[paraslash.git] / aft.c

/*
 * Copyright (C) 2007 Andre Noll <maan@systemlinux.org>
 *
 * Licensed under the GPL v2. For licencing details see COPYING.
 */

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

#include <dirent.h> /* readdir() */
#include "para.h"
#include "error.h"
#include "string.h"
#include <sys/mman.h>
#include <fnmatch.h>
#include "afh.h"
#include "afs.h"
#include "net.h"
#include "vss.h"
#include "fd.h"
#include "ipc.h"

static struct osl_table *audio_file_table;

/** The different sorting methods of the ls command. */
enum ls_sorting_method {
        /** -sp (default) */
        LS_SORT_BY_PATH,
        /** -ss */
        LS_SORT_BY_SCORE,
        /** -sl */
        LS_SORT_BY_LAST_PLAYED,
        /** -sn */
        LS_SORT_BY_NUM_PLAYED,
        /** -sf */
        LS_SORT_BY_FREQUENCY,
        /** -sc */
        LS_SORT_BY_CHANNELS,
        /** -si */
        LS_SORT_BY_IMAGE_ID,
        /** -sy */
        LS_SORT_BY_LYRICS_ID,
        /** -sb */
        LS_SORT_BY_BITRATE,
        /** -sd */
        LS_SORT_BY_DURATION,
        /** -sa */
        LS_SORT_BY_AUDIO_FORMAT,
        /** -sh */
        LS_SORT_BY_HASH,
};

/** The different listing modes of the ls command. */
enum ls_listing_mode {
        /** Default listing mode. */
        LS_MODE_SHORT,
        /** -l or -ll */
        LS_MODE_LONG,
        /** -lv */
        LS_MODE_VERBOSE,
        /** -lm */
        LS_MODE_MBOX
};

/** The flags accepted by the ls command. */
enum ls_flags {
        /** -p */
        LS_FLAG_FULL_PATH = 1,
        /** -a */
        LS_FLAG_ADMISSIBLE_ONLY = 2,
        /** -r */
        LS_FLAG_REVERSE = 4,
};

/**
 * The size of the individual output fields of the ls command.
 *
 * These depend on the actual content being listed. If, for instance only files
 * with duration less than an hour are being listed, then the duration with is
 * made smaller because then the duration is listed as mm:ss rather than
 * 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;
};

/** Data passed from the ls command handler to its callback function. */
struct ls_options {
        /** The given command line flags. */
        unsigned flags;
        /** The sorting method given at the command line. */
        enum ls_sorting_method sorting;
        /** The given listing mode (short, long, verbose, mbox). */
        enum ls_listing_mode mode;
        /** The arguments passed to the ls command. */
        char **patterns;
        /** Number of non-option arguments. */
        int num_patterns;
        /** 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 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,
        /** 3 bytes reserved space for future usage. */
        AFSI_AUDIO_FORMAT_UNUSED_OFFSET = 29,
        /** 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 load_afsi().
 */
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);
        memset(buf + AFSI_AUDIO_FORMAT_UNUSED_OFFSET, 0, 3);
}

/**
 *  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 Positive on success, negative on errors. Possible errors: \p E_BAD_AFS.
 *
 * \sa save_afsi().
 */
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);
        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
};

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 = osl_hash_compare,
                .data_size = HASH_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
};

/* We don't want * dot or dot-dot anywhere. */
static int verify_dotfile(const char *rest)
{
        /*
         * The first character was '.', but that has already been discarded, we
         * now test the rest.
         */
        switch (*rest) {
        case '\0': case '/': /* /foo/. and /foo/./bar are not ok */
                return -1;
        case '.': /* path start with /foo/.. */
                if (rest[1] == '\0' || rest[1] == '/')
                        return -1; /* /foo/.. or /foo/../bar are not ok */
                /* /foo/..bar is ok */
        }
        return 1;
}

/*
 * We fundamentally don't like some paths: We don't want double slashes or
 * slashes at the end that can make pathnames ambiguous.
 */
static int verify_path(const char *orig_path, char **resolved_path)
{
        char c;
        size_t len;
        char *path;

        if (*orig_path != '/') /* we only accept absolute paths */
                return -E_BAD_PATH;
        len = strlen(orig_path);
        *resolved_path = para_strdup(orig_path);
        path = *resolved_path;
        while (len > 1 && path[--len] == '/')
                path[len] = '\0'; /* remove slash at the end */
        c = *path++;
        while (c) {
                if (c == '/') {
                        c = *path++;
                        switch (c) {
                        case '/': /* double slash */
                                goto bad_path;
                        case '.':
                                if (verify_dotfile(path) < 0)
                                        goto bad_path;
                        default:
                                continue;
                        }
                }
                c = *path++;
        }
        return 1;
bad_path:
        free(*resolved_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,
        /** Location of the audio file header. */
        AFHI_HEADER_OFFSET_OFFSET = 12,
        /* Length of the audio file header. Zero means: No header. */
        AFHI_HEADER_LEN_OFFSET = 16,
        /** Number of channels is stored here. */
        AFHI_CHANNELS_OFFSET = 20,
        /** EOF timeout in ms. */
        AFHI_EOF_OFFSET = 21,
        /** The tag info position. */
        AFHI_INFO_STRING_OFFSET = 23,
        /** Minimal on-disk size of a valid afhi struct. */
        MIN_AFHI_SIZE = 24
};

static unsigned sizeof_afhi_buf(const struct afh_info *afhi)
{
        if (!afhi)
                return 0;
        return strlen(afhi->info_string) + MIN_AFHI_SIZE;
}

static void save_afhi(struct afh_info *afhi, char *buf)
{
        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_HEADER_OFFSET_OFFSET, afhi->header_offset);
        write_u32(buf + AFHI_HEADER_LEN_OFFSET, afhi->header_len);
        write_u8(buf + AFHI_CHANNELS_OFFSET, afhi->channels);
        write_u16(buf + AFHI_EOF_OFFSET, tv2ms(&afhi->eof_tv));
        strcpy(buf + AFHI_INFO_STRING_OFFSET, afhi->info_string); /* OK */
        PARA_DEBUG_LOG("last byte written: %p\n", buf + AFHI_INFO_STRING_OFFSET + strlen(afhi->info_string));
}

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->channels = read_u8(buf + AFHI_CHANNELS_OFFSET);
        afhi->header_offset = read_u32(buf + AFHI_HEADER_OFFSET_OFFSET);
        afhi->header_len = read_u32(buf + AFHI_HEADER_LEN_OFFSET);
        ms2tv(read_u16(buf + AFHI_EOF_OFFSET), &afhi->eof_tv);
        strcpy(afhi->info_string, buf + AFHI_INFO_STRING_OFFSET);
}

//#define SIZEOF_CHUNK_TABLE(afhi) (((afhi)->chunks_total + 1) * sizeof(uint32_t))

static unsigned sizeof_chunk_info_buf(struct afh_info *afhi)
{
        if (!afhi)
                return 0;
        return 4 * (afhi->chunks_total + 1) + 20;

}

/** The offsets of the data contained in the AFTCOL_CHUNKS column. */
enum chunk_info_offsets{
        /** The total number of chunks (4 bytes). */
        CHUNKS_TOTAL_OFFSET = 0,
        /** The length of the audio file header (4 bytes). */
        HEADER_LEN_OFFSET = 4,
        /** The start of the audio file header (4 bytes). */
        HEADER_OFFSET_OFFSET = 8,
        /** The seconds part of the chunk time (4 bytes). */
        CHUNK_TV_TV_SEC_OFFSET = 12,
        /** The microseconds part of the chunk time (4 bytes). */
        CHUNK_TV_TV_USEC = 16,
        /** Chunk table entries start here. */
        CHUNK_TABLE_OFFSET = 20,
};

static void save_chunk_table(struct afh_info *afhi, char *buf)
{
        int i;

