func (p *packIdxParser) parseIdx() *Idx {
p.idxParser.ConsumeString(PackIdxSignature)
p.idxParser.ConsumeBytes([]byte{0, 0, 0, PackVersion})
var counts [256]int
for i := range counts {
counts[i] = int(p.idxParser.ParseIntBigEndian(4))
}
//discard the fan-out values, just use the largest value,
//which is the total # of objects:
count := counts[255]
idToEntry := make(map[string]*PackedObjectId)
entries := make([]*PackedObjectId, count, count)
entriesByOid := make([]*PackedObjectId, count, count)
for i := 0; i < count; i++ {
b := p.idxParser.ReadNBytes(20)
oid, _ := objects.OidFromBytes(b)
entries[i] = &PackedObjectId{
ObjectId: oid,
}
entriesByOid[i] = entries[i]
}
for i := 0; i < count; i++ {
entries[i].crc32 = int64(p.idxParser.ParseIntBigEndian(4))
}
for i := 0; i < count; i++ {
//TODO: 8-byte #'s for some offsets for some pack files (packs > 2gb)
entries[i].offset = p.idxParser.ParseIntBigEndian(4)
}
checksumPack := p.idxParser.ReadNBytes(20)
checksumIdx := p.idxParser.ReadNBytes(20)
if !p.idxParser.EOF() {
util.PanicErrf("Found extraneous bytes! %x", p.idxParser.Bytes())
}
//order by offset
sort.Sort(packedObjectIds(entries))
for i, v := range entries {
v.index = i
}
packChecksum, _ := objects.OidFromBytes(checksumPack)
idxChecksum, _ := objects.OidFromBytes(checksumIdx)
return &Idx{
entries,
entriesByOid,
idToEntry,
&counts,
int64(count),
packChecksum,
idxChecksum,
}
}
func readPackedRefDelta(bytes []byte) (delta packedDelta, oid *objects.ObjectId) {
baseOidBytes := bytes[0:20]
deltaBytes := bytes[20:]
delta = packedDelta(deltaBytes)
oid, _ = objects.OidFromBytes(baseOidBytes)
return
}
// ParseOidBytes reads the next objects.OidSize bytes from
// the Reader and generates an ObjectId.
func (p *objectIdParser) ParseOidBytes() *objects.ObjectId {
b := p.Consume(objects.OidSize)
oid, e := objects.OidFromBytes(b)
if e != nil {
util.PanicErrf("expected: hash bytes %d long", objects.OidSize)
}
return oid
}