dotgit: synced write packfile and index generation

4 files changed, 116 insertions, 57 deletions

diff --git a/formats/idxfile/decoder_test.go b/formats/idxfile/decoder_test.go
index 8ce2bc7..02167a7 100644
--- a/formats/idxfile/decoder_test.go
+++ b/formats/idxfile/decoder_test.go
@@ -42,8 +42,9 @@ func (s *IdxfileSuite) TestDecodeCRCs(c *C) {
 	scanner := packfile.NewScanner(f.Packfile())
 	storage := memory.NewStorage()
 
-	pd := packfile.NewDecoder(scanner, storage.ObjectStorage())
-	_, err := pd.Decode()
+	pd, err := packfile.NewDecoder(scanner, storage.ObjectStorage())
+	c.Assert(err, IsNil)
+	_, err = pd.Decode()
 	c.Assert(err, IsNil)
 
 	i := &Idxfile{Version: VersionSupported}
diff --git a/formats/packfile/decoder.go b/formats/packfile/decoder.go
index c4b9182..4606a3f 100644
--- a/formats/packfile/decoder.go
+++ b/formats/packfile/decoder.go
@@ -30,11 +30,13 @@ var (
 	// ErrZLib is returned by Decode when there was an error unzipping
 	// the packfile contents.
 	ErrZLib = NewError("zlib reading error")
-	// ErrNotSeeker not seeker supported
-	ErrNotSeeker = NewError("no seeker capable decode")
 	// ErrCannotRecall is returned by RecallByOffset or RecallByHash if the object
 	// to recall cannot be returned.
 	ErrCannotRecall = NewError("cannot recall object")
+	// ErrNonSeekable is returned if a NewDecoder is used with a non-seekable
+	// reader and without a core.ObjectStorage or ReadObjectAt method is called
+	// without a seekable scanner
+	ErrNonSeekable = NewError("non-seekable scanner")
 )
 
 // Decoder reads and decodes packfiles from an input stream.
@@ -49,16 +51,25 @@ type Decoder struct {
 }
 
 // NewDecoder returns a new Decoder that reads from r.
-func NewDecoder(s *Scanner, o core.ObjectStorage) *Decoder {
+func NewDecoder(s *Scanner, o core.ObjectStorage) (*Decoder, error) {
+	if !s.IsSeekable && o == nil {
+		return nil, ErrNonSeekable
+	}
+
+	var tx core.TxObjectStorage
+	if o != nil {
+		tx = o.Begin()
+	}
+
 	return &Decoder{
 		s:  s,
 		o:  o,
-		tx: o.Begin(),
+		tx: tx,
 
 		offsetToHash: make(map[int64]core.Hash, 0),
 		hashToOffset: make(map[core.Hash]int64, 0),
 		crcs:         make(map[core.Hash]uint32, 0),
-	}
+	}, nil
 }
 
 // Decode reads a packfile and stores it in the value pointed to by s.
@@ -76,6 +87,10 @@ func (d *Decoder) doDecode() error {
 		return err
 	}
 
+	if d.o == nil {
+		return d.readObjects(count)
+	}
+
 	if err := d.readObjects(count); err != nil {
 		if err := d.tx.Rollback(); err != nil {
 			return nil
@@ -89,10 +104,19 @@ func (d *Decoder) doDecode() error {
 
 func (d *Decoder) readObjects(count uint32) error {
 	for i := 0; i < int(count); i++ {
-		_, err := d.ReadObject()
+		obj, err := d.ReadObject()
 		if err != nil {
 			return err
 		}
+
+		if d.o == nil {
+			continue
+		}
+
+		if _, err := d.tx.Set(obj); err != nil {
+			return err
+		}
+
 	}
 
 	return nil
@@ -105,7 +129,7 @@ func (d *Decoder) ReadObject() (core.Object, error) {
 		return nil, err
 	}
 
-	obj := d.o.NewObject()
+	obj := d.newObject()
 	obj.SetSize(h.Length)
 	obj.SetType(h.Type)
 	var crc uint32
@@ -128,15 +152,23 @@ func (d *Decoder) ReadObject() (core.Object, error) {
 	d.setOffset(hash, h.Offset)
 	d.setCRC(hash, crc)
 
-	if _, err := d.tx.Set(obj); err != nil {
-		return nil, err
+	return obj, nil
+}
+
+func (d *Decoder) newObject() core.Object {
+	if d.o == nil {
+		return &core.MemoryObject{}
 	}
 
