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/*
* 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
*/
/**
* @file
* @ingroup lavu_fifo
* A generic FIFO API
*/
#ifndef AVUTIL_FIFO_H
#define AVUTIL_FIFO_H
#include <stddef.h>
#include <stdint.h>
#include "attributes.h"
#include "version.h"
/**
* @defgroup lavu_fifo AVFifo
* @ingroup lavu_data
*
* @{
* A generic FIFO API
*/
typedef struct AVFifo AVFifo;
/**
* Callback for writing or reading from a FIFO, passed to (and invoked from) the
* av_fifo_*_cb() functions. It may be invoked multiple times from a single
* av_fifo_*_cb() call and may process less data than the maximum size indicated
* by nb_elems.
*
* @param opaque the opaque pointer provided to the av_fifo_*_cb() function
* @param buf the buffer for reading or writing the data, depending on which
* av_fifo_*_cb function is called
* @param nb_elems On entry contains the maximum number of elements that can be
* read from / written into buf. On success, the callback should
* update it to contain the number of elements actually written.
*
* @return 0 on success, a negative error code on failure (will be returned from
* the invoking av_fifo_*_cb() function)
*/
typedef int AVFifoCB(void *opaque, void *buf, size_t *nb_elems);
/**
* Automatically resize the FIFO on writes, so that the data fits. This
* automatic resizing happens up to a limit that can be modified with
* av_fifo_auto_grow_limit().
*/
#define AV_FIFO_FLAG_AUTO_GROW (1 << 0)
/**
* Allocate and initialize an AVFifo with a given element size.
*
* @param elems initial number of elements that can be stored in the FIFO
* @param elem_size Size in bytes of a single element. Further operations on
* the returned FIFO will implicitly use this element size.
* @param flags a combination of AV_FIFO_FLAG_*
*
* @return newly-allocated AVFifo on success, a negative error code on failure
*/
AVFifo *av_fifo_alloc2(size_t elems, size_t elem_size,
unsigned int flags);
/**
* @return Element size for FIFO operations. This element size is set at
* FIFO allocation and remains constant during its lifetime
*/
size_t av_fifo_elem_size(const AVFifo *f);
/**
* Set the maximum size (in elements) to which the FIFO can be resized
* automatically. Has no effect unless AV_FIFO_FLAG_AUTO_GROW is used.
*/
void av_fifo_auto_grow_limit(AVFifo *f, size_t max_elems);
/**
* @return number of elements available for reading from the given FIFO.
*/
size_t av_fifo_can_read(const AVFifo *f);
/**
* @return Number of elements that can be written into the given FIFO without
* growing it.
*
* In other words, this number of elements or less is guaranteed to fit
* into the FIFO. More data may be written when the
* AV_FIFO_FLAG_AUTO_GROW flag was specified at FIFO creation, but this
* may involve memory allocation, which can fail.
*/
size_t av_fifo_can_write(const AVFifo *f);
/**
* Enlarge an AVFifo.
*
* On success, the FIFO will be large enough to hold exactly
* inc + av_fifo_can_read() + av_fifo_can_write()
* elements. In case of failure, the old FIFO is kept unchanged.
*
* @param f AVFifo to resize
* @param inc number of elements to allocate for, in addition to the current
* allocated size
* @return a non-negative number on success, a negative error code on failure
*/
int av_fifo_grow2(AVFifo *f, size_t inc);
/**
* Write data into a FIFO.
*
* In case nb_elems > av_fifo_can_write(f) and the AV_FIFO_FLAG_AUTO_GROW flag
* was not specified at FIFO creation, nothing is written and an error
* is returned.
*
* Calling function is guaranteed to succeed if nb_elems <= av_fifo_can_write(f).
*
* @param f the FIFO buffer
* @param buf Data to be written. nb_elems * av_fifo_elem_size(f) bytes will be
* read from buf on success.
* @param nb_elems number of elements to write into FIFO
*
* @return a non-negative number on success, a negative error code on failure
*/
int av_fifo_write(AVFifo *f, const void *buf, size_t nb_elems);
/**
* Write data from a user-provided callback into a FIFO.
*
* @param f the FIFO buffer
* @param read_cb Callback supplying the data to the FIFO. May be called
* multiple times.
* @param opaque opaque user data to be provided to read_cb
* @param nb_elems Should point to the maximum number of elements that can be
* written. Will be updated to contain the number of elements
* actually written.
*
* @return non-negative number on success, a negative error code on failure
*/
int av_fifo_write_from_cb(AVFifo *f, AVFifoCB read_cb,
void *opaque, size_t *nb_elems);
/**
* Read data from a FIFO.
*
* In case nb_elems > av_fifo_can_read(f), nothing is read and an error
* is returned.
*
* @param f the FIFO buffer
* @param buf Buffer to store the data. nb_elems * av_fifo_elem_size(f) bytes
* will be written into buf on success.
