/* * a very simple circular buffer FIFO implementation * Copyright (c) 2000, 2001, 2002 Fabrice Bellard * Copyright (c) 2006 Roman Shaposhnik * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "common.h" #include "fifo.h" AVFifoBuffer *av_fifo_alloc(unsigned int size) { AVFifoBuffer *f= av_mallocz(sizeof(AVFifoBuffer)); if(!f) return NULL; f->wptr = f->rptr = f->buffer = av_malloc(size); f->end = f->buffer + size; if (!f->buffer) av_freep(&f); return f; } void av_fifo_free(AVFifoBuffer *f) { if(f){ av_free(f->buffer); av_free(f); } } int av_fifo_size(AVFifoBuffer *f) { return (uint32_t)(f->wndx - f->rndx); } #if LIBAVUTIL_VERSION_MAJOR < 50 void av_fifo_realloc(AVFifoBuffer *f, unsigned int new_size) { av_fifo_realloc2(f, new_size); } #endif int av_fifo_realloc2(AVFifoBuffer *f, unsigned int new_size) { unsigned int old_size= f->end - f->buffer; if(old_size < new_size){ int len= av_fifo_size(f); AVFifoBuffer *f2= av_fifo_alloc(new_size); if (!f2) return -1; av_fifo_read(f, f2->buffer, len); f2->wptr += len; f2->wndx += len; av_free(f->buffer); *f= *f2; av_free(f2); } return 0; } #if LIBAVUTIL_VERSION_MAJOR < 50 void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size) { av_fifo_generic_write(f, (void *)buf, size, NULL); } #endif int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int)) { int total = size; do { int len = FFMIN(f->end - f->wptr, size); if(func) { if(func(src, f->wptr, len) <= 0) break; } else { 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) { // 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); else{ 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. */ 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; }