butils

butils

###Bufferwise binary operations

• getBit(buffer, offset) returns true or false
• setBit(buffer, offset, boolean) returns the changed byte
• XOR(buffer, buffer2) returns the modifed first buffer
• OR(buffer, buffer2) returns the modifed first buffer
• AND(buffer, buffer2) return the modifed first buffer
• NOT(buffer) return the modifed buffer
• EQUAL(buffer, buffer2) returns a boolean
• leftShift(buffer, offset) returns a NEW buffer
• rightShift(buffer, offset) returns a NEW buffer
• signedRightShift(buffer, offset) returns a NEW buffer

These are some helper functions that appear to be significantly faster than core Buffer manipulation functions.

Functions included

• readInt(buffer, offset) -- (buffer.readInt8(offset))
• writeInt(buffer, int, offset) -- (buffer.writeInt8(int, offset))
• readInt32(buffer, offset) -- (buffer.readUInt32BE(offset))
• writeInt32(buffer, int, offset) -- (buffer.writeUInt32BE(int, offset))
• readString(buffer, start, end) -- (buffer.toString(start, end))
• writeString(buffer, str, offset) -- (Buffer.write(str, 'utf8', offset))
• readVarint(buffer, offset) -- (no equivalent)
• writeVarint(buffer, int, offset) -- (no equivalent)

Note that the Int32 functions are currently unsigned and big endian only, though I'd happily accept pull requests to add more functionality.

Benchmark

100,000,000 iterations of each function. (see bench.js)

• Buffer#writeInt8: 1225ms
• butils#writeInt: 166ms
• Buffer#readInt8: 761ms
• butils#readInt: 164ms
• Buffer#writeUInt32BE: 1544ms
• butils#writeInt32: 257ms
• Buffer#readUInt32BE: 1525ms
• butils#readInt32: 323ms
• Buffer#write: 45101ms
• butils#writeString: 2509ms
• Buffer#toString: 17505ms
• butils#readString: 7340ms
• butils#writeVarint: 1264ms
• butils#readVarint: 4777ms