rapier
Version:
A JavaScript Dota 2 (Source 2) replay parsing library.
56 lines • 2.04 kB
JavaScript
/**
* A pure JS implementation of Snappy decompression, for use in the browser
**/
var ByteBuffer = require('bytebuffer');
module.exports = {
uncompressSync: function(buf) {
var input = ByteBuffer.wrap(buf);
var size = input.readVarint32();
var output = new ByteBuffer(size);
output.offset = 0;
output.length = size;
input.littleEndian = true;
var copy = function(output, length, offset) {
var ptr = output.offset - offset;
for (var i = 0; i < length; ++i) {
output.writeByte(output.readByte(ptr + i));
}
};
while (input.remaining()) {
var tag = input.readUint8();
switch (tag & 3) {
case 0:
var length = (tag >> 2) + 1;
if (length >= 61) {
var bytes = length - 60;
length = 0;
for (var i = 0; i < bytes; ++i) {
length |= input.readUint8() << (8 * i);
}
length++;
}
for (var i = 0; i < length; ++i) {
output.writeByte(input.readByte());
}
break;
case 1:
var length = ((tag >> 2) & 7) + 4;
var offset = ((tag >> 5) << 8) | input.readUint8();
copy(output, length, offset);
break;
case 2:
var length = (tag >> 2) + 1;
var offset = input.readUint16();
copy(output, length, offset);
break;
case 3:
var length = (tag >> 2) + 1;
var offset = input.readUint32();
copy(output, length, offset);
break;
};
}
output.offset = 0;
return output.toBuffer();
}
};