74 lines
3.0 KiB
C
74 lines
3.0 KiB
C
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//
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// buffer.h : Multipurpose byte buffer structure and methods
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//
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// This byte-buffer structure provides an easy and efficient way to store
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// and process a stream of bytes. You can create as many buffers as you
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// like (within memory limits), and then use this common set of functions to
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// access each buffer. The buffers are designed for FIFO operation (first
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// in, first out). This means that the first byte you put in the buffer
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// will be the first one you get when you read out the buffer. Supported
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// functions include buffer initialize, get byte from front of buffer, add
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// byte to end of buffer, check if buffer is full, and flush buffer. The
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// buffer uses a circular design so no copying of data is ever necessary.
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// This buffer is not dynamically allocated, it has a user-defined fixed
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// maximum size. This buffer is used in many places in the avrlib code.
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//
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// Copyright (c) 2001-2002 Pascal Stang
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//
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// This program is free software; you can redistribute it and/or
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// modify it under the terms of the GNU General Public License
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// as published by the Free Software Foundation; either version 2
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// of the License, or (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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//
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// $Id$
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#ifndef BUFFER_H
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#define BUFFER_H
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// structure/typdefs
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//! cBuffer structure
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typedef struct struct_cBuffer
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{
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unsigned char *dataptr; ///< the physical memory address where the buffer is stored
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unsigned short size; ///< the allocated size of the buffer
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unsigned short datalength; ///< the length of the data currently in the buffer
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unsigned short dataindex; ///< the index into the buffer where the data starts
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} cBuffer;
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// function prototypes
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//! initialize a buffer to start at a given address and have given size
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void bufferInit(cBuffer* buffer, unsigned char *start, unsigned short size);
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//! get the first byte from the front of the buffer
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unsigned char bufferGetFromFront(cBuffer* buffer);
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//! dump (discard) the first numbytes from the front of the buffer
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void bufferDumpFromFront(cBuffer* buffer, unsigned short numbytes);
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//! get a byte at the specified index in the buffer (kind of like array access)
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// ** note: this does not remove the byte that was read from the buffer
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unsigned char bufferGetAtIndex(cBuffer* buffer, unsigned short index);
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//! add a byte to the end of the buffer
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unsigned char bufferAddToEnd(cBuffer* buffer, unsigned char data);
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//! check if the buffer is full/not full (returns zero value if full)
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unsigned short bufferIsNotFull(cBuffer* buffer);
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//! flush (clear) the contents of the buffer
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void bufferFlush(cBuffer* buffer);
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#endif
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