WireFormat module implements routines dealing with parsing and writing protocol messages.
All functions are also available as methods of BTC::WireFormat object.
Various structures have a variable-length data prepended by a length prefix which is itself of variable length. This length prefix is a variable-length integer, varint (aka CompactSize).
NB. varint refers to what Satoshi called CompactSize. BitcoinQT has later added even more compact format called CVarInt to use in its local block storage. CVarInt is not implemented here.
| Value Encoded | Storage Size (bytes) | Format |
|---|---|---|
| < 0xfd | 1 | uint8_t |
| ≤ 0xffff | 3 | 0xfd followed by the value as little endian uint16_t |
| ≤ 0xffffffff | 5 | 0xfe followed by the value as little endian uint32_t |
0xffffffff | 9 | 0xff followed by the value as little endian uint64_t
Returns [value, length] by reading from binary string data or stream.
Value is a decoded integer value. Length is number of bytes read (including offset bytes).
In case of failure, returns [nil, length] where length is a number of bytes read before the error was encountered.
Default offset is 0.
Returns binary varint representation of integer.
Encodes the integer and appends it to binary string data or writes to stream.
Returns binary varint representation of integer.
Returns [string, length] where length is number of bytes read (includes length prefix and offset bytes).
In case of failure, returns [nil, length] where length is a number of bytes read before the error was encountered.
Default offset is 0.
Returns binary representation of string (equals the string itself prepended with its byte length in varint format).
Encodes the string and appends it to binary string data or writes to stream.
Returns binary representation of string (that is, with varint length prefix).