        PARA_DEBUG_LOG("%lu chunks\n", afhi->chunks_total);
        for (i = 0; i <= afhi->chunks_total; i++)
                write_u32(buf + 4 * i, afhi->chunk_table[i]);
}

static void load_chunk_table(struct afh_info *afhi, char *buf)
{
        int i;
        for (i = 0; i <= afhi->chunks_total; i++)
                afhi->chunk_table[i] = read_u32(buf + 4 * i);
}

/* TODO: audio format handlers could just produce this */
static void save_chunk_info(struct afh_info *afhi, char *buf)
{
        if (!afhi)
                return;
        write_u32(buf + CHUNKS_TOTAL_OFFSET, afhi->chunks_total);
        write_u32(buf + HEADER_LEN_OFFSET, afhi->header_len);
        write_u32(buf + HEADER_OFFSET_OFFSET, afhi->header_offset);
        write_u32(buf + CHUNK_TV_TV_SEC_OFFSET, afhi->chunk_tv.tv_sec);
        write_u32(buf + CHUNK_TV_TV_USEC, afhi->chunk_tv.tv_usec);
        save_chunk_table(afhi, buf + CHUNK_TABLE_OFFSET);
}

static int load_chunk_info(struct osl_object *obj, struct afh_info *afhi)
{
        char *buf = obj->data;

        if (obj->size < CHUNK_TABLE_OFFSET)
                return -E_BAD_DATA_SIZE;

        afhi->chunks_total = read_u32(buf + CHUNKS_TOTAL_OFFSET);
        afhi->header_len = read_u32(buf + HEADER_LEN_OFFSET);
        afhi->header_offset = read_u32(buf + HEADER_OFFSET_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);

        if ((afhi->chunks_total + 1) * 4 + CHUNK_TABLE_OFFSET > obj->size)
                return -E_BAD_DATA_SIZE;
        afhi->chunk_table = para_malloc((afhi->chunks_total + 1) * 4);
        load_chunk_table(afhi, buf + CHUNK_TABLE_OFFSET);
        return 1;
}

/**
 * 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 The return value of the underlying call to osl_get_row().
 */
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_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 resul pointer.
 *
 * \return The return value of the underlying call to osl_get_row().
 */
int aft_get_row_of_hash(HASH_TYPE *hash, struct osl_row **row)
{
        const struct osl_object obj = {.data = hash, .size = HASH_SIZE};
        return osl_get_row(audio_file_table, AFTCOL_HASH, &obj, row);
}

/**
 * Get the osl object holding the audio file selector info of a row.
 *
 * \param row Pointer to a row in the audio file table.
 * \param obj Result pointer.
 *
 * \return The return value of the underlying call to osl_get_object().
 */
int get_afsi_object_of_row(const struct osl_row *row, struct osl_object *obj)
{
        return 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.
 */
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 Positive on success, negative on errors.
 */
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 mmapped 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_get_object(audio_file_table, row, AFTCOL_PATH,
                &path_obj);
        if (ret < 0)
                return ret;
        *path = path_obj.data;
        return 1;
}

/**
 * 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 get_hash_of_row().
 */
static int get_hash_object_of_aft_row(const struct osl_row *row, struct osl_object *obj)
{
        return 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, HASH_TYPE **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().
 *
 * \sa get_chunk_table_of_row().
 */
int get_afhi_of_row(const struct osl_row *row, struct afh_info *afhi)
{
        struct osl_object obj;
        int ret = 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)
                + 4 * (afd->afhi.chunks_total + 1);

        PARA_DEBUG_LOG("size: %zu\n", size);
        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;
        *(struct audio_file_data *)shm_afd = *afd;
        buf = shm_afd;
        buf += sizeof(*afd);
        save_chunk_table(&afd->afhi, buf);
        shm_detach(shm_afd);
        return shmid;
err:
        shm_destroy(shmid);
        return ret;
}

int load_afd(int shmid, struct audio_file_data *afd)
{
        void *shm_afd;
        char *buf;
        int ret;

        ret = shm_attach(shmid, ATTACH_RO, &shm_afd);
        if (ret < 0)
                return ret;
        *afd = *(struct audio_file_data *)shm_afd;
        buf = shm_afd;
        buf += sizeof(*afd);
        afd->afhi.chunk_table = para_malloc((afd->afhi.chunks_total + 1) * 4);
        load_chunk_table(&afd->afhi, buf);
        shm_detach(shm_afd);
        return 1;
}

/**
 * Mmap the given audio file and update statistics.
 *
 * \param aft_row Determines the audio file to be opened and updated.
 * \param afd Result pointer.
 *
 * 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 on success, negative on errors.
 */
int open_and_update_audio_file(struct osl_row *aft_row, struct audio_file_data *afd)
{
        HASH_TYPE *aft_hash, file_hash[HASH_SIZE];
        struct osl_object afsi_obj;
        struct afs_info new_afsi;
        int ret = get_hash_of_row(aft_row, &aft_hash);
        struct afsi_change_event_data aced;
        struct osl_object map, chunk_table_obj;
        char *tmp, *path;

        if (ret < 0)
                return ret;
        ret = get_audio_file_path_of_row(aft_row, &path);
        if (ret < 0)
                return ret;
        strncpy(afd->path, path, sizeof(afd->path) - 1);
        afd->path[sizeof(afd->path) - 1] = '\0';
        ret = get_afsi_object_of_row(aft_row, &afsi_obj);
        if (ret < 0)
                return ret;
        ret = load_afsi(&afd->afsi, &afsi_obj);
        if (ret < 0)
                return ret;
        ret = get_afhi_of_row(aft_row, &afd->afhi);
        if (ret < 0)
                return ret;
        ret = osl_open_disk_object(audio_file_table, aft_row,
                AFTCOL_CHUNKS, &chunk_table_obj);
        if (ret < 0)
                return ret;
        ret = mmap_full_file(path, O_RDONLY, &map.data,
                &map.size, &afd->fd);
        if (ret < 0)
                goto err;
        hash_function(map.data, map.size, file_hash);
        ret = hash_compare(file_hash, aft_hash);
        para_munmap(map.data, map.size);
        if (ret) {
                ret = -E_HASH_MISMATCH;
                goto err;
        }
        new_afsi = afd->afsi;
        new_afsi.num_played++;
        new_afsi.last_played = time(NULL);
        save_afsi(&new_afsi, &afsi_obj); /* in-place update */

        ret = load_chunk_info(&chunk_table_obj, &afd->afhi);
        if (ret < 0)
                goto err;
        ret = get_attribute_text(&afd->afsi.attributes, " ", &tmp);
        if (ret < 0)
                goto err;
        assert(tmp);
        strncpy(afd->attributes_string, tmp, sizeof(afd->attributes_string));
        afd->attributes_string[sizeof(afd->attributes_string) - 1] = '\0';
        free(tmp);

