bufferpool.h

目前的流媒体服务器代码有Darwin(苹果公司）

/* * 
 *  $Id$
 *  
 *  This file is part of Fenice
 *
 *  Fenice -- Open Media Server
 *
 *  Copyright (C) 2007 by
 *      
 *    - Giampaolo Mancini    <[e-mail]>
 *    - Francesco Varano    <[e-mail]>
 *    - Marco Penno        <[e-mail]>
 *    - Federico Ridolfo    <[e-mail]>
 *    - Eugenio Menegatti     <[e-mail]>
 *    - Stefano Cau
 *    - Giuliano Emma
 *    - Stefano Oldrini
 * 
 *  Fenice 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.
 *
 *  Fenice 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 Fenice; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *  
 * */

 /*
  * Fenice's bufferpool is projected to support ONE AND ONLY ONE producer
  * and many consumers.
  * Each consumer have it's own OMSConsumer structure that is NOT SHARED
  * with others readers.
  * So the only struct that must be locked with mutexes is OMSBuffer.
  * */

#ifndef _BUFFERPOOLH
#define _BUFFERPOOLH

// #define USE_VALID_READ_POS

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <fenice/fnc_log.h>
#include <sys/types.h>
#include <stdint.h>
#include <pthread.h>
#include <stdlib.h>
#include <stddef.h>
#include <limits.h>
#include <stdio.h>

//XXX remove them
#define omsbuff_min(x,y) ((x) < (y) ? (x) : (y))
#define omsbuff_max(x,y) ((x) > (y) ? (x) : (y))

#define OMSBUFF_MEM_PAGE 9

#define OMSBUFFER_DEFAULT_DIM OMSBUFF_MEM_PAGE

#define OMSSLOT_DATASIZE 65000

#define OMSBUFF_SHM_CTRLNAME "Buffer"
#define OMSBUFF_SHM_SLOTSNAME "Slots"
#define OMSBUFF_SHM_PAGE OMSBUFF_MEM_PAGE    // 9


#ifndef PATH_MAX
#define PATH_MAX 4096
#endif

#define OMSbuff_lock(buffer) pthread_mutex_lock(&buffer->control->syn)
#define OMSbuff_unlock(buffer) pthread_mutex_unlock(&buffer->control->syn)

typedef ptrdiff_t OMSSlotPtr;

typedef struct _OMSslot {
    uint16_t refs;
    uint64_t slot_seq; /*! monotone identifier of slot (NOT RTP seq) */
    double timestamp;
    double sendts; /*! send time of pkt */
    uint32_t rtp_time; // if != 0 it contains the calculated rtp timestamp
    uint8_t data[OMSSLOT_DATASIZE];
    uint32_t data_size;
    uint8_t marker;
    ptrdiff_t next;
} OMSSlot;

typedef struct _OMSControl {
    uint16_t refs;        /*! n.Consumers that share the buffer */
    uint32_t nslots;
    OMSSlotPtr write_pos;    /*! last write position */
#ifdef USE_VALID_READ_POS
    OMSSlotPtr valid_read_pos;    /*! valid read position for new consumers */
#endif // USE_VALID_READ_POS
    pthread_mutex_t syn;
} OMSControl;

typedef enum { buff_local = 0, buff_shm } OMSBufferType;

/*!
 * Buffer struct.
 * the pointers have different meaning if we use normally allocated memory
 * or shared memory.
 * Using a shared memory buffer pointer will be offsets relative to the
 * beginning of SHM.
 * This way the two processes can add the address returned by mmap to obtain
 * the absolute address.
 * */
typedef struct _OMSbuffer {
    OMSBufferType type;    //! whether buffer is on shared memory or not;
    OMSControl *control;
    OMSSlot *slots;        /*! Buffer head */
    uint32_t known_slots;    /*!< last known number of slots.
                                This member is only useful for SHM buffer. */
    char filename[PATH_MAX]; //! SHM object file
    // int fd; /*! pointer to File descriptor of incoming data*/
} OMSBuffer;

typedef struct _OMSconsumer {
    OMSSlotPtr read_pos;         /*! read position */
    OMSSlotPtr last_read_pos;    /*! last read position.
                                    used for managing the slot addition */
    uint64_t last_seq;
    OMSBuffer *buffer;
    int32_t frames;
    int32_t first_rtpseq;
    int64_t first_rtptime;
    // pthread_mutex_t mutex;
} OMSConsumer;

/*! This structure is useful if you need to do some syncronization 
 *  among different correlated buffers.
 * */
typedef struct _OMSAggregate {
    OMSBuffer *buffer;
    struct _OMSAggregate *next;
} OMSAggregate;

/*! API definitions*/
OMSBuffer *OMSbuff_new(uint32_t);
OMSConsumer *OMSbuff_ref(OMSBuffer *);
void OMSbuff_unref(OMSConsumer *);
int OMSbuff_read(OMSConsumer *, uint32_t *, uint8_t *, uint8_t *, uint32_t *);
OMSSlot *OMSbuff_getreader(OMSConsumer *);
int OMSbuff_gotreader(OMSConsumer *);
int OMSbuff_write(OMSBuffer *, uint64_t, double, uint32_t, uint8_t, uint8_t *, uint32_t);
OMSSlot *OMSbuff_getslot(OMSBuffer *);
OMSSlot *OMSbuff_addpage(OMSBuffer *, OMSSlot *);
//OMSSlot *OMSbuff_slotadd(OMSBuffer *, OMSSlot *);
void OMSbuff_free(OMSBuffer *);

int OMSbuff_isempty(OMSConsumer *);
double OMSbuff_nextts(OMSConsumer *);

// Shared Memory Bufferpool
OMSBuffer *OMSbuff_shm_create(char *, uint32_t);
OMSBuffer *OMSbuff_shm_map(char *);
OMSSlot *OMSbuff_shm_addpage(OMSBuffer *);
int OMSbuff_shm_remap(OMSBuffer *);
// int OMSbuff_shm_refresh(OMSBuffer *);
#define OMSbuff_shm_refresh(oms_buffer)    \
    (((oms_buffer->type == buff_shm) && \
      (oms_buffer->known_slots != oms_buffer->control->nslots)) ? \
        OMSbuff_shm_remap(oms_buffer) : 0)
int OMSbuff_shm_unmap(OMSBuffer *);
int OMSbuff_shm_destroy(OMSBuffer *);

// shared memory names
char *fnc_ipc_name(const char *, const char *);

// OMSSlotPtr manipulation
#define OMStoSlot(b, p) \
    ((p<0) ? NULL : (&b->slots[p])) //! used when a pointer could be NULL,
                                    //  otherwise we'll use buffe->slots[index]
#define OMStoSlotPtr(b, p) (p ? p - b->slots : -1)

// syncronization of aggregate consumers
OMSAggregate *OMBbuff_aggregate(OMSAggregate *, OMSBuffer *);
int OMSbuff_sync(OMSAggregate *);

// dump for debug 
#if ENABLE_DUMPBUFF
void OMSbuff_dump(OMSConsumer *, OMSBuffer *);
#else
#define OMSbuff_dump(x, y)
#endif


#endif