Circular Buffer

I recently needed a class that stored a character array as a circular buffer. If you are unfamiliar with circular buffer, it is a permanently allocated buffer that has both a read and write position. I have done a few of them in the past, but had lost all of my examples. So I wrote a new one and placed it into a class called CircularBuffer. The CircularBuffer can be read from and written to, and it has methods to get the read and write count. As the buffer is written to the write position increases til the end of the buffer is reached, at that point the write position is wrapped back to the start of the buffer and writing starts from there. The same happens to the read operation also, but the read position is incremented. It is important to note that the read position will never be greater than the write positon, since if it were we would be reading data that had not been written to the buffer. Likewise, the write position will never wrap the read position otherwise data that had not been read would be overwritten.

The basic operations are read and write, both fail if an overlap condition could occur.

To get the number of availible characters to read the readCount method is used. If the count is greater than zero use the read method to get the latest contents written into the buffer.

I have included a small test application in a project TestQue. The test driver is in the TestQue.cpp. It is multithreaded win32 console app developed using VC6. The CircularBuffer code is in CircularBuffer.cpp and h.

Downloads

Download demo project - 12 Kb


Comments

  • There are no comments yet. Be the first to comment!

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Java developers know that testing code changes can be a huge pain, and waiting for an application to redeploy after a code fix can take an eternity. Wouldn't it be great if you could see your code changes immediately, fine-tune, debug, explore and deploy code without waiting for ages? In this white paper, find out how that's possible with a Java plugin that drastically changes the way you develop, test and run Java applications. Discover the advantages of this plugin, and the changes you can expect to see …

  • IT decision support impacts all aspects of technology management, from governance and strategy to budgets and resource planning. IT decision support effectiveness often falls prey to data-driven challenges that make it difficult to understand the data in context. These challenges: overwhelming data volumes, heterogeneous data types, and growing data complexity. This Forrester Consulting Paper reports the three key findings from their study conducted, on behalf of BDNA, to test the hypothesis that data …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds