fast varintThis is a fork of https://github.com/chrisdickinson/varint with a faster decoder (10x faster on int32)
encode whole numbers to an array of protobuf-style varint bytes and also decode them.
var varint = require('varint') var bytes = varint.encode(300) // === [0xAC, 0x02] varint.decode(bytes) // 300 varint.decode.bytes // 2 (the last decode() call required 2 bytes)
varint = require('varint')
varint.encode(num, buffer=, offset=0) -> bufferEncodes
buffer, with the encoded varint written into it. If
bufferis not provided, it will default to a new array.
varint.encode.byteswill now be set to the number of bytes modified.
varint.decode(data, offset=0) -> numberdecodes
data, which can be either a buffer or array of integers, from position
offsetor default 0 and returns the decoded original integer.
datadoes not represent a valid encoding.
varint.decode.bytesif you also require the length (number of bytes) that were required to decode the integer you can access it via
varint.decode.bytes. this is an integer property that will tell you the number of bytes that the last .decode() call had to use to decode.
decode.byteswhen encoding a number it can be useful to know how many bytes where written (especially if you pass an output array). you can access this via
varint.encode.byteswhich holds the number of bytes written in the last encode.
varint.encodingLength(num)returns the number of bytes this number will be encoded as, up to a maximum of 8.
usage notesIf varint is passed a buffer that does not contain a valid end byte, then
decode.byteswill be set to 0. If you are reading from a streaming source, it's okay to pass an incomplete buffer into
decode, detect this case, and then concatenate the next buffer.