server: Implement ls --limit.

[paraslash.git] / aft.c

/* Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */

/** \file aft.c Audio file table functions. */

#include <regex.h>
#include <sys/mman.h>
#include <fnmatch.h>
#include <sys/shm.h>
#include <osl.h>
#include <lopsub.h>

#include "server_cmd.lsg.h"
#include "para.h"
#include "error.h"
#include "crypt.h"
#include "string.h"
#include "afh.h"
#include "afs.h"
#include "fd.h"
#include "ipc.h"
#include "portable_io.h"
#include "sideband.h"
#include "command.h"

/* Data about one audio file. Needed for ls and stat output. */
struct ls_data {
        /* Usual audio format handler information. */
        struct afh_info afhi;
        /* Audio file selector information. */
        struct afs_info afsi;
        /* The full path of the audio file. */
        char *path;
        /* The score value (if -a was given). */
        long score;
        /* The hash value of the audio file data. */
        unsigned char *hash;
};

/*
 * The internal state of the audio file table is described by the following
 * variables which are private to aft.c.
 */
static struct osl_table *audio_file_table; /* NULL if table not open */
static struct osl_row *current_aft_row; /* NULL if no audio file open */
static unsigned char current_hash[HASH2_SIZE]; /* only used on sighup */

static char *status_items;
static char *parser_friendly_status_items;
static struct ls_data status_item_ls_data;

/** The different sorting methods of the ls command. */
enum ls_sorting_method {
        LS_SORT_BY_PATH, /**< -s=p (default) */
        LS_SORT_BY_SCORE, /**< -s=s */
        LS_SORT_BY_LAST_PLAYED, /**< -s=l */
        LS_SORT_BY_NUM_PLAYED, /**< -s=n */
        LS_SORT_BY_FREQUENCY, /**< -s=f */
        LS_SORT_BY_CHANNELS, /**< -s=c */
        LS_SORT_BY_IMAGE_ID, /**< -s=i */
        LS_SORT_BY_LYRICS_ID, /**< -s=y */
        LS_SORT_BY_BITRATE, /**< -s=b */
        LS_SORT_BY_DURATION, /**< -s=d */
        LS_SORT_BY_AUDIO_FORMAT, /**< -s=a */
        LS_SORT_BY_HASH, /**< -s=h */
};

/** The different listing modes of the ls command. */
enum ls_listing_mode {
        LS_MODE_SHORT, /**< Default listing mode. */
        LS_MODE_LONG, /**< -l or -l=l */
        LS_MODE_VERBOSE, /** -l=v */
        LS_MODE_MBOX, /** -l=m */
        LS_MODE_CHUNKS, /** -l=c */
        LS_MODE_PARSER, /** -l=p */
};

/**
 * The size of the individual output fields of the ls command.
 *
 * These depend on the content being listed. For example, if each listed file
 * is shorter than an hour, the duration format is set to mm:ss. Otherwise it
 * is set to hh:mm:ss.
 */
struct ls_widths {
        /** size of the score field. */
        unsigned short score_width;
        /** size of the image id field. */
        unsigned short image_id_width;
        /** size of the lyrics id field. */
        unsigned short lyrics_id_width;
        /** size of the bitrate field. */
        unsigned short bitrate_width;
        /** size of the frequency field. */
        unsigned short frequency_width;
        /** size of the duration field. */
        unsigned short duration_width;
        /** size of the num played field. */
        unsigned short num_played_width;
        /** size of the amp field. */
        unsigned short amp_width;
        /** size of the audio format field. */
        unsigned short audio_format_width;
};

/** Data passed from the ls command handler to its callback function. */
struct ls_options {
        struct lls_parse_result *lpr;
        /* Derived from lpr */
        enum ls_sorting_method sorting;
        /* Derived from lpr */
        enum ls_listing_mode mode;
        /** Used for long listing mode to align the output fields. */
        struct ls_widths widths;
        /** Size of the \a data array. */
        uint32_t array_size;
        /** Number of used entries in the data array. */
        uint32_t num_matching_paths;
        /** Array of matching entries. */
        struct ls_data *data;
        /** Used to sort the array. */
        struct ls_data **data_ptr;
};

/**
 * Describes the layout of the mmapped-afs info struct.
 *
 * \sa struct \ref afs_info.
 */
enum afsi_offsets {
        /** Where .last_played is stored. */
        AFSI_LAST_PLAYED_OFFSET = 0,
        /** Storage position of the attributes bitmap. */
        AFSI_ATTRIBUTES_OFFSET = 8,
        /** Storage position of the .num_played field. */
        AFSI_NUM_PLAYED_OFFSET = 16,
        /** Storage position of the .image_id field. */
        AFSI_IMAGE_ID_OFFSET = 20,
        /** Storage position of the .lyrics_id field. */
        AFSI_LYRICS_ID_OFFSET = 24,
        /** Storage position of the .audio_format_id field. */
        AFSI_AUDIO_FORMAT_ID_OFFSET = 28,
        /** Storage position of the amplification field. */
        AFSI_AMP_OFFSET = 29,
        /** 2 bytes reserved space for future usage. */
        AFSI_AUDIO_FORMAT_UNUSED_OFFSET = 30,
        /** On-disk storage space needed. */
        AFSI_SIZE = 32
};

/*
 * Convert a struct afs_info to an osl object.
 *
 * \param afsi Pointer to the audio file info to be converted.
 * \param obj Result pointer.
 *
 * \sa \ref load_afsi().
 */
static void save_afsi(struct afs_info *afsi, struct osl_object *obj)
{
        char *buf = obj->data;

        write_u64(buf + AFSI_LAST_PLAYED_OFFSET, afsi->last_played);
        write_u64(buf + AFSI_ATTRIBUTES_OFFSET, afsi->attributes);
        write_u32(buf + AFSI_NUM_PLAYED_OFFSET, afsi->num_played);
        write_u32(buf + AFSI_IMAGE_ID_OFFSET, afsi->image_id);
        write_u32(buf + AFSI_LYRICS_ID_OFFSET, afsi->lyrics_id);
        write_u8(buf + AFSI_AUDIO_FORMAT_ID_OFFSET,
                afsi->audio_format_id);
        write_u8(buf + AFSI_AMP_OFFSET, afsi->amp);
        memset(buf + AFSI_AUDIO_FORMAT_UNUSED_OFFSET, 0, 2);
}

/*
 * Get the audio file selector info struct stored in an osl object.
 *
 * \param afsi Points to the audio_file info structure to be filled in.
 * \param obj The osl object holding the data.
 *
 * \return Standard.
 *
 * \sa \ref save_afsi().
 */
static int load_afsi(struct afs_info *afsi, struct osl_object *obj)
{
        char *buf = obj->data;
        if (obj->size < AFSI_SIZE)
                return -E_BAD_AFSI;
        afsi->last_played = read_u64(buf + AFSI_LAST_PLAYED_OFFSET);
        afsi->attributes = read_u64(buf + AFSI_ATTRIBUTES_OFFSET);
        afsi->num_played = read_u32(buf + AFSI_NUM_PLAYED_OFFSET);
        afsi->image_id = read_u32(buf + AFSI_IMAGE_ID_OFFSET);
        afsi->lyrics_id = read_u32(buf + AFSI_LYRICS_ID_OFFSET);
        afsi->audio_format_id = read_u8(buf +
                AFSI_AUDIO_FORMAT_ID_OFFSET);
        afsi->amp = read_u8(buf + AFSI_AMP_OFFSET);
        return 1;
}

/** The columns of the audio file table. */
enum audio_file_table_columns {
        /** The hash on the content of the audio file. */
        AFTCOL_HASH,
        /** The full path in the filesystem. */
        AFTCOL_PATH,
        /** The audio file selector info. */
        AFTCOL_AFSI,
        /** The audio format handler info. */
        AFTCOL_AFHI,
        /** The chunk table info and the chunk table of the audio file. */
        AFTCOL_CHUNKS,
        /** The number of columns of this table. */
        NUM_AFT_COLUMNS
};

/* compare function for the hash column */
static int aft_hash_compare(const struct osl_object *obj1,
                const struct osl_object *obj2)
{
        return hash_compare((unsigned char *)obj1->data,
                (unsigned char *)obj2->data);
}

static struct osl_column_description aft_cols[] = {
        [AFTCOL_HASH] = {
                .storage_type = OSL_MAPPED_STORAGE,
                .storage_flags = OSL_RBTREE | OSL_FIXED_SIZE | OSL_UNIQUE,
                .name = "hash",
                .compare_function = aft_hash_compare,
                .data_size = HASH2_SIZE
        },
        [AFTCOL_PATH] = {
                .storage_type = OSL_MAPPED_STORAGE,
                .storage_flags = OSL_RBTREE | OSL_UNIQUE,
                .name = "path",
                .compare_function = string_compare,
        },
        [AFTCOL_AFSI] = {
                .storage_type = OSL_MAPPED_STORAGE,
                .storage_flags = OSL_FIXED_SIZE,
                .name = "afs_info",
                .data_size = AFSI_SIZE
        },
        [AFTCOL_AFHI] = {
                .storage_type = OSL_MAPPED_STORAGE,
                .name = "afh_info",
        },
        [AFTCOL_CHUNKS] = {
                .storage_type = OSL_DISK_STORAGE,
                .name = "chunks",
        }
};

static struct osl_table_description audio_file_table_desc = {
        .name = "audio-files",
        .num_columns = NUM_AFT_COLUMNS,
        .flags = OSL_LARGE_TABLE,
        .column_descriptions = aft_cols
};

/*
 * Produce a canonicalized absolute pathname.
 *
 * Returns one if the resolved path a directory, zero if it is a regular file,
 * negative on errors.
 */
static int verify_path(const char *orig_path, char **resolved_path)
{
        int ret;
        char *path = NULL;
        struct stat statbuf;

        if (*orig_path != '/') /* we only accept absolute paths */
                goto fail;
        path = realpath(orig_path, NULL);
        if (!path)
                goto fail;
        if (stat(path, &statbuf) < 0)
                goto fail;
        if (S_ISREG(statbuf.st_mode))
                ret = 0;
        else if (S_ISDIR(statbuf.st_mode))
                ret = 1;
        else
                goto fail;
        *resolved_path = path;
        return ret;
fail:
        *resolved_path = NULL;
        free(path);
        return -E_BAD_PATH;
}

/** The on-disk layout of a afhi struct. */
enum afhi_offsets {
        /** Where the number of seconds is stored. */
        AFHI_SECONDS_TOTAL_OFFSET = 0,
        /** Position of the bitrate. */
        AFHI_BITRATE_OFFSET = 4,
        /** Position of the frequency. */
        AFHI_FREQUENCY_OFFSET = 8,
        /** Was: Location of the audio file header. */
        AFHI_UNUSED1_OFFSET = 12,
        /* Length of the audio file header. Zero means: No header. */
        AFHI_HEADER_LEN_OFFSET = 16,
        /** The total number of chunks (4 bytes). */
        CHUNKS_TOTAL_OFFSET = 20,
        /** The length of the audio file header (4 bytes). */
        HEADER_LEN_OFFSET = 24,
        /** Size of the largest chunk in bytes. (4 bytes). */
        AFHI_MAX_CHUNK_SIZE_OFFSET = 28,
        /** The seconds part of the chunk time (4 bytes). */
        CHUNK_TV_TV_SEC_OFFSET = 32,
        /** The microseconds part of the chunk time (4 bytes). */
        CHUNK_TV_TV_USEC_OFFSET = 36,
        /** Number of channels is stored here. (1 byte) */
        AFHI_CHANNELS_OFFSET = 40,
        /** The tag info position. */
        AFHI_INFO_STRING_OFFSET = 41,
        /** Minimal on-disk size of a valid afhi struct. */
        MIN_AFHI_SIZE = 47, /* at least 6 null bytes for techinfo/tags */
};

static unsigned sizeof_afhi_buf(const struct afh_info *afhi)
{
        if (!afhi)
                return 0;
        return MIN_AFHI_SIZE
                + strlen(afhi->techinfo)
                + strlen(afhi->tags.artist)
                + strlen(afhi->tags.title)
                + strlen(afhi->tags.year)
                + strlen(afhi->tags.album)
                + strlen(afhi->tags.comment);
}

static void save_afhi(struct afh_info *afhi, char *buf)
{
        char *p;

        if (!afhi)
                return;
        write_u32(buf + AFHI_SECONDS_TOTAL_OFFSET, afhi->seconds_total);
        write_u32(buf + AFHI_BITRATE_OFFSET, afhi->bitrate);
        write_u32(buf + AFHI_FREQUENCY_OFFSET, afhi->frequency);
        write_u32(buf + AFHI_UNUSED1_OFFSET, 0);
        write_u32(buf + AFHI_HEADER_LEN_OFFSET, afhi->header_len);
        write_u8(buf + AFHI_CHANNELS_OFFSET, afhi->channels);
        write_u32(buf + CHUNKS_TOTAL_OFFSET, afhi->chunks_total);
        write_u32(buf + HEADER_LEN_OFFSET, afhi->header_len);
        write_u32(buf + AFHI_MAX_CHUNK_SIZE_OFFSET, afhi->max_chunk_size);
        write_u32(buf + CHUNK_TV_TV_SEC_OFFSET, afhi->chunk_tv.tv_sec);
        write_u32(buf + CHUNK_TV_TV_USEC_OFFSET, afhi->chunk_tv.tv_usec);
        p = buf + AFHI_INFO_STRING_OFFSET;
        /*
         * The below sprintf(3) calls are OK because our caller already made
         * sure that buf is large enough.
         */
        p += sprintf(p, "%s", afhi->techinfo) + 1;
        p += sprintf(p, "%s", afhi->tags.artist) + 1;
        p += sprintf(p, "%s", afhi->tags.title) + 1;
        p += sprintf(p, "%s", afhi->tags.year) + 1;
        p += sprintf(p, "%s", afhi->tags.album) + 1;
        sprintf(p, "%s", afhi->tags.comment);
}

