[paraslash.git] / vss.c

/*
 * Copyright (C) 1997-2007 Andre Noll <maan@systemlinux.org>
 *
 * Licensed under the GPL v2. For licencing details see COPYING.
 */

/** \file vss.c the virtual streaming system
 *
 * This contains the audio streaming code of para_server which is independent
 * of the current audio format, audio file selector and of the activated
 * senders.
 */

#include "para.h"
#include "afh.h"
#include "server.h"
#include <sys/mman.h> /* mmap */
#include <sys/time.h> /* gettimeofday */
#include "server.cmdline.h"
#include "afs_common.h"
#include "vss.h"
#include "send.h"
#include "error.h"
#include "string.h"
#include "fd.h"

extern const char *status_item_list[];

static struct timeval announce_tv;
static struct timeval data_send_barrier;
static struct timeval eof_barrier;
static struct timeval autoplay_barrier;

extern struct misc_meta_data *mmd;
extern struct audio_file_selector selectors[];
extern struct sender senders[];

static int audio_file;
static char *map;

/* The mp3 audio format handler does not need any libs. */
void mp3_init(struct audio_format_handler *);

#ifdef HAVE_OGGVORBIS
        void ogg_init(struct audio_format_handler *);
#endif
#ifdef HAVE_FAAD
        void aac_afh_init(struct audio_format_handler *);
#endif

/**
 * The list of supported  audio formats.
 *
 * We always define the full array of audio formats even if some audio formats
 * were not compiled in. This is because for each audio file the number of its
 * audio format is stored in the databse. We don't want that numbers to become
 * stale just because the user installed a new version of paraslash that
 * supports a different set of audio formats.
 *
 * It can still be easily detected whether an audio format is compiled in by
 * checking if the init function pointer is not \p NULL.
 */
static struct audio_format_handler afl[] = {
        {
                .name = "mp3",
                .init = mp3_init,
        },
        {
                .name = "ogg",
#ifdef HAVE_OGGVORBIS
                .init = ogg_init,
#endif
        },
        {
                .name = "aac",
#ifdef HAVE_FAAD
                .init = aac_afh_init,
#endif
        },
        {
                .name = NULL,
        }
};

static inline int next_audio_format(int format)
{
        for (;;) {
                if (!afl[format].name)
                        return format;
                format++;
                if (afl[format].init)
                        return format;
        }

}

/** Iterate over each supported audio format. */
#define FOR_EACH_AUDIO_FORMAT(i) for (i = 0; afl[i].name; i = next_audio_format(i))


/**
 * check if vss status flag \a P (playing) is set
 *
 * \return greater than zero if playing, zero otherwise.
 *
 */
unsigned int vss_playing(void)
{
        return mmd->new_vss_status_flags & VSS_PLAYING;
}

/**
 * check if \a N (next) status flag is set
 *
 * \return greater than zero if set, zero if not.
 *
 */
unsigned int vss_next(void)
{
        return mmd->new_vss_status_flags & VSS_NEXT;
}

/**
 * check if a reposition request is pending
 *
 * \return greater than zero if true, zero otherwise.
 *
 */
unsigned int vss_repos(void)
{
        return mmd->new_vss_status_flags & VSS_REPOS;
}

/**
 * check if the vss is currently paused
 *
 * \return greater than zero if paused, zero otherwise.
 *
 */
unsigned int vss_paused(void)
{
        return !(mmd->new_vss_status_flags & VSS_NEXT)
                && !(mmd->new_vss_status_flags & VSS_PLAYING);
}

/**
 * Get the name of the given audio format.
 *
 * \param i The audio format number.
 *
 * This returns a pointer to statically allocated memory so it
 * must not be freed by the caller.
 */
const char *audio_format_name(int i)
{
        assert(i >= 0 && i < ARRAY_SIZE(afl));
        return afl[i].name;
}

/**
 * initialize the virtual streaming system
 *
 * Call the init functions of all supported audio format handlers and
 * initialize all supported senders.
 */
void vss_init(void)
{
        int i;
        char *hn = para_hostname(), *home = para_homedir();
        long unsigned announce_time = conf.announce_time_arg > 0?
                        conf.announce_time_arg : 300,
                autoplay_delay = conf.autoplay_delay_arg > 0?
                        conf.autoplay_delay_arg : 0;

