/*      $OpenBSD: sio.c,v 1.30 2026/03/10 06:47:41 ratchov Exp $        */
/*
 * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "debug.h"
#include "sio_priv.h"

#define SIO_PAR_MAGIC   0x83b905a4

void
sio_initpar(struct sio_par *par)
{
        memset(par, 0xff, sizeof(struct sio_par));
        par->__magic = SIO_PAR_MAGIC;
}

struct sio_hdl *
sio_open(const char *str, unsigned int mode, int nbio)
{
        static char devany[] = SIO_DEVANY;
        struct sio_hdl *hdl;

#ifdef DEBUG
        _sndio_debug_init();
#endif
        if ((mode & (SIO_PLAY | SIO_REC)) == 0)
                return NULL;
        if (str == NULL) /* backward compat */
                str = devany;
        if (strcmp(str, devany) == 0 && !issetugid()) {
                if ((mode & SIO_PLAY) == 0)
                        str = getenv("AUDIORECDEVICE");
                if ((mode & SIO_REC) == 0)
                        str = getenv("AUDIOPLAYDEVICE");
                if (mode == (SIO_PLAY | SIO_REC) || str == NULL)
                        str = getenv("AUDIODEVICE");
                if (str == NULL)
                        str = devany;
        }
        if (strcmp(str, devany) == 0) {
                hdl = _sio_aucat_open("snd/default", mode, nbio);
                if (hdl != NULL)
                        return hdl;
                return _sio_sun_open("rsnd/0", mode, nbio);
        }
        if (_sndio_parsetype(str, "snd"))
                return _sio_aucat_open(str, mode, nbio);
        if (_sndio_parsetype(str, "rsnd"))
                return _sio_sun_open(str, mode, nbio);
        DPRINTF("sio_open: %s: unknown device type\n", str);
        return NULL;
}

void
_sio_create(struct sio_hdl *hdl, struct sio_ops *ops,
    unsigned int mode, int nbio)
{
        hdl->ops = ops;
        hdl->mode = mode;
        hdl->nbio = nbio;
        hdl->started = 0;
        hdl->eof = 0;
        hdl->move_cb = NULL;
        hdl->xrun_cb = NULL;
        hdl->vol_cb = NULL;
}

void
sio_close(struct sio_hdl *hdl)
{
        hdl->ops->close(hdl);
}

int
sio_start(struct sio_hdl *hdl)
{
#ifdef DEBUG
        struct timespec ts;
#endif

        if (hdl->eof) {
                DPRINTF("sio_start: eof\n");
                return 0;
        }
        if (hdl->started) {
                DPRINTF("sio_start: already started\n");
                hdl->eof = 1;
                return 0;
        }
        hdl->cpos = 0;
        hdl->cpending = 0;
        hdl->rused = hdl->wused = 0;
        if (!sio_getpar(hdl, &hdl->par))
                return 0;
#ifdef DEBUG
        hdl->pollcnt = 0;
        clock_gettime(CLOCK_MONOTONIC, &ts);
        hdl->start_nsec = 1000000000LL * ts.tv_sec + ts.tv_nsec;
#endif
        hdl->rdrop = hdl->wsil = 0;
        if (!hdl->ops->start(hdl))
                return 0;
        hdl->started = 1;
        hdl->xrun = 0;
        return 1;
}

int
sio_stop(struct sio_hdl *hdl)
{
        if (hdl->ops->stop == NULL)
                return sio_flush(hdl);
        if (hdl->eof) {
                DPRINTF("sio_stop: eof\n");
                return 0;
        }
        if (!hdl->started) {
                DPRINTF("sio_stop: not started\n");
                hdl->eof = 1;
                return 0;
        }
        if (!hdl->ops->stop(hdl))
                return 0;
#ifdef DEBUG
        DPRINTFN(2, "libsndio: polls: %llu, samples = %llu\n",
            hdl->pollcnt, hdl->cpos);
#endif
        hdl->started = 0;
        return 1;
}

int
sio_flush(struct sio_hdl *hdl)
{
        if (hdl->eof) {
                DPRINTF("sio_flush: eof\n");
                return 0;
        }
        if (!hdl->started) {
                DPRINTF("sio_flush: not started\n");
                hdl->eof = 1;
                return 0;
        }
        if (!hdl->ops->flush(hdl))
                return 0;
#ifdef DEBUG
        DPRINTFN(2, "libsndio: polls: %llu, samples = %llu\n",
            hdl->pollcnt, hdl->cpos);
#endif
        hdl->started = 0;
        return 1;
}

int
sio_setpar(struct sio_hdl *hdl, struct sio_par *par)
{
        if (hdl->eof) {
                DPRINTF("sio_setpar: eof\n");
                return 0;
        }
        if (par->__magic != SIO_PAR_MAGIC) {
                DPRINTF("sio_setpar: uninitialized sio_par structure\n");
                hdl->eof = 1;
                return 0;
        }
        if (hdl->started) {
                DPRINTF("sio_setpar: already started\n");
                hdl->eof = 1;
                return 0;
        }
        if (par->bufsz != ~0U) {
                DPRINTF("sio_setpar: setting bufsz is deprecated\n");
                par->appbufsz = par->bufsz;
                par->bufsz = ~0U;
        }
        if (par->rate != ~0U && par->appbufsz == ~0U)
                par->appbufsz = par->rate * 200 / 1000;
        return hdl->ops->setpar(hdl, par);
}

int
sio_getpar(struct sio_hdl *hdl, struct sio_par *par)
{
        if (hdl->eof) {
                DPRINTF("sio_getpar: eof\n");
                return 0;
        }
        if (hdl->started) {
                DPRINTF("sio_getpar: already started\n");
                hdl->eof = 1;
                return 0;
        }
        if (!hdl->ops->getpar(hdl, par)) {
                par->__magic = 0;
                return 0;
        }
        par->__magic = 0;
        return 1;
}

int
sio_getcap(struct sio_hdl *hdl, struct sio_cap *cap)
{
        if (hdl->eof) {
                DPRINTF("sio_getcap: eof\n");
                return 0;
        }
        if (hdl->started) {
                DPRINTF("sio_getcap: already started\n");
                hdl->eof = 1;
                return 0;
        }
        return hdl->ops->getcap(hdl, cap);
}

static int
sio_psleep(struct sio_hdl *hdl, int event)
{
        struct pollfd pfd[SIO_MAXNFDS];
        int revents;
        int nfds;

        nfds = sio_nfds(hdl);
        if (nfds > SIO_MAXNFDS) {
                DPRINTF("sio_psleep: %d: too many descriptors\n", nfds);
                hdl->eof = 1;
                return 0;
        }
        for (;;) {
                nfds = sio_pollfd(hdl, pfd, event);
                while (poll(pfd, nfds, -1) == -1) {
                        if (errno == EINTR)
                                continue;
                        DPERROR("sio_psleep: poll");
                        hdl->eof = 1;
                        return 0;
                }
                revents = sio_revents(hdl, pfd);
                if (revents & POLLHUP) {
                        DPRINTF("sio_psleep: hang-up\n");
                        return 0;
                }
                if (revents & event)
                        break;
        }
        return 1;
}

static int
sio_rdrop(struct sio_hdl *hdl)
{
#define DROP_NMAX 0x1000
        static char dummy[DROP_NMAX];
        ssize_t n, todo;

        while (hdl->rdrop > 0) {
                todo = hdl->rdrop;
                if (todo > DROP_NMAX)
                        todo = DROP_NMAX;
                n = hdl->ops->read(hdl, dummy, todo);
                if (n == 0)
                        return 0;
                hdl->rdrop -= n;
                DPRINTF("sio_rdrop: dropped %zu bytes\n", n);
        }
        return 1;
}

static int
sio_wsil(struct sio_hdl *hdl)
{
#define ZERO_NMAX 0x1000
        static char zero[ZERO_NMAX];
        ssize_t n, todo;