/* does not load the chunk table */
static void load_afhi(const char *buf, struct afh_info *afhi)
{
        afhi->seconds_total = read_u32(buf + AFHI_SECONDS_TOTAL_OFFSET);
        afhi->bitrate = read_u32(buf + AFHI_BITRATE_OFFSET);
        afhi->frequency = read_u32(buf + AFHI_FREQUENCY_OFFSET);
        afhi->header_len = read_u32(buf + AFHI_HEADER_LEN_OFFSET);
        afhi->channels = read_u8(buf + AFHI_CHANNELS_OFFSET);
        afhi->chunks_total = read_u32(buf + CHUNKS_TOTAL_OFFSET);
        afhi->header_len = read_u32(buf + HEADER_LEN_OFFSET);
        afhi->max_chunk_size = read_u32(buf + AFHI_MAX_CHUNK_SIZE_OFFSET);
        afhi->chunk_tv.tv_sec = read_u32(buf + CHUNK_TV_TV_SEC_OFFSET);
        afhi->chunk_tv.tv_usec = read_u32(buf + CHUNK_TV_TV_USEC_OFFSET);
        afhi->techinfo = (char *)buf + AFHI_INFO_STRING_OFFSET;
        afhi->tags.artist = afhi->techinfo + strlen(afhi->techinfo) + 1;
        afhi->tags.title = afhi->tags.artist + strlen(afhi->tags.artist) + 1;
        afhi->tags.year = afhi->tags.title + strlen(afhi->tags.title) + 1;
        afhi->tags.album = afhi->tags.year + strlen(afhi->tags.year) + 1;
        afhi->tags.comment = afhi->tags.album + strlen(afhi->tags.album) + 1;
}

/* Only used for saving the chunk table, but not for loading. */
static unsigned sizeof_chunk_table(struct afh_info *afhi)
{
        if (!afhi || !afhi->chunk_table)
                return 0;
        return 4 * (afhi->chunks_total + 1);
}

static void save_chunk_table(struct afh_info *afhi, char *buf)
{
        uint32_t n;

        if (!afhi->chunk_table || afhi->chunks_total == 0)
                return;
        for (n = 0; n <= afhi->chunks_total; n++)
                write_u32(buf + 4 * n, afhi->chunk_table[n]);
}

static void load_chunk_table(struct afh_info *afhi, const struct osl_object *ct)
{
        int i;
        size_t sz;

        if (!ct->data || ct->size < 4 * (afhi->chunks_total + 1)) {
                afhi->chunk_table = NULL;
                return;
        }
        sz  = PARA_MIN(((size_t)afhi->chunks_total + 1) * 4, ct->size) + 1;
        afhi->chunk_table = alloc(sz);
        for (i = 0; i <= afhi->chunks_total && i * 4 + 3 < ct->size; i++)
                afhi->chunk_table[i] = read_u32(ct->data + 4 * i);
}

/**
 * Get the row of the audio file table corresponding to the given path.
 *
 * \param path The full path of the audio file.
 * \param row Result pointer.
 *
 * \return Standard.
 */
int aft_get_row_of_path(const char *path, struct osl_row **row)
{
        struct osl_object obj = {.data = (char *)path, .size = strlen(path) + 1};

        return osl(osl_get_row(audio_file_table, AFTCOL_PATH, &obj, row));
}

/**
 * Get the row of the audio file table corresponding to the given hash value.
 *
 * \param hash The hash value of the desired audio file.
 * \param row Result pointer.
 *
 * \return Standard.
 */
static int aft_get_row_of_hash(unsigned char *hash, struct osl_row **row)
{
        const struct osl_object obj = {.data = hash, .size = HASH2_SIZE};
        return osl(osl_get_row(audio_file_table, AFTCOL_HASH, &obj, row));
}

/*
 * Get the audio file selector info object of a row.
 *
 * \param row Pointer to a row in the audio file table.
 * \param obj Result pointer.
 *
 * \return Standard.
 */
static int get_afsi_object_of_row(const struct osl_row *row,
                struct osl_object *obj)
{
        return osl(osl_get_object(audio_file_table, row, AFTCOL_AFSI, obj));
}

/**
 * Get the osl object holding the audio file selector info, given a path.
 *
 *
 * \param path The full path of the audio file.
 * \param obj Result pointer.
 *
 * \return Positive on success, negative on errors.
 */
static int get_afsi_object_of_path(const char *path, struct osl_object *obj)
{
        struct osl_row *row;
        int ret = aft_get_row_of_path(path, &row);
        if (ret < 0)
                return ret;
        return get_afsi_object_of_row(row, obj);
}

/**
 * Get the audio file selector info, given a row of the audio file table.
 *
 * \param row Pointer to a row in the audio file table.
 * \param afsi Result pointer.
 *
 * \return Positive on success, negative on errors.
 */
int get_afsi_of_row(const struct osl_row *row, struct afs_info *afsi)
{
        struct osl_object obj;
        int ret = get_afsi_object_of_row(row, &obj);
        if (ret < 0)
                return ret;
        return load_afsi(afsi, &obj);
}

/*
 * Get the audio file selector info, given the path of an audio table.
 *
 * \param path The full path of the audio file.
 * \param afsi Result pointer.
 *
 * \return Standard.
 */
static int get_afsi_of_path(const char *path, struct afs_info *afsi)
{
        struct osl_object obj;
        int ret = get_afsi_object_of_path(path, &obj);
        if (ret < 0)
                return ret;
        return load_afsi(afsi, &obj);
}

/**
 * Get the path of an audio file, given a row of the audio file table.
 *
 * \param row Pointer to a row in the audio file table.
 * \param path Result pointer.
 *
 * The result is a pointer to memory-mapped data. The caller must not attempt
 * to free it.
 *
 * \return Standard.
 */
int get_audio_file_path_of_row(const struct osl_row *row, char **path)
{
        struct osl_object path_obj;
        int ret = osl(osl_get_object(audio_file_table, row, AFTCOL_PATH,
                &path_obj));

        if (ret < 0)
                *path = NULL;
        else
                *path = path_obj.data;
        return ret;
}

/**
 * Get the object containing the hash value of an audio file, given a row.
 *
 * \param row Pointer to a row of the audio file table.
 * \param obj Result pointer.
 *
 * \return The return value of the underlying call to osl_get_object().
 *
 * \sa \ref get_hash_of_row().
 */
static int get_hash_object_of_aft_row(const struct osl_row *row,
                struct osl_object *obj)
{
        return osl(osl_get_object(audio_file_table, row, AFTCOL_HASH, obj));
}

/**
 * Get the hash value of an audio file, given a row of the audio file table.
 *
 * \param row Pointer to a row of the audio file table.
 * \param hash Result pointer.
 *
 * \a hash points to mapped data and must not be freed by the caller.
 *
 * \return The return value of the underlying call to
 * get_hash_object_of_aft_row().
 */
static int get_hash_of_row(const struct osl_row *row, unsigned char **hash)
{
        struct osl_object obj;
        int ret = get_hash_object_of_aft_row(row, &obj);

        if (ret < 0)
                return ret;
        *hash = obj.data;
        return 1;
}

/**
 * Get the audio format handler info, given a row of the audio file table.
 *
 * \param row Pointer to a row of the audio file table.
 * \param afhi Result pointer.
 *
 * \return The return value of the underlying call to osl_get_object().
 *
 * After the call the members of the afhi structure point to mapped memory
 * which is owned by the osl table, Hence the caller must not attempt to free
 * this memory by calling \ref clear_afhi().
 */
int get_afhi_of_row(const struct osl_row *row, struct afh_info *afhi)
{
        struct osl_object obj;
        int ret;

        assert(row);
        ret = osl(osl_get_object(audio_file_table, row, AFTCOL_AFHI, &obj));
        if (ret < 0)
                return ret;
        load_afhi(obj.data, afhi);
        return 1;
}

/* returns shmid on success */
static int save_afd(struct audio_file_data *afd)
{
        size_t size = sizeof(*afd) + sizeof_chunk_table(&afd->afhi);
        int shmid, ret = shm_new(size);
        void *shm_afd;
        char *buf;

        if (ret < 0)
                return ret;
        shmid = ret;
        ret = shm_attach(shmid, ATTACH_RW, &shm_afd);
        if (ret < 0)
                goto err;
        buf = shm_afd;
        buf += sizeof(*afd);
        save_chunk_table(&afd->afhi, buf);
        if (afd->afhi.max_chunk_size == 0) { /* v0.5.x on-disk afhi */
                set_max_chunk_size(&afd->afhi);
                PARA_NOTICE_LOG("max chunk size unset, re-add required\n");
        } else
                PARA_INFO_LOG("using max chunk size from afhi\n");
        afd->max_chunk_size = afd->afhi.max_chunk_size;
        *(struct audio_file_data *)shm_afd = *afd;
        shm_detach(shm_afd);
        return shmid;
err:
        shm_destroy(shmid);
        return ret;
}

/**
 * Extract a afd stored in a shared memory area.
 *
 * Attach the shared memory area given by \a shmid, load the audio file data
 * stored therein and detach the area afterwards.  Called by vss, after
 * receiving a positive response to the request for the next audio file.
 +
 * \param shmid The identifier of the shared memory area containing the afd.
 * \param afd Result pointer.
 *
 * \return Standard.
 */
int load_afd(int shmid, struct audio_file_data *afd)
{
        void *shm_afd;
        int ret;
        struct osl_object obj;

        ret = shm_attach(shmid, ATTACH_RO, &shm_afd);
        if (ret < 0)
                return ret;
        ret = shm_size(shmid, &obj.size);
        if (ret < 0)
                goto detach;
        *afd = *(struct audio_file_data *)shm_afd;
        obj.data = shm_afd + sizeof(*afd);
        obj.size -= sizeof(*afd);
        load_chunk_table(&afd->afhi, &obj);
        ret = 1;
detach:
        shm_detach(shm_afd);
        return ret;
}

static int get_local_time(uint64_t *seconds, char *buf, size_t size,
        time_t current_time, enum ls_listing_mode lm)
{
        struct tm *tm;
        /*
         * Omit year but show time if the given value is closer to the current
         * time than this many seconds.
         */
        const time_t m = 6 * 30 * 24 * 3600; /* six months */

        tm = localtime((time_t *)seconds);
        if (!tm)
                return -E_LOCALTIME;
        if (lm == LS_MODE_MBOX) {
                if (!strftime(buf, size, "%c", tm))
                        return -E_STRFTIME;
                return 1;
        }
        if (*seconds > current_time - m && *seconds < current_time + m) {
                if (!strftime(buf, size, "%b %e %k:%M", tm))
                        return -E_STRFTIME;
                return 1;
        }
        /*
         * If the given time is more than six month away from the current time,
         * we print only the year. The additional space character in the format
         * string below makes the formatted date align nicely with dates that
         * contain the time (those written by the above strftime() statement).
         */
        if (!strftime(buf, size, "%b %e  %Y", tm))
                return -E_STRFTIME;
        return 1;
}

/** Compute the number of (decimal) digits of a number. */
#define GET_NUM_DIGITS(x, num) { \
        typeof((x)) _tmp = PARA_ABS(x); \
        *num = 1; \
        if ((_tmp)) \
                while ((_tmp) > 9) { \
                        (_tmp) /= 10; \
                        (*num)++; \
                } \
        }

