Accumulate the output of a stream into a string.

StreamAccumulator.js

/*
 * No sentinel results in reading the entire stream until it ends, a
 * numeric sentinel reads fixed length chunks, and a string sentinel
 * reads chunks bounded by the sentinel string
*/
exports.accumulate = function(stream,opts,callback){
	stream.pause();
	if(!callback){
		callback = opts;
		opts = {encoding:'utf8'};
	}
	stream.setEncoding(opts.encoding || 'utf8');
	switch(typeof opts.sentinel){
		case 'undefined':
		case false:
		default: dumpStream(stream,callback);break
		case 'string': readSentinel(stream,opts.sentinel,callback);break
		case 'number': readLength(stream,opts.sentinel,callback);
	}
	stream.resume();
}

function dumpStream(stream,callback){
	var str='';
	stream.on('data',function(data){str+=data;});
	stream.on('end',function(){callback(str);});
}

function readSentinel(stream,sentinel,callback){
	var str='',that=this,slen=sentinel.length;
	stream.on('data',function(data){
		var i=0,j;
		str += data;
		while((j = str.indexOf(sentinel,i))!==-1){
			j+=slen;
			callback(str.substring(i,j));
			i=j;
		}
		if(i){str = str.substr(i);}
	});
	stream.on('end',function(){callback(str);});
}

function readLength(stream,length,callback){
	var str='';
	stream.on('data',function(data){
		var i,j,end;
		str += data;
		end = str.length-length;
		for(i=0;i<end;i+=length){
			callback(str.substr(i,length));
		}
		if(i){str = str.substr(i);}
	});
	stream.on('end',function(){callback(str);});
}