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  • Your email address will not be published.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

  • Companies undertaking an IT project need to find the right balance between cost and functionality. It's important to start by determining whether to build a solution from scratch, buy an out-of-the-box solution, or a combination of both. In reality, most projects will require some system tailoring to meet business requirements. Decision-makers must understand how much software development is enough and craft a detailed implementation plan to ensure the project's success. This white paper examines the different …

  • On-demand Event Event Date: February 12, 2015 The evolution of systems engineering with the SysML modeling language has resulted in improved requirements specification, better architectural definition, and better hand-off to downstream engineering. Agile methods have proven successful in the software domain, but how can these methods be applied to systems engineering? Check out this webcast and join Bruce Powel Douglass, author of Real-Time Agility, as he discusses how agile methods have had a tremendous …

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date