__a_const static short unsigned get_duration_width(int seconds)
{
        short unsigned width;
        unsigned hours = seconds / 3600, mins = (seconds % 3600) / 60;

        if (!hours) /* less than one hour => m:ss or mm:ss => 4 or 5 digits */
                return 4 + (mins > 9);
        /* more than one hour => h:mm:ss, hh:mm:ss, hhh:mm:ss, ... */
        GET_NUM_DIGITS(hours, &width);
        return width + 6;
}

static void get_duration_buf(int seconds, char *buf, size_t bufsize,
                struct ls_options *opts)
{
        unsigned hours = seconds / 3600, mins = (seconds % 3600) / 60;
        short unsigned max_width;

        if (!hours) { /* m:ss or mm:ss */
                max_width = opts->mode == LS_MODE_LONG?
                        opts->widths.duration_width : 4;
                assert(max_width < bufsize - 1);
                sprintf(buf, "%*u:%02d", max_width - 3, mins, seconds % 60);
        } else { /* more than one hour => h:mm:ss, hh:mm:ss, hhh:mm:ss, ... */
                max_width = opts->mode == LS_MODE_LONG?
                        opts->widths.duration_width : 7;
                assert(max_width < bufsize - 1);
                sprintf(buf, "%*u:%02u:%02d", max_width - 6, hours, mins,
                        seconds % 60);
        }
}

static int write_attribute_items(struct para_buffer *b,
                const char *att_bitmap, struct afs_info *afsi)
{
        char *att_text;
        int ret;

        WRITE_STATUS_ITEM(b, SI_attributes_bitmap, "%s\n", att_bitmap);
        ret = get_attribute_text(&afsi->attributes, " ", &att_text);
        if (ret < 0)
                return ret;
        WRITE_STATUS_ITEM(b, SI_attributes_txt, "%s\n", att_text);
        free(att_text);
        return ret;
}

static void write_lyrics_items(struct para_buffer *b, struct afs_info *afsi)
{
        char *lyrics_name;

        WRITE_STATUS_ITEM(b, SI_lyrics_id, "%u\n", afsi->lyrics_id);
        lyr_get_name_by_id(afsi->lyrics_id, &lyrics_name);
        WRITE_STATUS_ITEM(b, SI_lyrics_name, "%s\n", lyrics_name?
                lyrics_name : "(none)");
}

static void write_image_items(struct para_buffer *b, struct afs_info *afsi)
{
        char *image_name;

        WRITE_STATUS_ITEM(b, SI_image_id, "%u\n", afsi->image_id);
        img_get_name_by_id(afsi->image_id, &image_name);
        WRITE_STATUS_ITEM(b, SI_image_name, "%s\n", image_name?
                image_name : "(none)");
}

static void write_filename_items(struct para_buffer *b, const char *path,
                bool basename)
{
        const char *slash;

        if (basename) {
                WRITE_STATUS_ITEM(b, SI_basename, "%s\n", path);
                return;
        }
        WRITE_STATUS_ITEM(b, SI_path, "%s\n", path);
        slash = strrchr(path, '/');
        WRITE_STATUS_ITEM(b, SI_basename, "%s\n", slash? slash + 1 : path);
        WRITE_STATUS_ITEM(b, SI_directory, "%.*s\n",
                slash? (int)(slash - path) : (int)strlen(path), path);
}

static int print_chunk_table(struct ls_data *d, struct para_buffer *b)
{
        struct osl_object chunk_table_obj;
        struct osl_row *aft_row;
        int ret, i;
        char *buf;

        para_printf(b, "%s\nchunk_time: %lu:%lu\n", d->path,
                (long unsigned) d->afhi.chunk_tv.tv_sec,
                (long unsigned) d->afhi.chunk_tv.tv_usec
        );
        if (afh_supports_dynamic_chunks(d->afsi.audio_format_id))
                return 0;
        ret = aft_get_row_of_hash(d->hash, &aft_row);
        if (ret < 0)
                return ret;
        ret = osl(osl_open_disk_object(audio_file_table, aft_row,
                AFTCOL_CHUNKS, &chunk_table_obj));
        if (ret < 0)
                return ret;
        para_printf(b, "chunk_offsets: ");
        buf = chunk_table_obj.data;
        for (
                i = 0;
                i <= d->afhi.chunks_total && 4 * i + 3 < chunk_table_obj.size;
                i++
        )
                para_printf(b, "%u ", (unsigned) read_u32(buf + 4 * i));
        para_printf(b, "\n");
        ret = 1;
        osl_close_disk_object(&chunk_table_obj);
        return ret;
}

static int print_list_item(struct ls_data *d, struct ls_options *opts,
        struct para_buffer *b, time_t current_time)
{
        const struct lls_opt_result *r_a = SERVER_CMD_OPT_RESULT(LS, ADMISSIBLE, opts->lpr);
        const struct lls_opt_result *r_b = SERVER_CMD_OPT_RESULT(LS, BASENAME, opts->lpr);
        const struct lls_opt_result *r_d = SERVER_CMD_OPT_RESULT(LS, UNIX_DATE, opts->lpr);
        int ret;
        char att_buf[65];
        char last_played_time[30];
        char duration_buf[30]; /* nobody has an audio file long enough to overflow this */
        struct afs_info *afsi = &d->afsi;
        struct afh_info *afhi = &d->afhi;
        char asc_hash[2 * HASH2_SIZE + 1];

        if (opts->mode == LS_MODE_SHORT) {
                para_printf(b, "%s\n", d->path);
                ret = 1;
                goto out;
        }
        if (opts->mode == LS_MODE_CHUNKS) {
                ret = print_chunk_table(d, b);
                goto out;
        }
        get_attribute_bitmap(&afsi->attributes, att_buf);
        if (lls_opt_given(r_d))
                sprintf(last_played_time, "%llu",
                        (long long unsigned)afsi->last_played);
        else {
                ret = get_local_time(&afsi->last_played, last_played_time,
                        sizeof(last_played_time), current_time, opts->mode);
                if (ret < 0)
                        goto out;
        }
        get_duration_buf(afhi->seconds_total, duration_buf,
                sizeof(duration_buf), opts);
        if (opts->mode == LS_MODE_LONG) {
                struct ls_widths *w = &opts->widths;
                if (lls_opt_given(r_a))
                        para_printf(b, "%*li ", opts->widths.score_width,
                                d->score);
                para_printf(b,
                        "%s "   /* attributes */
                        "%*u "  /* amp */
                        "%*u "  /* image_id  */
                        "%*u "  /* lyrics_id */
                        "%*u "  /* bitrate */
                        "%*s "  /* audio format */
                        "%*u "  /* frequency */
                        "%u "   /* channels */
                        "%s "   /* duration */
                        "%*u "  /* num_played */
                        "%s "   /* last_played */
                        "%s\n", /* path */
                        att_buf,
                        w->amp_width, afsi->amp,
                        w->image_id_width, afsi->image_id,
                        w->lyrics_id_width, afsi->lyrics_id,
                        w->bitrate_width, afhi->bitrate,
                        w->audio_format_width,
                        audio_format_name(afsi->audio_format_id),
                        w->frequency_width, afhi->frequency,
                        afhi->channels,
                        duration_buf,
                        w->num_played_width, afsi->num_played,
                        last_played_time,
                        d->path
                );
                ret = 1;
                goto out;
        }
        if (opts->mode == LS_MODE_MBOX) {
                const char *slash = strrchr(d->path, '/');
                para_printf(b,
                        "From foo@localhost %s\n"
                        "Received: from\nTo: bar\nFrom: a\n"
                        "Subject: %s\n\n",
                        last_played_time,
                        slash? slash + 1 : "?");
        }
        write_filename_items(b, d->path, lls_opt_given(r_b));
        if (lls_opt_given(r_a))
                WRITE_STATUS_ITEM(b, SI_score, "%li\n", d->score);
        ret = write_attribute_items(b, att_buf, afsi);
        if (ret < 0)
                goto out;
        write_image_items(b, afsi);
        write_lyrics_items(b, afsi);
        hash2_to_asc(d->hash, asc_hash);
        WRITE_STATUS_ITEM(b, SI_hash, "%s\n", asc_hash);
        WRITE_STATUS_ITEM(b, SI_bitrate, "%dkbit/s\n", afhi->bitrate);
        WRITE_STATUS_ITEM(b, SI_format, "%s\n",
                audio_format_name(afsi->audio_format_id));
        WRITE_STATUS_ITEM(b, SI_frequency, "%dHz\n", afhi->frequency);
        WRITE_STATUS_ITEM(b, SI_channels, "%d\n", afhi->channels);
        WRITE_STATUS_ITEM(b, SI_duration, "%s\n", duration_buf);
        WRITE_STATUS_ITEM(b, SI_seconds_total, "%" PRIu32 "\n",
                afhi->seconds_total);
        WRITE_STATUS_ITEM(b, SI_last_played, "%s\n", last_played_time);
        WRITE_STATUS_ITEM(b, SI_num_played, "%u\n", afsi->num_played);
        WRITE_STATUS_ITEM(b, SI_amplification, "%u\n", afsi->amp);
        WRITE_STATUS_ITEM(b, SI_chunk_time, "%lu\n", tv2ms(&afhi->chunk_tv));
        WRITE_STATUS_ITEM(b, SI_num_chunks, "%" PRIu32 "\n",
                afhi->chunks_total);
        WRITE_STATUS_ITEM(b, SI_max_chunk_size, "%" PRIu32 "\n",
                afhi->max_chunk_size);
        WRITE_STATUS_ITEM(b, SI_techinfo, "%s\n", afhi->techinfo);
        WRITE_STATUS_ITEM(b, SI_artist, "%s\n", afhi->tags.artist);
        WRITE_STATUS_ITEM(b, SI_title, "%s\n", afhi->tags.title);
        WRITE_STATUS_ITEM(b, SI_year, "%s\n", afhi->tags.year);
        WRITE_STATUS_ITEM(b, SI_album, "%s\n", afhi->tags.album);
        WRITE_STATUS_ITEM(b, SI_comment, "%s\n", afhi->tags.comment);
        if (opts->mode == LS_MODE_MBOX) {
                struct osl_object lyrics_def;
                lyr_get_def_by_id(afsi->lyrics_id, &lyrics_def);
                if (lyrics_def.data) {
                        para_printf(b, "Lyrics:\n~~~~~~~\n%s",
                                (char *)lyrics_def.data);
                        osl_close_disk_object(&lyrics_def);
                }
        }
out:
        return ret;
}

static void make_inode_status_items(struct para_buffer *pb)
{
        struct stat statbuf = {.st_size = 0};
        char *path, mtime_str[30] = "\0";
        struct tm mtime_tm;
        int ret;

        ret = get_audio_file_path_of_row(current_aft_row, &path);
        if (ret < 0)
                goto out;
        ret = stat(path, &statbuf);
        if (ret < 0)
                goto out;
        localtime_r(&statbuf.st_mtime, &mtime_tm);
        ret = strftime(mtime_str, 29, "%b %d %Y", &mtime_tm);
        assert(ret > 0); /* number of bytes placed in mtime_str */
out:
        WRITE_STATUS_ITEM(pb, SI_mtime, "%s\n", mtime_str);
        WRITE_STATUS_ITEM(pb, SI_file_size, "%ld\n", statbuf.st_size / 1024);
}

/**
 * Deallocate and invalidate the status item strings.
 *
 * This needs to be a public function so that afs.c can call it on shutdown.
 */
void free_status_items(void)
{
        freep(&status_items);
        freep(&parser_friendly_status_items);
}

static void make_status_items(void)
{
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(LS);
        char *argv[] = {"ls", "--admissible", "--listing-mode=verbose"};
        struct ls_options opts = {.mode = LS_MODE_VERBOSE};
        struct para_buffer pb = {.max_size = shm_get_shmmax() - 1};
        time_t current_time;
        int ret;

        free_status_items();
        if (!status_item_ls_data.path) /* no audio file open */
                return;
        ret = lls_parse(ARRAY_SIZE(argv), argv, cmd, &opts.lpr, NULL);
        assert(ret >= 0);
        time(&current_time);
        ret = print_list_item(&status_item_ls_data, &opts, &pb, current_time);
        if (ret < 0)
                goto out;
        make_inode_status_items(&pb);
        status_items = pb.buf;

        memset(&pb, 0, sizeof(pb));
        pb.max_size = shm_get_shmmax() - 1;
        pb.flags = PBF_SIZE_PREFIX;
        ret = print_list_item(&status_item_ls_data, &opts, &pb, current_time);
        if (ret < 0)
                goto out;
        make_inode_status_items(&pb);
        parser_friendly_status_items = pb.buf;
        ret = 1;
out:
        if (ret < 0) {
                PARA_WARNING_LOG("could not create status items: %s\n",
                        para_strerror(-ret));
                free_status_items();
        }
        lls_free_parse_result(opts.lpr, cmd);
}

