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Diffstat (limited to 'mpvcore/mp_ring.h')
-rw-r--r-- | mpvcore/mp_ring.h | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/mpvcore/mp_ring.h b/mpvcore/mp_ring.h new file mode 100644 index 0000000000..ba104af625 --- /dev/null +++ b/mpvcore/mp_ring.h @@ -0,0 +1,130 @@ +/* + * 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 |