Add cctalk parsers

lib/parsers/cctalk.js

@@ -0,0 +1,39 @@
+'use strict';
+const Buffer = require('safe-buffer').Buffer;
+const Transform = require('stream').Transform;
+
+const MAX_PACKET_LENGTH = 255 + 5;
+const debug = require('debug');
+
+module.exports = class ccTalkParser extends Transform {
+  constructor() {
+    super();
+    this.buffer = Buffer.alloc(MAX_PACKET_LENGTH); // maxium ccTalkMessage length
+    this.cursor = 0;
+  }
+  _transform(buffer, _, cb) {
+    debug('parser set')(this.buffer, this.cursor);
+    debug('parser set')(this.buffer.toString('hex'), buffer.buffer, this.cursor);
+
+    this.buffer.set(buffer, this.cursor);
+    this.cursor += buffer.length;
+    // full frame accumulated
+    const length = this.buffer[1] + 5;
+    debug('parse befor loop')(buffer, this.cursor);
+
+    while (this.cursor > 1 && this.cursor >= length) {
+      // console.log("length", length);
+
+      // copy command from the buffer
+      const frame = new Uint8Array(length);
+      frame.set(this.buffer.slice(0, length));
+
+      // copy remaining buffer to the begin of the buffer to prepare for next command
+      this.buffer.set(this.buffer.slice(length, this.cursor));
+      this.cursor -= length;
+      debug('parse push', frame, this.buffer, this.cursor);
+      this.push(frame);
+    }
+    cb();
+  }
+};

lib/parsers/index.js

@@ -76,6 +76,7 @@ parser.on('data', console.log);
 
 module.exports = {
   ByteLength: require('./byte-length'),
+  CCTalk: require('./cctalk'),
   Delimiter: require('./delimiter'),
   Readline: require('./readline'),
   Ready: require('./ready'),