        PARA_DEBUG_LOG("supported audio formats: %s\n",
                SUPPORTED_AUDIO_FORMATS);
        FOR_EACH_AUDIO_FORMAT(i) {
                PARA_NOTICE_LOG("initializing %s handler\n",
                        afl[i].name);
                afl[i].init(&afl[i]);
        }
        ms2tv(announce_time, &announce_tv);
        PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&announce_tv));
        for (i = 0; senders[i].name; i++) {
                PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
                senders[i].init(&senders[i]);
        }
        free(hn);
        free(home);
        if (conf.autoplay_given) {
                struct timeval now, tmp;
                mmd->vss_status_flags |= VSS_PLAYING;
                mmd->new_vss_status_flags |= VSS_PLAYING;
                gettimeofday(&now, NULL);
                ms2tv(autoplay_delay, &tmp);
                tv_add(&now, &tmp, &autoplay_barrier);
        }
}

static int get_file_info(int i)
{
        return  afl[i].get_file_info(map, mmd->size, &mmd->afi);
}

/**
 * guess the audio format judging from filename
 *
 * \param name the filename
 *
 * \return This function returns -1 if it has no idea what kind of audio
 * file this might be. Otherwise the (non-negative) number of the audio format
 * is returned.
 */
int guess_audio_format(const char *name)
{
        int i,j, len = strlen(name);

        FOR_EACH_AUDIO_FORMAT(i) {
                for (j = 0; afl[i].suffixes[j]; j++) {
                        const char *p = afl[i].suffixes[j];
                        int plen = strlen(p);
                        if (len < plen + 1)
                                continue;
                        if (name[len - plen - 1] != '.')
                                continue;
                        if (strcasecmp(name + len - plen, p))
                                continue;
//                      PARA_DEBUG_LOG("might be %s\n", audio_format_name(i));
                        return i;
                }
        }
        return -1;
}

static int get_audio_format(int omit)
{
        int i;

        FOR_EACH_AUDIO_FORMAT(i) {
                if (i == omit)
                        continue;
                if (get_file_info(i) > 0)
                        return i;
        }
        return -E_AUDIO_FORMAT;
}

/**
 * Call get_file_info() to obtain an afhi structure.
 *
 * \param path The full path of the audio file.
 * \param data Pointer to the contents of the (mapped) file.
 * \param size The file size in bytes.
 * \param afhi Result pointer.
 *
 * \return The number of the audio format on success, \p -E_AUDIO_FORMAT if no
 * compiled in audio format handler is able to handler the file.
 *
 * This function tries to find an audio format handler that can interpret the
 * file given by \a data and \a size.
 *
 * It first tries to determine the audio format from the filename given by \a
 * path. If this doesn't work, all other audio format handlers are tried until
 * one is found that can handle the file.
 */
int compute_afhi(const char *path, char *data, size_t size,
                struct audio_format_info *afhi)
{
        int ret, i, format = guess_audio_format(path);

        if (format >= 0) {
                ret = afl[format].get_file_info(data, size, afhi);
                if (ret >= 0)
                        return format;
        }
        FOR_EACH_AUDIO_FORMAT(i) {
                if (i == format) /* we already tried this one to no avail */
                        continue;
                ret = afl[i].get_file_info(data, size, afhi);
                if (ret >= 0)
                        return i;
                PARA_WARNING_LOG("%s\n", PARA_STRERROR(-ret));
        }
        return -E_AUDIO_FORMAT;
}

/*
 * upddate shared mem
 */
static int update_mmd(void)
{
        int i;

        i = guess_audio_format(mmd->filename);
        if (i < 0 || get_file_info(i) < 0)
                i = get_audio_format(i);
        if (i < 0)
                return i;
        mmd->audio_format = i;
        mmd->chunks_sent = 0;
        mmd->current_chunk = 0;
        mmd->offset = 0;
        mmd->events++;
        return 1;
}

static void vss_get_audio_file(void)
{
        char **sl = selectors[mmd->selector_num].get_audio_file_list(10);
        int i;
        struct stat file_status;

        if (!sl)
                goto err_out;
        for (i = 0; sl[i]; i++) {
                struct timeval now;
                PARA_INFO_LOG("trying %s\n", sl[i]);
                if (strlen(sl[i]) >= _POSIX_PATH_MAX)
                        continue;
                audio_file = open(sl[i], O_RDONLY);
                if (audio_file < 0)
                        continue;
                if (fstat(audio_file, &file_status) == -1 ||
                                !file_status.st_size) {
                        close(audio_file);
                        continue;
                }
                mmd->size = file_status.st_size;
                mmd->mtime = file_status.st_mtime;
                map = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE,
                        audio_file, 0);
                strcpy(mmd->filename, sl[i]);
                mmd->afi.header_len = 0; /* default: no header */
                if (update_mmd() < 0) { /* invalid file */
                        close(audio_file);
                        munmap(map, mmd->size);
                        map = NULL;
                        continue;
                }
                mmd->num_played++;
                if (selectors[mmd->selector_num].update_audio_file)
                        selectors[mmd->selector_num].update_audio_file(sl[i]);
                PARA_NOTICE_LOG("next audio file: %s\n", mmd->filename);
                mmd->new_vss_status_flags &= (~VSS_NEXT);
                gettimeofday(&now, NULL);
                tv_add(&now, &announce_tv, &data_send_barrier);
                goto free;
        }
err_out:
        PARA_ERROR_LOG("%s", "no valid files found\n");
        mmd->new_vss_status_flags = VSS_NEXT;
free:
        if (sl) {
                for (i = 0; sl[i]; i++)
                        free(sl[i]);
                free(sl);
        }
}