        {
                struct ls_data d = {
                        .afhi = afd->afhi,
                        .afsi = afd->afsi,
                        .path = path,
                        .score = afd->score,
                        .hash = file_hash
                };
                struct para_buffer pb = {.buf = NULL};
                ret = make_status_items(&d, &pb);
                if (ret < 0)
                        goto err;
                strncpy(afd->afs_status_info, pb.buf, AFS_STATUS_INFO_SIZE);
                afd->afs_status_info[AFS_STATUS_INFO_SIZE] = '\0';
                free(pb.buf);
        }
        aced.aft_row = aft_row;
        aced.old_afsi = &afd->afsi;
        afs_event(AFSI_CHANGE, NULL, &aced);
        ret = save_afd(afd);
        if (ret < 0)
                goto err;
        free(afd->afhi.chunk_table);
err:
        osl_close_disk_object(&chunk_table_obj);
        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 t;

        if (!localtime_r((time_t *)seconds, &t))
                return -E_LOCALTIME;
        if (lm == LS_MODE_MBOX) {
                if (!strftime(buf, size, "%c", &t))
                        return -E_STRFTIME;
                return 1;
        }
        if (*seconds + 6 * 30 * 24 * 3600 > current_time) {
                if (!strftime(buf, size, "%b %e %k:%M", &t))
                        return -E_STRFTIME;
                return 1;
        }
        if (!strftime(buf, size, "%b %e  %Y", &t))
                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 ((x)) \
                while ((_tmp) > 9) { \
                        (_tmp) /= 10; \
                        (*num)++; \
                } \
        }

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, short unsigned max_width)
{
        unsigned hours = seconds / 3600, mins = (seconds % 3600) / 60;

        if (!hours) /* m:ss or mm:ss */
                sprintf(buf, "%*u:%02u", max_width - 3, mins, seconds % 60);
        else /* more than one hour => h:mm:ss, hh:mm:ss, hhh:mm:ss, ... */
                sprintf(buf, "%*u:%02u:%02u", max_width - 6, hours, mins,
                        seconds % 60);
}

static char *make_attribute_lines(const char *att_bitmap, struct afs_info *afsi)
{
        char *att_text, *att_lines;

        get_attribute_text(&afsi->attributes, " ", &att_text);
        if (!att_text)
                return para_strdup(att_bitmap);
        att_lines = make_message("%s\nattributes_txt: %s",
                att_bitmap, att_text);
        free(att_text);
        return att_lines;
}

static char *make_lyrics_line(struct afs_info *afsi)
{
        char *lyrics_name;

        lyr_get_name_by_id(afsi->lyrics_id, &lyrics_name);
        if (!lyrics_name)
                return make_message("%u", afsi->lyrics_id);
        return make_message("%u (%s)", afsi->lyrics_id, lyrics_name);
}

static char *make_image_line(struct afs_info *afsi)
{
        char *image_name;
        img_get_name_by_id(afsi->image_id, &image_name);
        if (!image_name)
                return make_message("%u", afsi->image_id);
        return make_message("%u (%s)", afsi->image_id, image_name);
}

static int print_list_item(struct ls_data *d, struct ls_options *opts,
        struct para_buffer *b, time_t current_time)
{
        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 */
        char score_buf[30] = "";
        struct afs_info *afsi = &d->afsi;
        struct afh_info *afhi = &d->afhi;
        struct ls_widths *w = &opts->widths;
        int have_score = opts->flags & LS_FLAG_ADMISSIBLE_ONLY;
        char asc_hash[2 * HASH_SIZE + 1];
        char *att_lines, *lyrics_line, *image_line;

        if (opts->mode == LS_MODE_SHORT) {
                para_printf(b, "%s\n", d->path);
                return 1;
        }
        get_attribute_bitmap(&afsi->attributes, att_buf);
        ret = get_local_time(&afsi->last_played, last_played_time,
                sizeof(last_played_time), current_time, opts->mode);
        if (ret < 0)
                return ret;
        get_duration_buf(afhi->seconds_total, duration_buf, w->duration_width);
        if (have_score) {
                if (opts->mode == LS_MODE_LONG)
                        sprintf(score_buf, "%*li ", w->score_width, d->score);
                else
                        sprintf(score_buf, "%li ", d->score);
        }

        if (opts->mode == LS_MODE_LONG) {
                para_printf(b,
                        "%s"    /* score */
                        "%s "   /* attributes */
                        "%*d "  /* image_id  */
                        "%*d "  /* lyrics_id */
                        "%*d "  /* bitrate */
                        "%s "   /* audio format */
                        "%*d "  /* frequency */
                        "%d "   /* channels */
                        "%s "   /* duration */
                        "%*d "  /* num_played */
                        "%s "   /* last_played */
                        "%s\n", /* path */
                        score_buf,
                        att_buf,
                        w->image_id_width, afsi->image_id,
                        w->lyrics_id_width, afsi->lyrics_id,
                        w->bitrate_width, afhi->bitrate,
                        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
                );
                return 1;
        }
        hash_to_asc(d->hash, asc_hash);
        att_lines = make_attribute_lines(att_buf, afsi);
        lyrics_line = make_lyrics_line(afsi);
        image_line = make_image_line(afsi);
        if (opts->mode == LS_MODE_VERBOSE) {
                para_printf(b,
                        "%s: %s\n" /* path */
                        "%s%s%s" /* score */
                        "attributes: %s\n"
                        "hash: %s\n"
                        "image_id: %s\n"
                        "lyrics_id: %s\n"
                        "bitrate: %dkbit/s\n"
                        "format: %s\n"
                        "frequency: %dHz\n"
                        "channels: %d\n"
                        "duration: %s\n"
                        "num_played: %d\n"
                        "last_played: %s\n"
                        "tag info: %s\n",
                        (opts->flags & LS_FLAG_FULL_PATH)?
                                "path" : "file", d->path,
                        have_score? "score: " : "", score_buf,
                                have_score? "\n" : "",
                        att_lines,
                        asc_hash,
                        image_line,
                        lyrics_line,
                        afhi->bitrate,
                        audio_format_name(afsi->audio_format_id),
                        afhi->frequency,
                        afhi->channels,
                        duration_buf,
                        afsi->num_played,
                        last_played_time,
                        afhi->info_string
                );
        } else { /* mbox mode */
                struct osl_object lyrics_def;
                lyr_get_def_by_id(afsi->lyrics_id, &lyrics_def);
                para_printf(b,
                        "From foo@localhost %s\n"
                        "Received: from\nTo: bar\nFrom: a\n"
                        "Subject: %s\n\n" /* path */
                        "%s%s%s" /* score */
                        "%s\n" /* attributes */
                        "hash: %s\n"
                        "image_id: %s\n"
                        "lyrics_id: %s\n"
                        "bitrate: %dkbit/s\n"
                        "format: %s\n"
                        "frequency: %dHz\n"
                        "channels: %d\n"
                        "duration: %s\n"
                        "num_played: %d\n"
                        "tag info: %s\n"
                        "%s%s\n",
                        last_played_time,
                        d->path,
                        have_score? "score: " : "", score_buf,
                                have_score? "\n" : "",
                        att_lines,
                        asc_hash,
                        image_line,
                        lyrics_line,
                        afhi->bitrate,
                        audio_format_name(afsi->audio_format_id),
                        afhi->frequency,
                        afhi->channels,
                        duration_buf,
                        afsi->num_played,
                        afhi->info_string,
                        lyrics_def.data? "Lyrics:\n~~~~~~~\n" : "",
                        lyrics_def.data? (char *)lyrics_def.data : ""
                );
                if (lyrics_def.data)
                        osl_close_disk_object(lyrics_def.data);
        }
        free(att_lines);
        free(lyrics_line);
        free(image_line);
        return 1;
}

int make_status_items(struct ls_data *d, struct para_buffer *pb)
{
        struct ls_options opts = {
                .flags = LS_FLAG_FULL_PATH | LS_FLAG_ADMISSIBLE_ONLY,
                .mode = LS_MODE_VERBOSE,
        };
        time_t current_time;

        time(&current_time);
        return print_list_item(d, &opts, pb, current_time);
}


