apps/playlist.c

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2002 by wavey@wavey.org
 *
 * This program 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.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

/*
    Dynamic playlist design (based on design originally proposed by ricII)

    There are two files associated with a dynamic playlist:
    1. Playlist file : This file contains the initial songs in the playlist.
                       The file is created by the user and stored on the hard
                       drive.  NOTE: If we are playing the contents of a
                       directory, there will be no playlist file.
    2. Control file :  This file is automatically created when a playlist is
                       started and contains all the commands done to it.
    
    The first non-comment line in a control file must begin with
    "P:VERSION:DIR:FILE" where VERSION is the playlist control file version,
    DIR is the directory where the playlist is located and FILE is the
    playlist filename.  For dirplay, FILE will be empty.  An empty playlist
    will have both entries as null.

    Control file commands:
        a. Add track (A:<position>:<last position>:<path to track>)
            - Insert a track at the specified position in the current
              playlist.  Last position is used to specify where last insertion
              occurred.
        b. Queue track (Q:<position>:<last position>:<path to track>)
            - Queue a track at the specified position in the current
              playlist.  Queued tracks differ from added tracks in that they
              are deleted from the playlist as soon as they are played and
              they are not saved to disk as part of the playlist.
        c. Delete track (D:<position>)
            - Delete track from specified position in the current playlist.
        d. Shuffle playlist (S:<seed>:<index>)
            - Shuffle entire playlist with specified seed.  The index
              identifies the first index in the newly shuffled playlist
              (needed for repeat mode).
        e. Unshuffle playlist (U:<index>)
            - Unshuffle entire playlist.  The index identifies the first index
              in the newly unshuffled playlist.
        f. Reset last insert position (R)
            - Needed so that insertions work properly after resume

  Resume:
      The only resume info that needs to be saved is the current index in the
      playlist and the position in the track.  When resuming, all the commands
      in the control file will be reapplied so that the playlist indices are
      exactly the same as before shutdown.  To avoid unnecessary disk
      accesses, the shuffle mode settings are also saved in settings and only
      flushed to disk when required.
 */

#include <stdio.h>
#include <stdlib.h>      
#include <ctype.h>                      
#include "string-extra.h"
#include "playlist.h"
#include "ata_idle_notify.h"
#include "file.h"
#include "action.h"
#include "mv.h"
#include "debug.h"
#include "audio.h"
#include "lcd.h"
#include "kernel.h"
#include "settings.h"
#include "status.h"
#include "applimits.h"
#include "screens.h"
#include "core_alloc.h"
#include "misc.h"
#include "pathfuncs.h"
#include "button.h"
#include "filetree.h"
#include "abrepeat.h"
#include "thread.h"
#include "usb.h"
#include "filetypes.h"
#ifdef HAVE_LCD_BITMAP
#include "icons.h"
#endif
#include "system.h"

#include "lang.h"
#include "talk.h"
#include "splash.h"
#include "rbunicode.h"
#include "root_menu.h"
#include "plugin.h" /* To borrow a temp buffer to rewrite a .m3u8 file */
#include "panic.h"
#include "logdiskf.h"
#ifdef HAVE_DIRCACHE
#include "dircache.h"
#endif

#define PLAYLIST_CONTROL_FILE_VERSION 2

/*
    Each playlist index has a flag associated with it which identifies what
    type of track it is.  These flags are stored in the 4 high order bits of
    the index.
    
    NOTE: This limits the playlist file size to a max of 256M.

    Bits 31-30:
        00 = Playlist track
        01 = Track was prepended into playlist
        10 = Track was inserted into playlist
        11 = Track was appended into playlist
    Bit 29:
        0 = Added track
        1 = Queued track
    Bit 28:
        0 = Track entry is valid
        1 = Track does not exist on disk and should be skipped
 */
#define PLAYLIST_SEEK_MASK              0x0FFFFFFF
#define PLAYLIST_INSERT_TYPE_MASK       0xC0000000
#define PLAYLIST_QUEUE_MASK             0x20000000

#define PLAYLIST_INSERT_TYPE_PREPEND    0x40000000
#define PLAYLIST_INSERT_TYPE_INSERT     0x80000000
#define PLAYLIST_INSERT_TYPE_APPEND     0xC0000000

#define PLAYLIST_QUEUED                 0x20000000
#define PLAYLIST_SKIPPED                0x10000000

struct directory_search_context {
    struct playlist_info* playlist;
    int position;
    bool queue;
    int count;
};

static struct playlist_info current_playlist;

static void empty_playlist(struct playlist_info* playlist, bool resume);
static void new_playlist(struct playlist_info* playlist, const char *dir,
                         const char *file);
static void create_control(struct playlist_info* playlist);
static int  check_control(struct playlist_info* playlist);
static int  recreate_control(struct playlist_info* playlist);
static void update_playlist_filename(struct playlist_info* playlist,
                                     const char *dir, const char *file);
static int add_indices_to_playlist(struct playlist_info* playlist,
                                   char* buffer, size_t buflen);
static int add_track_to_playlist(struct playlist_info* playlist,
                                 const char *filename, int position,
                                 bool queue, int seek_pos);
static int directory_search_callback(char* filename, void* context);
static int remove_track_from_playlist(struct playlist_info* playlist,
                                      int position, bool write);
static int randomise_playlist(struct playlist_info* playlist,
                              unsigned int seed, bool start_current,
                              bool write);
static int sort_playlist(struct playlist_info* playlist, bool start_current,
                         bool write);
static int get_next_index(const struct playlist_info* playlist, int steps,
                          int repeat_mode);
static void find_and_set_playlist_index(struct playlist_info* playlist,
                                        unsigned int seek);
static int compare(const void* p1, const void* p2);
static int get_filename(struct playlist_info* playlist, int index, int seek,
                        bool control_file, char *buf, int buf_length);
static int get_next_directory(char *dir);
static int get_next_dir(char *dir, bool is_forward);
static int get_previous_directory(char *dir);
static int check_subdir_for_music(char *dir, const char *subdir, bool recurse);
static ssize_t format_track_path(char *dest, char *src, int buf_length,
                                 const char *dir);
static void display_playlist_count(int count, const unsigned char *fmt,
                                   bool final);
static void display_buffer_full(void);
static int flush_cached_control(struct playlist_info* playlist);
static int update_control(struct playlist_info* playlist,
                          enum playlist_command command, int i1, int i2,
                          const char* s1, const char* s2, void* data);
static void sync_control(struct playlist_info* playlist, bool force);
static int rotate_index(const struct playlist_info* playlist, int index);

