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path: root/plumbing/format/packfile/decoder.go
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Diffstat (limited to 'plumbing/format/packfile/decoder.go')
-rw-r--r--plumbing/format/packfile/decoder.go104
1 files changed, 53 insertions, 51 deletions
diff --git a/plumbing/format/packfile/decoder.go b/plumbing/format/packfile/decoder.go
index 21ddbbf..39680a3 100644
--- a/plumbing/format/packfile/decoder.go
+++ b/plumbing/format/packfile/decoder.go
@@ -56,10 +56,12 @@ type Decoder struct {
o storer.EncodedObjectStorer
tx storer.Transaction
- isDecoded bool
- offsetToHash map[int64]plumbing.Hash
- hashToOffset map[plumbing.Hash]int64
- crcs map[plumbing.Hash]uint32
+ isDecoded bool
+
+ // hasBuiltIndex indicates if the index is fully built or not. If it is not,
+ // will be built incrementally while decoding.
+ hasBuiltIndex bool
+ idx *Index
offsetToType map[int64]plumbing.ObjectType
decoderType plumbing.ObjectType
@@ -102,10 +104,7 @@ func NewDecoderForType(s *Scanner, o storer.EncodedObjectStorer,
s: s,
o: o,
- offsetToHash: make(map[int64]plumbing.Hash, 0),
- hashToOffset: make(map[plumbing.Hash]int64, 0),
- crcs: make(map[plumbing.Hash]uint32, 0),
-
+ idx: NewIndex(0),
offsetToType: make(map[int64]plumbing.ObjectType, 0),
decoderType: t,
@@ -139,6 +138,11 @@ func (d *Decoder) doDecode() error {
return err
}
+ if !d.hasBuiltIndex {
+ d.idx = NewIndex(int(count))
+ }
+ defer func() { d.hasBuiltIndex = true }()
+
_, isTxStorer := d.o.(storer.Transactioner)
switch {
case d.o == nil:
@@ -218,13 +222,22 @@ func (d *Decoder) DecodeObject() (plumbing.EncodedObject, error) {
}
func (d *Decoder) decodeIfSpecificType(h *ObjectHeader) (plumbing.EncodedObject, error) {
- var realType plumbing.ObjectType
- var err error
+ var (
+ obj plumbing.EncodedObject
+ realType plumbing.ObjectType
+ err error
+ )
switch h.Type {
case plumbing.OFSDeltaObject:
realType, err = d.ofsDeltaType(h.OffsetReference)
case plumbing.REFDeltaObject:
realType, err = d.refDeltaType(h.Reference)
+ if err == plumbing.ErrObjectNotFound {
+ obj, err = d.decodeByHeader(h)
+ if err != nil {
+ realType = obj.Type()
+ }
+ }
default:
realType = h.Type
}
@@ -236,6 +249,10 @@ func (d *Decoder) decodeIfSpecificType(h *ObjectHeader) (plumbing.EncodedObject,
d.offsetToType[h.Offset] = realType
if d.decoderType == realType {
+ if obj != nil {
+ return obj, nil
+ }
+
return d.decodeByHeader(h)
}
@@ -252,16 +269,12 @@ func (d *Decoder) ofsDeltaType(offset int64) (plumbing.ObjectType, error) {
}
func (d *Decoder) refDeltaType(ref plumbing.Hash) (plumbing.ObjectType, error) {
- if o, ok := d.hashToOffset[ref]; ok {
- return d.ofsDeltaType(o)
- }
-
- obj, err := d.o.EncodedObject(plumbing.AnyObject, ref)
- if err != nil {
- return plumbing.InvalidObject, err
+ e, ok := d.idx.LookupHash(ref)
+ if !ok {
+ return plumbing.InvalidObject, plumbing.ErrObjectNotFound
}
- return obj.Type(), nil
+ return d.ofsDeltaType(int64(e.Offset))
}
func (d *Decoder) decodeByHeader(h *ObjectHeader) (plumbing.EncodedObject, error) {
