var StringDecoder = exports.StringDecoder = function (encoding){ 
this.encoding = _AN_Call_replace('replace', (encoding || 'utf8').toLowerCase(), /[-_]/, ''); 
if (this.encoding === 'utf8') { 
this.charBuffer = new Buffer(4); 
this.charReceived = 0; 
this.charLength = 0; 
} 
} 
; 
StringDecoder.prototype.write = function (buffer){ 
if (this.encoding !== 'utf8') { 
return buffer.toString(this.encoding); 
} 
var charStr = ''; 
if (this.charLength) { 
var i = (_AN_Read_length('length', buffer) >= this.charLength - this.charReceived)? this.charLength - this.charReceived: _AN_Read_length('length', buffer); 
buffer.copy(this.charBuffer, this.charReceived, 0, i); 
this.charReceived += i; 
if (this.charReceived < this.charLength) { 
return ''; 
} 
charStr = this.charBuffer.slice(0, this.charLength).toString(); 
this.charReceived = this.charLength = 0; 
if (i == _AN_Read_length('length', buffer)) return charStr; 
buffer = buffer.slice(i, _AN_Read_length('length', buffer)); 
} 
var i = (_AN_Read_length('length', buffer) >= 3)? 3: _AN_Read_length('length', buffer); 
for (; i > 0; i-- ){ 
var c = buffer[_AN_Read_length('length', buffer) - i]; 
if (i == 1 && c >> 5 == 6) { 
this.charLength = 2; 
break ; 
} 
if (i <= 2 && c >> 4 == 14) { 
this.charLength = 3; 
break ; 
} 
if (i <= 3 && c >> 3 == 30) { 
this.charLength = 4; 
break ; 
} 
} 
if (!this.charLength) { 
return charStr + buffer.toString(); 
} 
buffer.copy(this.charBuffer, 0, _AN_Read_length('length', buffer) - i, _AN_Read_length('length', buffer)); 
this.charReceived = i; 
if (_AN_Read_length('length', buffer) - i > 0) { 
return charStr + buffer.toString('utf8', 0, _AN_Read_length('length', buffer) - i); 
} 
return charStr; 
} 
;