#ifdef HAVE_DIRCACHE
#define PLAYLIST_LOAD_POINTERS 1

static struct event_queue playlist_queue SHAREDBSS_ATTR;
static long playlist_stack[(DEFAULT_STACK_SIZE + 0x800)/sizeof(long)];
static const char playlist_thread_name[] = "playlist cachectrl";
#endif

static struct mutex current_playlist_mutex SHAREDBSS_ATTR;
static struct mutex created_playlist_mutex SHAREDBSS_ATTR;

#ifdef HAVE_DIRCACHE
static void copy_filerefs(struct dircache_fileref *dcfto,
                          const struct dircache_fileref *dcffrom,
                          int count)
{
    if (!dcfto)
        return;

    if (dcffrom)
        memmove(dcfto, dcffrom, count * sizeof (*dcfto));
    else
    {
        /* just initialize the destination */
        for (int i = 0; i < count; i++, dcfto++)
            dircache_fileref_init(dcfto);
    }
}
#endif /* HAVE_DIRCACHE */

/* Check if the filename suggests M3U or M3U8 format. */
static bool is_m3u8(const char* filename)
{
    int len = strlen(filename);

    /* Default to M3U8 unless explicitly told otherwise. */
    return !(len > 4 && strcasecmp(&filename[len - 4], ".m3u") == 0);
}


/* Convert a filename in an M3U playlist to UTF-8. 
 *
 * buf     - the filename to convert; can contain more than one line from the
 *           playlist.
 * buf_len - amount of buf that is used.
 * buf_max - total size of buf.
 * temp    - temporary conversion buffer, at least buf_max bytes.
 * 
 * Returns the length of the converted filename.
 */
static int convert_m3u(char* buf, int buf_len, int buf_max, char* temp)
{
    int i = 0;
    char* dest;

    /* Locate EOL. */
    while ((i < buf_len) && (buf[i] != '\n') && (buf[i] != '\r'))
    {
        i++;
    }

    /* Work back killing white space. */
    while ((i > 0) && isspace(buf[i - 1]))
    {
        i--;
    }
    
    buf_len = i;
    dest = temp;
    
    /* Convert char by char, so as to not overflow temp (iso_decode should
     * preferably handle this). No more than 4 bytes should be generated for
     * each input char.
     */
    for (i = 0; i < buf_len && dest < (temp + buf_max - 4); i++)
    {
        dest = iso_decode(&buf[i], dest, -1, 1);
    }
    
    *dest = 0;
    strcpy(buf, temp);
    return dest - temp;
}

/*
 * remove any files and indices associated with the playlist
 */
static void empty_playlist(struct playlist_info* playlist, bool resume)
{
    playlist->filename[0] = '\0';
    playlist->utf8 = true;

    if(playlist->fd >= 0)
        /* If there is an already open playlist, close it. */
        close(playlist->fd);
    playlist->fd = -1;

    if(playlist->control_fd >= 0)
        close(playlist->control_fd);
    playlist->control_fd = -1;
    playlist->control_created = false;

    playlist->in_ram = false;

    if (playlist->buffer)
        playlist->buffer[0] = 0;

    playlist->buffer_end_pos = 0;

    playlist->index = 0;
    playlist->first_index = 0;
    playlist->amount = 0;
    playlist->last_insert_pos = -1;
    playlist->seed = 0;
    playlist->shuffle_modified = false;
    playlist->deleted = false;
    playlist->num_inserted_tracks = 0;
    playlist->started = false;

    playlist->num_cached = 0;
    playlist->pending_control_sync = false;

    if (!resume && playlist->current)
    {
        /* start with fresh playlist control file when starting new
           playlist */
        create_control(playlist);
    }
}

/*
 * Initialize a new playlist for viewing/editing/playing.  dir is the
 * directory where the playlist is located and file is the filename.
 */
static void new_playlist(struct playlist_info* playlist, const char *dir,
                         const char *file)
{
    const char *fileused = file;
    const char *dirused = dir;
    empty_playlist(playlist, false);

    if (!fileused)
    {
        fileused = "";

        if (dirused && playlist->current) /* !current cannot be in_ram */
            playlist->in_ram = true;
        else
            dirused = ""; /* empty playlist */
    }
    
    update_playlist_filename(playlist, dirused, fileused);

    if (playlist->control_fd >= 0)
    {
        update_control(playlist, PLAYLIST_COMMAND_PLAYLIST,
            PLAYLIST_CONTROL_FILE_VERSION, -1, dirused, fileused, NULL);
        sync_control(playlist, false);
    }
}

/*
 * create control file for playlist
 */
static void create_control(struct playlist_info* playlist)
{
    playlist->control_fd = open(playlist->control_filename,
                                O_CREAT|O_RDWR|O_TRUNC, 0666);
    if (playlist->control_fd < 0)
    {
        if (check_rockboxdir())
        {
            cond_talk_ids_fq(LANG_PLAYLIST_CONTROL_ACCESS_ERROR);
            splashf(HZ*2, (unsigned char *)"%s (%d)",
                           str(LANG_PLAYLIST_CONTROL_ACCESS_ERROR),
                           playlist->control_fd);
        }
        playlist->control_created = false;
    }
    else
    {
        playlist->control_created = true;
    }
}

/*
 * validate the control file.  This may include creating/initializing it if
 * necessary;
 */
static int check_control(struct playlist_info* playlist)
{
    if (!playlist->control_created)
    {
        create_control(playlist);

        if (playlist->control_fd >= 0)
        {
            char* dir = playlist->filename;
            char* file = playlist->filename+playlist->dirlen;
            char c = playlist->filename[playlist->dirlen-1];

            playlist->filename[playlist->dirlen-1] = '\0';

            update_control(playlist, PLAYLIST_COMMAND_PLAYLIST,
                PLAYLIST_CONTROL_FILE_VERSION, -1, dir, file, NULL);
            sync_control(playlist, false);
            playlist->filename[playlist->dirlen-1] = c;
        }
    }

    if (playlist->control_fd < 0)
        return -1;

    return 0;
}

/*
 * recreate the control file based on current playlist entries
 */
static int recreate_control(struct playlist_info* playlist)
{
    const char file_suffix[] = "_temp\0";
    char temp_file[MAX_PATH + sizeof(file_suffix)];
    int  temp_fd = -1;
    int  i;
    int  result = 0;

    temp_file[0] = 0;

    if(playlist->control_fd >= 0)
    {
        char* dir = playlist->filename;
        char* file = playlist->filename+playlist->dirlen;
        char c = playlist->filename[playlist->dirlen-1];

        close(playlist->control_fd);
        playlist->control_fd = 0;

        snprintf(temp_file, sizeof(temp_file), "%s%s",
            playlist->control_filename, file_suffix);

        if (rename(playlist->control_filename, temp_file) < 0)
            return -1;

        temp_fd = open(temp_file, O_RDONLY);
        if (temp_fd < 0)
            return -1;

        playlist->control_fd = open(playlist->control_filename,
            O_CREAT|O_RDWR|O_TRUNC, 0666);
        if (playlist->control_fd < 0)
        {
            close(temp_fd);
            return -1;
        }

        playlist->filename[playlist->dirlen-1] = '\0';

