Documentation
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Overview ¶
Package binary implements sintax-sugar functions on top of the standard library binary package
Index ¶
- func Read(r io.Reader, data ...interface{}) error
- func ReadHash(r io.Reader) (core.Hash, error)
- func ReadUint16(r io.Reader) (uint16, error)
- func ReadUint32(r io.Reader) (uint32, error)
- func ReadUntil(r io.Reader, delim byte) ([]byte, error)
- func ReadVariableWidthInt(r io.Reader) (int64, error)
- func Write(w io.Writer, data ...interface{}) error
- func WriteUint16(w io.Writer, value uint16) error
- func WriteUint32(w io.Writer, value uint32) error
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Read ¶
Read reads structured binary data from r into data. Bytes are read and decoded in BigEndian order https://golang.org/pkg/encoding/binary/#Read
func ReadUint16 ¶
ReadUint16 reads 2 bytes and returns them as a BigEndian uint16
func ReadUint32 ¶
ReadUint32 reads 4 bytes and returns them as a Big ndian uint32
func ReadVariableWidthInt ¶
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);
func Write ¶
Write writes the binary representation of data into w, using BigEndian order https://golang.org/pkg/encoding/binary/#Write
func WriteUint16 ¶
WriteUint16 writes the binary representation of a uint16 into w, in BigEndian order
Types ¶
This section is empty.
Source Files