RingBuffer.cpp

00001 #include "RingBuffer.h"
00002 
00003 void RingBuffer::initialize_buffer(){
00004     start=0;
00005     end=0;
00006 }
00007 
00008 int16_t RingBuffer::buffer_size(){
00009     if(end >= start){
00010         return end - start;
00011     }
00012     return RING_BUFFER_SIZE - (start - end);
00013 }
00014 
00015 uint8_t RingBuffer::read_buffer_byte(){
00016     uint8_t a;
00017     a=buffer[start];
00018     start=(start+1)%RING_BUFFER_SIZE;
00019     return a;
00020 }
00021 
00022 int16_t RingBuffer::read_buffer_short(){
00023     int16_t a, b;
00024     a=buffer[start];
00025     b=buffer[(start+1)%RING_BUFFER_SIZE];
00026     start=(start+2)%RING_BUFFER_SIZE;
00027     return (a&0xff)|(b<<8);
00028 }
00029 
00030 void RingBuffer::read_buffer(uint8_t buf[], int16_t offset, int16_t size){
00031     int16_t i;
00032     uint8_t* p=buf+offset;
00033     
00034     for(i=0; i<size; i++){
00035         *(p++)=buffer[start];
00036         start=(start+1)%RING_BUFFER_SIZE;
00037     }
00038 }
00039 
00040 int16_t RingBuffer::buffer_capacity(){
00041     if(end >= start){
00042         return RING_BUFFER_SIZE-(end-start)-1;
00043     }
00044     return (start-end)-1;
00045 }
00046 
00047 void RingBuffer::write_buffer_byte(uint8_t ch){
00048     buffer[end]=ch;
00049     end=(end+1)%RING_BUFFER_SIZE;
00050 }
00051 
00052 void RingBuffer::write_buffer(const uint8_t buf[], int16_t offset, int16_t size){
00053     int16_t i;
00054     const uint8_t* p=buf+offset;
00055     for(i=0; i<size; i++){
00056         buffer[end]=*(p++);
00057         end=(end+1)%RING_BUFFER_SIZE;
00058     }
00059 }
00060 
00061 bool RingBuffer::is_buffer_empty(){
00062     return (start==end);
00063 }