88 lines
1.9 KiB
C++
88 lines
1.9 KiB
C++
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#include "ringbuffer.h"
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#include <cstdlib>
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#include <cstring>
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#include <cstddef>
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Ringbuffer::Ringbuffer()
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{
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Ringbuffer(1024*1024);
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}
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Ringbuffer::Ringbuffer(size_t size)
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{
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this->headptr = (unsigned char*)(malloc(size));
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this->pSize = size;
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this->endptr = this->headptr + size;
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this->readptr = this->headptr;
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this->writeptr = this->headptr;
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}
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Ringbuffer::~Ringbuffer()
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{
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free(headptr);
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headptr=endptr=0;
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readptr=writeptr=0;
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}
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size_t Ringbuffer::size() const
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{
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return pSize;
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}
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size_t Ringbuffer::size_free()
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{
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return pSize - size_used();
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}
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size_t Ringbuffer::size_used()
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{
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if(writeptr>=readptr){
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return writeptr - readptr;
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}
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return (writeptr-headptr) + (endptr - readptr);
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}
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size_t Ringbuffer::read(void *buf, size_t bufSize)
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{
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size_t currentStored = size_used();
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if(currentStored == 0){
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return 0;
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}
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size_t read = currentStored>=bufSize?bufSize:currentStored;
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if(readptr + read <= endptr){
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memcpy(buf, readptr, read);
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readptr = readptr + read;
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} else {
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// read with two step
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size_t first_size = endptr - readptr;
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size_t second_size = read - first_size;
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memcpy(buf, readptr, first_size);
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unsigned char* buf_n = (unsigned char*)(buf) + first_size;
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memcpy(buf_n, headptr, second_size);
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readptr = headptr + second_size;
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}
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return read;
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}
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bool Ringbuffer::write(void *buf, size_t bufSize)
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{
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size_t free = size_free();
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if(free < bufSize){
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return false;
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}
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if(writeptr + bufSize <= endptr){
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memcpy(writeptr, buf, bufSize);
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writeptr = writeptr + bufSize;
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} else {
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//write with two step
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size_t first_size = endptr - writeptr;
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size_t second_size = bufSize - first_size;
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memcpy(writeptr, buf, first_size);
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memcpy(headptr, (unsigned char*)buf+first_size, second_size);
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writeptr = headptr + second_size;
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}
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return true;
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}
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