src/pulse/simple.c

/***
  This file is part of PulseAudio.

  Copyright 2004-2006 Lennart Poettering

  PulseAudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published
  by the Free Software Foundation; either version 2.1 of the License,
  or (at your option) any later version.

  PulseAudio is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include <pulse/pulseaudio.h>
#include <pulse/thread-mainloop.h>
#include <pulse/xmalloc.h>

#include <pulsecore/log.h>
#include <pulsecore/macro.h>

#include "simple.h"

struct pa_simple {
    pa_threaded_mainloop *mainloop;
    pa_context *context;
    pa_stream *stream;
    pa_stream_direction_t direction;

    const void *read_data;
    size_t read_index, read_length;

    int operation_success;
};

#define CHECK_VALIDITY_RETURN_ANY(rerror, expression, error, ret)       \
    do {                                                                \
        if (!(expression)) {                                            \
            if (rerror)                                                 \
                *(rerror) = error;                                      \
            return (ret);                                               \
        }                                                               \
    } while(false);

#define CHECK_SUCCESS_GOTO(p, rerror, expression, label)        \
    do {                                                        \
        if (!(expression)) {                                    \
            if (rerror)                                         \
                *(rerror) = pa_context_errno((p)->context);     \
            goto label;                                         \
        }                                                       \
    } while(false);

#define CHECK_DEAD_GOTO(p, rerror, label)                               \
    do {                                                                \
        if (!(p)->context || !PA_CONTEXT_IS_GOOD(pa_context_get_state((p)->context)) || \
            !(p)->stream || !PA_STREAM_IS_GOOD(pa_stream_get_state((p)->stream))) { \
            if (((p)->context && pa_context_get_state((p)->context) == PA_CONTEXT_FAILED) || \
                ((p)->stream && pa_stream_get_state((p)->stream) == PA_STREAM_FAILED)) { \
                if (rerror)                                             \
                    *(rerror) = pa_context_errno((p)->context);         \
            } else                                                      \
                if (rerror)                                             \
                    *(rerror) = PA_ERR_BADSTATE;                        \
            goto label;                                                 \
        }                                                               \
    } while(false);

static void context_state_cb(pa_context *c, void *userdata) {
    pa_simple *p = userdata;
    pa_assert(c);
    pa_assert(p);

    switch (pa_context_get_state(c)) {
        case PA_CONTEXT_READY:
        case PA_CONTEXT_TERMINATED:
        case PA_CONTEXT_FAILED:
            pa_threaded_mainloop_signal(p->mainloop, 0);
            break;

        case PA_CONTEXT_UNCONNECTED:
        case PA_CONTEXT_CONNECTING:
        case PA_CONTEXT_AUTHORIZING:
        case PA_CONTEXT_SETTING_NAME:
            break;
    }
}

static void stream_state_cb(pa_stream *s, void * userdata) {
    pa_simple *p = userdata;
    pa_assert(s);
    pa_assert(p);

    switch (pa_stream_get_state(s)) {

        case PA_STREAM_READY:
        case PA_STREAM_FAILED:
        case PA_STREAM_TERMINATED:
            pa_threaded_mainloop_signal(p->mainloop, 0);
            break;

        case PA_STREAM_UNCONNECTED:
        case PA_STREAM_CREATING:
            break;
    }
}

static void stream_request_cb(pa_stream *s, size_t length, void *userdata) {
    pa_simple *p = userdata;
    pa_assert(p);

    pa_threaded_mainloop_signal(p->mainloop, 0);
}

static void stream_latency_update_cb(pa_stream *s, void *userdata) {
    pa_simple *p = userdata;

    pa_assert(p);

    pa_threaded_mainloop_signal(p->mainloop, 0);
}

pa_simple* pa_simple_new(
        const char *server,
        const char *name,
        pa_stream_direction_t dir,
        const char *dev,
        const char *stream_name,
        const pa_sample_spec *ss,
        const pa_channel_map *map,
        const pa_buffer_attr *attr,
        int *rerror) {

    pa_simple *p;
    int error = PA_ERR_INTERNAL, r;

