November 10, 2017 16:56 · Nov 10, 2017
diff --git a/networker.js b/networker.js
@@ -0,0 +1,122 @@
+'use strict';
+
+const debug = require('debug')('network');
+
+function Networker(socket, handler) {
+  this.socket = socket;
+  this._packet = {};
+
+  this._process = false;
+  this._state = 'HEADER';
+  this._payloadLength = 0;
+  this._bufferedBytes = 0;
+  this.queue = [];
+
+  this.handler = handler;
+}
+
+Networker.prototype.init = function () {
+  this.socket.on('data', (data) => {
+    this._bufferedBytes += data.length;
+    this.queue.push(data);
+
+    this._process = true;
+    this._onData();
+  });
+
+  this.socket.on('served', this.handler);
+};
+
+Networker.prototype._hasEnough = function (size) {
+  if (this._bufferedBytes >= size) {
+    return true;
+  }
+  this._process = false;
+  return false;
+}
+
+Networker.prototype._readBytes = function (size) {
+  let result;
+  this._bufferedBytes -= size;
+
+  if (size === this.queue[0].length) {
+    return this.queue.shift();
+  }
+
+  if (size < this.queue[0].length) {
+    result = this.queue[0].slice(0, size);
+    this.queue[0] = this.queue[0].slice(size);
+    return result;
+  }
+
+  result = Buffer.allocUnsafe(size);
+  let offset = 0;
+  let length;
+
+  while (size > 0) {
+    length = this.queue[0].length;
+
+    if (size >= length) {
+      this.queue[0].copy(result, offset);
+      offset += length;
+      this.queue.shift();
+    } else {
+      this.queue[0].copy(result, offset, 0, size);
+      this.queue[0] = this.queue[0].slice(size);
+    }
+
+    size -= length;
+  }
+
+  return result;
+}
+
+Networker.prototype._getHeader = function () {
+  if (this._hasEnough(2)) {
+    this._payloadLength = this._readBytes(2).readUInt16BE(0, true);
+    this._state = 'PAYLOAD';
+  }
+}
+
+Networker.prototype._getPayload = function () {
+  if (this._hasEnough(this._payloadLength)) {
+    let received = this._readBytes(this._payloadLength);
+    this.socket.emit('served', received);
+    this._state = 'HEADER';
+  }
+}
+
+Networker.prototype._onData = function (data) {
+  while (this._process) {
+    switch (this._state) {
+      case 'HEADER':
+        this._getHeader();
+        break;
+      case 'PAYLOAD':
+        this._getPayload();
+        break;
+    }
+  }
+}
+
+Networker.prototype.send = function (message) {
+  let buffer = Buffer.from(message);
+  this._header(buffer.length);
+  this._packet.message = buffer;
+  this._send();
+}
+
+Networker.prototype._header = function (messageLength) {
+  this._packet.header = { length: messageLength };
+};
+
+Networker.prototype._send = function () {
+  let contentLength = Buffer.allocUnsafe(2);
+  contentLength.writeUInt16BE(this._packet.header.length);
+  debug('Attempting to write...', this._packet);
+  this.socket.write(contentLength);
+  this.socket.write(this._packet.message);
+  this._packet = {};
+};
+
+module.exports = Networker;