usage.md

Livt.Utils Usage

CRC32 for One Short Message

using Livt.Utils.Hashing

component Crc32Example
{
    crc: Crc32

    new()
    {
        this.crc = new Crc32()
    }

    public fn ComputeCheckValue() byte[4]
    {
        this.crc.Reset()

        var blk: byte[16] = [
            0x31, 0x32, 0x33, 0x34,
            0x35, 0x36, 0x37, 0x38,
            0x39, 0x00, 0x00, 0x00,
            0x00, 0x00, 0x00, 0x00]

        this.crc.ProcessFinalBlock(blk, 9)
        return this.crc.GetCrc()
    }
}

The returned bytes are little-endian. For "123456789" the expected bytes are 0x26, 0x39, 0xF4, 0xCB.

CRC32 for Multiple Blocks

using Livt.Utils.Hashing

component Crc32StreamExample
{
    crc: Crc32

    new()
    {
        this.crc = new Crc32()
    }

    public fn Compute(first: byte[16], last: byte[16], lastLength: int) byte[4]
    {
        this.crc.Reset()
        this.crc.ProcessBlock(first)
        this.crc.ProcessFinalBlock(last, lastLength)
        return this.crc.GetCrc()
    }
}

Call ProcessFinalBlock() once at the end of the message. Passing len = 0 finalizes the current accumulator without adding more data.