integer-encoding-rs

full documentation

This crate provides encoding and decoding of integers to and from bytestring representations.

The format is described here: Google's protobuf integer encoding technique.

FixedInt

FixedInt basically executes a memcpy() from integer values to bytestrings and back. Formally, it uses little-endian byte order for encoded values -- however, this crate does not check the architecture for its byte order (so if you run on a big-endian architecture, this will cause issues).

VarInt

VarInt encodes integers in blocks of 7 bits; the MSB is set for every byte but the last, in which it is cleared.

Signed values are first converted to an unsigned representation using zigzag encoding (also described on the page linked above), and then encoded as every other unsigned number.