@@ -285,9 +298,9 @@ func (d *Decoder) decodeByHeader(h *ObjectHeader) (plumbing.EncodedObject, error
return obj, err
}
- hash := obj.Hash()
- d.setOffset(hash, h.Offset)
- d.setCRC(hash, crc)
+ if !d.hasBuiltIndex {
+ d.idx.Add(obj.Hash(), uint64(h.Offset), crc)
+ }
return obj, nil
}
@@ -365,10 +378,10 @@ func (d *Decoder) fillOFSDeltaObjectContent(obj plumbing.EncodedObject, offset i
return 0, err
}
- h := d.offsetToHash[offset]
+ e, ok := d.idx.LookupOffset(uint64(offset))
var base plumbing.EncodedObject
- if h != plumbing.ZeroHash {
- base = d.cache.Get(h)
+ if ok {
+ base = d.cache.Get(e.Hash)
}
if base == nil {
@@ -385,22 +398,13 @@ func (d *Decoder) fillOFSDeltaObjectContent(obj plumbing.EncodedObject, offset i
return crc, err
}
-func (d *Decoder) setOffset(h plumbing.Hash, offset int64) {
- d.offsetToHash[offset] = h
- d.hashToOffset[h] = offset
-}
-
-func (d *Decoder) setCRC(h plumbing.Hash, crc uint32) {
- d.crcs[h] = crc
-}
-
func (d *Decoder) recallByOffset(o int64) (plumbing.EncodedObject, error) {
if d.s.IsSeekable {
return d.DecodeObjectAt(o)
}
- if h, ok := d.offsetToHash[o]; ok {
- return d.recallByHashNonSeekable(h)
+ if e, ok := d.idx.LookupOffset(uint64(o)); ok {
+ return d.recallByHashNonSeekable(e.Hash)
}
return nil, plumbing.ErrObjectNotFound
@@ -408,8 +412,8 @@ func (d *Decoder) recallByOffset(o int64) (plumbing.EncodedObject, error) {
func (d *Decoder) recallByHash(h plumbing.Hash) (plumbing.EncodedObject, error) {
if d.s.IsSeekable {
- if o, ok := d.hashToOffset[h]; ok {
- return d.DecodeObjectAt(o)
+ if e, ok := d.idx.LookupHash(h); ok {
+ return d.DecodeObjectAt(int64(e.Offset))
}
}
@@ -432,22 +436,20 @@ func (d *Decoder) recallByHashNonSeekable(h plumbing.Hash) (obj plumbing.Encoded
return nil, plumbing.ErrObjectNotFound
}
-// SetOffsets sets the offsets, required when using the method DecodeObjectAt,
-// without decoding the full packfile
-func (d *Decoder) SetOffsets(offsets map[plumbing.Hash]int64) {
- d.hashToOffset = offsets
-}
-
-// Offsets returns the objects read offset, Decode method should be called
-// before to calculate the Offsets
-func (d *Decoder) Offsets() map[plumbing.Hash]int64 {
- return d.hashToOffset
+// SetIndex sets an index for the packfile. It is recommended to set this.
+// The index might be read from a file or reused from a previous Decoder usage
+// (see Index function).
+func (d *Decoder) SetIndex(idx *Index) {
+ d.hasBuiltIndex = true
+ d.idx = idx
}
-// CRCs returns the CRC-32 for each read object. Decode method should be called
-// before to calculate the CRCs
-func (d *Decoder) CRCs() map[plumbing.Hash]uint32 {
- return d.crcs
+// Index returns the index for the packfile. If index was set with SetIndex,
+// Index will return it. Otherwise, it will return an index that is built while
+// decoding. If neither SetIndex was called with a full index or Decode called
+// for the whole packfile, then the returned index will be incomplete.
+func (d *Decoder) Index() *Index {
+ return d.idx
}
// Close closes the Scanner. usually this mean that the whole reader is read and