        /* cannot call update_control() because of mutex */
        result = fdprintf(playlist->control_fd, "P:%d:%s:%s\n",
            PLAYLIST_CONTROL_FILE_VERSION, dir, file);

        playlist->filename[playlist->dirlen-1] = c;

        if (result < 0)
        {
            close(temp_fd);
            return result;
        }
    }

    playlist->seed = 0;
    playlist->shuffle_modified = false;
    playlist->deleted = false;
    playlist->num_inserted_tracks = 0;

    for (i=0; i<playlist->amount; i++)
    {
        if (playlist->indices[i] & PLAYLIST_INSERT_TYPE_MASK)
        {
            bool queue = playlist->indices[i] & PLAYLIST_QUEUE_MASK;
            char inserted_file[MAX_PATH+1];

            lseek(temp_fd, playlist->indices[i] & PLAYLIST_SEEK_MASK,
                SEEK_SET);
            read_line(temp_fd, inserted_file, sizeof(inserted_file));

            result = fdprintf(playlist->control_fd, "%c:%d:%d:",
                queue?'Q':'A', i, playlist->last_insert_pos);
            if (result > 0)
            {
                /* save the position in file where name is written */
                int seek_pos = lseek(playlist->control_fd, 0, SEEK_CUR);

                result = fdprintf(playlist->control_fd, "%s\n",
                    inserted_file);

                playlist->indices[i] =
                    (playlist->indices[i] & ~PLAYLIST_SEEK_MASK) | seek_pos;
            }

            if (result < 0)
                break;

            playlist->num_inserted_tracks++;
        }
    }

    close(temp_fd);
    remove(temp_file);
    fsync(playlist->control_fd);

    if (result < 0)
        return result;

    return 0;
}

/*
 * store directory and name of playlist file
 */
static void update_playlist_filename(struct playlist_info* playlist,
                                     const char *dir, const char *file)
{
    char *sep="";
    int dirlen = strlen(dir);

    playlist->utf8 = is_m3u8(file);
    
    /* If the dir does not end in trailing slash, we use a separator.
       Otherwise we don't. */
    if('/' != dir[dirlen-1])
    {
        sep="/";
        dirlen++;
    }

    playlist->dirlen = dirlen;
    
    snprintf(playlist->filename, sizeof(playlist->filename),
        "%s%s%s", dir, sep, file);
}

/*
 * calculate track offsets within a playlist file
 */
static int add_indices_to_playlist(struct playlist_info* playlist,
                                   char* buffer, size_t buflen)
{
    unsigned int nread;
    unsigned int i = 0;
    unsigned int count = 0;
    bool store_index;
    unsigned char *p;
    int result = 0;
    /* get emergency buffer so we don't fail horribly */
    if (!buflen)
        buffer = alloca((buflen = 64));

    if(-1 == playlist->fd)
        playlist->fd = open_utf8(playlist->filename, O_RDONLY);
    if(playlist->fd < 0)
        return -1; /* failure */
    if((i = lseek(playlist->fd, 0, SEEK_CUR)) > 0)
        playlist->utf8 = true; /* Override any earlier indication. */

    splash(0, ID2P(LANG_WAIT));

    store_index = true;

    while(1)
    {
        nread = read(playlist->fd, buffer, buflen);
        /* Terminate on EOF */
        if(nread <= 0)
            break;

        p = (unsigned char *)buffer;

        for(count=0; count < nread; count++,p++) {

            /* Are we on a new line? */
            if((*p == '\n') || (*p == '\r'))
            {
                store_index = true;
            }
            else if(store_index)
            {
                store_index = false;

                if(*p != '#')
                {
                    if ( playlist->amount >= playlist->max_playlist_size ) {
                        display_buffer_full();
                        result = -1;
                        goto exit;
                    }

                    /* Store a new entry */
                    playlist->indices[ playlist->amount ] = i+count;
                #ifdef HAVE_DIRCACHE
                    copy_filerefs(&playlist->dcfrefs[playlist->amount], NULL, 1);
                #endif
                    playlist->amount++;
                }
            }
        }

        i+= count;
    }

exit:
#ifdef HAVE_DIRCACHE
    queue_post(&playlist_queue, PLAYLIST_LOAD_POINTERS, 0);
#endif

    return result;
}

/*
 * Utility function to create a new playlist, fill it with the next or
 * previous directory, shuffle it if needed, and start playback.
 * If play_last is true and direction zero or negative, start playing
 * the last file in the directory, otherwise start playing the first.
 */
static int create_and_play_dir(int direction, bool play_last)
{
    char dir[MAX_PATH + 1];
    int res;
    int index = -1;

    if(direction > 0)
      res = get_next_directory(dir);
    else
      res = get_previous_directory(dir);

    if (res < 0)
        /* return the error encountered */
        return res;

    if (playlist_create(dir, NULL) != -1)
    {
        ft_build_playlist(tree_get_context(), 0);

        if (global_settings.playlist_shuffle)
             playlist_shuffle(current_tick, -1);

        if (play_last && direction <= 0)
            index = current_playlist.amount - 1;
        else
            index = 0;

#if (CONFIG_CODEC == SWCODEC)
        current_playlist.started = true;
#else
        playlist_start(index, 0, 0);
#endif
    }

