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/*
* This file is part of mpv.
* Copyright (c) 2012 wm4
* Copyright (c) 2013 Stefano Pigozzi <stefano.pigozzi@gmail.com>
*
* mpv is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* mpv 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef MPV_MP_RING_H
#define MPV_MP_RING_H
/**
* A simple non-blocking SPSC (single producer, single consumer) ringbuffer
* implementation. Thread safety is accomplished through atomic operations.
*/
struct mp_ring;
/**
* Instantiate a new ringbuffer
*
* talloc_ctx: talloc context of the newly created object
* size: total size in bytes
* return: the newly created ringbuffer
*/
struct mp_ring *mp_ring_new(void *talloc_ctx, int size);
/**
* Read data from the ringbuffer
*
* buffer: target ringbuffer instance
* dest: destination buffer for the read data. If NULL read data is discarded.
* len: maximum number of bytes to read
* return: number of bytes read
*/
int mp_ring_read(struct mp_ring *buffer, unsigned char *dest, int len);
/**
* Read data from the ringbuffer
*
* This function behaves similarly to `av_fifo_generic_read` and was actually
* added for compatibility with code that was written for it.
* This function will drain the returned amount of bytes from the ringbuffer
* so you don't have to handle that in inside `func`.
*
* buffer: target ringbuffer instance
* ctx: context for the callback function
* len: maximum number of bytes to read
* func: callback function to customize reading behaviour. It will be called
* by `mp_ring_read_cb` with the following parameters:
* ctx: context data provided to `mp_ring_read_cb`
* src: source buffer to read from
* len: the *exact* amount of bytes to read. These will be drained
* by the ring after this callback is called.
* return: number of bytes read
*/
int mp_ring_read_cb(struct mp_ring *buffer, void *ctx, int len,
void (*func)(void *ctx, void *src, int len));
/**
* Write data to the ringbuffer
*
* buffer: target ringbuffer instance
* src: source buffer for the write data
* len: maximum number of bytes to write
* return: number of bytes written
*/
int mp_ring_write(struct mp_ring *buffer, unsigned char *src, int len);
/**
* Drain data from the ringbuffer
*
* buffer: target ringbuffer instance
* len: maximum number of bytes to drain
* return: number of bytes drained
*/
int mp_ring_drain(struct mp_ring *buffer, int len);
/**
* Reset the ringbuffer discarding any content
*
* buffer: target ringbuffer instance
*/
void mp_ring_reset(struct mp_ring *buffer);
/**
* Get the available size for writing
*
* buffer: target ringbuffer instance
* return: number of bytes that can be written
*/
int mp_ring_available(struct mp_ring *buffer);
/**
* Get the total size
*
* buffer: target ringbuffer instance
* return: total ringbuffer size in bytes
*/
int mp_ring_size(struct mp_ring *buffer);
/**
* Get the available size for reading
*
* buffer: target ringbuffer instance
* return: number of bytes ready for reading
*/
int mp_ring_buffered(struct mp_ring *buffer);
/**
* Get a string representation of the ringbuffer
*
* buffer: target ringbuffer instance
* talloc_ctx: talloc context of the newly created string
* return: string representing the ringbuffer
*/
char *mp_ring_repr(struct mp_ring *buffer, void *talloc_ctx);
#endif
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