-	return obj, nil
+	return d.o.NewObject()
 }
 
 // ReadObjectAt reads an object at the given location
 func (d *Decoder) ReadObjectAt(offset int64) (core.Object, error) {
+	if !d.s.IsSeekable {
+		return nil, ErrNonSeekable
+	}
+
 	beforeJump, err := d.s.Seek(offset)
 	if err != nil {
 		return nil, err
@@ -204,23 +236,29 @@ func (d *Decoder) setCRC(h core.Hash, crc uint32) {
 }
 
 func (d *Decoder) recallByOffset(o int64) (core.Object, error) {
+	if d.s.IsSeekable {
+		return d.ReadObjectAt(o)
+	}
+
 	if h, ok := d.offsetToHash[o]; ok {
 		return d.tx.Get(core.AnyObject, h)
 	}
 
-	return d.ReadObjectAt(o)
+	return nil, core.ErrObjectNotFound
 }
 
 func (d *Decoder) recallByHash(h core.Hash) (core.Object, error) {
+	if d.s.IsSeekable {
+		if o, ok := d.hashToOffset[h]; ok {
+			return d.ReadObjectAt(o)
+		}
+	}
+
 	obj, err := d.tx.Get(core.AnyObject, h)
 	if err != core.ErrObjectNotFound {
 		return obj, err
 	}
 
-	if o, ok := d.hashToOffset[h]; ok {
-		return d.ReadObjectAt(o)
-	}
-
 	return nil, core.ErrObjectNotFound
 }
 
diff --git a/formats/packfile/decoder_test.go b/formats/packfile/decoder_test.go
index 9fe6142..cbf727e 100644
--- a/formats/packfile/decoder_test.go
+++ b/formats/packfile/decoder_test.go
@@ -25,56 +25,72 @@ func (s *ReaderSuite) TestDecode(c *C) {
 		scanner := NewScanner(f.Packfile())
 		storage := memory.NewStorage()
 
-		d := NewDecoder(scanner, storage.ObjectStorage())
+		d, err := NewDecoder(scanner, storage.ObjectStorage())
+		c.Assert(err, IsNil)
 
 		ch, err := d.Decode()
 		c.Assert(err, IsNil)
 		c.Assert(ch, Equals, f.PackfileHash)
 
-		AssertObjects(c, storage, []string{
-			"918c48b83bd081e863dbe1b80f8998f058cd8294",
-			"af2d6a6954d532f8ffb47615169c8fdf9d383a1a",
-			"1669dce138d9b841a518c64b10914d88f5e488ea",
-			"a5b8b09e2f8fcb0bb99d3ccb0958157b40890d69",
-			"b8e471f58bcbca63b07bda20e428190409c2db47",
-			"35e85108805c84807bc66a02d91535e1e24b38b9",
-			"b029517f6300c2da0f4b651b8642506cd6aaf45d",
-			"32858aad3c383ed1ff0a0f9bdf231d54a00c9e88",
-			"d3ff53e0564a9f87d8e84b6e28e5060e517008aa",
-			"c192bd6a24ea1ab01d78686e417c8bdc7c3d197f",
-			"d5c0f4ab811897cadf03aec358ae60d21f91c50d",
-			"49c6bb89b17060d7b4deacb7b338fcc6ea2352a9",
-			"cf4aa3b38974fb7d81f367c0830f7d78d65ab86b",
-			"9dea2395f5403188298c1dabe8bdafe562c491e3",
-			"586af567d0bb5e771e49bdd9434f5e0fb76d25fa",
-			"9a48f23120e880dfbe41f7c9b7b708e9ee62a492",
-			"5a877e6a906a2743ad6e45d99c1793642aaf8eda",
-			"c8f1d8c61f9da76f4cb49fd86322b6e685dba956",
-			"a8d315b2b1c615d43042c3a62402b8a54288cf5c",
-			"a39771a7651f97faf5c72e08224d857fc35133db",
-			"880cd14280f4b9b6ed3986d6671f907d7cc2a198",
-			"fb72698cab7617ac416264415f13224dfd7a165e",
-			"4d081c50e250fa32ea8b1313cf8bb7c2ad7627fd",
-			"eba74343e2f15d62adedfd8c883ee0262b5c8021",
-			"c2d30fa8ef288618f65f6eed6e168e0d514886f4",
-			"8dcef98b1d52143e1e2dbc458ffe38f925786bf2",
-			"aa9b383c260e1d05fbbf6b30a02914555e20c725",
-			"6ecf0ef2c2dffb796033e5a02219af86ec6584e5",
-			"dbd3641b371024f44d0e469a9c8f5457b0660de1",
-			"e8d3ffab552895c19b9fcf7aa264d277cde33881",
-			"7e59600739c96546163833214c36459e324bad0a",
-		})
+		AssertObjects(c, storage, expectedHashes)
+	})
+}
 