static int chk_barrier(const char *bname, const struct timeval *now,
                const struct timeval *barrier, struct timeval *diff,
                int print_log)
{
        long ms;

        if (tv_diff(now, barrier, diff) > 0)
                return 1;
        ms = tv2ms(diff);
        if (print_log && ms)
                PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
        return -1;
}

static void vss_next_chunk_time(struct timeval *due)
{
        struct timeval tmp;

        tv_scale(mmd->chunks_sent, &mmd->afi.chunk_tv, &tmp);
        tv_add(&tmp, &mmd->stream_start, due);
}

/*
 * != NULL: timeout for next chunk
 * NULL: nothing to do
 */
static struct timeval *vss_compute_timeout(void)
{
        static struct timeval the_timeout;
        struct timeval now, next_chunk;

        if (vss_next() && mmd->audio_format >= 0) {
                /* only sleep a bit, nec*/
                the_timeout.tv_sec = 0;
                the_timeout.tv_usec = 100;
                return &the_timeout;
        }
        gettimeofday(&now, NULL);
        if (chk_barrier("autoplay_delay", &now, &autoplay_barrier,
                        &the_timeout, 1) < 0)
                return &the_timeout;
        if (chk_barrier("eof", &now, &eof_barrier, &the_timeout, 1) < 0)
                return &the_timeout;
        if (chk_barrier("data send", &now, &data_send_barrier,
                        &the_timeout, 1) < 0)
                return &the_timeout;
        if (mmd->audio_format < 0 || !vss_playing() || !map)
                return NULL;
        vss_next_chunk_time(&next_chunk);
        if (chk_barrier(afl[mmd->audio_format].name, &now, &next_chunk,
                        &the_timeout, 0) < 0)
                return &the_timeout;
        /* chunk is due or bof */
        the_timeout.tv_sec = 0;
        the_timeout.tv_usec = 0;
        return &the_timeout;
}

static void vss_eof(void)
{
        struct timeval now;
        int i;
        char *tmp;

        if (!map) {
                for (i = 0; senders[i].name; i++)
                        senders[i].shutdown_clients();
                return;
        }
        gettimeofday(&now, NULL);
        tv_add(&mmd->afi.eof_tv, &now, &eof_barrier);
        munmap(map, mmd->size);
        map = NULL;
        close(audio_file);
        mmd->audio_format = -1;
        mmd->chunks_sent = 0;
        mmd->offset = 0;
        mmd->afi.seconds_total = 0;
        free(mmd->afi.chunk_table);
        mmd->afi.chunk_table = NULL;
        tmp  = make_message("%s:\n%s:\n%s:\n", status_item_list[SI_AUDIO_INFO1],
                status_item_list[SI_AUDIO_INFO2], status_item_list[SI_AUDIO_INFO3]);
        strcpy(mmd->afi.info_string, tmp);
        free(tmp);
        tmp  = make_message("%s:\n%s:\n%s:\n", status_item_list[SI_DBINFO1],
                status_item_list[SI_DBINFO2], status_item_list[SI_DBINFO3]);
        strcpy(mmd->selector_info, tmp);
        free(tmp);
        mmd->filename[0] = '\0';
        mmd->size = 0;
        mmd->events++;
}

/**
 * Get the header of the current audio file.
 *
 * \param header_len the length of the header is stored here
 *
 * \return a pointer to a buffer containing the header, or NULL, if no audio
 * file is selected or if the current audio format does not need special header
 * treamtment.
 *
 */
char *vss_get_header(size_t *header_len)
{
        if (mmd->audio_format < 0 || !map || !mmd->afi.header_len)
                return NULL;
        *header_len = mmd->afi.header_len;
        return map + mmd->afi.header_offset;
}

/**
 * get the list of all supported audio formats
 *
 * \return a space separated list of all supported audio formats
 * It is not allocated at runtime, i.e. there is no need to free
 * the returned string in the caller.
 */
const char *supported_audio_formats(void)
{
        return SUPPORTED_AUDIO_FORMATS;
}

/**
 * get the chunk time of the current audio file
 *
 * \return a pointer to a struct containing the chunk time, or NULL,
 * if currently no audio file is selected.
 */
struct timeval *vss_chunk_time(void)
{
        if (mmd->audio_format < 0)
                return NULL;
        return &mmd->afi.chunk_tv;
}