    CHECK_VALIDITY_RETURN_ANY(rerror, !server || *server, PA_ERR_INVALID, NULL);
    CHECK_VALIDITY_RETURN_ANY(rerror, dir == PA_STREAM_PLAYBACK || dir == PA_STREAM_RECORD, PA_ERR_INVALID, NULL);
    CHECK_VALIDITY_RETURN_ANY(rerror, !dev || *dev, PA_ERR_INVALID, NULL);
    CHECK_VALIDITY_RETURN_ANY(rerror, ss && pa_sample_spec_valid(ss), PA_ERR_INVALID, NULL);
    CHECK_VALIDITY_RETURN_ANY(rerror, !map || (pa_channel_map_valid(map) && map->channels == ss->channels), PA_ERR_INVALID, NULL)

    p = pa_xnew0(pa_simple, 1);
    p->direction = dir;

    if (!(p->mainloop = pa_threaded_mainloop_new()))
        goto fail;

    if (!(p->context = pa_context_new(pa_threaded_mainloop_get_api(p->mainloop), name)))
        goto fail;

    pa_context_set_state_callback(p->context, context_state_cb, p);

    if (pa_context_connect(p->context, server, 0, NULL) < 0) {
        error = pa_context_errno(p->context);
        goto fail;
    }

    pa_threaded_mainloop_lock(p->mainloop);

    if (pa_threaded_mainloop_start(p->mainloop) < 0)
        goto unlock_and_fail;

    for (;;) {
        pa_context_state_t state;

        state = pa_context_get_state(p->context);

        if (state == PA_CONTEXT_READY)
            break;

        if (!PA_CONTEXT_IS_GOOD(state)) {
            error = pa_context_errno(p->context);
            goto unlock_and_fail;
        }

        /* Wait until the context is ready */
        pa_threaded_mainloop_wait(p->mainloop);
    }

    if (!(p->stream = pa_stream_new(p->context, stream_name, ss, map))) {
        error = pa_context_errno(p->context);
        goto unlock_and_fail;
    }

    pa_stream_set_state_callback(p->stream, stream_state_cb, p);
    pa_stream_set_read_callback(p->stream, stream_request_cb, p);
    pa_stream_set_write_callback(p->stream, stream_request_cb, p);
    pa_stream_set_latency_update_callback(p->stream, stream_latency_update_cb, p);

    if (dir == PA_STREAM_PLAYBACK)
        r = pa_stream_connect_playback(p->stream, dev, attr,
                                       PA_STREAM_INTERPOLATE_TIMING
                                       |PA_STREAM_ADJUST_LATENCY
                                       |PA_STREAM_AUTO_TIMING_UPDATE, NULL, NULL);
    else
        r = pa_stream_connect_record(p->stream, dev, attr,
                                     PA_STREAM_INTERPOLATE_TIMING
                                     |PA_STREAM_ADJUST_LATENCY
                                     |PA_STREAM_AUTO_TIMING_UPDATE);

    if (r < 0) {
        error = pa_context_errno(p->context);
        goto unlock_and_fail;
    }

    for (;;) {
        pa_stream_state_t state;

        state = pa_stream_get_state(p->stream);

        if (state == PA_STREAM_READY)
            break;

        if (!PA_STREAM_IS_GOOD(state)) {
            error = pa_context_errno(p->context);
            goto unlock_and_fail;
        }

        /* Wait until the stream is ready */
        pa_threaded_mainloop_wait(p->mainloop);
    }

    pa_threaded_mainloop_unlock(p->mainloop);

    return p;

unlock_and_fail:
    pa_threaded_mainloop_unlock(p->mainloop);

fail:
    if (rerror)
        *rerror = error;
    pa_simple_free(p);
    return NULL;
}

void pa_simple_free(pa_simple *s) {
    pa_assert(s);

    if (s->mainloop)
        pa_threaded_mainloop_stop(s->mainloop);

    if (s->stream)
        pa_stream_unref(s->stream);

    if (s->context) {
        pa_context_disconnect(s->context);
        pa_context_unref(s->context);
    }

    if (s->mainloop)
        pa_threaded_mainloop_free(s->mainloop);

    pa_xfree(s);
}

int pa_simple_write(pa_simple *p, const void*data, size_t length, int *rerror) {
    pa_assert(p);

    CHECK_VALIDITY_RETURN_ANY(rerror, p->direction == PA_STREAM_PLAYBACK, PA_ERR_BADSTATE, -1);
    CHECK_VALIDITY_RETURN_ANY(rerror, data, PA_ERR_INVALID, -1);
    CHECK_VALIDITY_RETURN_ANY(rerror, length > 0, PA_ERR_INVALID, -1);

    pa_threaded_mainloop_lock(p->mainloop);