* @param nb_elems number of elements to read from FIFO
*
* @return a non-negative number on success, a negative error code on failure
*/
int av_fifo_read(AVFifo *f, void *buf, size_t nb_elems);
/**
* Feed data from a FIFO into a user-provided callback.
*
* @param f the FIFO buffer
* @param write_cb Callback the data will be supplied to. May be called
* multiple times.
* @param opaque opaque user data to be provided to write_cb
* @param nb_elems Should point to the maximum number of elements that can be
* read. Will be updated to contain the total number of elements
* actually sent to the callback.
*
* @return non-negative number on success, a negative error code on failure
*/
int av_fifo_read_to_cb(AVFifo *f, AVFifoCB write_cb,
void *opaque, size_t *nb_elems);
/**
* Read data from a FIFO without modifying FIFO state.
*
* Returns an error if an attempt is made to peek to nonexistent elements
* (i.e. if offset + nb_elems is larger than av_fifo_can_read(f)).
*
* @param f the FIFO buffer
* @param buf Buffer to store the data. nb_elems * av_fifo_elem_size(f) bytes
* will be written into buf.
* @param nb_elems number of elements to read from FIFO
* @param offset number of initial elements to skip.
*
* @return a non-negative number on success, a negative error code on failure
*/
int av_fifo_peek(const AVFifo *f, void *buf, size_t nb_elems, size_t offset);
/**
* Feed data from a FIFO into a user-provided callback.
*
* @param f the FIFO buffer
* @param write_cb Callback the data will be supplied to. May be called
* multiple times.
* @param opaque opaque user data to be provided to write_cb
* @param nb_elems Should point to the maximum number of elements that can be
* read. Will be updated to contain the total number of elements
* actually sent to the callback.
* @param offset number of initial elements to skip; offset + *nb_elems must not
* be larger than av_fifo_can_read(f).
*
* @return a non-negative number on success, a negative error code on failure
*/
int av_fifo_peek_to_cb(const AVFifo *f, AVFifoCB write_cb, void *opaque,
size_t *nb_elems, size_t offset);
/**
* Discard the specified amount of data from an AVFifo.
* @param size number of elements to discard, MUST NOT be larger than
* av_fifo_can_read(f)
*/
void av_fifo_drain2(AVFifo *f, size_t size);
/*
* Empty the AVFifo.
* @param f AVFifo to reset
*/
void av_fifo_reset2(AVFifo *f);
/**
* Free an AVFifo and reset pointer to NULL.
* @param f Pointer to an AVFifo to free. *f == NULL is allowed.
*/
void av_fifo_freep2(AVFifo **f);
#if FF_API_FIFO_OLD_API
typedef struct AVFifoBuffer {
uint8_t *buffer;
uint8_t *rptr, *wptr, *end;
uint32_t rndx, wndx;
} AVFifoBuffer;
/**
* Initialize an AVFifoBuffer.
* @param size of FIFO
* @return AVFifoBuffer or NULL in case of memory allocation failure
* @deprecated use av_fifo_alloc2()
*/
attribute_deprecated
AVFifoBuffer *av_fifo_alloc(unsigned int size);
/**
* Initialize an AVFifoBuffer.
* @param nmemb number of elements
* @param size size of the single element
* @return AVFifoBuffer or NULL in case of memory allocation failure
* @deprecated use av_fifo_alloc2()
*/
attribute_deprecated
AVFifoBuffer *av_fifo_alloc_array(size_t nmemb, size_t size);
/**
* Free an AVFifoBuffer.
* @param f AVFifoBuffer to free
* @deprecated use the AVFifo API with av_fifo_freep2()
*/
attribute_deprecated
void av_fifo_free(AVFifoBuffer *f);
/**
* Free an AVFifoBuffer and reset pointer to NULL.
* @param f AVFifoBuffer to free
* @deprecated use the AVFifo API with av_fifo_freep2()
*/
attribute_deprecated
void av_fifo_freep(AVFifoBuffer **f);
/**
* Reset the AVFifoBuffer to the state right after av_fifo_alloc, in particular it is emptied.
* @param f AVFifoBuffer to reset
* @deprecated use av_fifo_reset2() with the new AVFifo-API
*/
attribute_deprecated
void av_fifo_reset(AVFifoBuffer *f);
/**
* Return the amount of data in bytes in the AVFifoBuffer, that is the
* amount of data you can read from it.
* @param f AVFifoBuffer to read from
* @return size
* @deprecated use av_fifo_can_read() with the new AVFifo-API
*/
attribute_deprecated
int av_fifo_size(const AVFifoBuffer *f);
/**
* Return the amount of space in bytes in the AVFifoBuffer, that is the
* amount of data you can write into it.
* @param f AVFifoBuffer to write into
* @return size
* @deprecated use av_fifo_can_write() with the new AVFifo-API
*/
attribute_deprecated
int av_fifo_space(const AVFifoBuffer *f);
/**
* Feed data at specific position from an AVFifoBuffer to a user-supplied callback.
