/*
- * A very simple circular buffer FIFO implementation
+ * a very simple circular buffer FIFO implementation
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
* Copyright (c) 2006 Roman Shaposhnik
*
#include "common.h"
#include "fifo.h"
-int av_fifo_init(AVFifoBuffer *f, unsigned int size)
+AVFifoBuffer *av_fifo_alloc(unsigned int size)
{
- size= FFMAX(size, size+1);
- f->wptr = f->rptr =
+ AVFifoBuffer *f= av_mallocz(sizeof(AVFifoBuffer));
+ if(!f)
+ return NULL;
f->buffer = av_malloc(size);
f->end = f->buffer + size;
+ av_fifo_reset(f);
if (!f->buffer)
- return -1;
- return 0;
+ av_freep(&f);
+ return f;
}
void av_fifo_free(AVFifoBuffer *f)
{
- av_free(f->buffer);
+ if(f){
+ av_free(f->buffer);
+ av_free(f);
+ }
}
-int av_fifo_size(AVFifoBuffer *f)
+void av_fifo_reset(AVFifoBuffer *f)
{
- int size = f->wptr - f->rptr;
- if (size < 0)
- size += f->end - f->buffer;
- return size;
+ f->wptr = f->rptr = f->buffer;
+ f->wndx = f->rndx = 0;
}
-int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size)
+int av_fifo_size(AVFifoBuffer *f)
{
- return av_fifo_generic_read(f, buf_size, NULL, buf);
+ return (uint32_t)(f->wndx - f->rndx);
}
-/**
- * Resizes a FIFO.
- */
-void av_fifo_realloc(AVFifoBuffer *f, unsigned int new_size) {
- av_fifo_realloc2(f, new_size);
+int av_fifo_space(AVFifoBuffer *f)
+{
+ return f->end - f->buffer - av_fifo_size(f);
}
int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size) {
unsigned int old_size= f->end - f->buffer;
- if(old_size <= new_size){
+ if(old_size < new_size){
int len= av_fifo_size(f);
- AVFifoBuffer f2;
+ AVFifoBuffer *f2= av_fifo_alloc(new_size);
- if (av_fifo_init(&f2, new_size) < 0)
+ if (!f2)
return -1;
- av_fifo_read(f, f2.buffer, len);
- f2.wptr += len;
+ av_fifo_generic_read(f, f2->buffer, len, NULL);
+ f2->wptr += len;
+ f2->wndx += len;
av_free(f->buffer);
- *f= f2;
+ *f= *f2;
+ av_free(f2);
}
return 0;
}
-void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size)
-{
- av_fifo_generic_write(f, (void *)buf, size, NULL);
-}
-
int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int))
{
int total = size;
memcpy(f->wptr, src, len);
src = (uint8_t*)src + len;
}
+// Write memory barrier needed for SMP here in theory
f->wptr += len;
if (f->wptr >= f->end)
f->wptr = f->buffer;
+ f->wndx += len;
size -= len;
} while (size > 0);
return total - size;
}
-int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest)
+int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int))
{
+// Read memory barrier needed for SMP here in theory
do {
int len = FFMIN(f->end - f->rptr, buf_size);
if(func) func(dest, f->rptr, len);
memcpy(dest, f->rptr, len);
dest = (uint8_t*)dest + len;
}
+// memory barrier needed for SMP here in theory
av_fifo_drain(f, len);
buf_size -= len;
} while (buf_size > 0);
return 0;
}
-/** discard data from the fifo */
+/** Discard data from the FIFO. */
void av_fifo_drain(AVFifoBuffer *f, int size)
{
f->rptr += size;
if (f->rptr >= f->end)
f->rptr -= f->end - f->buffer;
+ f->rndx += size;
}