From 3abbe1488144825793f8fa0f78846af77448c623 Mon Sep 17 00:00:00 2001 From: Filip Navara Date: Thu, 25 Apr 2019 15:23:16 +0200 Subject: plumbing: format/idxfile, avoid creating temporary buffers to decode integers Signed-off-by: Filip Navara --- plumbing/format/idxfile/idxfile.go | 47 ++++++++++++-------------------------- 1 file changed, 15 insertions(+), 32 deletions(-) (limited to 'plumbing/format/idxfile/idxfile.go') diff --git a/plumbing/format/idxfile/idxfile.go b/plumbing/format/idxfile/idxfile.go index 26cca59..6b77190 100644 --- a/plumbing/format/idxfile/idxfile.go +++ b/plumbing/format/idxfile/idxfile.go @@ -5,8 +5,9 @@ import ( "io" "sort" + encbin "encoding/binary" + "gopkg.in/src-d/go-git.v4/plumbing" - "gopkg.in/src-d/go-git.v4/utils/binary" ) const ( @@ -122,41 +123,32 @@ func (idx *MemoryIndex) FindOffset(h plumbing.Hash) (int64, error) { return 0, plumbing.ErrObjectNotFound } - offset, err := idx.getOffset(k, i) + offset := idx.getOffset(k, i) if !idx.offsetHashIsFull { // Save the offset for reverse lookup if idx.offsetHash == nil { idx.offsetHash = make(map[int64]plumbing.Hash) } - idx.offsetHash[offset] = h + idx.offsetHash[int64(offset)] = h } - return offset, err + return int64(offset), nil } const isO64Mask = uint64(1) << 31 -func (idx *MemoryIndex) getOffset(firstLevel, secondLevel int) (int64, error) { +func (idx *MemoryIndex) getOffset(firstLevel, secondLevel int) uint64 { offset := secondLevel << 2 - buf := bytes.NewBuffer(idx.Offset32[firstLevel][offset : offset+4]) - ofs, err := binary.ReadUint32(buf) - if err != nil { - return -1, err - } + ofs := encbin.BigEndian.Uint32(idx.Offset32[firstLevel][offset : offset+4]) if (uint64(ofs) & isO64Mask) != 0 { offset := 8 * (uint64(ofs) & ^isO64Mask) - buf := bytes.NewBuffer(idx.Offset64[offset : offset+8]) - n, err := binary.ReadUint64(buf) - if err != nil { - return -1, err - } - - return int64(n), nil + n := encbin.BigEndian.Uint64(idx.Offset64[offset : offset+8]) + return n } - return int64(ofs), nil + return uint64(ofs) } // FindCRC32 implements the Index interface. @@ -167,13 +159,12 @@ func (idx *MemoryIndex) FindCRC32(h plumbing.Hash) (uint32, error) { return 0, plumbing.ErrObjectNotFound } - return idx.getCRC32(k, i) + return idx.getCRC32(k, i), nil } -func (idx *MemoryIndex) getCRC32(firstLevel, secondLevel int) (uint32, error) { +func (idx *MemoryIndex) getCRC32(firstLevel, secondLevel int) uint32 { offset := secondLevel << 2 - buf := bytes.NewBuffer(idx.CRC32[firstLevel][offset : offset+4]) - return binary.ReadUint32(buf) + return encbin.BigEndian.Uint32(idx.CRC32[firstLevel][offset : offset+4]) } // FindHash implements the Index interface. @@ -303,16 +294,8 @@ func (i *idxfileEntryIter) Next() (*Entry, error) { pos := i.idx.FanoutMapping[entry.Hash[0]] - offset, err := i.idx.getOffset(pos, i.secondLevel) - if err != nil { - return nil, err - } - entry.Offset = uint64(offset) - - entry.CRC32, err = i.idx.getCRC32(pos, i.secondLevel) - if err != nil { - return nil, err - } + entry.Offset = i.idx.getOffset(pos, i.secondLevel) + entry.CRC32 = i.idx.getCRC32(pos, i.secondLevel) i.secondLevel++ i.total++ -- cgit