        while (hdl->wsil > 0) {
                todo = hdl->wsil;
                if (todo > ZERO_NMAX)
                        todo = ZERO_NMAX;
                n = hdl->ops->write(hdl, zero, todo);
                if (n == 0)
                        return 0;
                hdl->wsil -= n;
                DPRINTF("sio_wsil: inserted %zu bytes\n", n);
        }
        return 1;
}

size_t
sio_read(struct sio_hdl *hdl, void *buf, size_t len)
{
        unsigned int n;
        char *data = buf;
        size_t todo = len, maxread;

        if (hdl->eof) {
                DPRINTF("sio_read: eof\n");
                return 0;
        }
        if (!hdl->started || !(hdl->mode & SIO_REC)) {
                DPRINTF("sio_read: recording not started\n");
                hdl->eof = 1;
                return 0;
        }
        while (todo > 0) {
                if (!sio_rdrop(hdl))
                        return 0;
                maxread = hdl->rused;
                if (maxread > todo)
                        maxread = todo;
                n = maxread > 0 ? hdl->ops->read(hdl, data, maxread) : 0;
                if (n == 0) {
                        if (hdl->nbio || hdl->eof || todo < len)
                                break;
                        if (!sio_psleep(hdl, POLLIN))
                                break;
                        continue;
                }
                data += n;
                todo -= n;
                hdl->rused -= n;
        }
        return len - todo;
}

size_t
sio_write(struct sio_hdl *hdl, const void *buf, size_t len)
{
        unsigned int n;
        const unsigned char *data = buf;
        size_t todo = len, maxwrite;

        if (hdl->eof) {
                DPRINTF("sio_write: eof\n");
                return 0;
        }
        if (!hdl->started || !(hdl->mode & SIO_PLAY)) {
                DPRINTF("sio_write: playback not started\n");
                hdl->eof = 1;
                return 0;
        }
        while (todo > 0) {
                if (!sio_wsil(hdl))
                        return 0;
                maxwrite = hdl->par.bufsz * hdl->par.pchan * hdl->par.bps -
                    hdl->wused;
                if (maxwrite > todo)
                        maxwrite = todo;
                n = maxwrite > 0 ? hdl->ops->write(hdl, data, maxwrite) : 0;
                if (n == 0) {
                        if (hdl->nbio || hdl->eof)
                                break;
                        if (!sio_psleep(hdl, POLLOUT))
                                break;
                        continue;
                }
                data += n;
                todo -= n;
                hdl->wused += n;
        }
        return len - todo;
}

int
sio_nfds(struct sio_hdl *hdl)
{
        return hdl->ops->nfds(hdl);
}

int
sio_pollfd(struct sio_hdl *hdl, struct pollfd *pfd, int events)
{
        if (hdl->eof)
                return 0;
        if (!hdl->started)
                events = 0;
        return hdl->ops->pollfd(hdl, pfd, events);
}

int
sio_revents(struct sio_hdl *hdl, struct pollfd *pfd)
{
        int revents;
#ifdef DEBUG
        struct timespec ts0, ts1;

        if (_sndio_debug >= 4)
                clock_gettime(CLOCK_MONOTONIC, &ts0);
#endif
        if (hdl->eof)
                return POLLHUP;
#ifdef DEBUG
        hdl->pollcnt++;
#endif
        revents = hdl->ops->revents(hdl, pfd);
        if (!hdl->started)
                return revents & POLLHUP;
#ifdef DEBUG
        if (_sndio_debug >= 4) {
                clock_gettime(CLOCK_MONOTONIC, &ts1);
                DPRINTF("%09lld: sio_revents: revents = 0x%x, took %lldns\n",
                    1000000000LL * ts0.tv_sec +
                    ts0.tv_nsec - hdl->start_nsec,
                    revents,
                    1000000000LL * (ts1.tv_sec - ts0.tv_sec) +
                    ts1.tv_nsec - ts0.tv_nsec);
        }
#endif
        if ((hdl->mode & SIO_PLAY) && !sio_wsil(hdl))
                revents &= ~POLLOUT;
        if ((hdl->mode & SIO_REC) && !sio_rdrop(hdl))
                revents &= ~POLLIN;
        return revents;
}

int
sio_eof(struct sio_hdl *hdl)
{
        return hdl->eof;
}

void
sio_onmove(struct sio_hdl *hdl, void (*cb)(void *, int), void *addr)
{
        if (hdl->started) {
                DPRINTF("sio_onmove: already started\n");
                hdl->eof = 1;
                return;
        }
        hdl->move_cb = cb;
        hdl->move_addr = addr;
}