    /* we've overwritten the dircache when getting the next/previous dir,
       so the tree browser context will need to be reloaded */
    reload_directory();

    return index;
}

/*
 * Removes all tracks, from the playlist, leaving the presently playing
 * track queued.
 */
int playlist_remove_all_tracks(struct playlist_info *playlist)
{
    int result;

    if (playlist == NULL)
        playlist = &current_playlist;

    while (playlist->index > 0)
        if ((result = remove_track_from_playlist(playlist, 0, true)) < 0)
            return result;

    while (playlist->amount > 1)
        if ((result = remove_track_from_playlist(playlist, 1, true)) < 0)
            return result;

    if (playlist->amount == 1) {
        playlist->indices[0] |= PLAYLIST_QUEUED;
    }

    return 0;
}


/*
 * Add track to playlist at specified position. There are seven special
 * positions that can be specified:
 *  PLAYLIST_PREPEND              - Add track at beginning of playlist
 *  PLAYLIST_INSERT               - Add track after current song.  NOTE: If
 *                                  there are already inserted tracks then track
 *                                  is added to the end of the insertion list
 *  PLAYLIST_INSERT_FIRST         - Add track immediately after current song, no
 *                                  matter what other tracks have been inserted
 *  PLAYLIST_INSERT_LAST          - Add track to end of playlist
 *  PLAYLIST_INSERT_SHUFFLED      - Add track at some random point between the
 *                                  current playing track and end of playlist
 *  PLAYLIST_INSERT_LAST_SHUFFLED - Add tracks in random order to the end of
 *                                  the playlist.
 *  PLAYLIST_REPLACE              - Erase current playlist, Cue the current track
 *                                  and inster this track at the end.
 */
static int add_track_to_playlist(struct playlist_info* playlist,
                                 const char *filename, int position,
                                 bool queue, int seek_pos)
{
    int insert_position, orig_position;
    unsigned long flags = PLAYLIST_INSERT_TYPE_INSERT;
    int i;

    insert_position = orig_position = position;

    if (playlist->amount >= playlist->max_playlist_size)
    {
        display_buffer_full();
        return -1;
    }

    switch (position)
    {
        case PLAYLIST_PREPEND:
            position = insert_position = playlist->first_index;
            break;
        case PLAYLIST_INSERT:
            /* if there are already inserted tracks then add track to end of
               insertion list else add after current playing track */
            if (playlist->last_insert_pos >= 0 &&
                playlist->last_insert_pos < playlist->amount &&
                (playlist->indices[playlist->last_insert_pos]&
                    PLAYLIST_INSERT_TYPE_MASK) == PLAYLIST_INSERT_TYPE_INSERT)
                position = insert_position = playlist->last_insert_pos+1;
            else if (playlist->amount > 0)
                position = insert_position = playlist->index + 1;
            else
                position = insert_position = 0;

            playlist->last_insert_pos = position;
            break;
        case PLAYLIST_INSERT_FIRST:
            if (playlist->amount > 0)
                position = insert_position = playlist->index + 1;
            else
                position = insert_position = 0;

            playlist->last_insert_pos = position;
            break;
        case PLAYLIST_INSERT_LAST:
            if (playlist->first_index > 0)
                position = insert_position = playlist->first_index;
            else
                position = insert_position = playlist->amount;

            playlist->last_insert_pos = position;
            break;
        case PLAYLIST_INSERT_SHUFFLED:
        {
            if (playlist->started)
            {
                int offset;
                int n = playlist->amount -
                    rotate_index(playlist, playlist->index);
                
                if (n > 0)
                    offset = rand() % n;
                else
                    offset = 0;
                
                position = playlist->index + offset + 1;
                if (position >= playlist->amount)
                    position -= playlist->amount;
                
                insert_position = position;
            }
            else
                position = insert_position = (rand() % (playlist->amount+1));
            break;
        }
        case PLAYLIST_INSERT_LAST_SHUFFLED:
        {
            position = insert_position = playlist->last_shuffled_start +
                          rand() % (playlist->amount - playlist->last_shuffled_start + 1);
            break;
        }
        case PLAYLIST_REPLACE:
            if (playlist_remove_all_tracks(playlist) < 0)
                return -1;
    
            playlist->last_insert_pos = position = insert_position = playlist->index + 1;
            break;
    }
    
    if (queue)
        flags |= PLAYLIST_QUEUED;

    /* shift indices so that track can be added */
    for (i=playlist->amount; i>insert_position; i--)
    {
        playlist->indices[i] = playlist->indices[i-1];
#ifdef HAVE_DIRCACHE
        if (playlist->dcfrefs)
            playlist->dcfrefs[i] = playlist->dcfrefs[i-1];
#endif
    }
    
    /* update stored indices if needed */

    if (orig_position < 0)
    {
        if (playlist->amount > 0 && insert_position <= playlist->index &&
            playlist->started)
            playlist->index++;

        if (playlist->amount > 0 && insert_position <= playlist->first_index &&
            orig_position != PLAYLIST_PREPEND && playlist->started)
            playlist->first_index++;
    }

    if (insert_position < playlist->last_insert_pos ||
        (insert_position == playlist->last_insert_pos && position < 0))
        playlist->last_insert_pos++;

    if (seek_pos < 0 && playlist->control_fd >= 0)
    {
        int result = update_control(playlist,
            (queue?PLAYLIST_COMMAND_QUEUE:PLAYLIST_COMMAND_ADD), position,
            playlist->last_insert_pos, filename, NULL, &seek_pos);

        if (result < 0)
            return result;
    }

    playlist->indices[insert_position] = flags | seek_pos;

#ifdef HAVE_DIRCACHE
    copy_filerefs(&playlist->dcfrefs[insert_position], NULL, 1);
#endif

    playlist->amount++;
    playlist->num_inserted_tracks++;
    
    return insert_position;
}

/*
 * Callback for playlist_directory_tracksearch to insert track into
 * playlist.
 */
static int directory_search_callback(char* filename, void* context)
{
    struct directory_search_context* c =
        (struct directory_search_context*) context;
    int insert_pos;

    insert_pos = add_track_to_playlist(c->playlist, filename, c->position,
        c->queue, -1);

    if (insert_pos < 0)
        return -1;
    
    (c->count)++;
    
    /* Make sure tracks are inserted in correct order if user requests
       INSERT_FIRST */
    if (c->position == PLAYLIST_INSERT_FIRST || c->position >= 0)
        c->position = insert_pos + 1;
    
    if (((c->count)%PLAYLIST_DISPLAY_COUNT) == 0)
    {
        unsigned char* count_str;

        if (c->queue)
            count_str = ID2P(LANG_PLAYLIST_QUEUE_COUNT);
        else
            count_str = ID2P(LANG_PLAYLIST_INSERT_COUNT);

        display_playlist_count(c->count, count_str, false);
        
        if ((c->count) == PLAYLIST_DISPLAY_COUNT &&
            (audio_status() & AUDIO_STATUS_PLAY) &&
            c->playlist->started)
            audio_flush_and_reload_tracks();
    }

    return 0;
}

/*
 * remove track at specified position
 */
static int remove_track_from_playlist(struct playlist_info* playlist,
                                      int position, bool write)
{
    int i;
    bool inserted;

    if (playlist->amount <= 0)
        return -1;

    inserted = playlist->indices[position] & PLAYLIST_INSERT_TYPE_MASK;