/**
 * Open the audio file with highest score and set up an afd structure.
 *
 * This determines and opens the next audio file, verifies that it did not
 * change by comparing the recomputed the hash value of the file contents
 * against the value stored in the audio file table. If all goes well, it
 * creates a shared memory area containing the serialized version of the afd
 * structure, including the chunk table, if any. The caller can then send the
 * ID of this area and the open fd to the server process.
 *
 * \param fd Result pointer for the file descriptor of the audio file.
 *
 * On success, the numplayed field of the audio file selector info is increased
 * and the lastplayed time is set to the current time. Finally, the score of
 * the audio file is updated.
 *
 * \return Positive shmid on success, negative on errors.
 */
int open_and_update_audio_file(int *fd)
{
        unsigned char file_hash[HASH2_SIZE];
        struct osl_object afsi_obj;
        struct afs_info new_afsi;
        int ret;
        struct afsi_change_event_data aced;
        struct osl_object map, chunk_table_obj;
        struct ls_data *d = &status_item_ls_data;
        unsigned char *tmp_hash;
        struct audio_file_data afd;
again:
        ret = score_get_best(&current_aft_row, &d->score);
        if (ret < 0)
                return ret;
        /*
         * get_hash_of_row() and get_audio_file_path_of_row() initialize
         * their pointer argument to point to memory-mapped files. These pointers
         * become stale after a new audio file has been added or after the
         * server process received SIGHUP. For in both cases libosl unmaps and
         * remaps the underlying database files, and this remapping may well
         * change the starting address of the mapping. To avoid stale pointer
         * references we create copies on the heap.
         */
        ret = get_hash_of_row(current_aft_row, &tmp_hash);
        if (ret < 0)
                return ret;
        if (!d->hash)
                d->hash = alloc(HASH2_SIZE);
        memcpy(d->hash, tmp_hash, HASH2_SIZE);
        free(d->path);
        ret = get_audio_file_path_of_row(current_aft_row, &d->path);
        if (ret < 0)
                return ret;
        PARA_NOTICE_LOG("%s\n", d->path);
        d->path = para_strdup(d->path);

        ret = get_afsi_object_of_row(current_aft_row, &afsi_obj);
        if (ret < 0)
                return ret;
        ret = load_afsi(&d->afsi, &afsi_obj);
        if (ret < 0)
                return ret;
        ret = get_afhi_of_row(current_aft_row, &afd.afhi);
        if (ret < 0)
                return ret;
        d->afhi = afd.afhi;
        d->afhi.chunk_table = afd.afhi.chunk_table = NULL;
        ret = osl(osl_open_disk_object(audio_file_table, current_aft_row,
                AFTCOL_CHUNKS, &chunk_table_obj));
        if (ret < 0) {
                if (!afh_supports_dynamic_chunks(d->afsi.audio_format_id))
                        return ret;
                PARA_INFO_LOG("no chunk table for %s\n", d->path);
                chunk_table_obj.data = NULL;
                chunk_table_obj.size = 0;
        } else {
                PARA_INFO_LOG("chunk table: %zu bytes\n", chunk_table_obj.size);
        }
        ret = mmap_full_file(d->path, O_RDONLY, &map.data, &map.size, fd);
        if (ret < 0)
                goto out;
        hash2_function(map.data, map.size, file_hash);
        ret = hash2_compare(file_hash, d->hash);
        para_munmap(map.data, map.size);
        if (ret) {
                ret = -E_HASH_MISMATCH;
                goto out;
        }
        new_afsi = d->afsi;
        new_afsi.num_played++;
        new_afsi.last_played = time(NULL);
        save_afsi(&new_afsi, &afsi_obj); /* in-place update */

        afd.audio_format_id = d->afsi.audio_format_id;
        load_chunk_table(&afd.afhi, &chunk_table_obj);
        aced.aft_row = current_aft_row;
        aced.old_afsi = &d->afsi;
        /*
         * No need to update the status items as the AFSI_CHANGE event will
         * recreate them.
         */
        ret = afs_event(AFSI_CHANGE, NULL, &aced);
        if (ret < 0)
                goto out;
        ret = save_afd(&afd);
out:
        free(afd.afhi.chunk_table);
        if (chunk_table_obj.data)
                osl_close_disk_object(&chunk_table_obj);
        if (ret < 0) {
                PARA_ERROR_LOG("%s: %s\n", d->path, para_strerror(-ret));
                ret = score_delete(current_aft_row);
                if (ret >= 0)
                        goto again;
        }
        return ret;
}

static int ls_hash_compare(const void *a, const void *b)
{
        struct ls_data *d1 = *(struct ls_data **)a, *d2 = *(struct ls_data **)b;
        return memcmp(d1->hash, d2->hash, HASH2_SIZE);
}

static int ls_audio_format_compare(const void *a, const void *b)
{
        struct ls_data *d1 = *(struct ls_data **)a, *d2 = *(struct ls_data **)b;
        return NUM_COMPARE(d1->afsi.audio_format_id, d2->afsi.audio_format_id);
}

static int ls_duration_compare(const void *a, const void *b)
{
        struct ls_data *d1 = *(struct ls_data **)a, *d2 = *(struct ls_data **)b;
        return NUM_COMPARE(d1->afhi.seconds_total, d2->afhi.seconds_total);
}

static int ls_bitrate_compare(const void *a, const void *b)
{
        struct ls_data *d1 = *(struct ls_data **)a, *d2 = *(struct ls_data **)b;
        return NUM_COMPARE(d1->afhi.bitrate, d2->afhi.bitrate);
}

static int ls_lyrics_id_compare(const void *a, const void *b)
{
        struct ls_data *d1 = *(struct ls_data **)a, *d2 = *(struct ls_data **)b;
        return NUM_COMPARE(d1->afsi.lyrics_id, d2->afsi.lyrics_id);
}

static int ls_image_id_compare(const void *a, const void *b)
{
        struct ls_data *d1 = *(struct ls_data **)a, *d2 = *(struct ls_data **)b;
        return NUM_COMPARE(d1->afsi.image_id, d2->afsi.image_id);
}

static int ls_channels_compare(const void *a, const void *b)
{
        struct ls_data *d1 = *(struct ls_data **)a, *d2 = *(struct ls_data **)b;
        return NUM_COMPARE(d1->afhi.channels, d2->afhi.channels);
}

static int ls_frequency_compare(const void *a, const void *b)
{
        struct ls_data *d1 = *(struct ls_data **)a, *d2 = *(struct ls_data **)b;
        return NUM_COMPARE(d1->afhi.frequency, d2->afhi.frequency);
}

static int ls_num_played_compare(const void *a, const void *b)
{
        struct ls_data *d1 = *(struct ls_data **)a, *d2 = *(struct ls_data **)b;
        return NUM_COMPARE(d1->afsi.num_played, d2->afsi.num_played);
}

static int ls_last_played_compare(const void *a, const void *b)
{
        struct ls_data *d1 = *(struct ls_data **)a, *d2 = *(struct ls_data **)b;
        return NUM_COMPARE(d1->afsi.last_played, d2->afsi.last_played);
}

static int ls_score_compare(const void *a, const void *b)
{
        struct ls_data *d1 = *(struct ls_data **)a, *d2 = *(struct ls_data **)b;
        return NUM_COMPARE(d1->score, d2->score);
}

static int ls_path_compare(const void *a, const void *b)
{
        struct ls_data *d1 = *(struct ls_data **)a, *d2 = *(struct ls_data **)b;
        return strcmp(d1->path, d2->path);
}

static inline bool admissible_only(struct ls_options *opts)
{
        return SERVER_CMD_OPT_GIVEN(LS, ADMISSIBLE, opts->lpr)
                || opts->sorting == LS_SORT_BY_SCORE;
}

static int sort_matching_paths(struct ls_options *options)
{
        const struct lls_opt_result *r_b = SERVER_CMD_OPT_RESULT(LS, BASENAME,
                options->lpr);
        size_t nmemb = options->num_matching_paths;
        size_t size = sizeof(*options->data_ptr);
        int (*compar)(const void *, const void *);
        int i;

        options->data_ptr = arr_alloc(nmemb, sizeof(*options->data_ptr));
        for (i = 0; i < nmemb; i++)
                options->data_ptr[i] = options->data + i;

        /* In these cases the array is already sorted */
        if (admissible_only(options)) {
                if (options->sorting == LS_SORT_BY_SCORE)
                        return 1;
        } else {
                if (options->sorting == LS_SORT_BY_PATH && !lls_opt_given(r_b))
                        return 1;
        }

        switch (options->sorting) {
        case LS_SORT_BY_PATH:
                compar = ls_path_compare; break;
        case LS_SORT_BY_SCORE:
                compar = ls_score_compare; break;
        case LS_SORT_BY_LAST_PLAYED:
                compar = ls_last_played_compare; break;
        case LS_SORT_BY_NUM_PLAYED:
                compar = ls_num_played_compare; break;
        case LS_SORT_BY_FREQUENCY:
                compar = ls_frequency_compare; break;
        case LS_SORT_BY_CHANNELS:
                compar = ls_channels_compare; break;
        case LS_SORT_BY_IMAGE_ID:
                compar = ls_image_id_compare; break;
        case LS_SORT_BY_LYRICS_ID:
                compar = ls_lyrics_id_compare; break;
        case LS_SORT_BY_BITRATE:
                compar = ls_bitrate_compare; break;
        case LS_SORT_BY_DURATION:
                compar = ls_duration_compare; break;
        case LS_SORT_BY_AUDIO_FORMAT:
                compar = ls_audio_format_compare; break;
        case LS_SORT_BY_HASH:
                compar = ls_hash_compare; break;
        default:
                return -E_BAD_SORT;
        }
        qsort(options->data_ptr, nmemb, size, compar);
        return 1;
}

/* row is either an aft_row or a row of the score table */
/* TODO: Only compute widths if we need them */
static int prepare_ls_row(struct osl_row *row, void *ls_opts)
{
        int ret, i;
        struct ls_options *options = ls_opts;
        bool basename_given = SERVER_CMD_OPT_GIVEN(LS, BASENAME, options->lpr);
        struct ls_data *d;
        struct ls_widths *w;
        unsigned short num_digits;
        unsigned tmp, num_inputs;
        struct osl_row *aft_row;
        long score;
        char *path;

        if (admissible_only(options)) {
                ret = get_score_and_aft_row(row, &score, &aft_row);
                if (ret < 0)
                        return ret;
        } else {
                aft_row = row;
                score = 0;
        }
        ret = get_audio_file_path_of_row(aft_row, &path);
        if (ret < 0)
                return ret;
        if (basename_given) {
                char *p = strrchr(path, '/');
                if (p)
                        path = p + 1;
        }
        num_inputs = lls_num_inputs(options->lpr);
        if (num_inputs > 0) {
                for (i = 0; i < num_inputs; i++) {
                        ret = fnmatch(lls_input(i, options->lpr), path, 0);
                        if (!ret)
                                break;
                        if (ret == FNM_NOMATCH)
                                continue;
                        return -E_FNMATCH;
                }
                if (i >= num_inputs) /* no match */
                        return 1;
        }
        tmp = options->num_matching_paths++;
        if (options->num_matching_paths > options->array_size) {
                options->array_size++;
                options->array_size *= 2;
                options->data = arr_realloc(options->data, options->array_size,
                        sizeof(*options->data));
        }
        d = options->data + tmp;
        ret = get_afsi_of_row(aft_row, &d->afsi);
        if (ret < 0)
                return ret;
        ret = get_afhi_of_row(aft_row, &d->afhi);
        if (ret < 0)
                return ret;
        d->path = path;
        ret = get_hash_of_row(aft_row, &d->hash);
        if (ret < 0)
                goto err;
        w = &options->widths;
        GET_NUM_DIGITS(d->afsi.image_id, &num_digits);
        w->image_id_width = PARA_MAX(w->image_id_width, num_digits);
        GET_NUM_DIGITS(d->afsi.lyrics_id, &num_digits);
        w->lyrics_id_width = PARA_MAX(w->lyrics_id_width, num_digits);
        GET_NUM_DIGITS(d->afhi.bitrate, &num_digits);
        w->bitrate_width = PARA_MAX(w->bitrate_width, num_digits);
        GET_NUM_DIGITS(d->afhi.frequency, &num_digits);
        w->frequency_width = PARA_MAX(w->frequency_width, num_digits);
        GET_NUM_DIGITS(d->afsi.num_played, &num_digits);
        w->num_played_width = PARA_MAX(w->num_played_width, num_digits);
        /* get the number of chars to print this amount of time */
        num_digits = get_duration_width(d->afhi.seconds_total);
        w->duration_width = PARA_MAX(w->duration_width, num_digits);
        GET_NUM_DIGITS(d->afsi.amp, &num_digits);
        w->amp_width = PARA_MAX(w->amp_width, num_digits);
        num_digits = strlen(audio_format_name(d->afsi.audio_format_id));
        w->audio_format_width = PARA_MAX(w->audio_format_width, num_digits);
        if (admissible_only(options)) {
                GET_NUM_DIGITS(score, &num_digits);
                num_digits++; /* add one for the sign (space or "-") */
                w->score_width = PARA_MAX(w->score_width, num_digits);
                d->score = score;
        }
        return 1;
err:
        return ret;
}

