add writable binary stream support

Author: tmpvar

midi.js

@@ -19,23 +19,51 @@ midi.createReadStream = function(input) {
     var packet = new Buffer(message);
 
     if (!stream.paused) {
-      var res = stream.emit('data', packet);
+      stream.emit('data', packet);
     } else {
       stream.queue.push(packet);
     }
-
-    if (!res) {
-      stream.paused = true;
-      stream.once('drain', function() {
-        while (stream.queue.length && stream.write(queue.shift())) {}
-      });
-    }
   });
 
+  stream.pause = function() {
+    stream.paused = true;
+  };
+
+  stream.resume = function() {
+    stream.paused = false;
+    while (stream.queue.length && stream.write(queue.shift())) {}
+  };
+
   return stream;
 };
 
 
-midi.createWriteStream = function() {
+midi.createWriteStream = function(output) {
+  output = output || new midi.output();
+  var stream = new Stream();
+  stream.writable = true;
+  stream.paused = false;
+  stream.queue = [];
+
+  stream.write = function(d) {
 
+    if (Buffer.isBuffer(d)) {
+      d = [d[0], d[1], d[2]];
+    }
+
+    output.sendMessage(d);
+
+    return !this.paused;
+  }
+
+  stream.end = function(buf) {
+    buf && stream.write(buf);
+    stream.writable = false;
+  };
+
+  stream.destroy = function() {
+    stream.writable = false;
+  }
+
+  return stream;
 };

test/fixture/144-23-81.bin

@@ -0,0 +1 @@
+�Q

test/virtual-writeStream-test.js

@@ -0,0 +1,31 @@
+var midi = require("../midi.js");
+var virtualInput = new midi.input();
+var output = new midi.output();
+var assert = require('assert');
+var fs = require('fs');
+var expect = [144, 23, 81];
+var called = false;
+var writer = midi.createWriteStream(output);
+
+virtualInput.openVirtualPort("node-midi");
+virtualInput.on('message', function(deltaTime, buffer) {
+  assert.deepEqual(buffer, expect);
+  called = true;
+});
+
+
+for (var i = 0; i < output.getPortCount(); ++i) {
+  if (output.getPortName(i) === 'node-midi') {
+    output.openPort(i);
+    break;
+  }
+}
+
+fs.createReadStream(__dirname + '/fixture/144-23-81.bin').pipe(writer);
+
+setTimeout(function() {
+  assert(called);
+  output.closePort();
+  virtualInput.closePort();
+  process.exit(0);
+}, 100);