node-gamedig/lib/reader.js

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JavaScript
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2014-10-29 08:02:03 +01:00
var Iconv = require('iconv-lite'),
Long = require('long');
function readUInt64BE(buffer,offset) {
var high = buffer.readUInt32BE(offset);
var low = buffer.readUInt32BE(offset+4);
return new Long(low,high,true);
}
function readUInt64LE(buffer,offset) {
var low = buffer.readUInt32LE(offset);
var high = buffer.readUInt32LE(offset+4);
return new Long(low,high,true);
}
function Reader(query,buffer) {
this.query = query;
this.buffer = buffer;
this.i = 0;
}
Reader.prototype = {
offset: function() { return this.i; },
skip: function(i) { this.i += i; },
string: function() {
var args = Array.prototype.slice.call(arguments);
var options = {};
if(args.length == 0) {
options = {};
} else if(args.length == 1) {
if(typeof args[0] == 'string') options = { delimiter: args[0] };
else if(typeof args[0] == 'number') options = { length: args[0] };
else options = args[0];
}
options.encoding = options.encoding || this.query.encoding;
if(options.encoding == 'latin1') options.encoding = 'win1252';
var start = this.i+0;
var end = start;
if(!('length' in options)) {
// terminated by the delimiter
var delim = options.delimiter || this.query.delimiter;
if(typeof delim == 'string') delim = delim.charCodeAt(0);
while(true) {
if(end >= this.buffer.length) {
end = this.buffer.length;
break;
}
if(this.buffer.readUInt8(end) == delim) break;
end++;
}
this.i = end+1;
} else {
end = start+options.length;
if(end >= this.buffer.length) {
end = this.buffer.length;
}
this.i = end;
}
var out = this.buffer.slice(start, end);
var enc = options.encoding;
if(enc == 'utf8' || enc == 'ucs2' || enc == 'binary') {
out = out.toString(enc);
} else {
out = Iconv.decode(out,enc);
}
return out;
},
int: function(bytes) {
var r = 0;
if(this.remaining() >= bytes) {
if(this.query.byteorder == 'be') {
if(bytes == 1) r = this.buffer.readInt8(this.i);
else if(bytes == 2) r = this.buffer.readInt16BE(this.i);
else if(bytes == 4) r = this.buffer.readInt32BE(this.i);
} else {
if(bytes == 1) r = this.buffer.readInt8(this.i);
else if(bytes == 2) r = this.buffer.readInt16LE(this.i);
else if(bytes == 4) r = this.buffer.readInt32LE(this.i);
}
}
this.i += bytes;
return r;
},
uint: function(bytes) {
var r = 0;
if(this.remaining() >= bytes) {
if(this.query.byteorder == 'be') {
if(bytes == 1) r = this.buffer.readUInt8(this.i);
else if(bytes == 2) r = this.buffer.readUInt16BE(this.i);
else if(bytes == 4) r = this.buffer.readUInt32BE(this.i);
else if(bytes == 8) r = readUInt64BE(this.buffer,this.i).toString();
} else {
if(bytes == 1) r = this.buffer.readUInt8(this.i);
else if(bytes == 2) r = this.buffer.readUInt16LE(this.i);
else if(bytes == 4) r = this.buffer.readUInt32LE(this.i);
else if(bytes == 8) r = readUInt64LE(this.buffer,this.i).toString();
}
}
this.i += bytes;
return r;
},
float: function() {
var r = 0;
if(this.remaining() >= 4) {
if(this.query.byteorder == 'be') r = this.buffer.readFloatBE(this.i);
else r = this.buffer.readFloatLE(this.i);
}
this.i += 4;
return r;
},
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part: function(bytes) {
var r;
if(this.remaining() >= bytes) {
r = this.buffer.slice(this.i,this.i+bytes);
} else {
r = new Buffer();
}
this.i += bytes;
return r;
},
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remaining: function() {
return this.buffer.length-this.i;
},
rest: function() {
return this.buffer.slice(this.i);
},
done: function() {
return this.i >= this.buffer.length;
}
};
module.exports = Reader;