package idxfile import "gopkg.in/src-d/go-git.v4/plumbing" const ( // VersionSupported is the only idx version supported. VersionSupported = 2 offsetLimit = 0x7fffffff ) var ( idxHeader = []byte{255, 't', 'O', 'c'} ) // Idxfile is the in memory representation of an idx file. type Idxfile struct { Version uint32 Fanout [255]uint32 ObjectCount uint32 Entries EntryList PackfileChecksum [20]byte IdxChecksum [20]byte } func NewIdxfile() *Idxfile { return &Idxfile{} } // Entry is the in memory representation of an object entry in the idx file. type Entry struct { Hash plumbing.Hash CRC32 uint32 Offset uint64 } // Add adds a new Entry with the given values to the Idxfile. func (idx *Idxfile) Add(h plumbing.Hash, offset uint64, crc32 uint32) { idx.Entries = append(idx.Entries, &Entry{ Hash: h, Offset: offset, CRC32: crc32, }) } func (idx *Idxfile) isValid() bool { fanout := idx.calculateFanout() for k, c := range idx.Fanout { if fanout[k] != c { return false } } return true } func (idx *Idxfile) calculateFanout() [256]uint32 { fanout := [256]uint32{} for _, e := range idx.Entries { fanout[e.Hash[0]]++ } for i := 1; i < 256; i++ { fanout[i] += fanout[i-1] } return fanout }