static int com_ls_callback(struct afs_callback_arg *aca)
{
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(LS);
        struct ls_options *opts = aca->query.data;
        int ret;
        time_t current_time;
        const struct lls_opt_result *r_r;
        uint32_t limit, k, n;

        ret = lls_deserialize_parse_result(
                (char *)aca->query.data + sizeof(*opts), cmd, &opts->lpr);
        assert(ret >= 0);
        r_r = SERVER_CMD_OPT_RESULT(LS, REVERSE, opts->lpr);

        aca->pbout.flags = (opts->mode == LS_MODE_PARSER)? PBF_SIZE_PREFIX : 0;
        if (admissible_only(opts))
                ret = score_loop(prepare_ls_row, opts);
        else
                ret = osl(osl_rbtree_loop(audio_file_table, AFTCOL_PATH, opts,
                        prepare_ls_row));
        if (ret < 0)
                goto out;
        n = opts->num_matching_paths;
        if (n == 0) {
                ret = lls_num_inputs(opts->lpr) > 0? -E_NO_MATCH : 0;
                goto out;
        }
        ret = sort_matching_paths(opts);
        if (ret < 0)
                goto out;
        time(&current_time);
        limit = SERVER_CMD_UINT32_VAL(LS, LIMIT, opts->lpr);
        for (k = 0; k < n && (limit == 0 || k < limit); k++) {
                uint32_t idx = lls_opt_given(r_r)? n - 1 - k : k;
                ret = print_list_item(opts->data_ptr[idx], opts, &aca->pbout,
                        current_time);
                if (ret < 0)
                        goto out;
        }
out:
        lls_free_parse_result(opts->lpr, cmd);
        free(opts->data);
        free(opts->data_ptr);
        return ret;
}

static int com_ls(struct command_context *cc, struct lls_parse_result *lpr)
{
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(LS);
        struct ls_options *opts;
        struct osl_object query;
        const struct lls_opt_result *r_l = SERVER_CMD_OPT_RESULT(LS, LISTING_MODE,
                lpr);
        const struct lls_opt_result *r_s = SERVER_CMD_OPT_RESULT(LS, SORT, lpr);
        int ret;
        char *slpr;

        ret = lls_serialize_parse_result(lpr, cmd, NULL, &query.size);
        assert(ret >= 0);
        query.size += sizeof(*opts);
        query.data = alloc(query.size);
        opts = query.data;
        memset(opts, 0, sizeof(*opts));
        slpr = query.data + sizeof(*opts);
        ret = lls_serialize_parse_result(lpr, cmd, &slpr, NULL);
        assert(ret >= 0);
        opts->mode = LS_MODE_SHORT;
        opts->sorting = LS_SORT_BY_PATH;
        if (lls_opt_given(r_l)) {
                const char *val = lls_string_val(0, r_l);
                if (!strcmp(val, "l") || !strcmp(val, "long"))
                        opts->mode = LS_MODE_LONG;
                else if (!strcmp(val, "s") || !strcmp(val, "short"))
                        opts->mode = LS_MODE_SHORT;
                else if (!strcmp(val, "v") || !strcmp(val, "verbose"))
                        opts->mode = LS_MODE_VERBOSE;
                else if (!strcmp(val, "m") || !strcmp(val, "mbox"))
                        opts->mode = LS_MODE_MBOX;
                else if (!strcmp(val, "c") || !strcmp(val, "chunk-table"))
                        opts->mode = LS_MODE_CHUNKS;
                else if (!strcmp(val, "p") || !strcmp(val, "parser-friendly"))
                        opts->mode = LS_MODE_PARSER;
                else {
                        ret = -ERRNO_TO_PARA_ERROR(EINVAL);
                        goto out;
                }
        }
        if (lls_opt_given(r_s)) {
                const char *val = lls_string_val(0, r_s);
                if (!strcmp(val, "p") || !strcmp(val, "path"))
                        opts->sorting = LS_SORT_BY_PATH;
                else if (!strcmp(val, "s") || !strcmp(val, "score"))
                        opts->sorting = LS_SORT_BY_SCORE;
                else if (!strcmp(val, "l") || !strcmp(val, "lastplayed"))
                        opts->sorting = LS_SORT_BY_LAST_PLAYED;
                else if (!strcmp(val, "n") || !strcmp(val, "numplayed"))
                        opts->sorting = LS_SORT_BY_NUM_PLAYED;
                else if (!strcmp(val, "f") || !strcmp(val, "frquency"))
                        opts->sorting = LS_SORT_BY_FREQUENCY;
                else if (!strcmp(val, "c") || !strcmp(val, "channels"))
                        opts->sorting = LS_SORT_BY_CHANNELS;
                else if (!strcmp(val, "i") || !strcmp(val, "image-id"))
                        opts->sorting = LS_SORT_BY_IMAGE_ID;
                else if (!strcmp(val, "y") || !strcmp(val, "lyrics-id"))
                        opts->sorting = LS_SORT_BY_LYRICS_ID;
                else if (!strcmp(val, "b") || !strcmp(val, "bitrate"))
                        opts->sorting = LS_SORT_BY_BITRATE;
                else if (!strcmp(val, "d") || !strcmp(val, "duration"))
                        opts->sorting = LS_SORT_BY_DURATION;
                else if (!strcmp(val, "a") || !strcmp(val, "audio-format"))
                        opts->sorting = LS_SORT_BY_AUDIO_FORMAT;
                else if (!strcmp(val, "h") || !strcmp(val, "hash"))
                        opts->sorting = LS_SORT_BY_HASH;
                else {
                        ret = -ERRNO_TO_PARA_ERROR(EINVAL);
                        goto out;
                }
        }
        ret = send_callback_request(com_ls_callback, &query,
                afs_cb_result_handler, cc);
out:
        free(query.data);
        return ret;
}
EXPORT_SERVER_CMD_HANDLER(ls);

/**
 * Call the given function for each file in the audio file table.
 *
 * \param private_data An arbitrary data pointer, passed to \a func.
 * \param func The custom function to be called.
 *
 * \return Standard.
 */
int audio_file_loop(void *private_data, osl_rbtree_loop_func *func)
{
        return osl(osl_rbtree_loop(audio_file_table, AFTCOL_HASH, private_data,
                func));
}

static int find_hash_sister(unsigned char *hash, struct osl_row **result)
{
        int ret = aft_get_row_of_hash(hash, result);

        if (ret == -OSL_ERRNO_TO_PARA_ERROR(E_OSL_RB_KEY_NOT_FOUND))
                return 0;
        return ret;
}

static int find_path_brother(const char *path, struct osl_row **result)
{
        int ret = aft_get_row_of_path(path, result);

        if (ret == -OSL_ERRNO_TO_PARA_ERROR(E_OSL_RB_KEY_NOT_FOUND))
                return 0;
        return ret;
}

/** The format of the data stored by save_audio_file_data(). */
enum com_add_buffer_offsets {
        /* afhi (if present) starts at this offset. */
        CAB_AFHI_OFFSET_POS = 0,
        /** Start of the chunk table (if present). */
        CAB_CHUNKS_OFFSET_POS = 4,
        /** Start of the (serialized) lopsub parse result. */
        CAB_LPR_OFFSET = 8,
        /** Audio format id. */
        CAB_AUDIO_FORMAT_ID_OFFSET = 12,
        /** The hash of the audio file being added. */
        CAB_HASH_OFFSET = 13,
        /** Start of the path of the audio file. */
        CAB_PATH_OFFSET = (CAB_HASH_OFFSET + HASH2_SIZE),
};

/*
 * Store the given data to a single buffer. Doesn't need the audio file selector
 * info struct as the server knows it as well.
 *
 * It's OK to call this with afhi == NULL. In this case, the audio format
 * handler info won't be stored in the buffer.
 */
static void save_add_callback_buffer(unsigned char *hash, const char *path,
                struct afh_info *afhi, const char *slpr, size_t slpr_size,
                uint8_t audio_format_num, struct osl_object *obj)
{
        size_t path_len = strlen(path) + 1;
        size_t afhi_size = sizeof_afhi_buf(afhi);
        size_t size = CAB_PATH_OFFSET + path_len + afhi_size
                + sizeof_chunk_table(afhi) + slpr_size;
        char *buf = alloc(size);
        uint32_t pos;

        assert(size <= ~(uint32_t)0);
        write_u8(buf + CAB_AUDIO_FORMAT_ID_OFFSET, audio_format_num);
        memcpy(buf + CAB_HASH_OFFSET, hash, HASH2_SIZE);
        strcpy(buf + CAB_PATH_OFFSET, path);
        pos = CAB_PATH_OFFSET + path_len;
        write_u32(buf + CAB_AFHI_OFFSET_POS, pos);
        save_afhi(afhi, buf + pos);
        pos += afhi_size;
        write_u32(buf + CAB_CHUNKS_OFFSET_POS, pos);
        if (afhi) {
                save_chunk_table(afhi, buf + pos);
                pos += sizeof_chunk_table(afhi);
        }
        write_u32(buf + CAB_LPR_OFFSET, pos);
        memcpy(buf + pos, slpr, slpr_size);
        assert(pos + slpr_size == size);
        obj->data = buf;
        obj->size = size;
}

/*

Overview of the add command.

Input: What was passed to the callback by the command handler.
~~~~~~
HS:     Hash sister. Whether an audio file with identical hash
        already exists in the osl database.

PB:     Path brother. Whether a file with the given path exists
        in the table.

F:      Force flag given. Whether add was called with -f.

output: Action performed by the callback.
~~~~~~~
AFHI:   Whether afhi and chunk table are computed and sent.
ACTION: Table modifications to be done by the callback.

