1 files changed, 145 insertions, 0 deletions
diff --git a/node_modules/map-stream/package/index.js b/node_modules/map-stream/package/index.js
new file mode 100644
index 000000000..09ae829de
--- /dev/null
+++ b/node_modules/map-stream/package/index.js
@@ -0,0 +1,145 @@
+//filter will reemit the data if cb(err,pass) pass is truthy
+
+// reduce is more tricky
+// maybe we want to group the reductions or emit progress updates occasionally
+// the most basic reduce just emits one 'data' event after it has recieved 'end'
+
+
+var Stream = require('stream').Stream
+
+
+//create an event stream and apply function to each .write
+//emitting each response as data
+//unless it's an empty callback
+
+module.exports = function (mapper, opts) {
+
+  var stream = new Stream()
+    , self = this
+    , inputs = 0
+    , outputs = 0
+    , ended = false
+    , paused = false
+    , destroyed = false
+    , lastWritten = 0
+    , inNext = false
+
+  this.opts = opts || {};
+  var errorEventName = this.opts.failures ? 'failure' : 'error';
+
+  // Items that are not ready to be written yet (because they would come out of
+  // order) get stuck in a queue for later.
+  var writeQueue = {}
+
+  stream.writable = true
+  stream.readable = true
+
+  function queueData (data, number) {
+    var nextToWrite = lastWritten + 1
+
+    if (number === nextToWrite) {
+      // If it's next, and its not undefined write it
+      if (data !== undefined) {
+        stream.emit.apply(stream, ['data', data])
+      }
+      lastWritten ++
+      nextToWrite ++
+    } else {
+      // Otherwise queue it for later.
+      writeQueue[number] = data
+    }
+
+    // If the next value is in the queue, write it
+    if (writeQueue.hasOwnProperty(nextToWrite)) {
+      var dataToWrite = writeQueue[nextToWrite]
+      delete writeQueue[nextToWrite]
+      return queueData(dataToWrite, nextToWrite)
+    }
+
+    outputs ++
+    if(inputs === outputs) {
+      if(paused) paused = false, stream.emit('drain') //written all the incoming events
+      if(ended) end()
+    }
+  }
+
+  function next (err, data, number) {
+    if(destroyed) return
+    inNext = true
+
+    if (!err || self.opts.failures) {
+      queueData(data, number)
+    }
+
+    if (err) {
+      stream.emit.apply(stream, [ errorEventName, err ]);
+    }
+
+    inNext = false;
+  }
+
+  // Wrap the mapper function by calling its callback with the order number of
+  // the item in the stream.
+  function wrappedMapper (input, number, callback) {
+    return mapper.call(null, input, function(err, data){
+      callback(err, data, number)
+    })
+  }
+
+  stream.write = function (data) {
+    if(ended) throw new Error('map stream is not writable')
+    inNext = false
+    inputs ++
+
+    try {
+      //catch sync errors and handle them like async errors
+      var written = wrappedMapper(data, inputs, next)
+      paused = (written === false)
+      return !paused
+    } catch (err) {
+      //if the callback has been called syncronously, and the error
+      //has occured in an listener, throw it again.
+      if(inNext)
+        throw err
+      next(err)
+      return !paused
+    }
+  }
+
+  function end (data) {
+    //if end was called with args, write it, 
+    ended = true //write will emit 'end' if ended is true
+    stream.writable = false
+    if(data !== undefined) {
+      return queueData(data, inputs)
+    } else if (inputs == outputs) { //wait for processing 
+      stream.readable = false, stream.emit('end'), stream.destroy() 
+    }
+  }
+
+  stream.end = function (data) {
+    if(ended) return
+    end()
+  }
+
+  stream.destroy = function () {
+    ended = destroyed = true
+    stream.writable = stream.readable = paused = false
+    process.nextTick(function () {
+      stream.emit('close')
+    })
+  }
+  stream.pause = function () {
+    paused = true
+  }
+
+  stream.resume = function () {
+    paused = false
+  }
+
+  return stream
+}
+
+
+
+