Super Simple Ring Buffer Macros

In ringbuffer.h are some naughty macros for easily owning and manipulating generic ring buffers. Yes, they are slightly evil in readability, but they are really fast, and they work great. If you don't like them, don't use them. I use them because it's the only DRY and sane way to add generic ring buffers to your C application.

For limited resources systems such as microcontrollers there is RINGBUFFER_USE_STATIC_MEMORY and RINGBUFFER_AVOID_MODULO defines.

Example usage:

#include <stdio.h>

// So we can use this in any method, this gives us a typedef named 'intBuffer'.
// Really, this is the only *truely* naughty portion of these macros as it
// creates a complete type definition for you. This is something people will
// have to read the header in order to grok.
ringBuffer_typedef(int, intBuffer);

// The above macro translates exactly to:
typedef struct {
  int size;
  int start;
  int end;
  int* elems;
} intBuffer;


int main() {
  // Declare vars.
  intBuffer myBuffer;

  bufferInit(myBuffer,1024,int);

  // We must have the pointer. All of the macros deal with the pointer.
  // (except for init.)
  intBuffer* myBuffer_ptr;
  myBuffer_ptr = &myBuffer;

  // Write two values.
  bufferWrite(myBuffer_ptr,37);
  bufferWrite(myBuffer_ptr,72);

  // Check how much space is used
  int used_space = bufferUsedSpace(myBuffer_ptr);

  // Check how much space is available
  int free_space = bufferFreeSpace(myBuffer_ptr);

  // Read a value into a local variable.
  int first;
  bufferRead(myBuffer_ptr,first);
  assert(first == 37); // true

  // Get reference of the current element to avoid copies
  int* second_ptr = &bufferReadPeek(myBuffer_ptr);
  assert(*second_ptr == 72); // true
  operate_on_reference(second_prt);
 
  // move to next value
  bufferReadSkip(myBuffer_ptr);

  // Reset to the state after initialization
  bufferReset(myBuffer_ptr);

  // Peek the last 32 values written to the buffer
  for (int i = 0; i < 32; i++) {
    int value;
    bufferPeekBack(myBuffer_ptr, i, value);
  }

  return 0;
}

License

The MIT License (MIT)

Copyright (c) 2013 Philip Thrasher

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
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the Software, and to permit persons to whom the Software is furnished to do so,
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The above copyright notice and this permission notice shall be included in all
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