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Ignore whitespace Rev 506 → Rev 507

/programy/C/avr/akcelerometr/buffer.c
0,0 → 1,149
/*! \file buffer.c \brief Multipurpose byte buffer structure and methods. */
//*****************************************************************************
//
// File Name : 'buffer.c'
// Title : Multipurpose byte buffer structure and methods
// Author : Pascal Stang - Copyright (C) 2001-2002
// Created : 9/23/2001
// Revised : 9/23/2001
// Version : 1.0
// Target MCU : any
// Editor Tabs : 4
//
// This code is distributed under the GNU Public License
// which can be found at http://www.gnu.org/licenses/gpl.txt
//
//*****************************************************************************
 
#include "buffer.h"
#include "global.h"
#include "avr/io.h"
 
#ifndef CRITICAL_SECTION_START
#define CRITICAL_SECTION_START unsigned char _sreg = SREG; cli()
#define CRITICAL_SECTION_END SREG = _sreg
#endif
 
// global variables
 
// initialization
 
void bufferInit(cBuffer* buffer, unsigned char *start, unsigned short size)
{
// begin critical section
CRITICAL_SECTION_START;
// set start pointer of the buffer
buffer->dataptr = start;
buffer->size = size;
// initialize index and length
buffer->dataindex = 0;
buffer->datalength = 0;
// end critical section
CRITICAL_SECTION_END;
}
 
// access routines
unsigned char bufferGetFromFront(cBuffer* buffer)
{
unsigned char data = 0;
// begin critical section
CRITICAL_SECTION_START;
// check to see if there's data in the buffer
if(buffer->datalength)
{
// get the first character from buffer
data = buffer->dataptr[buffer->dataindex];
// move index down and decrement length
buffer->dataindex++;
if(buffer->dataindex >= buffer->size)
{
buffer->dataindex -= buffer->size;
}
buffer->datalength--;
}
// end critical section
CRITICAL_SECTION_END;
// return
return data;
}
 
void bufferDumpFromFront(cBuffer* buffer, unsigned short numbytes)
{
// begin critical section
CRITICAL_SECTION_START;
// dump numbytes from the front of the buffer
// are we dumping less than the entire buffer?
if(numbytes < buffer->datalength)
{
// move index down by numbytes and decrement length by numbytes
buffer->dataindex += numbytes;
if(buffer->dataindex >= buffer->size)
{
buffer->dataindex -= buffer->size;
}
buffer->datalength -= numbytes;
}
else
{
// flush the whole buffer
buffer->datalength = 0;
}
// end critical section
CRITICAL_SECTION_END;
}
 
unsigned char bufferGetAtIndex(cBuffer* buffer, unsigned short index)
{
// begin critical section
CRITICAL_SECTION_START;
// return character at index in buffer
unsigned char data = buffer->dataptr[(buffer->dataindex+index)%(buffer->size)];
// end critical section
CRITICAL_SECTION_END;
return data;
}
 
unsigned char bufferAddToEnd(cBuffer* buffer, unsigned char data)
{
// begin critical section
CRITICAL_SECTION_START;
// make sure the buffer has room
if(buffer->datalength < buffer->size)
{
// save data byte at end of buffer
buffer->dataptr[(buffer->dataindex + buffer->datalength) % buffer->size] = data;
// increment the length
buffer->datalength++;
// end critical section
CRITICAL_SECTION_END;
// return success
return -1;
}
// end critical section
CRITICAL_SECTION_END;
// return failure
return 0;
}
 
unsigned short bufferIsNotFull(cBuffer* buffer)
{
// begin critical section
CRITICAL_SECTION_START;
// check to see if the buffer has room
// return true if there is room
unsigned short bytesleft = (buffer->size - buffer->datalength);
// end critical section
CRITICAL_SECTION_END;
return bytesleft;
}
 
void bufferFlush(cBuffer* buffer)
{
// begin critical section
CRITICAL_SECTION_START;
// flush contents of the buffer
buffer->datalength = 0;
// end critical section
CRITICAL_SECTION_END;
}
 
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Added: svn:executable
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