+----+----+---+------+---------------------------------------------------+
| HS | PB | F | AFHI | ACTION
+----+----+---+------+---------------------------------------------------+
| Y  |  Y | Y |  Y   | if HS != PB: remove PB. HS: force afhi update,
|                    | update path, keep afsi
+----+----+---+------+---------------------------------------------------+
| Y  |  Y | N |  N   | if HS == PB: do not send callback request at all.
|                    | otherwise: remove PB, HS: update path, keep afhi,
|                    | afsi.
+----+----+---+------+---------------------------------------------------+
| Y  |  N | Y |  Y   | (rename) force afhi update of HS, update path of
|                    | HS, keep afsi
+----+----+---+------+---------------------------------------------------+
| Y  |  N | N |  N   | (file rename) update path of HS, keep afsi, afhi
+----+----+---+------+---------------------------------------------------+
| N  |  Y | Y |  Y   | (file change) update afhi, hash, of PB, keep afsi
|                    | (force has no effect)
+----+----+---+------+---------------------------------------------------+
| N  |  Y | N |  Y   | (file change) update afhi, hash of PB, keep afsi
+----+----+---+------+---------------------------------------------------+
| N  |  N | Y |  Y   | (new file) create new entry (force has no effect)
+----+----+---+------+---------------------------------------------------+
| N  |  N | N |  Y   | (new file) create new entry
+----+----+---+------+---------------------------------------------------+

Notes:

        afhi <=> force or no HS
        F => AFHI

*/

static int com_add_callback(struct afs_callback_arg *aca)
{
        char *buf = aca->query.data, *path;
        struct osl_row *pb, *aft_row;
        struct osl_row *hs;
        struct osl_object objs[NUM_AFT_COLUMNS];
        unsigned char *hash;
        char asc[2 * HASH2_SIZE + 1];
        int ret;
        char afsi_buf[AFSI_SIZE];
        uint32_t slpr_offset = read_u32(buf + CAB_LPR_OFFSET);
        char *slpr = buf + slpr_offset;
        struct afs_info default_afsi = {.last_played = 0};
        uint16_t afhi_offset, chunks_offset;
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(ADD);
        const struct lls_opt_result *r_f, *r_v;

        ret = lls_deserialize_parse_result(slpr, cmd, &aca->lpr);
        assert(ret >= 0);
        r_f = SERVER_CMD_OPT_RESULT(ADD, FORCE, aca->lpr);
        r_v = SERVER_CMD_OPT_RESULT(ADD, VERBOSE, aca->lpr);

        hash = (unsigned char *)buf + CAB_HASH_OFFSET;
        hash2_to_asc(hash, asc);
        objs[AFTCOL_HASH].data = buf + CAB_HASH_OFFSET;
        objs[AFTCOL_HASH].size = HASH2_SIZE;

        path = buf + CAB_PATH_OFFSET;
        objs[AFTCOL_PATH].data = path;
        objs[AFTCOL_PATH].size = strlen(path) + 1;

        PARA_INFO_LOG("request to add %s\n", path);
        ret = find_hash_sister(hash, &hs);
        if (ret < 0)
                goto out;
        ret = find_path_brother(path, &pb);
        if (ret < 0)
                goto out;
        if (hs && pb && hs == pb && !lls_opt_given(r_f)) {
                if (lls_opt_given(r_v))
                        para_printf(&aca->pbout, "ignoring duplicate\n");
                ret = 1;
                goto out;
        }
        if (hs && hs != pb) {
                struct osl_object obj;
                if (pb) { /* hs trumps pb, remove pb */
                        if (lls_opt_given(r_v))
                                para_printf(&aca->pbout, "removing %s\n", path);
                        ret = afs_event(AUDIO_FILE_REMOVE, &aca->pbout, pb);
                        if (ret < 0)
                                goto out;
                        ret = osl(osl_del_row(audio_file_table, pb));
                        if (ret < 0)
                                goto out;
                        pb = NULL;
                }
                /* file rename, update hs' path */
                if (lls_opt_given(r_v)) {
                        ret = osl(osl_get_object(audio_file_table, hs,
                                AFTCOL_PATH, &obj));
                        if (ret < 0)
                                goto out;
                        para_printf(&aca->pbout, "renamed from %s\n",
                                (char *)obj.data);
                }
                ret = osl(osl_update_object(audio_file_table, hs, AFTCOL_PATH,
                        &objs[AFTCOL_PATH]));
                if (ret < 0)
                        goto out;
                ret = afs_event(AUDIO_FILE_RENAME, &aca->pbout, hs);
                if (ret < 0)
                        goto out;
                if (!lls_opt_given(r_f))
                        goto out;
        }
        /* no hs or force mode, child must have sent afhi */
        afhi_offset = read_u32(buf + CAB_AFHI_OFFSET_POS);
        chunks_offset = read_u32(buf + CAB_CHUNKS_OFFSET_POS);
        assert(chunks_offset <= slpr_offset);

        objs[AFTCOL_AFHI].data = buf + afhi_offset;
        objs[AFTCOL_AFHI].size = chunks_offset - afhi_offset;
        ret = -E_NO_AFHI;
        if (!objs[AFTCOL_AFHI].size) /* "impossible" */
                goto out;
        objs[AFTCOL_CHUNKS].data = buf + chunks_offset;
        objs[AFTCOL_CHUNKS].size = slpr_offset - chunks_offset;
        if (pb && !hs) { /* update pb's hash */
                char old_asc[2 * HASH2_SIZE + 1];
                unsigned char *old_hash;
                ret = get_hash_of_row(pb, &old_hash);
                if (ret < 0)
                        goto out;
                hash2_to_asc(old_hash, old_asc);
                if (lls_opt_given(r_v))
                        para_printf(&aca->pbout, "file change: %s -> %s\n",
                                old_asc, asc);
                ret = osl(osl_update_object(audio_file_table, pb, AFTCOL_HASH,
                        &objs[AFTCOL_HASH]));
                if (ret < 0)
                        goto out;
        }
        if (hs || pb) { /* (hs != NULL and pb != NULL) implies hs == pb */
                struct osl_row *row = pb? pb : hs;
                /* update afhi and chunk_table */
                if (lls_opt_given(r_v))
                        para_printf(&aca->pbout,
                                "updating afhi and chunk table\n");
                ret = osl(osl_update_object(audio_file_table, row, AFTCOL_AFHI,
                        &objs[AFTCOL_AFHI]));
                if (ret < 0)
                        goto out;
                /* truncate the file to size zero if there is no chunk table */
                ret = osl(osl_update_object(audio_file_table, row, AFTCOL_CHUNKS,
                        &objs[AFTCOL_CHUNKS]));
                if (ret < 0)
                        goto out;
                ret = afs_event(AFHI_CHANGE, &aca->pbout, row);
                goto out;
        }
        /* new entry, use default afsi */
        if (lls_opt_given(r_v))
                para_printf(&aca->pbout, "new file\n");
        default_afsi.last_played = time(NULL) - 365 * 24 * 60 * 60;
        default_afsi.audio_format_id = read_u8(buf + CAB_AUDIO_FORMAT_ID_OFFSET);

        objs[AFTCOL_AFSI].data = &afsi_buf;
        objs[AFTCOL_AFSI].size = AFSI_SIZE;
        save_afsi(&default_afsi, &objs[AFTCOL_AFSI]);
        ret = osl(osl_add_and_get_row(audio_file_table, objs, &aft_row));
        if (ret < 0)
                goto out;
        ret = afs_event(AUDIO_FILE_ADD, &aca->pbout, aft_row);
out:
        if (ret < 0)
                afs_error(aca, "could not add %s\n", path);
        lls_free_parse_result(aca->lpr, cmd);
        return ret;
}

/* Used by com_add(). */
struct private_add_data {
        /* The pointer passed to the original command handler. */
        struct command_context *cc;
        /* Contains the flags given at the command line. */
        struct lls_parse_result *lpr;
        /* Serialized lopsub parse result. */
        char *slpr;
        /* Number of bytes. */
        size_t slpr_size;
};

static int path_brother_callback(struct afs_callback_arg *aca)
{
        char *path = aca->query.data;
        struct osl_row *path_brother;
        int ret = find_path_brother(path, &path_brother);
        if (ret <= 0)
                return ret;
        return pass_buffer_as_shm(aca->fd, SBD_OUTPUT, (char *)&path_brother,
                sizeof(path_brother));
}

static int hash_sister_callback(struct afs_callback_arg *aca)
{
        unsigned char *hash = aca->query.data;
        struct osl_row *hash_sister;
        int ret = find_hash_sister(hash, &hash_sister);

        if (ret <= 0)
                return ret;
        return pass_buffer_as_shm(aca->fd, SBD_OUTPUT, (char *)&hash_sister,
                sizeof(hash_sister));
}

static int get_row_pointer_from_result(struct osl_object *result,
                __a_unused uint8_t band, void *private)
{
        struct osl_row **row = private;

        if (band == SBD_OUTPUT)
                *row = *(struct osl_row **)(result->data);
        return 1;
}

static int add_one_audio_file(const char *path, void *private_data)
{
        int ret, send_ret = 1, fd;
        uint8_t format_num = -1;
        struct private_add_data *pad = private_data;
        struct afh_info afhi, *afhi_ptr = NULL;
        struct osl_row *pb = NULL, *hs = NULL; /* path brother/hash sister */
        struct osl_object map, obj = {.data = NULL}, query;
        unsigned char hash[HASH2_SIZE];
        bool a_given = SERVER_CMD_OPT_GIVEN(ADD, ALL, pad->lpr);
        bool f_given = SERVER_CMD_OPT_GIVEN(ADD, FORCE, pad->lpr);
        bool l_given = SERVER_CMD_OPT_GIVEN(ADD, LAZY, pad->lpr);
        bool v_given = SERVER_CMD_OPT_GIVEN(ADD, VERBOSE, pad->lpr);

        ret = guess_audio_format(path);
        if (ret < 0 && !a_given) {
                ret = 0;
                goto out_free;
        }
        query.data = (char *)path;
        query.size = strlen(path) + 1;
        ret = send_callback_request(path_brother_callback, &query,
                get_row_pointer_from_result, &pb);
        if (ret < 0 && ret != -OSL_ERRNO_TO_PARA_ERROR(E_OSL_RB_KEY_NOT_FOUND))
                goto out_free;
        ret = 1;
        if (pb && l_given) { /* lazy is really cheap */
                if (v_given)
                        send_ret = send_sb_va(&pad->cc->scc, SBD_OUTPUT,
                                "lazy-ignore: %s\n", path);
                goto out_free;
        }
        /* We still want to add this file. Compute its hash. */
        ret = mmap_full_file(path, O_RDONLY, &map.data, &map.size, &fd);
        if (ret < 0)
                goto out_free;
        hash2_function(map.data, map.size, hash);

        /* Check whether the database contains a file with the same hash. */
        query.data = hash;
        query.size = HASH2_SIZE;
        ret = send_callback_request(hash_sister_callback, &query,
                get_row_pointer_from_result, &hs);
        if (ret < 0)
                goto out_unmap;
        /* Return success if we already know this file. */
        ret = 1;
        if (pb && hs && hs == pb && !f_given) {
                if (v_given)
                        send_ret = send_sb_va(&pad->cc->scc, SBD_OUTPUT,
                                "%s exists, not forcing update\n", path);
                goto out_unmap;
        }
        /*
         * We won't recalculate the audio format info and the chunk table if
         * there is a hash sister and FORCE was not given.
         */
        if (!hs || f_given) {
                ret = compute_afhi(path, map.data, map.size, fd, &afhi);
                if (ret < 0)
                        goto out_unmap;
                format_num = ret;
                afhi_ptr = &afhi;
        }
        munmap(map.data, map.size);
        close(fd);
        if (v_given) {
                send_ret = send_sb_va(&pad->cc->scc, SBD_OUTPUT,
                        "adding %s\n", path);
                if (send_ret < 0)
                        goto out_free;
        }
        save_add_callback_buffer(hash, path, afhi_ptr, pad->slpr,
                pad->slpr_size, format_num, &obj);
        /* Ask afs to consider this entry for adding. */
        ret = send_callback_request(com_add_callback, &obj,
                afs_cb_result_handler, pad->cc);
        goto out_free;

out_unmap:
        close(fd);
        munmap(map.data, map.size);
out_free:
        if (ret < 0 && send_ret >= 0)
                send_ret = send_sb_va(&pad->cc->scc, SBD_ERROR_LOG,
                        "failed to add %s (%s)\n", path, para_strerror(-ret));
        free(obj.data);
        clear_afhi(afhi_ptr);
        /* Stop adding files only on send errors. */
        return send_ret;
}

static int com_add(struct command_context *cc, struct lls_parse_result *lpr)
{
        int i, ret;
        struct private_add_data pad = {.cc = cc, .lpr = lpr};
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(ADD);
        unsigned num_inputs;
        char *errctx;

        ret = lls(lls_check_arg_count(lpr, 1, INT_MAX, &errctx));
        if (ret < 0) {
                send_errctx(cc, errctx);
                return ret;
        }
        ret = lls_serialize_parse_result(lpr, cmd, &pad.slpr, &pad.slpr_size);
        assert(ret >= 0);
        num_inputs = lls_num_inputs(lpr);
        for (i = 0; i < num_inputs; i++) {
                char *path;
                ret = verify_path(lls_input(i, lpr), &path);
                if (ret < 0) {
                        ret = send_sb_va(&cc->scc, SBD_ERROR_LOG, "%s: %s\n",
                                lls_input(i, lpr), para_strerror(-ret));
                        if (ret < 0)
                                goto out;
                        continue;
                }
                if (ret == 1) /* directory */
                        ret = for_each_file_in_dir(path, add_one_audio_file,
                                &pad);
                else /* regular file */
                        ret = add_one_audio_file(path, &pad);
                if (ret < 0) {
                        send_sb_va(&cc->scc, SBD_OUTPUT, "%s: %s\n", path,
                                para_strerror(-ret));
                        free(path);
                        return ret;
                }
                free(path);
        }
        ret = 1;
out:
        free(pad.slpr);
        return ret;
}
EXPORT_SERVER_CMD_HANDLER(add);