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 int sort_matching_paths(struct ls_options *options)
{
        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 = para_malloc(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 (options->sorting == LS_SORT_BY_PATH
                && !(options->flags & LS_FLAG_ADMISSIBLE_ONLY)
                && (options->flags & LS_FLAG_FULL_PATH))
                return 1;
        if (options->sorting == LS_SORT_BY_SCORE &&
                        options->flags & LS_FLAG_ADMISSIBLE_ONLY)
                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;
        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;
        struct ls_data *d;
        struct ls_widths *w;
        unsigned short num_digits;
        unsigned tmp;
        struct osl_row *aft_row;
        long score;
        char *path;

        if (options->flags & LS_FLAG_ADMISSIBLE_ONLY) {
                ret = get_score_and_aft_row(row, &score, &aft_row);
                if (ret < 0)
                        return ret;
        } else
                aft_row = row;
        ret = get_audio_file_path_of_row(aft_row, &path);
        if (ret < 0)
                return ret;
        if (!(options->flags & LS_FLAG_FULL_PATH)) {
                char *p = strrchr(path, '/');
                if (p)
                        path = p + 1;
        }
        if (options->num_patterns) {
                for (i = 0; i < options->num_patterns; i++) {
                        ret = fnmatch(options->patterns[i], path, 0);
                        if (!ret)
                                break;
                        if (ret == FNM_NOMATCH)
                                continue;
                        return -E_FNMATCH;
                }
                if (i >= options->num_patterns) /* 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 = para_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)
                return ret;
        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 */
        tmp = get_duration_width(d->afhi.seconds_total);
        w->duration_width = PARA_MAX(w->duration_width, tmp);
        if (options->flags & LS_FLAG_ADMISSIBLE_ONLY) {
                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;
}

static int com_ls_callback(const struct osl_object *query,
                struct osl_object *ls_output)
{
        struct ls_options *opts = query->data;
        char *p, *pattern_start = (char *)query->data + sizeof(*opts);
        struct para_buffer b = {.buf = NULL, .size = 0};
        int i = 0, ret;
        time_t current_time;


        if (opts->num_patterns) {
                opts->patterns = para_malloc(opts->num_patterns * sizeof(char *));
                for (i = 0, p = pattern_start; i < opts->num_patterns; i++) {
                        opts->patterns[i] = p;
                        p += strlen(p) + 1;
                }
        } else
                opts->patterns = NULL;
        if (opts->flags & LS_FLAG_ADMISSIBLE_ONLY)
                ret = admissible_file_loop(opts, prepare_ls_row);
        else
                ret = osl_rbtree_loop(audio_file_table, AFTCOL_PATH, opts,
                        prepare_ls_row);
        if (ret < 0)
                goto out;
        ret = opts->num_patterns? -E_NO_MATCH : 0;
        if (!opts->num_matching_paths)
                goto out;
        ret = sort_matching_paths(opts);
        if (ret < 0)
                goto out;
        time(&current_time);
        if (opts->flags & LS_FLAG_REVERSE)
                for (i = opts->num_matching_paths - 1; i >= 0; i--) {
                        ret = print_list_item(opts->data_ptr[i], opts, &b, current_time);
                        if (ret < 0)
                                break;
                }
        else
                for (i = 0; i < opts->num_matching_paths; i++) {
                        ret = print_list_item(opts->data_ptr[i], opts, &b, current_time);
                        if (ret < 0)
                                break;
                }
        ret = 1;
out:
        ls_output->data = b.buf;
        ls_output->size = b.size;
        free(opts->data);
        free(opts->data_ptr);
        free(opts->patterns);
        return ret;
}

/*
 * TODO: flags -h (sort by hash)
 */
int com_ls(int fd, int argc, char * const * const argv)
{
        int i, ret;
        unsigned flags = 0;
        enum ls_sorting_method sort = LS_SORT_BY_PATH;
        enum ls_listing_mode mode = LS_MODE_SHORT;
        struct ls_options opts = {.patterns = NULL};
        struct osl_object query = {.data = &opts, .size = sizeof(opts)},
                ls_output;

        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
                if (arg[0] != '-')
                        break;
                if (!strcmp(arg, "--")) {
                        i++;
                        break;
                }
                if (!strncmp(arg, "-l", 2)) {
                        if (!*(arg + 2)) {
                                mode = LS_MODE_LONG;
                                continue;
                        }
                        if (*(arg + 3))
                                return -E_AFT_SYNTAX;
                        switch(*(arg + 2)) {
                        case 's':
                                mode = LS_MODE_SHORT;
                                continue;
                        case 'l':
                                mode = LS_MODE_LONG;
                                continue;
                        case 'v':
                                mode = LS_MODE_VERBOSE;
                                continue;
                        case 'm':
                                mode = LS_MODE_MBOX;
                                continue;
                        default:
                                return -E_AFT_SYNTAX;
                        }
                }
                if (!strcmp(arg, "-p")) {
                        flags |= LS_FLAG_FULL_PATH;
                        continue;
                }
                if (!strcmp(arg, "-a")) {
                        flags |= LS_FLAG_ADMISSIBLE_ONLY;
                        continue;
                }
                if (!strcmp(arg, "-r")) {
                        flags |= LS_FLAG_REVERSE;
                        continue;
                }
                if (!strncmp(arg, "-s", 2)) {
                        if (!*(arg + 2) || *(arg + 3))
                                return -E_AFT_SYNTAX;
                        switch(*(arg + 2)) {
                        case 'p':
                                sort = LS_SORT_BY_PATH;
                                continue;
                        case 's': /* -ss implies -a */
                                sort = LS_SORT_BY_SCORE;
                                flags |= LS_FLAG_ADMISSIBLE_ONLY;
                                continue;
                        case 'l':
                                sort = LS_SORT_BY_LAST_PLAYED;
                                continue;
                        case 'n':
                                sort = LS_SORT_BY_NUM_PLAYED;
                                continue;
                        case 'f':
                                sort = LS_SORT_BY_FREQUENCY;
                                continue;
                        case 'c':
                                sort = LS_SORT_BY_CHANNELS;
                                continue;
                        case 'i':
                                sort = LS_SORT_BY_IMAGE_ID;
                                continue;
                        case 'y':
                                sort = LS_SORT_BY_LYRICS_ID;
                                continue;
                        case 'b':
                                sort = LS_SORT_BY_BITRATE;
                                continue;
                        case 'd':
                                sort = LS_SORT_BY_DURATION;
                                continue;
                        case 'a':
                                sort = LS_SORT_BY_AUDIO_FORMAT;
                                continue;
                        default:
                                return -E_AFT_SYNTAX;
                        }
                }
                return -E_AFT_SYNTAX;
        }
        opts.flags = flags;
        opts.sorting = sort;
        opts.mode = mode;
        opts.num_patterns = argc - i;
        ret = send_option_arg_callback_request(&query, opts.num_patterns,
                argv + i, com_ls_callback, &ls_output);
        if (ret > 0) {
                ret = send_buffer(fd, (char *)ls_output.data);
                free(ls_output.data);
        }
        return ret;
}

/**
 * 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 The return value of the underlying call to osl_rbtree_loop().
 */
int audio_file_loop(void *private_data, osl_rbtree_loop_func *func)
{
        return osl_rbtree_loop(audio_file_table, AFTCOL_HASH, private_data,
                func);
}

static struct osl_row *find_hash_sister(HASH_TYPE *hash)
{
        const struct osl_object obj = {.data = hash, .size = HASH_SIZE};
        struct osl_row *row;

        osl_get_row(audio_file_table, AFTCOL_HASH, &obj, &row);
        return row;
}

enum aft_row_offsets {
        AFTROW_AFHI_OFFSET_POS = 0,
        AFTROW_CHUNKS_OFFSET_POS = 2,
        AFTROW_AUDIO_FORMAT_OFFSET = 4,
        AFTROW_FLAGS_OFFSET = 5,
        AFTROW_HASH_OFFSET = 9,
        AFTROW_PATH_OFFSET = (AFTROW_HASH_OFFSET + HASH_SIZE),
};