    /* shift indices now that track has been removed */
    for (i=position; i<playlist->amount; i++)
    {
        playlist->indices[i] = playlist->indices[i+1];
#ifdef HAVE_DIRCACHE
        if (playlist->dcfrefs)
            playlist->dcfrefs[i] = playlist->dcfrefs[i+1];
#endif
    }

    playlist->amount--;

    if (inserted)
        playlist->num_inserted_tracks--;
    else
        playlist->deleted = true;

    /* update stored indices if needed */
    if (position < playlist->index)
        playlist->index--;

    if (position < playlist->first_index)
    {
        playlist->first_index--;
    }

    if (position <= playlist->last_insert_pos)
        playlist->last_insert_pos--;

    if (write && playlist->control_fd >= 0)
    {
        int result = update_control(playlist, PLAYLIST_COMMAND_DELETE,
            position, -1, NULL, NULL, NULL);

        if (result < 0)
            return result;

        sync_control(playlist, false);
    }
    
    return 0;
}

/*
 * randomly rearrange the array of indices for the playlist.  If start_current
 * is true then update the index to the new index of the current playing track
 */
static int randomise_playlist(struct playlist_info* playlist,
                              unsigned int seed, bool start_current,
                              bool write)
{
    int count;
    int candidate;
    unsigned int current = playlist->indices[playlist->index];
    
    /* seed 0 is used to identify sorted playlist for resume purposes */
    if (seed == 0)
        seed = 1;

    /* seed with the given seed */
    srand(seed);

    /* randomise entire indices list */
    for(count = playlist->amount - 1; count >= 0; count--)
    {
        /* the rand is from 0 to RAND_MAX, so adjust to our value range */
        candidate = rand() % (count + 1);

        /* now swap the values at the 'count' and 'candidate' positions */
        int indextmp = playlist->indices[candidate];
        playlist->indices[candidate] = playlist->indices[count];
        playlist->indices[count] = indextmp;
#ifdef HAVE_DIRCACHE
        if (playlist->dcfrefs)
        {
            struct dircache_fileref dcftmp = playlist->dcfrefs[candidate];
            playlist->dcfrefs[candidate] = playlist->dcfrefs[count];
            playlist->dcfrefs[count] = dcftmp;
        }
#endif
    }

    if (start_current)
        find_and_set_playlist_index(playlist, current);

    /* indices have been moved so last insert position is no longer valid */
    playlist->last_insert_pos = -1;

    playlist->seed = seed;
    if (playlist->num_inserted_tracks > 0 || playlist->deleted)
        playlist->shuffle_modified = true;

    if (write)
    {
        update_control(playlist, PLAYLIST_COMMAND_SHUFFLE, seed,
            playlist->first_index, NULL, NULL, NULL);
    }
    
    return 0;
}

/*
 * Sort the array of indices for the playlist. If start_current is true then
 * set the index to the new index of the current song.
 * Also while going to unshuffled mode set the first_index to 0.
 */
static int sort_playlist(struct playlist_info* playlist, bool start_current,
                         bool write)
{
    unsigned int current = playlist->indices[playlist->index];

    if (playlist->amount > 0)
        qsort((void*)playlist->indices, playlist->amount,
            sizeof(playlist->indices[0]), compare);

#ifdef HAVE_DIRCACHE
    /** We need to re-check the song names from disk because qsort can't
     * sort two arrays at once :/
     * FIXME: Please implement a better way to do this. */
    copy_filerefs(playlist->dcfrefs, NULL, playlist->max_playlist_size);
    queue_post(&playlist_queue, PLAYLIST_LOAD_POINTERS, 0);
#endif

    if (start_current)
        find_and_set_playlist_index(playlist, current);

    /* indices have been moved so last insert position is no longer valid */
    playlist->last_insert_pos = -1;

    if (!playlist->num_inserted_tracks && !playlist->deleted)
        playlist->shuffle_modified = false;
    if (write && playlist->control_fd >= 0)
    {
        playlist->first_index = 0;
        update_control(playlist, PLAYLIST_COMMAND_UNSHUFFLE,
            playlist->first_index, -1, NULL, NULL, NULL);
    }
    
    return 0;
}

/* Calculate how many steps we have to really step when skipping entries
 * marked as bad.
 */
static int calculate_step_count(const struct playlist_info *playlist, int steps)
{
    int i, count, direction;
    int index;
    int stepped_count = 0;
    
    if (steps < 0)
    {
        direction = -1;
        count = -steps;
    }
    else
    {
        direction = 1;
        count = steps;
    }

    index = playlist->index;
    i = 0;
    do {
        /* Boundary check */
        if (index < 0)
            index += playlist->amount;
        if (index >= playlist->amount)
            index -= playlist->amount;

        /* Check if we found a bad entry. */
        if (playlist->indices[index] & PLAYLIST_SKIPPED)
        {
            steps += direction;
            /* Are all entries bad? */
            if (stepped_count++ > playlist->amount)
                break ;
        }
        else
            i++;

        index += direction;
    } while (i <= count);

    return steps;
}

#if CONFIG_CODEC == SWCODEC
/* Marks the index of the track to be skipped that is "steps" away from
 * current playing track.
 */
void playlist_skip_entry(struct playlist_info *playlist, int steps)
{
    int index;

    if (playlist == NULL)
        playlist = &current_playlist;
    
    /* need to account for already skipped tracks */
    steps = calculate_step_count(playlist, steps);

    index = playlist->index + steps;
    if (index < 0)
        index += playlist->amount;
    else if (index >= playlist->amount)
        index -= playlist->amount;

    playlist->indices[index] |= PLAYLIST_SKIPPED;
}
#endif /* CONFIG_CODEC == SWCODEC */