/** Flags used by the touch command. */
enum touch_flags {
        /** Whether the \p FNM_PATHNAME flag should be passed to fnmatch(). */
        TOUCH_FLAG_FNM_PATHNAME = 1,
        /** Activates verbose mode. */
        TOUCH_FLAG_VERBOSE = 2
};

static int touch_audio_file(__a_unused struct osl_table *table,
                struct osl_row *row, const char *name, void *data)
{
        struct afs_callback_arg *aca = data;
        bool v_given = SERVER_CMD_OPT_GIVEN(TOUCH, VERBOSE, aca->lpr);
        const struct lls_opt_result *r_n, *r_l, *r_i, *r_y, *r_a;
        int ret;
        struct osl_object obj;
        struct afs_info old_afsi, new_afsi;
        bool no_options;
        struct afsi_change_event_data aced;

        r_n = SERVER_CMD_OPT_RESULT(TOUCH, NUMPLAYED, aca->lpr);
        r_l = SERVER_CMD_OPT_RESULT(TOUCH, LASTPLAYED, aca->lpr);
        r_i = SERVER_CMD_OPT_RESULT(TOUCH, IMAGE_ID, aca->lpr);
        r_y = SERVER_CMD_OPT_RESULT(TOUCH, LYRICS_ID, aca->lpr);
        r_a = SERVER_CMD_OPT_RESULT(TOUCH, AMP, aca->lpr);
        no_options = !lls_opt_given(r_n) && !lls_opt_given(r_l) && !lls_opt_given(r_i)
                && !lls_opt_given(r_y) && !lls_opt_given(r_a);

        ret = get_afsi_object_of_row(row, &obj);
        if (ret < 0) {
                afs_error(aca, "cannot touch %s\n", name);
                return ret;
        }
        ret = load_afsi(&old_afsi, &obj);
        if (ret < 0) {
                afs_error(aca, "cannot touch %s\n", name);
                return ret;
        }
        new_afsi = old_afsi;
        if (no_options) {
                new_afsi.num_played++;
                new_afsi.last_played = time(NULL);
                if (v_given)
                        para_printf(&aca->pbout, "%s: num_played = %u, "
                                "last_played = now()\n", name,
                                new_afsi.num_played);
        } else {
                if (lls_opt_given(r_l))
                        new_afsi.last_played = lls_uint64_val(0, r_l);
                if (lls_opt_given(r_n))
                        new_afsi.num_played = lls_uint32_val(0, r_n);
                if (lls_opt_given(r_i))
                        new_afsi.image_id = lls_uint32_val(0, r_i);
                if (lls_opt_given(r_y))
                        new_afsi.lyrics_id = lls_uint32_val(0, r_y);
                if (lls_opt_given(r_a))
                        new_afsi.amp = lls_uint32_val(0, r_a);
                if (v_given)
                        para_printf(&aca->pbout, "touching %s\n", name);
        }
        save_afsi(&new_afsi, &obj); /* in-place update */
        aced.aft_row = row;
        aced.old_afsi = &old_afsi;
        return afs_event(AFSI_CHANGE, &aca->pbout, &aced);
}

static int com_touch_callback(struct afs_callback_arg *aca)
{
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(TOUCH);
        bool p_given;
        const struct lls_opt_result *r_i, *r_y;
        int ret;
        struct pattern_match_data pmd = {
                .table = audio_file_table,
                .loop_col_num = AFTCOL_HASH,
                .match_col_num = AFTCOL_PATH,
                .data = aca,
                .action = touch_audio_file
        };

        ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
        assert(ret >= 0);
        pmd.lpr = aca->lpr;

        r_i = SERVER_CMD_OPT_RESULT(TOUCH, IMAGE_ID, aca->lpr);
        if (lls_opt_given(r_i)) {
                uint32_t id = lls_uint32_val(0, r_i);
                ret = img_get_name_by_id(id, NULL);
                if (ret < 0) {
                        afs_error(aca, "invalid image ID: %u\n", id);
                        return ret;
                }
        }
        r_y = SERVER_CMD_OPT_RESULT(TOUCH, LYRICS_ID, aca->lpr);
        if (lls_opt_given(r_y)) {
                uint32_t id = lls_uint32_val(0, r_y);
                ret = lyr_get_name_by_id(id, NULL);
                if (ret < 0) {
                        afs_error(aca, "invalid lyrics ID: %u\n", id);
                        return ret;
                }
        }
        p_given = SERVER_CMD_OPT_GIVEN(TOUCH, PATHNAME_MATCH, aca->lpr);
        if (p_given)
                pmd.fnmatch_flags |= FNM_PATHNAME;
        ret = for_each_matching_row(&pmd);
        if (ret >= 0 && pmd.num_matches == 0)
                ret = -E_NO_MATCH;
        lls_free_parse_result(aca->lpr, cmd);
        return ret;
}

static int com_touch(struct command_context *cc, struct lls_parse_result *lpr)
{
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(TOUCH);
        int ret;
        char *errctx;

        ret = lls(lls_check_arg_count(lpr, 1, INT_MAX, &errctx));
        if (ret < 0) {
                send_errctx(cc, errctx);
                return ret;
        }
        return send_lls_callback_request(com_touch_callback, cmd, lpr, cc);
}
EXPORT_SERVER_CMD_HANDLER(touch);

static int remove_audio_file(__a_unused struct osl_table *table,
                struct osl_row *row, const char *name, void *data)
{
        struct afs_callback_arg *aca = data;
        bool v_given = SERVER_CMD_OPT_GIVEN(RM, VERBOSE, aca->lpr);
        int ret;

        if (v_given)
                para_printf(&aca->pbout, "removing %s\n", name);
        ret = afs_event(AUDIO_FILE_REMOVE, &aca->pbout, row);
        if (ret < 0)
                return ret;
        ret = osl(osl_del_row(audio_file_table, row));
        if (ret < 0)
                afs_error(aca, "cannot remove %s\n", name);
        return ret;
}

static int com_rm_callback(struct afs_callback_arg *aca)
{
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(RM);
        int ret;
        struct pattern_match_data pmd = {
                .table = audio_file_table,
                .loop_col_num = AFTCOL_HASH,
                .match_col_num = AFTCOL_PATH,
                .data = aca,
                .action = remove_audio_file
        };
        bool v_given, p_given, f_given;

        ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
        assert(ret >= 0);
        pmd.lpr = aca->lpr;
        v_given = SERVER_CMD_OPT_GIVEN(RM, VERBOSE, aca->lpr);
        p_given = SERVER_CMD_OPT_GIVEN(RM, PATHNAME_MATCH, aca->lpr);
        f_given = SERVER_CMD_OPT_GIVEN(RM, FORCE, aca->lpr);

        if (p_given)
                pmd.fnmatch_flags |= FNM_PATHNAME;
        ret = for_each_matching_row(&pmd);
        if (ret < 0)
                goto out;
        if (pmd.num_matches == 0) {
                if (!f_given)
                        ret = -E_NO_MATCH;
        } else if (v_given)
                para_printf(&aca->pbout, "removed %u file(s)\n",
                        pmd.num_matches);
out:
        lls_free_parse_result(aca->lpr, cmd);
        return ret;
}

/* TODO options: -r (recursive) */
static int com_rm(struct command_context *cc, struct lls_parse_result *lpr)
{
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(RM);
        char *errctx;
        int ret;

        ret = lls(lls_check_arg_count(lpr, 1, INT_MAX, &errctx));
        if (ret < 0) {
                send_errctx(cc, errctx);
                return ret;
        }
        return send_lls_callback_request(com_rm_callback, cmd, lpr, cc);
}
EXPORT_SERVER_CMD_HANDLER(rm);

/** Data passed to the action handler of com_cpsi(). */
struct cpsi_action_data {
        /** Values are copied from here. */
        struct afs_info source_afsi;
        /** What was passed to com_cpsi_callback(). */
        struct afs_callback_arg *aca;
        bool copy_all;
};

static int copy_selector_info(__a_unused struct osl_table *table,
                struct osl_row *row, const char *name, void *data)
{
        struct cpsi_action_data *cad = data;
        struct osl_object target_afsi_obj;
        int ret;
        struct afs_info old_afsi, target_afsi;
        struct afsi_change_event_data aced;
        bool a_given, y_given, i_given, l_given, n_given, v_given;

        a_given = SERVER_CMD_OPT_GIVEN(CPSI, ATTRIBUTE_BITMAP, cad->aca->lpr);
        y_given = SERVER_CMD_OPT_GIVEN(CPSI, LYRICS_ID, cad->aca->lpr);
        i_given = SERVER_CMD_OPT_GIVEN(CPSI, IMAGE_ID, cad->aca->lpr);
        l_given = SERVER_CMD_OPT_GIVEN(CPSI, LASTPLAYED, cad->aca->lpr);
        n_given = SERVER_CMD_OPT_GIVEN(CPSI, NUMPLAYED, cad->aca->lpr);
        v_given = SERVER_CMD_OPT_GIVEN(CPSI, VERBOSE, cad->aca->lpr);

        ret = get_afsi_object_of_row(row, &target_afsi_obj);
        if (ret < 0)
                return ret;
        ret = load_afsi(&target_afsi, &target_afsi_obj);
        if (ret < 0)
                return ret;
        old_afsi = target_afsi;
        if (cad->copy_all || y_given)
                target_afsi.lyrics_id = cad->source_afsi.lyrics_id;
        if (cad->copy_all || i_given)
                target_afsi.image_id = cad->source_afsi.image_id;
        if (cad->copy_all || l_given)
                target_afsi.last_played = cad->source_afsi.last_played;
        if (cad->copy_all || n_given)
                target_afsi.num_played = cad->source_afsi.num_played;
        if (cad->copy_all || a_given)
                target_afsi.attributes = cad->source_afsi.attributes;
        save_afsi(&target_afsi, &target_afsi_obj); /* in-place update */
        if (v_given)
                para_printf(&cad->aca->pbout, "copied afsi to %s\n", name);
        aced.aft_row = row;
        aced.old_afsi = &old_afsi;
        return afs_event(AFSI_CHANGE, &cad->aca->pbout, &aced);
}

static int com_cpsi_callback(struct afs_callback_arg *aca)
{
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(CPSI);
        bool a_given, y_given, i_given, l_given, n_given, v_given;
        struct cpsi_action_data cad = {.aca = aca};
        int ret;
        struct pattern_match_data pmd = {
                .table = audio_file_table,
                .loop_col_num = AFTCOL_HASH,
                .match_col_num = AFTCOL_PATH,
                .input_skip = 1, /* skip first argument (source file) */
                .data = &cad,
                .action = copy_selector_info
        };

        ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
        assert(ret >= 0);
        pmd.lpr = aca->lpr;

        a_given = SERVER_CMD_OPT_GIVEN(CPSI, ATTRIBUTE_BITMAP, aca->lpr);
        y_given = SERVER_CMD_OPT_GIVEN(CPSI, LYRICS_ID, aca->lpr);
        i_given = SERVER_CMD_OPT_GIVEN(CPSI, IMAGE_ID, aca->lpr);
        l_given = SERVER_CMD_OPT_GIVEN(CPSI, LASTPLAYED, aca->lpr);
        n_given = SERVER_CMD_OPT_GIVEN(CPSI, NUMPLAYED, aca->lpr);
        v_given = SERVER_CMD_OPT_GIVEN(CPSI, VERBOSE, aca->lpr);
        cad.copy_all = !a_given && !y_given && !i_given && !l_given && !n_given;

        ret = get_afsi_of_path(lls_input(0, aca->lpr), &cad.source_afsi);
        if (ret < 0)
                goto out;
        ret = for_each_matching_row(&pmd);
        if (ret < 0)
                goto out;
        if (pmd.num_matches > 0) {
                if (v_given)
                        para_printf(&aca->pbout, "updated afsi of %u file(s)\n",
                                pmd.num_matches);
        } else
                ret = -E_NO_MATCH;
out:
        lls_free_parse_result(aca->lpr, cmd);
        return ret;
}

static int com_cpsi(struct command_context *cc, struct lls_parse_result *lpr)
{
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(CPSI);
        char *errctx;
        int ret = lls(lls_check_arg_count(lpr, 2, INT_MAX, &errctx));
        if (ret < 0) {
                send_errctx(cc, errctx);
                return ret;
        }
        return send_lls_callback_request(com_cpsi_callback, cmd, lpr, cc);
}
EXPORT_SERVER_CMD_HANDLER(cpsi);

struct change_atts_data {
        uint64_t add_mask, del_mask;
        struct afs_callback_arg *aca;
};

static int change_atts(__a_unused struct osl_table *table,
                struct osl_row *row, __a_unused const char *name, void *data)
{
        int ret;
        struct osl_object obj;
        struct afs_info old_afsi, new_afsi;
        struct afsi_change_event_data aced = {
                .aft_row = row,
                .old_afsi = &old_afsi
        };
        struct change_atts_data *cad = data;

        ret = get_afsi_object_of_row(row, &obj);
        if (ret < 0)
                return ret;
        ret = load_afsi(&old_afsi, &obj);
        if (ret < 0)
                return ret;
        new_afsi = old_afsi;
        new_afsi.attributes |= cad->add_mask;
        new_afsi.attributes &= ~cad->del_mask;
        save_afsi(&new_afsi, &obj); /* in-place update */
        return afs_event(AFSI_CHANGE, &cad->aca->pbout, &aced);
}

static int com_setatt_callback(struct afs_callback_arg *aca)
{
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SETATT);
        int i, ret;
        struct change_atts_data cad = {.aca = aca};
        struct pattern_match_data pmd = {
                .table = audio_file_table,
                .loop_col_num = AFTCOL_HASH,
                .match_col_num = AFTCOL_PATH,
                .pm_flags = PM_SKIP_EMPTY_NAME,
                .data = &cad,
                .action = change_atts
        };
        unsigned num_inputs;

        ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
        assert(ret >= 0);
        pmd.lpr = aca->lpr;

        num_inputs = lls_num_inputs(aca->lpr);
        for (i = 0; i < num_inputs; i++) {
                unsigned char bitnum;
                uint64_t one = 1;
                const char *arg = lls_input(i, aca->lpr);
                char c, *p;
                size_t len = strlen(arg);

                ret = -E_ATTR_SYNTAX;
                if (len == 0)
                        goto out;
                c = arg[len - 1];
                if (c != '+' && c != '-') {
                        if (cad.add_mask == 0 && cad.del_mask == 0)
                                goto out; /* no attribute modifier given */
                        goto set_atts;
                }
                p = alloc(len);
                memcpy(p, arg, len - 1);
                p[len - 1] = '\0';
                ret = get_attribute_bitnum_by_name(p, &bitnum);
                free(p);
                if (ret < 0) {
                        afs_error(aca, "invalid argument: %s\n", arg);
                        goto out;
                }
                if (c == '+')
                        cad.add_mask |= (one << bitnum);
                else
                        cad.del_mask |= (one << bitnum);
        }
        /* no pattern given */
        ret = -E_ATTR_SYNTAX;
        goto out;
set_atts:
        pmd.input_skip = i;
        ret = for_each_matching_row(&pmd);
        if (ret >= 0 && pmd.num_matches == 0)
                ret = -E_NO_MATCH;
out:
        lls_free_parse_result(aca->lpr, cmd);
        return ret;
}

static int com_setatt(struct command_context *cc, struct lls_parse_result *lpr)
{
        const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SETATT);
        char *errctx;
        int ret = lls(lls_check_arg_count(lpr, 2, INT_MAX, &errctx));

        if (ret < 0) {
                send_errctx(cc, errctx);
                return ret;
        }
        return send_lls_callback_request(com_setatt_callback, cmd, lpr, cc);
}
EXPORT_SERVER_CMD_HANDLER(setatt);

static int afs_stat_callback(struct afs_callback_arg *aca)
{
        int *parser_friendly = aca->query.data;
        char *buf = *parser_friendly?
                parser_friendly_status_items : status_items;

        if (!buf)
                return 0;
        return pass_buffer_as_shm(aca->fd, SBD_OUTPUT, buf, strlen(buf));
}

/**
 * Get the current afs status items from the afs process and send it.
 *
 * \param cc The command context, used e.g. for data encryption.
 * \param parser_friendly Whether parser-friendly output format should be used.
 *
 * As the contents of the afs status items change in time and the command
 * handler only has a COW version created at fork time, it can not send
 * up-to-date afs status items directly. Therefore the usual callback mechanism
 * is used to pass the status items from the afs process to the command handler
 * via a shared memory area and a pipe.
 *
 * \return The return value of the underlying call to \ref send_callback_request().
 */
int send_afs_status(struct command_context *cc, int parser_friendly)
{
        struct osl_object query = {.data = &parser_friendly,
                .size = sizeof(parser_friendly)};

        return send_callback_request(afs_stat_callback, &query,
                afs_cb_result_handler, cc);
}

/* returns success on non-fatal errors to keep the loop going */
static int check_audio_file(struct osl_row *row, void *data)
{
        char *path;
        struct para_buffer *pb = data;
        struct stat statbuf;
        int ret = get_audio_file_path_of_row(row, &path);
        struct afs_info afsi;
        char *blob_name;

        if (ret < 0) {
                para_printf(pb, "%s\n", para_strerror(-ret));
                return ret;
        }
        if (stat(path, &statbuf) < 0)
                para_printf(pb, "%s: stat error (%s)\n", path, strerror(errno));
        else if (!S_ISREG(statbuf.st_mode))
                para_printf(pb, "%s: not a regular file\n", path);
        ret = get_afsi_of_row(row, &afsi);
        if (ret < 0) {
                para_printf(pb, "%s: %s\n", path, para_strerror(-ret));
                return 1;
        }
        ret = lyr_get_name_by_id(afsi.lyrics_id, &blob_name);
        if (ret < 0)
                para_printf(pb, "%s lyrics id %u: %s\n", path, afsi.lyrics_id,
                        para_strerror(-ret));
        ret = img_get_name_by_id(afsi.image_id, &blob_name);
        if (ret < 0)
                para_printf(pb, "%s image id %u: %s\n", path, afsi.image_id,
                        para_strerror(-ret));
        return 0;
}

/**
 * Check the audio file table for inconsistencies.
 *
 * \param aca Only ->pbout is used for diagnostics.
 *
 * \return Standard. Inconsistencies are reported but not regarded as an error.
 */
int aft_check_callback(struct afs_callback_arg *aca)
{
        para_printf(&aca->pbout, "checking audio file table...\n");
        return audio_file_loop(&aca->pbout, check_audio_file);
}

struct aft_check_atts_data {
        uint64_t att_mask;
        struct para_buffer *pb;
};

static int check_atts_of_audio_file(struct osl_row *row, void *data)
{
        struct aft_check_atts_data *acad = data;
        int ret;
        struct afs_info afsi;
        char *path;
        uint64_t bad_bits;

        ret = get_afsi_of_row(row, &afsi);
        if (ret < 0) {
                para_printf(acad->pb, "cannot get afsi\n");
                return ret;
        }
        bad_bits = afsi.attributes & ~acad->att_mask;
        if (bad_bits == 0) /* OK */
                return 0;
        ret = get_audio_file_path_of_row(row, &path);
        if (ret < 0) {
                para_printf(acad->pb, "cannot get path\n");
                return ret;
        }
        para_printf(acad->pb, "invalid attribute bits (%" PRIu64 "): %s\n",
                bad_bits, path);
        /* return success to keep looping */
        return 1;
}

/**
 * Iterate over all audio files and check the attribute bit mask.
 *
 * \param att_mask The mask of all valid attributes.
 * \param pb Used for reporting inconsistencies.
 *
 * This reads the attribute bit mask of each audio file from the afs info
 * structure stored in the audio file table and verifies that all set bits are
 * also turned on in \a att_mask, i.e., correspond to an attribute of the
 * attribute table. Audio files for which this is not the case are reported via
 * \a pb.
 *
 * \return Standard. Inconsistencies are not regarded as errors.
 *
 * \sa \ref attribute_check_callback().
 */
int aft_check_attributes(uint64_t att_mask, struct para_buffer *pb)
{
        struct aft_check_atts_data acad = {.att_mask = att_mask, .pb = pb};

        para_printf(pb, "checking attributes, mask: %" PRIx64 "\n", att_mask);
        return audio_file_loop(&acad, check_atts_of_audio_file);
}

/*
 * This sets audio_file_table to NULL, but leaves current_aft_row unmodified,
 * though stale (pointing to unmapped memory). If the table is being closed
 * because we received SIGHUP, the table will be reopened after the config file
 * has been reloaded. We remember the hash of the current audio file here so
 * that aft_open() can initialize current_aft_row by looking up the saved hash.
 */
static void aft_close(void)
{
        int ret;
        unsigned char *p;

        if (current_aft_row) {
                ret = get_hash_of_row(current_aft_row, &p);
                if (ret < 0) {
                        PARA_WARNING_LOG("hash lookup failure\n");
                        current_aft_row = NULL;
                } else
                        memcpy(current_hash, p, HASH2_SIZE);
        }
        osl_close_table(audio_file_table, OSL_MARK_CLEAN);
        audio_file_table = NULL;
}

static int aft_open(const char *dir)
{
        int ret;

        audio_file_table_desc.dir = dir;
        ret = osl(osl_open_table(&audio_file_table_desc, &audio_file_table));
        if (ret >= 0) {
                unsigned num;
                osl_get_num_rows(audio_file_table, &num);
                PARA_INFO_LOG("audio file table contains %u files\n", num);
                if (!current_aft_row) {
                        PARA_DEBUG_LOG("no current aft row\n");
                        return 1;
                }
                /* SIGHUP case, update current_aft_row */
                ret = aft_get_row_of_hash(current_hash, &current_aft_row);
                if (ret < 0) { /* not fatal */
                        PARA_WARNING_LOG("current hash lookup failure: %s\n",
                                para_strerror(-ret));
                        current_aft_row = NULL;
                        return 1;
                }
                PARA_NOTICE_LOG("current audio file hash lookup: success\n");
                return 1;
        }
        audio_file_table = NULL;
        if (ret == -OSL_ERRNO_TO_PARA_ERROR(E_OSL_NOENT)) {
                PARA_WARNING_LOG("no audio file table\n");
                return 1;
        }
        PARA_NOTICE_LOG("failed to open audio file table\n");
        return ret;
}

static int aft_create(const char *dir)
{
        audio_file_table_desc.dir = dir;
        return osl(osl_create_table(&audio_file_table_desc));
}

static int clear_attribute(struct osl_row *row, void *data)
{
        struct rmatt_event_data *red = data;
        struct afs_info afsi;
        struct osl_object obj;
        int ret = get_afsi_object_of_row(row, &obj);
        uint64_t mask = ~(1ULL << red->bitnum);

        if (ret < 0)
                return ret;
        ret = load_afsi(&afsi, &obj);
        if (ret < 0)
                return ret;
        afsi.attributes &= mask;
        save_afsi(&afsi, &obj);
        return 1;
}

static int aft_event_handler(enum afs_events event, struct para_buffer *pb,
                void *data)
{
        int ret;

        switch (event) {
        case ATTRIBUTE_REMOVE: {
                const struct rmatt_event_data *red = data;
                para_printf(pb, "clearing attribute %s (bit %u) from all "
                        "entries in the audio file table\n", red->name,
                        red->bitnum);
                return audio_file_loop(data, clear_attribute);
        } case AFSI_CHANGE: {
                struct afsi_change_event_data *aced = data;
                uint64_t old_last_played = status_item_ls_data.afsi.last_played;
                if (aced->aft_row != current_aft_row)
                        return 0;
                ret = get_afsi_of_row(aced->aft_row, &status_item_ls_data.afsi);
                if (ret < 0)
                        return ret;
                status_item_ls_data.afsi.last_played = old_last_played;
                make_status_items();
                return 1;
        } case AUDIO_FILE_RENAME: {
                char *path;
                if (data != current_aft_row)
                        return 0;
                ret = get_audio_file_path_of_row(current_aft_row, &path);
                if (ret < 0)
                        return ret;
                free(status_item_ls_data.path);
                status_item_ls_data.path = para_strdup(path);
                make_status_items();
                return 1;
        } case AFHI_CHANGE: {
                if (data != current_aft_row)
                        return 0;
                ret = get_afhi_of_row(data, &status_item_ls_data.afhi);
                if (ret < 0)
                        return ret;
                make_status_items();
                return 1;
        } case AUDIO_FILE_REMOVE: {
                if (data == current_aft_row)
                        current_aft_row = NULL;
                return 0;
        }
        case BLOB_RENAME:
        case BLOB_REMOVE:
        case BLOB_ADD: {
                /*
                 * These events are rare. We don't bother to check whether the
                 * current status items are affected and simply recreate them
                 * whenever an audio file is open.
                 */
                if (!current_aft_row)
                        return 0;
                ret = get_afhi_of_row(current_aft_row,
                        &status_item_ls_data.afhi);
                if (ret < 0)
                        return ret;
                make_status_items();
                return 0;
        } default:
                return 0;
        }
}

/** The audio file table contains information about known audio files. */
const struct afs_table_operations aft_ops = {
        .open = aft_open,
        .close = aft_close,
        .create = aft_create,
        .event_handler = aft_event_handler,
};