Convert Number to int, byte 32, adler32, crc32 - Node.js Number

Node.js examples for Number:Int

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Description

Convert Number to int, byte 32, adler32, crc32

Demo Code

Number.prototype.toUInt = function () {
    return this < 0 ? this + 4294967296 : this;
};
Number.prototype.bytes32 = function () {
    return [(this >>> 24) & 0xff, (this >>> 16) & 0xff, (this >>> 8) & 0xff, this & 0xff];
};
Number.prototype.bytes16sw = function () {
    return [this & 0xff, (this >>> 8) & 0xff];
};

Array.prototype.adler32 = function (start, len) {
    switch (arguments.length) {
    case 0://from w  ww.j ava 2  s.  c  o  m
        start = 0;
    case 1:
        len = this.length - start;
    }
    var a = 1,
        b = 0;
    for (var i = 0; i < len; i++) {
        a = (a + this[start + i]) % 65521;
        b = (b + a) % 65521;
    }
    return ((b << 16) | a).toUInt();
};

Array.prototype.crc32 = function (start, len) {
    switch (arguments.length) {
    case 0:
        start = 0;
    case 1:
        len = this.length - start;
    }
    var table = arguments.callee.crctable;
    if (!table) {
        table = [];
        var c;
        for (var n = 0; n < 256; n++) {
            c = n;
            for (var k = 0; k < 8; k++)
                c = c & 1 ? 0xedb88320 ^ (c >>> 1) : c >>> 1;
            table[n] = c.toUInt();
        }
        arguments.callee.crctable = table;
    }
    var c = 0xffffffff;
    for (var i = 0; i < len; i++)
        c = table[(c ^ this[start + i]) & 0xff] ^ (c >>> 8);

    return (c ^ 0xffffffff).toUInt();
};

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