/*
 * returns the index of the track that is "steps" away from current playing
 * track.
 */
static int get_next_index(const struct playlist_info* playlist, int steps,
                          int repeat_mode)
{
    int current_index = playlist->index;
    int next_index    = -1;

    if (playlist->amount <= 0)
        return -1;

    if (repeat_mode == -1)
        repeat_mode = global_settings.repeat_mode;

    if (repeat_mode == REPEAT_SHUFFLE && playlist->amount <= 1)
        repeat_mode = REPEAT_ALL;

    steps = calculate_step_count(playlist, steps);
    switch (repeat_mode)
    {
        case REPEAT_SHUFFLE:
            /* Treat repeat shuffle just like repeat off.  At end of playlist,
               play will be resumed in playlist_next() */
        case REPEAT_OFF:
        {
            current_index = rotate_index(playlist, current_index);
            next_index = current_index+steps;
            if ((next_index < 0) || (next_index >= playlist->amount))
                next_index = -1;
            else
                next_index = (next_index+playlist->first_index) %
                    playlist->amount;

            break;
        }

        case REPEAT_ONE:
#ifdef AB_REPEAT_ENABLE
        case REPEAT_AB:
#endif
            next_index = current_index;
            break;

        case REPEAT_ALL:
        default:
        {
            next_index = (current_index+steps) % playlist->amount;
            while (next_index < 0)
                next_index += playlist->amount;

            if (steps >= playlist->amount)
            {
                int i, index;

                index = next_index;
                next_index = -1;

                /* second time around so skip the queued files */
                for (i=0; i<playlist->amount; i++)
                {
                    if (playlist->indices[index] & PLAYLIST_QUEUE_MASK)
                        index = (index+1) % playlist->amount;
                    else
                    {
                        next_index = index;
                        break;
                    }
                }
            }
            break;
        }
    }

    /* No luck if the whole playlist was bad. */
    if (playlist->indices[next_index] & PLAYLIST_SKIPPED)
        return -1;
    
    return next_index;
}

/*
 * Search for the seek track and set appropriate indices.  Used after shuffle
 * to make sure the current index is still pointing to correct track.
 */
static void find_and_set_playlist_index(struct playlist_info* playlist,
                                        unsigned int seek)
{
    int i;
    
    /* Set the index to the current song */
    for (i=0; i<playlist->amount; i++)
    {
        if (playlist->indices[i] == seek)
        {
            playlist->index = playlist->first_index = i;

            break;
        }
    }
}

/*
 * used to sort track indices.  Sort order is as follows:
 * 1. Prepended tracks (in prepend order)
 * 2. Playlist/directory tracks (in playlist order)
 * 3. Inserted/Appended tracks (in insert order)
 */
static int compare(const void* p1, const void* p2)
{
    unsigned long* e1 = (unsigned long*) p1;
    unsigned long* e2 = (unsigned long*) p2;
    unsigned long flags1 = *e1 & PLAYLIST_INSERT_TYPE_MASK;
    unsigned long flags2 = *e2 & PLAYLIST_INSERT_TYPE_MASK;

    if (flags1 == flags2)
        return (*e1 & PLAYLIST_SEEK_MASK) - (*e2 & PLAYLIST_SEEK_MASK);
    else if (flags1 == PLAYLIST_INSERT_TYPE_PREPEND ||
        flags2 == PLAYLIST_INSERT_TYPE_APPEND)
        return -1;
    else if (flags1 == PLAYLIST_INSERT_TYPE_APPEND ||
        flags2 == PLAYLIST_INSERT_TYPE_PREPEND)
        return 1;
    else if (flags1 && flags2)
        return (*e1 & PLAYLIST_SEEK_MASK) - (*e2 & PLAYLIST_SEEK_MASK);
    else
        return *e1 - *e2;
}

#ifdef HAVE_DIRCACHE
/**
 * Thread to update filename pointers to dircache on background
 * without affecting playlist load up performance.  This thread also flushes
 * any pending control commands when the disk spins up.
 */
static void playlist_flush_callback(void)
{
    struct playlist_info *playlist;
    playlist = &current_playlist;
    if (playlist->control_fd >= 0)
    {
        if (playlist->num_cached > 0)
        {
            mutex_lock(playlist->control_mutex);
            flush_cached_control(playlist);
            mutex_unlock(playlist->control_mutex);
        }
        sync_control(playlist, true);
    }
}

static void playlist_thread(void)
{
    struct queue_event ev;
    bool dirty_pointers = false;
    static char tmp[MAX_PATH+1];

    struct playlist_info *playlist;
    int index;
    int seek;
    bool control_file;

    int sleep_time = 5;

#ifdef HAVE_DISK_STORAGE
    if (global_settings.disk_spindown > 1 &&
        global_settings.disk_spindown <= 5)
        sleep_time = global_settings.disk_spindown - 1;
#endif

    while (1)
    {
        queue_wait_w_tmo(&playlist_queue, &ev, HZ*sleep_time);

        switch (ev.id)
        {
            case PLAYLIST_LOAD_POINTERS:
                dirty_pointers = true;
                break ;

            /* Start the background scanning after either the disk spindown
               timeout or 5s, whichever is less */
            case SYS_TIMEOUT:
            {
                playlist = &current_playlist;
                if (playlist->control_fd >= 0)
                {
                    if (playlist->num_cached > 0)
                        register_storage_idle_func(playlist_flush_callback);
                }

                if (!playlist->dcfrefs || playlist->amount <= 0)
                    break ;
                
                /* Check if previously loaded pointers are intact. */
                if (!dirty_pointers)
                    break ;

                struct dircache_info info;
                dircache_get_info(&info);

                if (info.status != DIRCACHE_READY)
                    break ;

                trigger_cpu_boost();

                for (index = 0; index < playlist->amount
                     && queue_empty(&playlist_queue); index++)
                {
                    /* Process only pointers that are superficially stale. */
                    if (dircache_search(DCS_FILEREF, &playlist->dcfrefs[index], NULL) > 0)
                        continue ;
                    
                    control_file = playlist->indices[index] & PLAYLIST_INSERT_TYPE_MASK;
                    seek = playlist->indices[index] & PLAYLIST_SEEK_MASK;

                    /* Load the filename from playlist file. */
                    if (get_filename(playlist, index, seek, control_file, tmp,
                        sizeof(tmp)) < 0)
                    {
                        break ;
                    }

                    /* Obtain the dircache file entry cookie. */
                    dircache_search(DCS_CACHED_PATH | DCS_UPDATE_FILEREF,
                                    &playlist->dcfrefs[index], tmp);

                    /* And be on background so user doesn't notice any delays. */
                    yield();
                }

                cancel_cpu_boost();

                if (index == playlist->amount)
                    dirty_pointers = false;
            
                break ;
            }
            
            case SYS_USB_CONNECTED:
                usb_acknowledge(SYS_USB_CONNECTED_ACK);
                usb_wait_for_disconnect(&playlist_queue);
                break ;
        }
    }
}
#endif