/* never save the afsi, as the server knows it too. Note that afhi might be NULL.
 * In this case, afhi won't be stored in the buffer  */
static void save_audio_file_info(HASH_TYPE *hash, const char *path,
                struct afh_info *afhi, uint32_t flags,
                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 = AFTROW_PATH_OFFSET + path_len + afhi_size
                + sizeof_chunk_info_buf(afhi);
        char *buf = para_malloc(size);
        uint16_t pos;

        write_u8(buf + AFTROW_AUDIO_FORMAT_OFFSET, audio_format_num);
        write_u32(buf + AFTROW_FLAGS_OFFSET, flags);

        memcpy(buf + AFTROW_HASH_OFFSET, hash, HASH_SIZE);
        strcpy(buf + AFTROW_PATH_OFFSET, path);

        pos = AFTROW_PATH_OFFSET + path_len;
        PARA_DEBUG_LOG("size: %zu, afhi starts at %d\n", size, pos);
        PARA_DEBUG_LOG("last afhi byte: %p, pos %zu\n", buf + pos + afhi_size - 1,
                pos + afhi_size - 1);
        write_u16(buf + AFTROW_AFHI_OFFSET_POS, pos);
        save_afhi(afhi, buf + pos);

        pos += afhi_size;
        PARA_DEBUG_LOG("size: %zu, chunks start at %d\n", size, pos);
        write_u16(buf + AFTROW_CHUNKS_OFFSET_POS, pos);
        save_chunk_info(afhi, buf + pos);
        PARA_DEBUG_LOG("last byte in buf: %p\n", buf + size - 1);
        obj->data = buf;
        obj->size = size;
}

/*
input:
~~~~~~
HS:     hash sister
PB:     path brother
F:      force flag given

output:
~~~~~~~
AFHI:   whether afhi and chunk table are computed and sent
ACTION: table modifications to be performed

+---+----+-----+------+---------------------------------------------------+
| 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
+---+----+-----+------+---------------------------------------------------+

afhi <=> force or no HS

*/

/** Flags passed to the add command. */
enum com_add_flags {
        /** Skip paths that exist already. */
        ADD_FLAG_LAZY = 1,
        /** Force adding. */
        ADD_FLAG_FORCE = 2,
        /** Print what is being done. */
        ADD_FLAG_VERBOSE = 4,
        /** Try to add files with unknown suffixes. */
        ADD_FLAG_ALL = 8,
};

static int com_add_callback(const struct osl_object *query,
                struct osl_object *result)
{
        char *buf = query->data, *path;
        struct osl_row *pb, *aft_row;
        struct osl_row *hs;
        struct osl_object objs[NUM_AFT_COLUMNS];
        HASH_TYPE *hash;
        char asc[2 * HASH_SIZE + 1];
        int ret;
        char afsi_buf[AFSI_SIZE];
        uint32_t flags = read_u32(buf + AFTROW_FLAGS_OFFSET);
        struct afs_info default_afsi = {.last_played = 0};
        struct para_buffer msg = {.buf = NULL};

        hash = (HASH_TYPE *)buf + AFTROW_HASH_OFFSET;
        hash_to_asc(hash, asc);;
        objs[AFTCOL_HASH].data = buf + AFTROW_HASH_OFFSET;
        objs[AFTCOL_HASH].size = HASH_SIZE;

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

        PARA_INFO_LOG("request to add %s\n", path);
        hs = find_hash_sister(hash);
        ret = aft_get_row_of_path(path, &pb);
        if (ret < 0 && ret != -E_RB_KEY_NOT_FOUND)
                return ret;
        if (hs && pb && hs == pb && !(flags & ADD_FLAG_FORCE)) {
                if (flags & ADD_FLAG_VERBOSE)
                        para_printf(&msg, "ignoring duplicate\n");
                ret = 1;
                goto out;
        }
        if (hs && hs != pb) {
                struct osl_object obj;
                if (pb) { /* hs trumps pb, remove pb */
                        if (flags & ADD_FLAG_VERBOSE)
                                para_printf(&msg, "removing path brother\n");
                        ret = osl_del_row(audio_file_table, pb);
                        if (ret < 0)
                                goto out;
                        pb = NULL;
                }
                /* file rename, update hs' path */
                if (flags & ADD_FLAG_VERBOSE) {
                        ret = osl_get_object(audio_file_table, hs,
                                AFTCOL_PATH, &obj);
                        if (ret < 0)
                                goto out;
                        para_printf(&msg, "renamed from %s\n", (char *)obj.data);
                }
                ret = osl_update_object(audio_file_table, hs, AFTCOL_PATH,
                        &objs[AFTCOL_PATH]);
                if (ret < 0)
                        goto out;
                afs_event(AUDIO_FILE_RENAME, &msg, hs);
                if (!(flags & ADD_FLAG_FORCE))
                        goto out;
        }
        /* no hs or force mode, child must have sent afhi */
        uint16_t afhi_offset = read_u16(buf + AFTROW_AFHI_OFFSET_POS);
        uint16_t chunks_offset = read_u16(buf + AFTROW_CHUNKS_OFFSET_POS);

        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 = query->size - chunks_offset;
        if (pb && !hs) { /* update pb's hash */
                char old_asc[2 * HASH_SIZE + 1];
                HASH_TYPE *old_hash;
                ret = get_hash_of_row(pb, &old_hash);
                if (ret < 0)
                        goto out;
                hash_to_asc(old_hash, old_asc);
                if (flags & ADD_FLAG_VERBOSE)
                        para_printf(&msg, "file change: %s -> %s\n",
                                old_asc, asc);
                ret = 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 (flags & ADD_FLAG_VERBOSE)
                        para_printf(&msg, "updating afhi and chunk table\n");
                ret = osl_update_object(audio_file_table, row, AFTCOL_AFHI,
                        &objs[AFTCOL_AFHI]);
                if (ret < 0)
                        goto out;
                ret = osl_update_object(audio_file_table, row, AFTCOL_CHUNKS,
                        &objs[AFTCOL_CHUNKS]);
                if (ret < 0)
                        goto out;
                afs_event(AFHI_CHANGE, &msg, row);
                goto out;
        }
        /* new entry, use default afsi */
        if (flags & ADD_FLAG_VERBOSE)
                para_printf(&msg, "new file\n");
        default_afsi.last_played = time(NULL) - 365 * 24 * 60 * 60;
        default_afsi.audio_format_id = read_u8(buf + AFTROW_AUDIO_FORMAT_OFFSET);

        objs[AFTCOL_AFSI].data = &afsi_buf;
        objs[AFTCOL_AFSI].size = AFSI_SIZE;
        save_afsi(&default_afsi, &objs[AFTCOL_AFSI]);
        ret = osl_add_and_get_row(audio_file_table, objs, &aft_row);
out:
        if (ret < 0)
                para_printf(&msg, "%s\n", PARA_STRERROR(-ret));
        if (!msg.buf)
                return 0;
        result->data = msg.buf;
        result->size = msg.size;
        afs_event(AUDIO_FILE_ADD, &msg, aft_row);
        return 1;
}