+func (s *ReaderSuite) TestDecodeInMemory(c *C) {
+	fixtures.Basic().Test(c, func(f *fixtures.Fixture) {
+		scanner := NewScanner(f.Packfile())
+		d, err := NewDecoder(scanner, nil)
+		c.Assert(err, IsNil)
+
+		ch, err := d.Decode()
+		c.Assert(err, IsNil)
+		c.Assert(ch, Equals, f.PackfileHash)
 	})
 }
+
+var expectedHashes = []string{
+	"918c48b83bd081e863dbe1b80f8998f058cd8294",
+	"af2d6a6954d532f8ffb47615169c8fdf9d383a1a",
+	"1669dce138d9b841a518c64b10914d88f5e488ea",
+	"a5b8b09e2f8fcb0bb99d3ccb0958157b40890d69",
+	"b8e471f58bcbca63b07bda20e428190409c2db47",
+	"35e85108805c84807bc66a02d91535e1e24b38b9",
+	"b029517f6300c2da0f4b651b8642506cd6aaf45d",
+	"32858aad3c383ed1ff0a0f9bdf231d54a00c9e88",
+	"d3ff53e0564a9f87d8e84b6e28e5060e517008aa",
+	"c192bd6a24ea1ab01d78686e417c8bdc7c3d197f",
+	"d5c0f4ab811897cadf03aec358ae60d21f91c50d",
+	"49c6bb89b17060d7b4deacb7b338fcc6ea2352a9",
+	"cf4aa3b38974fb7d81f367c0830f7d78d65ab86b",
+	"9dea2395f5403188298c1dabe8bdafe562c491e3",
+	"586af567d0bb5e771e49bdd9434f5e0fb76d25fa",
+	"9a48f23120e880dfbe41f7c9b7b708e9ee62a492",
+	"5a877e6a906a2743ad6e45d99c1793642aaf8eda",
+	"c8f1d8c61f9da76f4cb49fd86322b6e685dba956",
+	"a8d315b2b1c615d43042c3a62402b8a54288cf5c",
+	"a39771a7651f97faf5c72e08224d857fc35133db",
+	"880cd14280f4b9b6ed3986d6671f907d7cc2a198",
+	"fb72698cab7617ac416264415f13224dfd7a165e",
+	"4d081c50e250fa32ea8b1313cf8bb7c2ad7627fd",
+	"eba74343e2f15d62adedfd8c883ee0262b5c8021",
+	"c2d30fa8ef288618f65f6eed6e168e0d514886f4",
+	"8dcef98b1d52143e1e2dbc458ffe38f925786bf2",
+	"aa9b383c260e1d05fbbf6b30a02914555e20c725",
+	"6ecf0ef2c2dffb796033e5a02219af86ec6584e5",
+	"dbd3641b371024f44d0e469a9c8f5457b0660de1",
+	"e8d3ffab552895c19b9fcf7aa264d277cde33881",
+	"7e59600739c96546163833214c36459e324bad0a",
+}
+
 func (s *ReaderSuite) TestDecodeCRCs(c *C) {
 	f := fixtures.Basic().ByTag("ofs-delta").One()
 
 	scanner := NewScanner(f.Packfile())
 	storage := memory.NewStorage()
 
-	d := NewDecoder(scanner, storage.ObjectStorage())
-	_, err := d.Decode()
+	d, err := NewDecoder(scanner, storage.ObjectStorage())
+	c.Assert(err, IsNil)
+	_, err = d.Decode()
 	c.Assert(err, IsNil)
 
 	var sum uint64
@@ -88,9 +104,8 @@ func (s *ReaderSuite) TestDecodeCRCs(c *C) {
 func (s *ReaderSuite) TestReadObjectAt(c *C) {
 	f := fixtures.Basic().One()
 	scanner := NewScanner(f.Packfile())
-	storage := memory.NewStorage()
-
-	d := NewDecoder(scanner, storage.ObjectStorage())
+	d, err := NewDecoder(scanner, nil)
+	c.Assert(err, IsNil)
 
 	// when the packfile is ref-delta based, the offsets are required
 	if f.Is("ref-delta") {
diff --git a/formats/packfile/scanner.go b/formats/packfile/scanner.go
index 86092a1..a5e4215 100644
--- a/formats/packfile/scanner.go
+++ b/formats/packfile/scanner.go
@@ -49,6 +49,10 @@ type Scanner struct {
 	// is waiting to be read
 	pendingObject    *ObjectHeader
 	version, objects uint32
+
+	// lsSeekable says if this scanner can do Seek or not, to have a Scanner
+	// seekable a r implementing io.Seeker is required
+	IsSeekable bool
 }
 
 // NewScanner returns a new Scanner based on a reader, if the given reader
@@ -65,7 +69,8 @@ func NewScanner(r io.Reader) *Scanner {
 			newByteReadSeeker(seeker),
 			crc,
 		},
-		crc: crc,
+		crc:        crc,
+		IsSeekable: ok,
 	}
 }