#ifdef DEBUG
void
_sio_printpos(struct sio_hdl *hdl)
{
        struct timespec ts;
        long long rpos, rdiff;
        long long cpos, cdiff;
        long long wpos, wdiff;
        unsigned rbpf, wbpf, rround, wround;

        clock_gettime(CLOCK_MONOTONIC, &ts);
        rbpf = (hdl->mode & SIO_REC) ? hdl->par.bps * hdl->par.rchan : 1;
        wbpf = (hdl->mode & SIO_PLAY) ? hdl->par.bps * hdl->par.pchan : 1;
        rround = hdl->par.round * rbpf;
        wround = hdl->par.round * wbpf;

        rpos = (hdl->mode & SIO_REC) ?
            hdl->cpos * rbpf - hdl->rused : 0;
        wpos = (hdl->mode & SIO_PLAY) ?
            hdl->cpos * wbpf + hdl->wused : 0;

        cdiff = hdl->cpos % hdl->par.round;
        cpos  = hdl->cpos / hdl->par.round;
        if (cdiff > hdl->par.round / 2) {
                cpos++;
                cdiff = cdiff - hdl->par.round;
        }
        rdiff = rpos % rround;
        rpos  = rpos / rround;
        if (rdiff > rround / 2) {
                rpos++;
                rdiff = rdiff - rround;
        }
        wdiff = wpos % wround;
        wpos  = wpos / wround;
        if (wdiff > wround / 2) {
                wpos++;
                wdiff = wdiff - wround;
        }
        DPRINTF("%011lld: "
            "clk %+5lld%+5lld, wr %+5lld%+5lld rd: %+5lld%+5lld (cpending: %d)\n",
            1000000000LL * ts.tv_sec + ts.tv_nsec - hdl->start_nsec,
            cpos, cdiff, wpos, wdiff, rpos, rdiff, hdl->cpending);
}
#endif

/*
 * Restart the device restoring its state (i.e. hdl->cpos, hdl->wused,
 * hdl->rused), making the restart transparent to upper layers.
 */
int
_sio_xrun(struct sio_hdl *hdl)
{
        int cmove;

#ifdef DEBUG
        if (_sndio_debug >= 1)
                _sio_printpos(hdl);
#endif
        /*
         * The device restarts with empty buffers and block aligned.
         */
        if (!hdl->ops->flush(hdl))
                return 0;

        _sio_onxrun_cb(hdl);

        if (!hdl->ops->start(hdl))
                return 0;

        DPRINTFN(1, "%s: rused = %d, wused = %d\n", __func__,
            hdl->rused, hdl->wused);

        /*
         * To restore the device state, we play silence, drop recorded data,
         * and advance the clock. We suppose that it takes N blocks to restore
         * the state (where N is any integer).
         *
         * After N blocks of operation cpos (the clock) must have advanced to
         * the next block boundary (the stream must remain block-aligned):
         *
         *      cpos' = cpos + round - cpos % round
         *
         * on the other hand, cpos advances by N * par->round frames plus
         * hdl->delta (the advance we report immediately):
         *
         *      cpos' = cpos + delta + N * round
         *
         * by combining above expressions, we obtain the advance to report:
         *
         *      delta = - cpos % round - (N - 1) * round
         *
         * For playback, after N blocks, the buffer usage has decreased by
         * the elapsed time:
         *
         *      wused' = wused - (cpos' - cpos)
         *
         * on the other hand it is equal to the amount of silence we have
         * inserted minus the N blocks that the device has consumed:
         *
         *      wused' = wsil - N * par->round
         *
         * by combining both expressions, we obtain the amount of silence
         * we've to insert:
         *
         *      wsil = wused + (N - 1) * par->round + cpos % round
         *
         * Similarly, for recording the buffer usage has increased by
         * the elapsed time:
         *
         *      rused' = rused + (cpos' - cpos)
         *
         * it is also equal to the N blocks the device has produced minus
         * the amount of frames we drop:
         *
         *      rused' = N * round - rdrop
         *
         * by combining both expressions, we obtain the amount of frames
         * to drop:
         *
         *      rdrop = cpos % round + (N - 1) * round - rused;
         *
         * We're free to choose N. The smaller N (ideally 1) the sooner
         * performance will resume. But wsil and rdrop may not be negative.
         *
         */

