sha256"
+	alphaHeaderRE = regexp.MustCompile(`\A# (.*git-media|external)`)
+	linebreak     = []byte("\n")
 )
 
 type Pointer struct {
 	Version string
 	Oid     string
 	Size    int64
+	OidType string
 }
 
 func NewPointer(oid string, size int64) *Pointer {
-	return &Pointer{alpha, oid, size}
+	return &Pointer{alpha, oid, size, oidType}
 }
 
 func Encode(writer io.Writer, pointer *Pointer) (int, error) {
@@ -33,25 +38,27 @@ func Encode(writer io.Writer, pointer *Pointer) (int, error) {
 }
 
 func Decode(reader io.Reader) (*Pointer, error) {
-	buf := make([]byte, 100)
+	buf := make([]byte, 200)
 	written, err := reader.Read(buf)
 	if err != nil {
 		return nil, err
 	}
 
-	lines := bytes.Split(buf[0:written], []byte("\n"))
-	matched, err := regexp.Match("# (.*git-media|external)", lines[0])
-	if err != nil {
-		return nil, err
-	}
+	data := bytes.TrimSpace(buf[0:written])
 
-	if len(lines) < 2 {
-		return nil, errors.New("No sha in meta file")
+	if alphaHeaderRE.Match(data) {
+		return decodeAlpha(data)
+	} else {
+		return nil, errors.New("No INI decoder yet")
 	}
-
-	if matched {
-		return &Pointer{alpha, string(lines[1]), 0}, nil
-	}
-
-	return nil, errors.New("Could not decode meta file")
+}
+
+func decodeAlpha(data []byte) (*Pointer, error) {
+	lines := bytes.Split(data, linebreak)
+	last := len(lines) - 1
+	if last == 0 {
+		return nil, errors.New("No sha in pointer file")
+	}
+
+	return &Pointer{alpha, string(lines[last]), 0, oidType}, nil
 }

metafile/metafile_test.go

@@ -2,6 +2,7 @@ package metafile
 
 import (
 	"bytes"
+	"github.com/bmizerany/assert"
 	"testing"
 )
 
@@ -32,6 +33,20 @@ func TestEncode(t *testing.T) {
 	}
 }
 
+func TestIniDecode(t *testing.T) {
+	buf := bytes.NewBufferString(`[git-media]
+version="http://git-media.io/v/2"
+oid=sha256:4d7a214614ab2935c943f9e0ff69d22eadbb8f32b1258daaa5e2ca24d17e2393
+size=12345
+`)
+
+	p, err := Decode(buf)
+	assert.Equal(t, nil, err)
+	assert.Equal(t, latest, p.Version)
+	assert.Equal(t, "4d7a214614ab2935c943f9e0ff69d22eadbb8f32b1258daaa5e2ca24d17e2393", p.Oid)
+	assert.Equal(t, int64(12345), p.Size)
+}
+
 func TestAlphaDecode(t *testing.T) {
 	buf := bytes.NewBufferString("# git-media\nabc\n")
 	if pointer, _ := Decode(buf); pointer.Oid != "abc" {