/** Used by com_add(). */
struct private_add_data {
        /** The socket file descriptor. */
        int fd;
        /** The given add flags. */
        uint32_t flags;
};

static int path_brother_callback(const struct osl_object *query,
                struct osl_object *result)
{
        char *path = query->data;
        struct osl_row *path_brother;
        int ret = aft_get_row_of_path(path, &path_brother);
        if (ret < 0)
                return ret;
        result->data = para_malloc(sizeof(path_brother));
        result->size = sizeof(path_brother);
        *(struct osl_row **)(result->data) = path_brother;
        return 1;
}

static int hash_sister_callback(const struct osl_object *query,
                struct osl_object *result)
{
        HASH_TYPE *hash = query->data;
        struct osl_row *hash_sister;

        hash_sister = find_hash_sister(hash);
        if (!hash_sister)
                return -E_RB_KEY_NOT_FOUND;
        result->data = para_malloc(sizeof(hash_sister));
        result->size = sizeof(hash_sister);
        *(struct osl_row **)(result->data) = hash_sister;
        return 1;
}

static int add_one_audio_file(const char *path, const void *private_data)
{
        int ret, ret2;
        uint8_t format_num = -1;
        const 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, result = {.data = NULL};
        HASH_TYPE hash[HASH_SIZE];

        afhi.header_offset = 0;
        afhi.header_len = 0;
        ret = guess_audio_format(path);
        if (ret < 0 && !(pad->flags & ADD_FLAG_ALL))
                goto out_free;
        query.data = (char *)path;
        query.size = strlen(path) + 1;
        ret = send_callback_request(path_brother_callback, &query, &result);
        if (ret < 0 && ret != -E_RB_KEY_NOT_FOUND)
                goto out_free;
        if (ret >= 0) {
                pb = *(struct osl_row **)result.data;
                free(result.data);
        }
        ret = 1;
        if (pb && (pad->flags & ADD_FLAG_LAZY)) { /* lazy is really cheap */
                if (pad->flags & ADD_FLAG_VERBOSE)
                        ret = send_va_buffer(pad->fd, "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, NULL);
        if (ret < 0)
                goto out_free;
        hash_function(map.data, map.size, hash);

        /* Check whether database contains file with the same hash. */
        query.data = hash;
        query.size = HASH_SIZE;
        ret = send_callback_request(hash_sister_callback, &query, &result);
        if (ret < 0 && ret != -E_RB_KEY_NOT_FOUND)
                goto out_free;
        if (ret >= 0) {
                hs = *(struct osl_row **)result.data;
                free(result.data);
        }
        /* Return success if we already know this file. */
        ret = 1;
        if (pb && hs && hs == pb && (!(pad->flags & ADD_FLAG_FORCE))) {
                if (pad->flags & ADD_FLAG_VERBOSE)
                        ret = send_va_buffer(pad->fd,
                                "%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 unless in FORCE mode.
         */
        if (!hs || (pad->flags & ADD_FLAG_FORCE)) {
                ret = compute_afhi(path, map.data, map.size, &afhi);
                if (ret < 0)
                        goto out_unmap;
                format_num = ret;
                afhi_ptr = &afhi;
        }
        if (pad->flags & ADD_FLAG_VERBOSE) {
                ret = send_va_buffer(pad->fd, "adding %s\n", path);
                if (ret < 0)
                        goto out_unmap;
        }
        munmap(map.data, map.size);
        save_audio_file_info(hash, path, afhi_ptr, pad->flags, format_num, &obj);
        /* Ask afs to consider this entry for adding. */
        ret = send_callback_request(com_add_callback, &obj, &result);
        if (ret > 0) {
                ret2 = send_va_buffer(pad->fd, "%s", (char *)result.data);
                free(result.data);
                if (ret >= 0 && ret2 < 0)
                        ret = ret2;
        }
        goto out_free;

out_unmap:
        munmap(map.data, map.size);
out_free:
        if (ret < 0 && ret != -E_SEND)
                send_va_buffer(pad->fd, "failed to add %s (%s)\n", path,
                        PARA_STRERROR(-ret));
        free(obj.data);
        if (afhi_ptr)
                free(afhi_ptr->chunk_table);
        /* it's not an error if not all files could be added */
        return ret == -E_SEND? ret : 1;
}

int com_add(int fd, int argc, char * const * const argv)
{
        int i, ret;
        struct private_add_data pad = {.fd = fd, .flags = 0};
        struct stat statbuf;

        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
                if (arg[0] != '-')
                        break;
                if (!strcmp(arg, "--")) {
                        i++;
                        break;
                }
                if (!strcmp(arg, "-a")) {
                        pad.flags |= ADD_FLAG_ALL;
                        continue;
                }
                if (!strcmp(arg, "-l")) {
                        pad.flags |= ADD_FLAG_LAZY;
                        continue;
                }
                if (!strcmp(arg, "-f")) {
                        pad.flags |= ADD_FLAG_FORCE;
                        continue;
                }
                if (!strcmp(arg, "-v")) {
                        pad.flags |= ADD_FLAG_VERBOSE;
                        continue;
                }
        }
        if (argc <= i)
                return -E_AFT_SYNTAX;
        for (; i < argc; i++) {
                char *path;
                ret = verify_path(argv[i], &path);
                if (ret < 0) {
                        ret = send_va_buffer(fd, "%s: %s\n", argv[i], PARA_STRERROR(-ret));
                        if (ret < 0)
                                return ret;
                        continue;
                }
                ret = stat(path, &statbuf);
                if (ret < 0) {
                        ret = send_va_buffer(fd, "failed to stat %s (%s)\n", path,
                                strerror(errno));
                        free(path);
                        if (ret < 0)
                                return ret;
                        continue;
                }
                if (S_ISDIR(statbuf.st_mode))
                        ret = for_each_file_in_dir(path, add_one_audio_file,
                                &pad);
                else
                        ret = add_one_audio_file(path, &pad);
                if (ret < 0) {
                        send_va_buffer(fd, "%s: %s\n", path, PARA_STRERROR(-ret));
                        free(path);
                        return ret;
                }
                free(path);
        }
        return 1;

}

/**
 * Flags used by the touch command.
 *
 * \sa com_touch().
 */
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
};

/** Options used by com_touch(). */
struct com_touch_options {
        /** New num_played value. */
        int32_t num_played;
        /** New last played count. */
        int64_t last_played;
        /** new lyrics id. */
        int32_t lyrics_id;
        /** new image id. */
        int32_t image_id;
        /** command line flags (see \ref touch_flags). */
        unsigned flags;
};