        cmove = hdl->cpos % hdl->par.round;

        if (hdl->mode & SIO_REC) {
                while (1) {
                        hdl->rdrop = cmove * hdl->par.bps * hdl->par.rchan - hdl->rused;
                        if (hdl->rdrop >= 0)
                                break;
                        /*
                         * rdrop can't be negative, try a larger 'N'
                         */
                        cmove += hdl->par.round;
                }
        }

        if (hdl->mode & SIO_PLAY)
                hdl->wsil = hdl->wused + cmove * hdl->par.bps * hdl->par.pchan;

        DPRINTFN(1, "%s: cmove = %d, wsil = %d, rdrop = %d\n", __func__,
            cmove, hdl->wsil, hdl->rdrop);

        _sio_onmove_cb(hdl, -cmove);
        return 1;
}

void
_sio_onmove_cb(struct sio_hdl *hdl, int delta)
{
        hdl->cpending += delta;
        if (hdl->cpending <= 0)
                return;

        hdl->cpos += hdl->cpending;
        if (hdl->mode & SIO_REC)
                hdl->rused += hdl->cpending * (hdl->par.bps * hdl->par.rchan);
        if (hdl->mode & SIO_PLAY)
                hdl->wused -= hdl->cpending * (hdl->par.bps * hdl->par.pchan);
#ifdef DEBUG
        if (_sndio_debug >= 3)
                _sio_printpos(hdl);
        if ((hdl->mode & SIO_PLAY) && hdl->wused < 0) {
                DPRINTFN(1, "sndio: h/w failure: negative buffer usage\n");
                hdl->eof = 1;
                return;
        }
#endif
        if (hdl->move_cb)
                hdl->move_cb(hdl->move_addr, hdl->cpending);
        hdl->cpending = 0;
        hdl->xrun = 0;
}

int
sio_setvol(struct sio_hdl *hdl, unsigned int ctl)
{
        if (hdl->eof)
                return 0;
        if (!hdl->ops->setvol)
                return 1;
        if (!hdl->ops->setvol(hdl, ctl))
                return 0;
        hdl->ops->getvol(hdl);
        return 1;
}

int
sio_onvol(struct sio_hdl *hdl, void (*cb)(void *, unsigned int), void *addr)
{
        if (hdl->started) {
                DPRINTF("sio_onvol: already started\n");
                hdl->eof = 1;
                return 0;
        }
        if (!hdl->ops->setvol)
                return 0;
        hdl->vol_cb = cb;
        hdl->vol_addr = addr;
        hdl->ops->getvol(hdl);
        return 1;
}

void
_sio_onvol_cb(struct sio_hdl *hdl, unsigned int ctl)
{
        if (hdl->vol_cb)
                hdl->vol_cb(hdl->vol_addr, ctl);
}

void
sio_onxrun(struct sio_hdl *hdl, void (*cb)(void *), void *addr)
{
        if (hdl->started) {
                DPRINTF("sio_onxrun: already started\n");
                hdl->eof = 1;
                return;
        }
        hdl->xrun_cb = cb;
        hdl->xrun_addr = addr;
}

void
_sio_onxrun_cb(struct sio_hdl *hdl)
{
        if (!hdl->xrun) {
                hdl->xrun = 1;
                if (hdl->xrun_cb)
                        hdl->xrun_cb(hdl->xrun_addr);
        }
        DPRINTFN(1, "sndio: xrun\n");
}