title: Google Protocol Buffers - Storing messages into file
body: <p>I'm using google protocol buffer to serialize equity market data (ie. timestamp, bid,ask fields).
  I can store one message into a file and deserialize it without issue.</p>
  
  <p>How can I store multiple messages into a single file? Not sure how I can separate the messages. I need to be able to append new messages to the file on the fly.</p>