/*! \file buffer.h \brief Multipurpose byte buffer structure and methods. */ //***************************************************************************** // // File Name : 'buffer.h' // Title : Multipurpose byte buffer structure and methods // Author : Pascal Stang - Copyright (C) 2001-2002 // Created : 9/23/2001 // Revised : 11/16/2002 // Version : 1.1 // Target MCU : any // Editor Tabs : 4 // /// \ingroup general /// \defgroup buffer Circular Byte-Buffer Structure and Function Library (buffer.c) /// \code #include "buffer.h" \endcode /// \par Overview /// This byte-buffer structure provides an easy and efficient way to store /// and process a stream of bytes.  You can create as many buffers as you /// like (within memory limits), and then use this common set of functions to /// access each buffer.  The buffers are designed for FIFO operation (first /// in, first out).  This means that the first byte you put in the buffer /// will be the first one you get when you read out the buffer.  Supported /// functions include buffer initialize, get byte from front of buffer, add /// byte to end of buffer, check if buffer is full, and flush buffer.  The /// buffer uses a circular design so no copying of data is ever necessary. /// This buffer is not dynamically allocated, it has a user-defined fixed /// maximum size.  This buffer is used in many places in the avrlib code. // // This code is distributed under the GNU Public License // which can be found at http://www.gnu.org/licenses/gpl.txt // //***************************************************************************** //@{ #ifndef BUFFER_H #define BUFFER_H // structure/typdefs //! cBuffer structure typedef struct struct_cBuffer { unsigned char *dataptr; ///< the physical memory address where the buffer is stored unsigned short size; ///< the allocated size of the buffer unsigned short datalength; ///< the length of the data currently in the buffer unsigned short dataindex; ///< the index into the buffer where the data starts } cBuffer; // function prototypes //! initialize a buffer to start at a given address and have given size void bufferInit(cBuffer* buffer, unsigned char *start, unsigned short size); //! get the first byte from the front of the buffer unsigned char bufferGetFromFront(cBuffer* buffer); //! dump (discard) the first numbytes from the front of the buffer void bufferDumpFromFront(cBuffer* buffer, unsigned short numbytes); //! get a byte at the specified index in the buffer (kind of like array access) // ** note: this does not remove the byte that was read from the buffer unsigned char bufferGetAtIndex(cBuffer* buffer, unsigned short index); //! add a byte to the end of the buffer unsigned char bufferAddToEnd(cBuffer* buffer, unsigned char data); //! check if the buffer is full/not full (returns zero value if full) unsigned short bufferIsNotFull(cBuffer* buffer); //! flush (clear) the contents of the buffer void bufferFlush(cBuffer* buffer); #endif //@}