/*
 * gets pathname for track at seek index
 */
static int get_filename(struct playlist_info* playlist, int index, int seek,
                        bool control_file, char *buf, int buf_length)
{
    int fd;
    int max = -1;
    char tmp_buf[MAX_PATH+1];
    char dir_buf[MAX_PATH+1];
    bool utf8 = playlist->utf8;

    if (buf_length > MAX_PATH+1)
        buf_length = MAX_PATH+1;

#ifdef HAVE_DIRCACHE
    if (playlist->dcfrefs)
    {
        max = dircache_get_fileref_path(&playlist->dcfrefs[index],
                                        tmp_buf, sizeof(tmp_buf));
    }
#endif /* HAVE_DIRCACHE */
    
    if (playlist->in_ram && !control_file && max < 0)
    {
        max = strlcpy(tmp_buf, (char*)&playlist->buffer[seek], sizeof(tmp_buf));
    }
    else if (max < 0)
    {
        mutex_lock(playlist->control_mutex);

        if (control_file)
        {
            fd = playlist->control_fd;
            utf8 = true;
        }
        else
        {
            if(-1 == playlist->fd)
                playlist->fd = open(playlist->filename, O_RDONLY);
            
            fd = playlist->fd;
        }
        
        if(-1 != fd)
        {
            
            if (lseek(fd, seek, SEEK_SET) != seek)
                max = -1;
            else
            {
                max = read(fd, tmp_buf, MIN((size_t) buf_length, sizeof(tmp_buf)));
                
                if (max > 0)
                {
                    /* playlist file may end without a new line - terminate buffer */
                    tmp_buf[MIN(max, (int)sizeof(tmp_buf) - 1)] = '\0';

                    /* Use dir_buf as a temporary buffer. Note that dir_buf must
                     * be as large as tmp_buf.
                     */
                    if (!utf8)
                        max = convert_m3u(tmp_buf, max, sizeof(tmp_buf), dir_buf);
                }
            }
        }

        mutex_unlock(playlist->control_mutex);

        if (max < 0)
        {
            if (usb_detect() == USB_INSERTED)
                ; /* ignore error on usb plug */
            else if (control_file)
                splash(HZ*2, ID2P(LANG_PLAYLIST_CONTROL_ACCESS_ERROR));
            else
                splash(HZ*2, ID2P(LANG_PLAYLIST_ACCESS_ERROR));

            return max;
        }
    }

    strlcpy(dir_buf, playlist->filename, playlist->dirlen);

    return format_track_path(buf, tmp_buf, buf_length, dir_buf);

    (void)index;
}

static int get_next_directory(char *dir){
    return get_next_dir(dir, true);
}

static int get_previous_directory(char *dir){
    return get_next_dir(dir, false);
}

/*
 * search through all the directories (starting with the current) to find
 * one that has tracks to play
 */
static int get_next_dir(char *dir, bool is_forward)
{
    struct playlist_info* playlist = &current_playlist;
    int result = -1;
    char *start_dir = NULL;
    bool exit = false;
    struct tree_context* tc = tree_get_context();
    int saved_dirfilter = *(tc->dirfilter);
    unsigned int base_len;

    if (global_settings.constrain_next_folder)
    {
        /* constrain results to directories below user's start directory */
        strcpy(dir, global_settings.start_directory);
        base_len = strlen(dir);

        /* strip any trailing slash from base directory */
        if (base_len > 0 && dir[base_len - 1] == '/')
        {
            base_len--;
            dir[base_len] = '\0';
        }
    }
    else
    {
        /* start from root directory */
        dir[0] = '\0';
        base_len = 0;
    }

    /* process random folder advance */
    if (global_settings.next_folder == FOLDER_ADVANCE_RANDOM)
    {
        int fd = open(ROCKBOX_DIR "/folder_advance_list.dat", O_RDONLY);
        if (fd >= 0)
        {
            int folder_count = 0;
            read(fd,&folder_count,sizeof(int));
            if (folder_count)
            {
                char buffer[MAX_PATH];
                /* give up looking for a directory after we've had four
                   times as many tries as there are directories. */
                unsigned long allowed_tries = folder_count * 4;
                int i;
                srand(current_tick);
                *(tc->dirfilter) = SHOW_MUSIC;
                tc->sort_dir = global_settings.sort_dir;
                while (!exit && allowed_tries--)
                {
                    i = rand() % folder_count;
                    lseek(fd, sizeof(int) + (MAX_PATH * i), SEEK_SET);
                    read(fd, buffer, MAX_PATH);
                    /* is the current dir within our base dir and has music? */
                    if ((base_len == 0 || !strncmp(buffer, dir, base_len))
                        && check_subdir_for_music(buffer, "", false) == 0)
                            exit = true;
                }
                close(fd);
                *(tc->dirfilter) = saved_dirfilter;
                tc->sort_dir = global_settings.sort_dir;
                reload_directory();
                if (exit)
                {
                    strcpy(dir,buffer);
                    return 0;
                }
            }
            else
                close(fd);
        }
    }

    /* if the current file is within our base dir, use its dir instead */
    if (base_len == 0 || !strncmp(playlist->filename, dir, base_len))
        strlcpy(dir, playlist->filename, playlist->dirlen);

    /* use the tree browser dircache to load files */
    *(tc->dirfilter) = SHOW_ALL;

    /* set up sorting/direction */
    tc->sort_dir = global_settings.sort_dir;
    if (!is_forward)
    {
        static const char sortpairs[] =
        {
            [SORT_ALPHA] = SORT_ALPHA_REVERSED,
            [SORT_DATE] = SORT_DATE_REVERSED,
            [SORT_TYPE] = SORT_TYPE_REVERSED,
            [SORT_ALPHA_REVERSED] = SORT_ALPHA,
            [SORT_DATE_REVERSED] = SORT_DATE,
            [SORT_TYPE_REVERSED] = SORT_TYPE,
        };
        
        if ((unsigned)tc->sort_dir < sizeof(sortpairs))
            tc->sort_dir = sortpairs[tc->sort_dir];
    }

    while (!exit)
    {
        struct entry *files;
        int num_files = 0;
        int i;

        if (ft_load(tc, (dir[0]=='\0')?"/":dir) < 0)
        {
            exit = true;
            result = -1;
            break;
        }
        