/**
 * compute the timeout for para_server's main select-loop
 *
 * This function gets called from para_server to determine the timeout value
 * for its main select loop.
 *
 * Before the timeout is computed, the current vss status flags are evaluated
 * and acted upon by calling appropriate functions from the lower layers.
 * Possible actions include
 *
 *      - request a new file list from the current audio file selector
 *      - shutdown of all senders (stop/pause command)
 *      - reposition the stream (ff/jmp command)
 *
 * \return A pointer to a struct timeval containing the timeout for the next
 * chunk of data to be sent, or NULL if we're not sending right now.
 */
struct timeval *vss_preselect(void)
{
        struct audio_format_handler *af = NULL;
        int i, format;
        struct timeval *ret;
again:
        format = mmd->audio_format;
        if (format >= 0)
                af = afl + format;
        else
                for (i = 0; senders[i].name; i++)
                        senders[i].shutdown_clients();
        if (vss_next() && af) {
                vss_eof();
                return vss_compute_timeout();
        }
        if (vss_paused() || vss_repos()) {
                for (i = 0; senders[i].name; i++)
                        senders[i].shutdown_clients();
                if (af) {
                        struct timeval now;
                        gettimeofday(&now, NULL);
                        if (!vss_paused() || mmd->chunks_sent)
                                tv_add(&mmd->afi.eof_tv, &now, &eof_barrier);
                        if (vss_repos())
                                tv_add(&now, &announce_tv, &data_send_barrier);
                        if (mmd->new_vss_status_flags & VSS_NOMORE)
                                mmd->new_vss_status_flags = VSS_NEXT;
                }
                mmd->chunks_sent = 0;
        }
        if (vss_repos()) {
                mmd->new_vss_status_flags &= ~(VSS_REPOS);
                mmd->current_chunk = mmd->repos_request;
        }
        ret = vss_compute_timeout();
        if (!ret && !map && vss_playing() &&
                        !(mmd->new_vss_status_flags & VSS_NOMORE)) {
                PARA_DEBUG_LOG("%s", "ready and playing, but no audio file\n");
                vss_get_audio_file();
                goto again;
        }
        return ret;
}

static void get_chunk(long unsigned chunk_num, char **buf, size_t *len)
{
        size_t pos = mmd->afi.chunk_table[chunk_num];
        *buf = map + pos;
        *len = mmd->afi.chunk_table[chunk_num + 1] - pos;
}

/**
 * Get the data of the given chunk.
 *
 * \param chunk_num The number of the desired chunk.
 * \param buf Chunk data.
 * \param len Chunk length in bytes.
 *
 * \return Positive on success, negative on errors.
 */
int vss_get_chunk(long unsigned chunk_num, char **buf, size_t *len)
{
        if (mmd->audio_format < 0 || !map || !vss_playing())
                return -E_CHUNK;
        if (chunk_num >= mmd->afi.chunks_total)
                return -E_CHUNK;
        get_chunk(chunk_num, buf, len);
        return 1;
}

/**
 * main sending function
 *
 * This function gets called from para_server as soon as the next chunk of
 * data should be pushed out. It first calls the read_chunk() function of
 * the current audio format handler to obtain a pointer to the data to be
 * sent out as well as its length. This information is then passed to each
 * supported sender's send() function which does the actual sending.
 */
void vss_send_chunk(void)
{
        int i;
        struct audio_format_handler *af;
        struct timeval now, due;

        if (mmd->audio_format < 0 || !map || !vss_playing())
                return;
        af = &afl[mmd->audio_format];
        gettimeofday(&now, NULL);
        vss_next_chunk_time(&due);
        if (tv_diff(&due, &now, NULL) > 0)
                return;
        if (chk_barrier("eof", &now, &eof_barrier, &due, 1) < 0)
                return;
        if (chk_barrier("data send", &now, &data_send_barrier,
                        &due, 1) < 0)
                return;
        mmd->new_vss_status_flags &= ~VSS_REPOS;
        if (mmd->current_chunk >= mmd->afi.chunks_total) { /* eof */
                mmd->new_vss_status_flags |= VSS_NEXT;
                return vss_eof();
        }
        /*
         * We call the send function also in case of empty chunks as they
         * might have still some data queued which can be sent in this case.
         */
        if (!mmd->chunks_sent) {
                struct timeval tmp;
                gettimeofday(&mmd->stream_start, NULL);
                tv_scale(mmd->current_chunk, &mmd->afi.chunk_tv, &tmp);
                mmd->offset = tv2ms(&tmp);
                mmd->events++;
        }
        for (i = 0; senders[i].name; i++) {
                char *buf;
                size_t len;
                get_chunk(mmd->current_chunk, &buf, &len);
                senders[i].send(mmd->current_chunk, mmd->chunks_sent, buf, len);
        }
        mmd->new_vss_status_flags |= VSS_PLAYING;
        mmd->chunks_sent++;
        mmd->current_chunk++;
}