* Similar as av_fifo_gereric_read but without discarding data.
* @param f AVFifoBuffer to read from
* @param offset offset from current read position
* @param buf_size number of bytes to read
* @param func generic read function
* @param dest data destination
*
* @return a non-negative number on success, a negative error code on failure
*
* @deprecated use the new AVFifo-API with av_fifo_peek() when func == NULL,
* av_fifo_peek_to_cb() otherwise
*/
attribute_deprecated
int av_fifo_generic_peek_at(AVFifoBuffer *f, void *dest, int offset, int buf_size, void (*func)(void*, void*, int));
/**
* Feed data from an AVFifoBuffer to a user-supplied callback.
* Similar as av_fifo_gereric_read but without discarding data.
* @param f AVFifoBuffer to read from
* @param buf_size number of bytes to read
* @param func generic read function
* @param dest data destination
*
* @return a non-negative number on success, a negative error code on failure
*
* @deprecated use the new AVFifo-API with av_fifo_peek() when func == NULL,
* av_fifo_peek_to_cb() otherwise
*/
attribute_deprecated
int av_fifo_generic_peek(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int));
/**
* Feed data from an AVFifoBuffer to a user-supplied callback.
* @param f AVFifoBuffer to read from
* @param buf_size number of bytes to read
* @param func generic read function
* @param dest data destination
*
* @return a non-negative number on success, a negative error code on failure
*
* @deprecated use the new AVFifo-API with av_fifo_read() when func == NULL,
* av_fifo_read_to_cb() otherwise
*/
attribute_deprecated
int av_fifo_generic_read(AVFifoBuffer *f, void *dest, int buf_size, void (*func)(void*, void*, int));
/**
* Feed data from a user-supplied callback to an AVFifoBuffer.
* @param f AVFifoBuffer to write to
* @param src data source; non-const since it may be used as a
* modifiable context by the function defined in func
* @param size number of bytes to write
* @param func generic write function; the first parameter is src,
* the second is dest_buf, the third is dest_buf_size.
* func must return the number of bytes written to dest_buf, or <= 0 to
* indicate no more data available to write.
* If func is NULL, src is interpreted as a simple byte array for source data.
* @return the number of bytes written to the FIFO or a negative error code on failure
*
* @deprecated use the new AVFifo-API with av_fifo_write() when func == NULL,
* av_fifo_write_from_cb() otherwise
*/
attribute_deprecated
int av_fifo_generic_write(AVFifoBuffer *f, void *src, int size, int (*func)(void*, void*, int));
/**
* Resize an AVFifoBuffer.
* In case of reallocation failure, the old FIFO is kept unchanged.
*
* @param f AVFifoBuffer to resize
* @param size new AVFifoBuffer size in bytes
* @return <0 for failure, >=0 otherwise
*
* @deprecated use the new AVFifo-API with av_fifo_grow2() to increase FIFO size,
* decreasing FIFO size is not supported
*/
attribute_deprecated
int av_fifo_realloc2(AVFifoBuffer *f, unsigned int size);
/**
* Enlarge an AVFifoBuffer.
* In case of reallocation failure, the old FIFO is kept unchanged.
* The new fifo size may be larger than the requested size.
*
* @param f AVFifoBuffer to resize
* @param additional_space the amount of space in bytes to allocate in addition to av_fifo_size()
* @return <0 for failure, >=0 otherwise
*
* @deprecated use the new AVFifo-API with av_fifo_grow2(); note that unlike
* this function it adds to the allocated size, rather than to the used size
*/
attribute_deprecated
int av_fifo_grow(AVFifoBuffer *f, unsigned int additional_space);
/**
* Read and discard the specified amount of data from an AVFifoBuffer.
* @param f AVFifoBuffer to read from
* @param size amount of data to read in bytes
*
* @deprecated use the new AVFifo-API with av_fifo_drain2()
*/
attribute_deprecated
void av_fifo_drain(AVFifoBuffer *f, int size);
#if FF_API_FIFO_PEEK2
/**
* Return a pointer to the data stored in a FIFO buffer at a certain offset.
* The FIFO buffer is not modified.
*
* @param f AVFifoBuffer to peek at, f must be non-NULL
* @param offs an offset in bytes, its absolute value must be less
* than the used buffer size or the returned pointer will
* point outside to the buffer data.
* The used buffer size can be checked with av_fifo_size().
* @deprecated use the new AVFifo-API with av_fifo_peek() or av_fifo_peek_to_cb()
*/
attribute_deprecated
static inline uint8_t *av_fifo_peek2(const AVFifoBuffer *f, int offs)
{
uint8_t *ptr = f->rptr + offs;
if (ptr >= f->end)
ptr = f->buffer + (ptr - f->end);
else if (ptr < f->buffer)
ptr = f->end - (f->buffer - ptr);
return ptr;
}
#endif
#endif
/**
* @}
*/
#endif /* AVUTIL_FIFO_H */