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/* GStreamer
* Copyright (C) <2009> Collabora Ltd
* @author: Olivier Crete <olivier.crete@collabora.co.uk
* Copyright (C) <2009> Nokia Inc
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/*
* None of this code is thread safe, if you want to use it in a
* multi-threaded context, please protect it with a mutex.
*
* First, create a writer with sp_writer_create(), then select() on
* the socket returned by sp_get_fd(). If the socket is closed or any
* function returns an error, the app should call sp_close() and
* assume the other side is dead. The writer calls
* sp_writer_accept_client() when there is something to read from the
* main server fd. This returns a new ShmClient (representing a client
* connection), the writer needs to do a select() on the socket
* returned by sp_writer_get_client_fd(). If it gets an error on that
* socket, it calls sp_writer_close_client(). If there is something to
* read, it calls sp_writer_recv().
*
* The writer allocates a block containing a free buffer with
* sp_writer_alloc_block(), then writes something in the buffer
* (retrieved with sp_writer_block_get_buf(), then calls
* sp_writer_send_buf() to send the buffer or a subsection to the
* other side. When it is done with the block, it calls
* sp_writer_free_block(). If alloc fails, then the server must wait
* for events on the client fd (the ones where sp_writer_recv() is
* called), and then try to re-alloc.
*
* The reader (client) connect to the writer with sp_client_open() And
* select()s on the fd from sp_get_fd() until there is something to
* read. Then they must read using sp_client_recv() which will return
* the size of the buffer (positive) if there is a valid buffer (which
* is read only). It will return 0 if it is an internal message and a
* negative number if there was an error. If there was an error, the
* application must close the pipe with sp_close() and assume that all
* buffers are no longer valid. If was valid buffer was received, the
* client must release it with sp_client_recv_finish() when it is done
* reading from it.
*/
#ifndef __SHMPIPE_H__
#define __SHMPIPE_H__
#include <stdlib.h>
#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#ifdef __cplusplus
extern "C" {
#endif
typedef struct _ShmClient ShmClient;
typedef struct _ShmPipe ShmPipe;
typedef struct _ShmBlock ShmBlock;
typedef struct _ShmBuffer ShmBuffer;
typedef void (*sp_buffer_free_callback) (void * tag, void * user_data);
ShmPipe *sp_writer_create (const char *path, size_t size, mode_t perms);
const char *sp_writer_get_path (ShmPipe *pipe);
void sp_writer_close (ShmPipe * self, sp_buffer_free_callback callback,
void * user_data);
void *sp_get_data (ShmPipe * self);
void sp_set_data (ShmPipe * self, void *data);
int sp_writer_setperms_shm (ShmPipe * self, mode_t perms);
int sp_writer_resize (ShmPipe * self, size_t size);
int sp_get_fd (ShmPipe * self);
int sp_writer_get_client_fd (ShmClient * client);
ShmBlock *sp_writer_alloc_block (ShmPipe * self, size_t size);
void sp_writer_free_block (ShmBlock *block);
int sp_writer_send_buf (ShmPipe * self, char *buf, size_t size, void * tag);
char *sp_writer_block_get_buf (ShmBlock *block);
ShmPipe *sp_writer_block_get_pipe (ShmBlock *block);
size_t sp_writer_get_max_buf_size (ShmPipe * self);
ShmClient * sp_writer_accept_client (ShmPipe * self);
void sp_writer_close_client (ShmPipe *self, ShmClient * client,
sp_buffer_free_callback callback, void * user_data);
int sp_writer_recv (ShmPipe * self, ShmClient * client, void ** tag);
int sp_writer_pending_writes (ShmPipe * self);
ShmBuffer *sp_writer_get_pending_buffers (ShmPipe * self);
ShmBuffer *sp_writer_get_next_buffer (ShmBuffer * buffer);
void *sp_writer_buf_get_tag (ShmBuffer * buffer);
ShmPipe *sp_client_open (const char *path);
long int sp_client_recv (ShmPipe * self, char **buf);
int sp_client_recv_finish (ShmPipe * self, char *buf);
void sp_client_close (ShmPipe * self);
#ifdef __cplusplus
}
#endif
#endif /* __SHMPIPE_H__ */
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