/** Data passed to the action handler of com_touch(). */
struct touch_action_data {
        /** Command line options (see \ref com_touch_options). */
        struct com_touch_options *cto;
        /** Message buffer. */
        struct para_buffer pb;
};

static int touch_audio_file(__a_unused struct osl_table *table,
                struct osl_row *row, const char *name, void *data)
{
        struct touch_action_data *tad = data;
        struct osl_object obj;
        struct afs_info old_afsi, new_afsi;
        int ret, no_options = tad->cto->num_played < 0 && tad->cto->last_played < 0 &&
                tad->cto->lyrics_id < 0 && tad->cto->image_id < 0;
        struct afsi_change_event_data aced;

        ret = get_afsi_object_of_row(row, &obj);
        if (ret < 0) {
                para_printf(&tad->pb, "%s: %s\n", name, PARA_STRERROR(-ret));
                return 1;
        }
        ret = load_afsi(&old_afsi, &obj);
        if (ret < 0) {
                para_printf(&tad->pb, "%s: %s\n", name, PARA_STRERROR(-ret));
                return 1;
        }
        new_afsi = old_afsi;
        if (no_options) {
                new_afsi.num_played++;
                new_afsi.last_played = time(NULL);
                if (tad->cto->flags & TOUCH_FLAG_VERBOSE)
                        para_printf(&tad->pb, "%s: num_played = %u, "
                                "last_played = now()\n", name,
                                new_afsi.num_played);
        } else {
                if (tad->cto->flags & TOUCH_FLAG_VERBOSE)
                        para_printf(&tad->pb, "touching %s\n", name);
                if (tad->cto->lyrics_id >= 0)
                        new_afsi.lyrics_id = tad->cto->lyrics_id;
                if (tad->cto->image_id >= 0)
                        new_afsi.image_id = tad->cto->image_id;
                if (tad->cto->num_played >= 0)
                        new_afsi.num_played = tad->cto->num_played;
                if (tad->cto->last_played >= 0)
                        new_afsi.last_played = tad->cto->last_played;
        }
        save_afsi(&new_afsi, &obj); /* in-place update */
        aced.aft_row = row;
        aced.old_afsi = &old_afsi;
        afs_event(AFSI_CHANGE, &tad->pb, &aced);
        return 1;
}

static int com_touch_callback(const struct osl_object *query,
                struct osl_object *result)
{
        struct touch_action_data tad = {.cto = query->data};
        int ret;
        struct pattern_match_data pmd = {
                .table = audio_file_table,
                .loop_col_num = AFTCOL_HASH,
                .match_col_num = AFTCOL_PATH,
                .patterns = {.data = (char *)query->data + sizeof(*tad.cto),
                        .size = query->size - sizeof(*tad.cto)},
                .data = &tad,
                .action = touch_audio_file
        };
        if (tad.cto->flags & TOUCH_FLAG_FNM_PATHNAME)
                pmd.fnmatch_flags |= FNM_PATHNAME;
        ret = for_each_matching_row(&pmd);
        if (ret < 0)
                para_printf(&tad.pb, "%s\n", PARA_STRERROR(-ret));
        if (tad.pb.buf) {
                result->data = tad.pb.buf;
                result->size = tad.pb.size;
                return 1;
        }
        return ret < 0? ret : 0;
}

int com_touch(int fd, int argc, char * const * const argv)
{
        struct com_touch_options cto = {
                .num_played = -1,
                .last_played = -1,
                .lyrics_id = -1,
                .image_id = -1
        };
        struct osl_object query = {.data = &cto, .size = sizeof(cto)},
                result;
        int i, ret;


        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
                if (arg[0] != '-')
                        break;
                if (!strcmp(arg, "--")) {
                        i++;
                        break;
                }
                if (!strncmp(arg, "-n", 2)) {
                        ret = para_atoi32(arg + 2, &cto.num_played);
                        if (ret < 0)
                                return ret;
                        continue;
                }
                if (!strncmp(arg, "-l", 2)) {
                        ret = para_atoi64(arg + 2, &cto.last_played);
                        if (ret < 0)
                                return ret;
                        continue;
                }
                if (!strncmp(arg, "-y", 2)) {
                        ret = para_atoi32(arg + 2, &cto.lyrics_id);
                        if (ret < 0)
                                return ret;
                        continue;
                }
                if (!strncmp(arg, "-i", 2)) {
                        ret = para_atoi32(arg + 2, &cto.image_id);
                        if (ret < 0)
                                return ret;
                        continue;
                }
                if (!strcmp(arg, "-p")) {
                        cto.flags |= TOUCH_FLAG_FNM_PATHNAME;
                        continue;
                }
                if (!strcmp(arg, "-v")) {
                        cto.flags |= TOUCH_FLAG_VERBOSE;
                        continue;
                }
                break; /* non-option starting with dash */
        }
        if (i >= argc)
                return -E_AFT_SYNTAX;
        ret = send_option_arg_callback_request(&query, argc - i,
                argv + i, com_touch_callback, &result);
        if (ret > 0) {
                send_buffer(fd, (char *)result.data);
                free(result.data);
        } else if (ret < 0)
                send_va_buffer(fd, "%s\n", PARA_STRERROR(-ret));
        return ret;
}

/** Flags for com_rm(). */
enum rm_flags {
        /** -v */
        RM_FLAG_VERBOSE = 1,
        /** -f */
        RM_FLAG_FORCE = 2,
        /** -p */
        RM_FLAG_FNM_PATHNAME = 4
};

/** Data passed to the action handler of com_rm(). */
struct com_rm_action_data {
        /** Command line flags ((see \ref rm_flags). */
        uint32_t flags;
        /** Message buffer. */
        struct para_buffer pb;
        /** Number of audio files removed. */
        unsigned num_removed;
};

static int remove_audio_file(__a_unused struct osl_table *table,
                struct osl_row *row, const char *name, void *data)
{
        struct com_rm_action_data *crd = data;
        int ret;

        if (crd->flags & RM_FLAG_VERBOSE)
                para_printf(&crd->pb, "removing %s\n", name);
        afs_event(AUDIO_FILE_REMOVE, &crd->pb, row);
        ret = osl_del_row(audio_file_table, row);
        if (ret < 0)
                para_printf(&crd->pb, "%s: %s\n", name, PARA_STRERROR(-ret));
        else
                crd->num_removed++;
        return 1;
}

static int com_rm_callback(const struct osl_object *query,
                __a_unused struct osl_object *result)
{
        struct com_rm_action_data crd = {.flags = *(uint32_t *)query->data};
        int ret;
        struct pattern_match_data pmd = {
                .table = audio_file_table,
                .loop_col_num = AFTCOL_HASH,
                .match_col_num = AFTCOL_PATH,
                .patterns = {.data = (char *)query->data + sizeof(uint32_t),
                        .size = query->size - sizeof(uint32_t)},
                .data = &crd,
                .action = remove_audio_file
        };
        if (crd.flags & RM_FLAG_FNM_PATHNAME)
                pmd.fnmatch_flags |= FNM_PATHNAME;
        ret = for_each_matching_row(&pmd);
        if (ret < 0)
                para_printf(&crd.pb, "%s\n", PARA_STRERROR(-ret));
        if (!crd.num_removed && !(crd.flags & RM_FLAG_FORCE))
                para_printf(&crd.pb, "no matches -- nothing removed\n");
        else {
                if (crd.flags & RM_FLAG_VERBOSE)
                        para_printf(&crd.pb, "removed %u files\n", crd.num_removed);
        }
        if (crd.pb.buf) {
                result->data = crd.pb.buf;
                result->size = crd.pb.size;
                return 1;
        }
        return ret < 0? ret : 0;
}

/* TODO options: -r (recursive) */
int com_rm(int fd, int argc,  char * const * const argv)
{
        uint32_t flags = 0;
        struct osl_object query = {.data = &flags, .size = sizeof(flags)},
                result;
        int i, ret;

        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
                if (arg[0] != '-')
                        break;
                if (!strcmp(arg, "--")) {
                        i++;
                        break;
                }
                if (!strcmp(arg, "-f")) {
                        flags |= RM_FLAG_FORCE;
                        continue;
                }
                if (!strcmp(arg, "-p")) {
                        flags |= RM_FLAG_FNM_PATHNAME;
                        continue;
                }
                if (!strcmp(arg, "-v")) {
                        flags |= RM_FLAG_VERBOSE;
                        continue;
                }
                break;
        }
        if (i >= argc)
                return -E_AFT_SYNTAX;
        ret = send_option_arg_callback_request(&query, argc - i, argv + i,
                com_rm_callback, &result);
        if (ret > 0) {
                send_buffer(fd, (char *)result.data);
                free(result.data);
        } else if (ret < 0)
                send_va_buffer(fd, "%s\n", PARA_STRERROR(-ret));
        return ret;
}

