timeshift.c

VLC Player Source Code

          msleep( 10000 );
          continue;
        }

        p_sys->i_data += p_block->i_buffer;

        /* Write block */
        if( !p_sys->p_write_list && !p_sys->p_read_list &&
            block_FifoSize( p_sys->p_fifo ) < TIMESHIFT_FIFO_MAX )
        {
            /* If there isn't too much timeshifted data,
             * write directly to FIFO */
            block_FifoPut( p_sys->p_fifo, p_block );
            continue;
        }

        WriteBlockToFile( p_access, p_block );
        block_Release( p_block );

        /* Read from file to fill up the fifo */
        while( block_FifoSize( p_sys->p_fifo ) < TIMESHIFT_FIFO_MIN &&
               vlc_object_alive (p_access) )
        {
            p_block = ReadBlockFromFile( p_access );
            if( !p_block ) break;

            block_FifoPut( p_sys->p_fifo, p_block );
        }
    }

    msg_Dbg( p_access, "timeshift: no more input data" );

    while( vlc_object_alive (p_access) &&
           (p_sys->p_read_list || block_FifoSize( p_sys->p_fifo ) ) )
    {
        /* Read from file to fill up the fifo */
        while( block_FifoSize( p_sys->p_fifo ) < TIMESHIFT_FIFO_MIN &&
               vlc_object_alive (p_access) && p_sys->p_read_list )
        {
            p_block = ReadBlockFromFile( p_access );
            if( !p_block ) break;

            block_FifoPut( p_sys->p_fifo, p_block );
        }

        msleep( 100000 );
    }

    msg_Dbg( p_access, "timeshift: EOF" );
    p_src->info.b_eof = true;

    /* Send dummy packet to avoid deadlock in Block() */
    block_FifoPut( p_sys->p_fifo, block_New( p_access, 0 ) );
    return NULL;
}

/*****************************************************************************
 * NextFileWrite:
 *****************************************************************************/
static void NextFileWrite( access_t *p_access )
{
    access_sys_t *p_sys = p_access->p_sys;
    ts_entry_t   *p_next;

    if( !p_sys->p_write_list )
    {
        p_sys->i_write_size = 0;
        return;
    }

    p_next = p_sys->p_write_list->p_next;

    /* Put written file in read list */
    if( p_sys->i_write_size < p_sys->i_file_size )
        ftruncate( fileno( p_sys->p_write_list->file ), p_sys->i_write_size );

    fseek( p_sys->p_write_list->file, 0, SEEK_SET );
    *p_sys->pp_read_last = p_sys->p_write_list;
    p_sys->pp_read_last = &p_sys->p_write_list->p_next;
    p_sys->p_write_list->p_next = 0;

    /* Switch to next file to write */
    p_sys->p_write_list = p_next;
    if( !p_sys->p_write_list ) p_sys->pp_write_last = &p_sys->p_write_list;

    p_sys->i_write_size = 0;
}

/*****************************************************************************
 * NextFileRead:
 *****************************************************************************/
static void NextFileRead( access_t *p_access )
{
    access_sys_t *p_sys = p_access->p_sys;
    ts_entry_t   *p_next;

    if( !p_sys->p_read_list ) return;

    p_next = p_sys->p_read_list->p_next;

    /* Put read file in write list */
    fseek( p_sys->p_read_list->file, 0, SEEK_SET );
    *p_sys->pp_write_last = p_sys->p_read_list;
    p_sys->pp_write_last = &p_sys->p_read_list->p_next;
    p_sys->p_read_list->p_next = 0;

    /* Switch to next file to read */
    p_sys->p_read_list = p_next;
    if( !p_sys->p_read_list ) p_sys->pp_read_last = &p_sys->p_read_list;
}

/*****************************************************************************
 * WriteBlockToFile:
 *****************************************************************************/
static int WriteBlockToFile( access_t *p_access, block_t *p_block )
{
    access_sys_t *p_sys = p_access->p_sys;
    int i_write, i_buffer;

    if( p_sys->i_write_size == p_sys->i_file_size ) NextFileWrite( p_access );

    /* Open new file if necessary */
    if( !p_sys->p_write_list )
    {
        FILE *file;

        sprintf( p_sys->psz_filename, "%s%u.dat",
                 p_sys->psz_filename_base, p_sys->i_files );
        file = utf8_fopen( p_sys->psz_filename, "w+b" );

        if( !file && p_sys->i_files < 2 )
        {
            /* We just can't work with less than 2 buffer files */
            msg_Err( p_access, "cannot open temporary file '%s' (%m)",
                     p_sys->psz_filename );
            return VLC_EGENERIC;
        }
        else if( !file ) return VLC_EGENERIC;

        p_sys->p_write_list = malloc( sizeof(ts_entry_t) );
        p_sys->p_write_list->p_next = 0;
        p_sys->p_write_list->file = file;
        p_sys->pp_write_last = &p_sys->p_write_list->p_next;

        p_sys->i_files++;
    }

    /* Write to file */
    i_buffer = __MIN( p_block->i_buffer,
                      p_sys->i_file_size - p_sys->i_write_size );

    i_write = fwrite( p_block->p_buffer, 1, i_buffer,
                      p_sys->p_write_list->file );

    if( i_write > 0 ) p_sys->i_write_size += i_write;

