minecraft.js/lib/network/packet.js

Minecraft data serialization/deserialization and networking

var protocol = require(__dirname + '/protocol.js');

/** @constructor */
var Packet = module.exports = function(id, data, isServer) {
    this.id = id;
    this.data = data || {};
    this.format = protocol.get(id, isServer);
};

Packet.prototype.toString = function(encoding) {
    var buf = new Buffer(this.getSize());
    var offset = 0;

    buf.writeUInt8(this.id, offset);
    var subBuffer = buf.slice(1);

    for(var i = 0; i < this.format.length; i++) {
    	var toPack = this.data[this.format[i].name] || protocol.datatypes[this.format[i].type.toUpperCase()].empty;
        var size = protocol.datatypes[this.format[i].type.toUpperCase()].pack(toPack, subBuffer);
        subBuffer = subBuffer.slice(size);
    }

    if(encoding == 'buffer') return buf;
    else return buf.toString(encoding || 'utf8');
};

Packet.prototype.getSize = function() {
    if( typeof this._size != 'undefined')
        return this._size;

    var output = 1;

    for(var i = 0; i < this.format.length; i++) {
        if(!protocol.datatypes[this.format[i].type.toUpperCase()].dynamic) {
            output += protocol.datatypes[this.format[i].type.toUpperCase()].size;
        } else {
            output += protocol.datatypes[this.format[i].type.toUpperCase()].getSize(this.data[this.format[i].name]);
        }
    }

    return output;
};