playlist.c

编译后直接运行的ＭＰ３播放器全部Ｃ语言源代码 一个包含FAT文件系统、系统引导 Boot、FLASH Driver等内容的

                    case resume_shuffle:
                    {
                        /* str1=seed str2=first_index */
                        int seed;
                        
                        if (!str1 || !str2)
                        {
                            result = -1;
                            exit_loop = true;
                            break;
                        }
                        
                        if (!sorted)
                        {
                            /* Always sort list before shuffling */
                            sort_playlist(playlist, false, false);
                        }

                        seed = atoi(str1);
                        playlist->first_index = atoi(str2);
                        
                        if (randomise_playlist(playlist, seed, false,
                                false) < 0)
                            return -1;

                        sorted = false;
                        break;
                    }
                    case resume_unshuffle:
                    {
                        /* str1=first_index */
                        if (!str1)
                        {
                            result = -1;
                            exit_loop = true;
                            break;
                        }
                        
                        playlist->first_index = atoi(str1);
                        
                        if (sort_playlist(playlist, false, false) < 0)
                            return -1;

                        sorted = true;
                        break;
                    }
                    case resume_reset:
                    {
                        playlist->last_insert_pos = -1;
                        break;
                    }
                    case resume_comment:
                    default:
                        break;
                }

                newline = true;

                /* to ignore any extra newlines */
                current_command = resume_comment;
            } 
            else if(newline) 
            {
                newline = false;

                /* first non-comment line must always specify playlist */
                if (first && *p != 'P' && *p != '#')
                {
                    result = -1;
                    exit_loop = true;
                    break;
                }

                switch (*p)
                {
                    case 'P':
                        /* playlist can only be specified once */
                        if (!first)
                        {
                            result = -1;
                            exit_loop = true;
                            break;
                        }

                        current_command = resume_playlist;
                        break;
                    case 'A':
                        current_command = resume_add;
                        break;
                    case 'Q':
                        current_command = resume_queue;
                        break;
                    case 'D':
                        current_command = resume_delete;
                        break;
                    case 'S':
                        current_command = resume_shuffle;
                        break;
                    case 'U':
                        current_command = resume_unshuffle;
                        break;
                    case 'R':
                        current_command = resume_reset;
                        break;
                    case '#':
                        current_command = resume_comment;
                        break;
                    default:
                        result = -1;
                        exit_loop = true;
                        break;
                }

                str_count = -1;
                str1 = NULL;
                str2 = NULL;
                str3 = NULL;
            }
            else if(current_command != resume_comment)
            {
                /* all control file strings are separated with a colon.
                   Replace the colon with 0 to get proper strings that can be
                   used by commands above */
                if (*p == ':')
                {
                    *p = '\0';
                    str_count++;

                    if ((count+1) < nread)
                    {
                        switch (str_count)
                        {
                        case 0:
                            str1 = p+1;
                            break;
                        case 1:
                            str2 = p+1;
                            break;
                        case 2:
                            str3 = p+1;
                            break;
                        default:
                            /* allow last string to contain colons */
                            *p = ':';
                            break;
                        }
                    }
                }
            }
        }

        if (result < 0)
        {
            splash(HZ*2, true, str(LANG_PLAYLIST_CONTROL_INVALID));
            return result;
        }

        if (!newline || (exit_loop && count<nread))
        {
            /* We didn't end on a newline or we exited loop prematurely.
               Either way, re-read the remainder.
               NOTE: because of this, control file must always end with a
                     newline */
            count = last_newline;
            lseek(playlist->control_fd, total_read+count, SEEK_SET);
        }

        total_read += count;

        if (first)
            /* still looking for header */
            nread = read(playlist->control_fd, buffer,
                PLAYLIST_COMMAND_SIZE<buflen?PLAYLIST_COMMAND_SIZE:buflen);
        else
            nread = read(playlist->control_fd, buffer, buflen);

        /* Terminate on EOF */
        if(nread <= 0)
        {
            if (global_settings.resume_seed >= 0)
            {
                /* Apply shuffle command saved in settings */
                if (global_settings.resume_seed == 0)
                    sort_playlist(playlist, false, true);
                else
                {
                    if (!sorted)
                        sort_playlist(playlist, false, false);

                    randomise_playlist(playlist, global_settings.resume_seed,
                        false, true);
                }

                playlist->first_index = global_settings.resume_first_index;
            }

            break;
        }
    }

    return 0;
}

/* 
 * Add track to in_ram playlist.  Used when playing directories.
 */
int playlist_add(char *filename)
{
    struct playlist_info* playlist = &current_playlist;
    int len = strlen(filename);
    
    if((len+1 > playlist->buffer_size - playlist->buffer_end_pos) || 
       (playlist->amount >= playlist->max_playlist_size))
    {
        display_buffer_full();
        return -1;
    }

    playlist->indices[playlist->amount++] = playlist->buffer_end_pos;

    strcpy(&playlist->buffer[playlist->buffer_end_pos], filename);
    playlist->buffer_end_pos += len;
    playlist->buffer[playlist->buffer_end_pos++] = '\0';

    return 0;
}

/* shuffle newly created playlist using random seed. */
int playlist_shuffle(int random_seed, int start_index)
{
    struct playlist_info* playlist = &current_playlist;

    unsigned int seek_pos = 0;
    bool start_current = false;

    if (start_index >= 0 && global_settings.play_selected)
    {
        /* store the seek position before the shuffle */
        seek_pos = playlist->indices[start_index];        
        playlist->index = global_settings.resume_first_index =
            playlist->first_index = start_index;
        start_current = true;
    }

    splash(0, true, str(LANG_PLAYLIST_SHUFFLE));
    
    randomise_playlist(playlist, random_seed, start_current, true);

