Package binary implements sintax-sugar functions on top of the standard library binary package
IsBinary detects if data is a binary value based on: http://git.kernel.org/cgit/git/git.git/tree/xdiff-interface.c?id=HEAD#n198
Read reads structured binary data from r into data. Bytes are read and decoded in BigEndian order https://golang.org/pkg/encoding/binary/#Read
ReadHash reads a plumbing.Hash from r
ReadUint16 reads 2 bytes and returns them as a BigEndian uint16
ReadUint32 reads 4 bytes and returns them as a BigEndian uint32
ReadUint64 reads 8 bytes and returns them as a BigEndian uint32
ReadUntil reads from r untin delim is found
ReadUntilFromBufioReader is like bufio.ReadBytes but drops the delimiter from the result.
ReadVariableWidthInt reads and returns an int in Git VLQ special format:
Ordinary VLQ has some redundancies, example: the number 358 can be encoded as the 2-octet VLQ 0x8166 or the 3-octet VLQ 0x808166 or the 4-octet VLQ 0x80808166 and so forth.
To avoid these redundancies, the VLQ format used in Git removes this prepending redundancy and extends the representable range of shorter VLQs by adding an offset to VLQs of 2 or more octets in such a way that the lowest possible value for such an (N+1)-octet VLQ becomes exactly one more than the maximum possible value for an N-octet VLQ. In particular, since a 1-octet VLQ can store a maximum value of 127, the minimum 2-octet VLQ (0x8000) is assigned the value 128 instead of 0. Conversely, the maximum value of such a 2-octet VLQ (0xff7f) is 16511 instead of just 16383. Similarly, the minimum 3-octet VLQ (0x808000) has a value of 16512 instead of zero, which means that the maximum 3-octet VLQ (0xffff7f) is 2113663 instead of just 2097151. And so forth.
This is how the offset is saved in C:
dheader[pos] = ofs & 127; while (ofs >>= 7) dheader[--pos] = 128 | (--ofs & 127);
Write writes the binary representation of data into w, using BigEndian order https://golang.org/pkg/encoding/binary/#Write
WriteUint16 writes the binary representation of a uint16 into w, in BigEndian order
WriteUint32 writes the binary representation of a uint32 into w, in BigEndian order
WriteUint64 writes the binary representation of a uint64 into w, in BigEndian order