    //p_access->info.i_size += i_write;
    //p_access->info.i_update |= INPUT_UPDATE_SIZE;

    if( i_write < i_buffer )
    {
        /* Looks like we're short of space */

        if( !p_sys->p_write_list->p_next )
        {
            msg_Warn( p_access, "no more space, overwritting old data" );
            NextFileRead( p_access );
            NextFileRead( p_access );
        }

        /* Make sure we switch to next file in write list */
        p_sys->i_write_size = p_sys->i_file_size;
    }

    p_block->p_buffer += i_write;
    p_block->i_buffer -= i_write;

    /* Check if we have some data left */
    if( p_block->i_buffer ) return WriteBlockToFile( p_access, p_block );

    return VLC_SUCCESS;
}

/*****************************************************************************
 * ReadBlockFromFile:
 *****************************************************************************/
static block_t *ReadBlockFromFile( access_t *p_access )
{
    access_sys_t *p_sys = p_access->p_sys;
    block_t *p_block;

    if( !p_sys->p_read_list && p_sys->p_write_list )
    {
        /* Force switching to next write file, that should
         * give us something to read */
        NextFileWrite( p_access );
    }

    if( !p_sys->p_read_list ) return 0;

    p_block = block_New( p_access, 4096 );
    p_block->i_buffer = fread( p_block->p_buffer, 1, 4096,
                               p_sys->p_read_list->file );

    if( p_block->i_buffer == 0 ) NextFileRead( p_access );

    //p_access->info.i_size -= p_block->i_buffer;
    //p_access->info.i_update |= INPUT_UPDATE_SIZE;

    return p_block;
}

/*****************************************************************************
 * Seek: seek to a specific location in a file
 *****************************************************************************/
static int Seek( access_t *p_access, int64_t i_pos )
{
    //access_sys_t *p_sys = p_access->p_sys;
    (void)p_access;
    (void)i_pos;
    return VLC_SUCCESS;
}

/*****************************************************************************
 *
 *****************************************************************************/
static int Control( access_t *p_access, int i_query, va_list args )
{
    bool   *pb_bool;
    int          *pi_int;

    switch( i_query )
    {
    case ACCESS_CAN_SEEK:
    case ACCESS_CAN_FASTSEEK:
        pb_bool = (bool*)va_arg( args, bool* );
        *pb_bool = true;
        break;

    case ACCESS_CAN_CONTROL_PACE:   /* Not really true */
    case ACCESS_CAN_PAUSE:
        pb_bool = (bool*)va_arg( args, bool* );
        *pb_bool = true;
        break;

    case ACCESS_GET_MTU:
        pi_int = (int*)va_arg( args, int * );
        *pi_int = 0;
        break;

    case ACCESS_SET_PAUSE_STATE:
        break;

    /* Forward everything else to the source access */
    default:
        return access_vaControl( p_access->p_source, i_query, args );
    }
    return VLC_SUCCESS;
}

/*****************************************************************************
 * GetTmpFilePath:
 *****************************************************************************/
#ifdef WIN32
#define getpid() (int)GetCurrentProcessId()
#endif
static char *GetTmpFilePath( access_t *p_access )
{
    char *psz_dir = var_GetNonEmptyString( p_access, "timeshift-dir" );
    char *psz_filename_base;

    if( psz_dir == NULL )
    {
#ifdef WIN32
        DWORD ret = GetTempPathW (0, NULL);
        wchar_t wdir[ret + 3]; // can at least old "C:" + nul
        const wchar_t *pwdir = wdir;
        wchar_t *pwdir_free = NULL;

        if (GetTempPathW (ret + 1, wdir) == 0)
        {
            pwdir_free = pwdir = _wgetcwd (NULL, 0);
            if (pwdir == NULL)
                pwdir = L"C:";
        }

        psz_dir = FromWide (pwdir);
        if (pwdir_free != NULL)
            free (pwdir_free);

        /* remove trailing antislash if any */
        if (psz_dir[strlen (psz_dir) - 1] == '\\')
            psz_dir[strlen (psz_dir) - 1] = '\0';
#else
        psz_dir = strdup( "/tmp" );
#endif
    }

    if( asprintf( &psz_filename_base, "%s/vlc-timeshift-%d-%d-",
              psz_dir, getpid(), p_access->i_object_id ) == -1 )
        psz_filename_base = NULL;
    free( psz_dir );

    return psz_filename_base;
}