    /* Flush shuffle command to disk */
    flush_pending_control(playlist);

    return playlist->index;
}

/* start playing current playlist at specified index/offset */
int playlist_start(int start_index, int offset)
{
    struct playlist_info* playlist = &current_playlist;

    playlist->index = start_index;
    mpeg_play(offset);

    return 0;
}

/* Returns false if 'steps' is out of bounds, else true */
bool playlist_check(int steps)
{
    struct playlist_info* playlist = &current_playlist;
    int index = get_next_index(playlist, steps);
    return (index >= 0);
}

/* get trackname of track that is "steps" away from current playing track.
   NULL is used to identify end of playlist */
char* playlist_peek(int steps)
{
    struct playlist_info* playlist = &current_playlist;
    int seek;
    int fd;
    char *temp_ptr;
    int index;
    bool control_file;

    index = get_next_index(playlist, steps);
    if (index < 0)
        return NULL;

    control_file = playlist->indices[index] & PLAYLIST_INSERT_TYPE_MASK;
    seek = playlist->indices[index] & PLAYLIST_SEEK_MASK;

    if (get_filename(playlist, seek, control_file, now_playing,
            MAX_PATH+1) < 0)
        return NULL;

    temp_ptr = now_playing;

    if (!playlist->in_ram || control_file)
    {
        /* remove bogus dirs from beginning of path
           (workaround for buggy playlist creation tools) */
        while (temp_ptr)
        {
            fd = open(temp_ptr, O_RDONLY);
            if (fd >= 0)
            {
                close(fd);
                break;
            }
            
            temp_ptr = strchr(temp_ptr+1, '/');
        }
        
        if (!temp_ptr)
        {
            /* Even though this is an invalid file, we still need to pass a
               file name to the caller because NULL is used to indicate end
               of playlist */
            return now_playing;
        }
    }

    return temp_ptr;
}

/*
 * Update indices as track has changed
 */
int playlist_next(int steps)
{
    struct playlist_info* playlist = &current_playlist;
    int index;

    if (steps > 0 && global_settings.repeat_mode != REPEAT_ONE)
    {
        int i, j;

        /* We need to delete all the queued songs */
        for (i=0, j=steps; i<j; i++)
        {
            index = get_next_index(playlist, i);
            
            if (playlist->indices[index] & PLAYLIST_QUEUE_MASK)
            {
                remove_track_from_playlist(playlist, index, true);
                steps--; /* one less track */
            }
        }
    }

    index = get_next_index(playlist, steps);
    playlist->index = index;

    if (playlist->last_insert_pos >= 0 && steps > 0)
    {
        /* check to see if we've gone beyond the last inserted track */
        int cur = rotate_index(playlist, index);
        int last_pos = rotate_index(playlist, playlist->last_insert_pos);

        if (cur > last_pos)
        {
            /* reset last inserted track */
            playlist->last_insert_pos = -1;

            if (playlist->control_fd >= 0)
            {
                int result = -1;

                mutex_lock(&playlist->control_mutex);
            
                if (lseek(playlist->control_fd, 0, SEEK_END) >= 0)
                {
                    if (fprintf(playlist->control_fd, "R\n") > 0)
                    {
                        fsync(playlist->control_fd);
                        result = 0;
                    }
                }

                mutex_unlock(&playlist->control_mutex);

                if (result < 0)
                {
                    splash(HZ*2, true,
                        str(LANG_PLAYLIST_CONTROL_UPDATE_ERROR));
                    return result;
                }
            }
        }
    }

    return index;
}

/* Get resume info for current playing song.  If return value is -1 then
   settings shouldn't be saved. */
int playlist_get_resume_info(int *resume_index)
{
    struct playlist_info* playlist = &current_playlist;

    *resume_index = playlist->index;

    return 0;
}

/* Returns index of current playing track for display purposes.  This value
   should not be used for resume purposes as it doesn't represent the actual
   index into the playlist */
int playlist_get_display_index(void)
{
    struct playlist_info* playlist = &current_playlist;

    /* first_index should always be index 0 for display purposes */
    int index = rotate_index(playlist, playlist->index);

    return (index+1);
}

/* returns number of tracks in current playlist */
int playlist_amount(void)
{
    return playlist_amount_ex(NULL);
}

/*
 * Create a new playlist  If playlist is not NULL then we're loading a
 * playlist off disk for viewing/editing.  The index_buffer is used to store
 * playlist indices (required for and only used if !current playlist).  The
 * temp_buffer (if not NULL) is used as a scratchpad when loading indices.
 */
int playlist_create_ex(struct playlist_info* playlist, char* dir, char* file,
                       void* index_buffer, int index_buffer_size,
                       void* temp_buffer, int temp_buffer_size)
{
    if (!playlist)
        playlist = &current_playlist;
    else
    {
        /* Initialize playlist structure */
        int r = rand() % 10;
        playlist->current = false;

        /* Use random name for control file */
        snprintf(playlist->control_filename, sizeof(playlist->control_filename),
            "%s.%d", PLAYLIST_CONTROL_FILE, r);