        tree_lock_cache(tc);
        files = tree_get_entries(tc);
        num_files = tc->filesindir;

        for (i=0; i<num_files; i++)
        {
            /* user abort */
            if (action_userabort(TIMEOUT_NOBLOCK))
            {
                result = -1;
                exit = true;
                break;
            }

            if (files[i].attr & ATTR_DIRECTORY)
            {
                if (!start_dir)
                {
                    result = check_subdir_for_music(dir, files[i].name, true);
                    if (result != -1)
                    {
                        exit = true;
                        break;
                    }
                }
                else if (!strcmp(start_dir, files[i].name))
                    start_dir = NULL;
            }
        }
        tree_unlock_cache(tc);

        if (!exit)
        {
            /* we've already descended to the base dir with nothing found,
               check whether that contains music */
            if (strlen(dir) <= base_len)
            {
                result = check_subdir_for_music(dir, "", true);
                if (result == -1)
                    /* there's no music files in the base directory,
                       treat as a fatal error */
                    result = -2;
                break;
            }
            else
            {
                /* move down to parent directory.  current directory name is
                   stored as the starting point for the search in parent */
                start_dir = strrchr(dir, '/');
                if (start_dir)
                {
                    *start_dir = '\0';
                    start_dir++;
                }
                else
                    break;
            }
        }
    }

    /* restore dirfilter */
    *(tc->dirfilter) = saved_dirfilter;
    tc->sort_dir = global_settings.sort_dir;

    return result;
}

/*
 * Checks if there are any music files in the dir or any of its
 * subdirectories.  May be called recursively.
 */
static int check_subdir_for_music(char *dir, const char *subdir, bool recurse)
{
    int result = -1;
    size_t dirlen = strlen(dir);
    int num_files = 0;
    int i;
    struct entry *files;
    bool has_music = false;
    bool has_subdir = false;
    struct tree_context* tc = tree_get_context();

    if (path_append(dir + dirlen, PA_SEP_HARD, subdir, MAX_PATH - dirlen) >=
            MAX_PATH - dirlen)
    {
        return 0;
    }
    
    if (ft_load(tc, dir) < 0)
    {
        return -2;
    }
    
    tree_lock_cache(tc);
    files = tree_get_entries(tc);
    num_files = tc->filesindir;

    for (i=0; i<num_files; i++)
    {
        if (files[i].attr & ATTR_DIRECTORY)
            has_subdir = true;
        else if ((files[i].attr & FILE_ATTR_MASK) == FILE_ATTR_AUDIO)
        {
            has_music = true;
            break;
        }
    }

    if (has_music)
    {
        tree_unlock_cache(tc);
        return 0;
    }

    if (has_subdir && recurse)
    {
        for (i=0; i<num_files; i++)
        {
            if (action_userabort(TIMEOUT_NOBLOCK))
            {
                result = -2;
                break;
            }

            if (files[i].attr & ATTR_DIRECTORY)
            {
                result = check_subdir_for_music(dir, files[i].name, true);
                if (!result)
                    break;
            }
        }
    }
    tree_unlock_cache(tc);

    if (result < 0)
    {
        if (dirlen)
        {
            dir[dirlen] = '\0';
        }
        else
        {
            strcpy(dir, PATH_ROOTSTR);
        }

        /* we now need to reload our current directory */
        if(ft_load(tc, dir) < 0)
            splash(HZ*2, ID2P(LANG_PLAYLIST_DIRECTORY_ACCESS_ERROR));
    }
    return result;
}

/*
 * Returns absolute path of track
 */
static ssize_t format_track_path(char *dest, char *src, int buf_length,
                                 const char *dir)
{
    size_t len = 0;

    /* Look for the end of the string */
    while (1)
    {
        int c = src[len];
        if (c == '\n' || c == '\r' || c == '\0')
            break;
        len++;
    }

    /* Now work back killing white space */
    while (len > 0)
    {
        int c = src[len - 1];
        if (c != '\t' && c != ' ')
            break;
        len--;
    }

    src[len] = '\0';

    /* Replace backslashes with forward slashes */
    path_correct_separators(src, src);

    /* Drive letters have no meaning here; handle DOS style drive letter
     * and parse greedily so that:
     *
     * 1) "c:/foo" is fully qualified, use directory volume only
     * 2) "c:foo" is relative to current directory on C, use directory path
     *
     * Assume any volume on the beginning of the directory path is actually
     * the volume on which it resides. This may not be the case if the dir
     * param contains a path such as "/<1>/foo/../../<0>/bar", which refers
     * to "/<0>/bar" (aka "/bar" at this time). *fingers crossed*
     *
     * If any stripped drive spec was absolute, prepend the playlist
     * directory's volume spec, or root if none. Relative paths remain
     * relative and the playlist's directory fully qualifies them. Absolute
     * UNIX-style paths remain unaltered.
     */
    if (path_strip_drive(src, (const char **)&src, true) >= 0 &&
        src[-1] == PATH_SEPCH)
    {
    #ifdef HAVE_MULTIVOLUME
        const char *p;
        path_strip_volume(dir, &p, false);
        dir = strmemdupa(dir, p - dir); /* empty if no volspec on dir */
    #else
        dir = "";                       /* only volume is root */
    #endif
    }

    len = path_append(dest, *dir ? dir : PATH_ROOTSTR, src, buf_length);
    if (len >= (size_t)buf_length)
        return -1; /* buffer too small */

    return len;
}

/*
 * Display splash message showing progress of playlist/directory insertion or
 * save.
 */
static void display_playlist_count(int count, const unsigned char *fmt,
                                   bool final)
{
    static long talked_tick = 0;
    long id = P2ID(fmt);
    if(global_settings.talk_menu && id>=0)
    {
        if(final || (count && (talked_tick == 0
                               || TIME_AFTER(current_tick, talked_tick+5*HZ))))
        {
            talked_tick = current_tick;
            talk_number(count, false);
            talk_id(id, true);
        }
    }
    fmt = P2STR(fmt);

    splashf(0, fmt, count, str(LANG_OFF_ABORT));
}

/*
 * Display buffer full message
 */
static void display_buffer_full(void)
{
    splash(HZ*2, ID2P(LANG_PLAYLIST_BUFFER_FULL));
}

/*
 * Flush any cached control commands to disk.  Called when playlist is being
 * modified.  Returns 0 on success and -1 on failure.
 */
static int flush_cached_control(struct playlist_info* playlist)
{
    int result = 0;
    int i;

    if (!playlist->num_cached)
        return 0;