/**
 * Flags used by the cpsi command.
 *
 * \sa com_cpsi().
 */
enum cpsi_flags {
        /** Whether the lyrics id should be copied. */
        CPSI_FLAG_COPY_LYRICS_ID = 1,
        /** Whether the image id should be copied. */
        CPSI_FLAG_COPY_IMAGE_ID = 2,
        /** Whether the lastplayed time should be copied. */
        CPSI_FLAG_COPY_LASTPLAYED = 4,
        /** Whether the numplayed count should be copied. */
        CPSI_FLAG_COPY_NUMPLAYED = 8,
        /** Whether the attributes should be copied. */
        CPSI_FLAG_COPY_ATTRIBUTES = 16,
        /** Activates verbose mode. */
        CPSI_FLAG_VERBOSE = 32,
};

/** Data passed to the action handler of com_cpsi(). */
struct cpsi_action_data {
        /** command line flags (see \ref cpsi_flags). */
        unsigned flags;
        /** Number of audio files changed. */
        unsigned num_copied;
        /** Message buffer. */
        struct para_buffer pb;
        /** Values are copied from here. */
        struct afs_info source_afsi;
};

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;

        ret = get_afsi_object_of_row(row, &target_afsi_obj);
        if (ret < 0)
                return ret;
        load_afsi(&target_afsi, &target_afsi_obj);
        old_afsi = target_afsi;
        if (cad->flags & CPSI_FLAG_COPY_LYRICS_ID)
                target_afsi.lyrics_id = cad->source_afsi.lyrics_id;
        if (cad->flags & CPSI_FLAG_COPY_IMAGE_ID)
                target_afsi.image_id = cad->source_afsi.image_id;
        if (cad->flags & CPSI_FLAG_COPY_LASTPLAYED)
                target_afsi.last_played = cad->source_afsi.last_played;
        if (cad->flags & CPSI_FLAG_COPY_NUMPLAYED)
                target_afsi.num_played = cad->source_afsi.num_played;
        if (cad->flags & CPSI_FLAG_COPY_ATTRIBUTES)
                target_afsi.attributes = cad->source_afsi.attributes;
        save_afsi(&target_afsi, &target_afsi_obj); /* in-place update */
        cad->num_copied++;
        if (cad->flags & CPSI_FLAG_VERBOSE)
                para_printf(&cad->pb, "copied afsi to %s\n", name);
        aced.aft_row = row;
        aced.old_afsi = &old_afsi;
        afs_event(AFSI_CHANGE, &cad->pb, &aced);
        return 1;
}

static int com_cpsi_callback(const struct osl_object *query,
                struct osl_object *result)
{
        struct cpsi_action_data cad = {.flags = *(unsigned *)query->data};
        int ret;
        char *source_path = (char *)query->data + sizeof(cad.flags);

        ret = get_afsi_of_path(source_path, &cad.source_afsi);
        if (ret < 0)
                goto out;
        struct pattern_match_data pmd = {
                .table = audio_file_table,
                .loop_col_num = AFTCOL_HASH,
                .match_col_num = AFTCOL_PATH,
                .patterns = {.data = source_path + strlen(source_path) + 1,
                        .size = query->size - sizeof(cad.flags)
                                - strlen(source_path) - 1},
                .data = &cad,
                .action = copy_selector_info
        };
        ret = for_each_matching_row(&pmd);
out:
        if (ret < 0)
                para_printf(&cad.pb, "%s\n", PARA_STRERROR(-ret));
        if (cad.flags & CPSI_FLAG_VERBOSE) {
                if (cad.num_copied)
                        para_printf(&cad.pb, "copied requested afsi from %s "
                                "to %u files\n",
                                source_path, cad.num_copied);
                else
                        para_printf(&cad.pb, "nothing copied\n");
        }
        if (cad.pb.buf) {
                result->data = cad.pb.buf;
                result->size = cad.pb.size;
                return 1;
        }
        return ret < 0? ret : 0;
}

int com_cpsi(int fd, int argc,  char * const * const argv)
{
        unsigned flags = 0;
        int i, ret;
        struct osl_object options = {.data = &flags, .size = sizeof(flags)},
                result;

        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
                if (arg[0] != '-')
                        break;
                if (!strcmp(arg, "--")) {
                        i++;
                        break;
                }
                if (!strcmp(arg, "-y")) {
                        flags |= CPSI_FLAG_COPY_LYRICS_ID;
                        continue;
                }
                if (!strcmp(arg, "-i")) {
                        flags |= CPSI_FLAG_COPY_IMAGE_ID;
                        continue;
                }
                if (!strcmp(arg, "-l")) {
                        flags |= CPSI_FLAG_COPY_LASTPLAYED;
                        continue;
                }
                if (!strcmp(arg, "-n")) {
                        flags |= CPSI_FLAG_COPY_NUMPLAYED;
                        continue;
                }
                if (!strcmp(arg, "-a")) {
                        flags |= CPSI_FLAG_COPY_ATTRIBUTES;
                        continue;
                }
                if (!strcmp(arg, "-v")) {
                        flags |= CPSI_FLAG_VERBOSE;
                        continue;
                }
                break;
        }
        if (i + 1 >= argc) /* need at least souce file and pattern */
                return -E_AFT_SYNTAX;
        if (!(flags & ~CPSI_FLAG_VERBOSE)) /* no copy flags given */
                flags = ~(unsigned)CPSI_FLAG_VERBOSE | flags;
        ret = send_option_arg_callback_request(&options, argc - i, argv + i,
                com_cpsi_callback, &result);
        if (ret > 0) {
                send_buffer(fd, (char *)result.data);
                free(result.data);
        } else
                send_va_buffer(fd, "%s\n", PARA_STRERROR(-ret));
        return ret;
}

/* TODO: optionally fix problems by removing offending rows */
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 1;
        }
        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 1;
}

/**
 * Check the audio file table for inconsistencies.
 *
 * \param query Unused.
 * \param result Contains message string upon return.
 *
 * This function always succeeds.
 *
 * \sa com_check().
 */
int aft_check_callback(__a_unused const struct osl_object *query, struct osl_object *result)
{
        struct para_buffer pb = {.buf = NULL};

        para_printf(&pb, "checking audio file table...\n");
        audio_file_loop(&pb, check_audio_file);
        result->data = pb.buf;
        result->size = pb.size;
        return 1;

}

/**
 * Close the audio file table.
 *
 * \param flags Usual flags that are passed to osl_close_table().
 *
 * \sa osl_close_table().
 */
static void aft_close(void)
{
        osl_close_table(audio_file_table, OSL_MARK_CLEAN);
        audio_file_table = NULL;
}

/**
 * Open the audio file table.
 *
 * \param dir The database directory.
 *
 * \return Standard.
 *
 * \sa osl_open_table().
 */
static int aft_open(const char *dir)
{
        int ret;

        audio_file_table_desc.dir = dir;
        ret = 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 %d files\n", num);
                return ret;
        }
        PARA_INFO_LOG("failed to open audio file table\n");
        audio_file_table = NULL;
        if (ret >= 0 || is_errno(-ret, ENOENT))
                return 1;
        return ret;
}

static int aft_create(const char *dir)
{
        audio_file_table_desc.dir = dir;
        return 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)
{
        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);
                }
        default:
                return 1;
        }
}

void aft_init(struct afs_table *t)
{
        t->name = audio_file_table_desc.name;
        t->open = aft_open;
        t->close = aft_close;
        t->create = aft_create;
        t->event_handler = aft_event_handler;
}