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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 position, 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
To get the number of availible characters to read the
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 CicularBuffer.cpp and h.