LCOV - code coverage report
Current view: top level - libavutil - fifo.h (source / functions) Hit Total Coverage
Test: coverage.info Lines: 6 7 85.7 %
Date: 2017-12-15 02:19:58 Functions: 1 1 100.0 %

          Line data    Source code
       1             : /*
       2             :  * This file is part of FFmpeg.
       3             :  *
       4             :  * FFmpeg is free software; you can redistribute it and/or
       5             :  * modify it under the terms of the GNU Lesser General Public
       6             :  * License as published by the Free Software Foundation; either
       7             :  * version 2.1 of the License, or (at your option) any later version.
       8             :  *
       9             :  * FFmpeg is distributed in the hope that it will be useful,
      10             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      11             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12             :  * Lesser General Public License for more details.
      13             :  *
      14             :  * You should have received a copy of the GNU Lesser General Public
      15             :  * License along with FFmpeg; if not, write to the Free Software
      16             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      17             :  */
      18             : 
      19             : /**
      20             :  * @file
      21             :  * a very simple circular buffer FIFO implementation
      22             :  */
      23             : 
      24             : #ifndef AVUTIL_FIFO_H
      25             : #define AVUTIL_FIFO_H
      26             : 
      27             : #include <stdint.h>
      28             : #include "avutil.h"
      29             : #include "attributes.h"
      30             : 
      31             : typedef struct AVFifoBuffer {
      32             :     uint8_t *buffer;
      33             :     uint8_t *rptr, *wptr, *end;
      34             :     uint32_t rndx, wndx;
      35             : } AVFifoBuffer;
      36             : 
      37             : /**
      38             :  * Initialize an AVFifoBuffer.
      39             :  * @param size of FIFO
      40             :  * @return AVFifoBuffer or NULL in case of memory allocation failure
      41             :  */
      42             : AVFifoBuffer *av_fifo_alloc(unsigned int size);
      43             : 
      44             : /**
      45             :  * Initialize an AVFifoBuffer.
      46             :  * @param nmemb number of elements
      47             :  * @param size  size of the single element
      48             :  * @return AVFifoBuffer or NULL in case of memory allocation failure
      49             :  */
      50             : AVFifoBuffer *av_fifo_alloc_array(size_t nmemb, size_t size);
      51             : 
      52             : /**
      53             :  * Free an AVFifoBuffer.
      54             :  * @param f AVFifoBuffer to free
      55             :  */
      56             : void av_fifo_free(AVFifoBuffer *f);
      57             : 
      58             : /**
      59             :  * Free an AVFifoBuffer and reset pointer to NULL.
      60             :  * @param f AVFifoBuffer to free
      61             :  */
      62             : void av_fifo_freep(AVFifoBuffer **f);
      63             : 
      64             : /**
      65             :  * Reset the AVFifoBuffer to the state right after av_fifo_alloc, in particular it is emptied.
      66             :  * @param f AVFifoBuffer to reset
      67             :  */
      68             : void av_fifo_reset(AVFifoBuffer *f);
      69             : 
      70             : /**
      71             :  * Return the amount of data in bytes in the AVFifoBuffer, that is the
      72             :  * amount of data you can read from it.
      73             :  * @param f AVFifoBuffer to read from
      74             :  * @return size
      75             :  */
      76             : int av_fifo_size(const AVFifoBuffer *f);
      77             : 
      78             : /**
      79             :  * Return the amount of space in bytes in the AVFifoBuffer, that is the
      80             :  * amount of data you can write into it.
      81             :  * @param f AVFifoBuffer to write into
      82             :  * @return size
      83             :  */
      84             : int av_fifo_space(const AVFifoBuffer *f);
      85             : 
      86             : /**
      87             :  * Feed data at specific position from an AVFifoBuffer to a user-supplied callback.
      88             :  * Similar as av_fifo_gereric_read but without discarding data.
      89             :  * @param f AVFifoBuffer to read from
      90             :  * @param offset offset from current read position
      91             :  * @param buf_size number of bytes to read
      92             :  * @param func generic read function
      93             :  * @param dest data destination
      94             :  */
      95             : int av_fifo_generic_peek_at(AVFifoBuffer *f, void *dest, int offset, int buf_size, void (*func)(void*, void*, int));
      96             : 
      97             : /**
      98             :  * Feed data from an AVFifoBuffer to a user-supplied callback.
