wishthis/node_modules/multipipe/index.js
2022-01-21 09:28:41 +01:00

72 lines
1.2 KiB
JavaScript

/**
* Module dependencies.
*/
var duplexer = require('duplexer2');
var Stream = require('stream');
/**
* Slice reference.
*/
var slice = [].slice;
/**
* Duplexer options.
*/
var opts = {
bubbleErrors: false
};
/**
* Expose `pipe`.
*/
module.exports = pipe;
/**
* Pipe.
*
* @param {Stream,...,[Function]}
* @return {Stream}
* @api public
*/
function pipe(){
if (arguments.length == 1) return arguments[0];
var streams = slice.call(arguments);
var cb;
if ('function' == typeof streams[streams.length - 1]) {
cb = streams.splice(-1)[0];
}
var first = streams[0];
var last = streams[streams.length - 1];
var ret;
if (first.writable && last.readable) ret = duplexer(opts, first, last);
else if (first.writable) ret = first;
else if (last.readable) ret = last;
else ret = new Stream;
streams.forEach(function(stream, i){
var next = streams[i+1];
if (next) stream.pipe(next);
if (stream != ret) stream.on('error', ret.emit.bind(ret, 'error'));
});
if (cb) {
var ended = false;
ret.on('error', end);
last.on('finish', end);
function end(err){
if (ended) return;
ended = true;
cb(err);
}
}
return ret;
}