      99             :  * Similar as av_fifo_gereric_read but without discarding data.
     100             :  * @param f AVFifoBuffer to read from
     101             :  * @param buf_size number of bytes to read
     102             :  * @param func generic read function
     103             :  * @param dest data destination
     104             :  */
     105             : int av_fifo_generic_peek(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int));
     106             : 
     107             : /**
     108             :  * Feed data from an AVFifoBuffer to a user-supplied callback.
     109             :  * @param f AVFifoBuffer to read from
     110             :  * @param buf_size number of bytes to read
     111             :  * @param func generic read function
     112             :  * @param dest data destination
     113             :  */
     114             : int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int));
     115             : 
     116             : /**
     117             :  * Feed data from a user-supplied callback to an AVFifoBuffer.
     118             :  * @param f AVFifoBuffer to write to
     119             :  * @param src data source; non-const since it may be used as a
     120             :  * modifiable context by the function defined in func
     121             :  * @param size number of bytes to write
     122             :  * @param func generic write function; the first parameter is src,
     123             :  * the second is dest_buf, the third is dest_buf_size.
     124             :  * func must return the number of bytes written to dest_buf, or <= 0 to
     125             :  * indicate no more data available to write.
     126             :  * If func is NULL, src is interpreted as a simple byte array for source data.
     127             :  * @return the number of bytes written to the FIFO
     128             :  */
     129             : int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int));
     130             : 
     131             : /**
     132             :  * Resize an AVFifoBuffer.
     133             :  * In case of reallocation failure, the old FIFO is kept unchanged.
     134             :  *
     135             :  * @param f AVFifoBuffer to resize
     136             :  * @param size new AVFifoBuffer size in bytes
     137             :  * @return <0 for failure, >=0 otherwise
     138             :  */
     139             : int av_fifo_realloc2(AVFifoBuffer *f, unsigned int size);
     140             : 
     141             : /**
     142             :  * Enlarge an AVFifoBuffer.
     143             :  * In case of reallocation failure, the old FIFO is kept unchanged.
     144             :  * The new fifo size may be larger than the requested size.
     145             :  *
     146             :  * @param f AVFifoBuffer to resize
     147             :  * @param additional_space the amount of space in bytes to allocate in addition to av_fifo_size()
     148             :  * @return <0 for failure, >=0 otherwise
     149             :  */
     150             : int av_fifo_grow(AVFifoBuffer *f, unsigned int additional_space);
     151             : 
     152             : /**
     153             :  * Read and discard the specified amount of data from an AVFifoBuffer.
     154             :  * @param f AVFifoBuffer to read from
     155             :  * @param size amount of data to read in bytes
     156             :  */
     157             : void av_fifo_drain(AVFifoBuffer *f, int size);
     158             : 
     159             : /**
     160             :  * Return a pointer to the data stored in a FIFO buffer at a certain offset.
     161             :  * The FIFO buffer is not modified.
     162             :  *
     163             :  * @param f    AVFifoBuffer to peek at, f must be non-NULL
     164             :  * @param offs an offset in bytes, its absolute value must be less
     165             :  *             than the used buffer size or the returned pointer will
     166             :  *             point outside to the buffer data.
     167             :  *             The used buffer size can be checked with av_fifo_size().
     168             :  */
     169      569809 : static inline uint8_t *av_fifo_peek2(const AVFifoBuffer *f, int offs)
     170             : {
     171      569809 :     uint8_t *ptr = f->rptr + offs;
     172      569809 :     if (ptr >= f->end)
     173           0 :         ptr = f->buffer + (ptr - f->end);
     174      569809 :     else if (ptr < f->buffer)
     175          12 :         ptr = f->end - (f->buffer - ptr);
     176      569809 :     return ptr;
     177             : }
     178             : 
     179             : #endif /* AVUTIL_FIFO_H */

Generated by: LCOV version 1.13