    CHECK_DEAD_GOTO(p, rerror, unlock_and_fail);

    while (length > 0) {
        size_t l;
        int r;

        while (!(l = pa_stream_writable_size(p->stream))) {
            pa_threaded_mainloop_wait(p->mainloop);
            CHECK_DEAD_GOTO(p, rerror, unlock_and_fail);
        }

        CHECK_SUCCESS_GOTO(p, rerror, l != (size_t) -1, unlock_and_fail);

        if (l > length)
            l = length;

        r = pa_stream_write(p->stream, data, l, NULL, 0LL, PA_SEEK_RELATIVE);
        CHECK_SUCCESS_GOTO(p, rerror, r >= 0, unlock_and_fail);

        data = (const uint8_t*) data + l;
        length -= l;
    }

    pa_threaded_mainloop_unlock(p->mainloop);
    return 0;

unlock_and_fail:
    pa_threaded_mainloop_unlock(p->mainloop);
    return -1;
}

int pa_simple_read(pa_simple *p, void*data, size_t length, int *rerror) {
    pa_assert(p);

    CHECK_VALIDITY_RETURN_ANY(rerror, p->direction == PA_STREAM_RECORD, PA_ERR_BADSTATE, -1);
    CHECK_VALIDITY_RETURN_ANY(rerror, data, PA_ERR_INVALID, -1);
    CHECK_VALIDITY_RETURN_ANY(rerror, length > 0, PA_ERR_INVALID, -1);

    pa_threaded_mainloop_lock(p->mainloop);

    CHECK_DEAD_GOTO(p, rerror, unlock_and_fail);

    while (length > 0) {
        size_t l;

        while (!p->read_data) {
            int r;

            r = pa_stream_peek(p->stream, &p->read_data, &p->read_length);
            CHECK_SUCCESS_GOTO(p, rerror, r == 0, unlock_and_fail);

            if (p->read_length <= 0) {
                pa_threaded_mainloop_wait(p->mainloop);
                CHECK_DEAD_GOTO(p, rerror, unlock_and_fail);
            } else if (!p->read_data) {
                /* There's a hole in the stream, skip it. We could generate
                 * silence, but that wouldn't work for compressed streams. */
                r = pa_stream_drop(p->stream);
                CHECK_SUCCESS_GOTO(p, rerror, r == 0, unlock_and_fail);
            } else
                p->read_index = 0;
        }

        l = p->read_length < length ? p->read_length : length;
        memcpy(data, (const uint8_t*) p->read_data+p->read_index, l);

        data = (uint8_t*) data + l;
        length -= l;

        p->read_index += l;
        p->read_length -= l;

        if (!p->read_length) {
            int r;

            r = pa_stream_drop(p->stream);
            p->read_data = NULL;
            p->read_length = 0;
            p->read_index = 0;

            CHECK_SUCCESS_GOTO(p, rerror, r == 0, unlock_and_fail);
        }
    }

    pa_threaded_mainloop_unlock(p->mainloop);
    return 0;

unlock_and_fail:
    pa_threaded_mainloop_unlock(p->mainloop);
    return -1;
}

static void success_cb(pa_stream *s, int success, void *userdata) {
    pa_simple *p = userdata;

    pa_assert(s);
    pa_assert(p);

    p->operation_success = success;
    pa_threaded_mainloop_signal(p->mainloop, 0);
}

int pa_simple_drain(pa_simple *p, int *rerror) {
    pa_operation *o = NULL;

    pa_assert(p);

    CHECK_VALIDITY_RETURN_ANY(rerror, p->direction == PA_STREAM_PLAYBACK, PA_ERR_BADSTATE, -1);

    pa_threaded_mainloop_lock(p->mainloop);
    CHECK_DEAD_GOTO(p, rerror, unlock_and_fail);

    o = pa_stream_drain(p->stream, success_cb, p);
    CHECK_SUCCESS_GOTO(p, rerror, o, unlock_and_fail);

    p->operation_success = 0;
    while (pa_operation_get_state(o) == PA_OPERATION_RUNNING) {
        pa_threaded_mainloop_wait(p->mainloop);
        CHECK_DEAD_GOTO(p, rerror, unlock_and_fail);
    }
    CHECK_SUCCESS_GOTO(p, rerror, p->operation_success, unlock_and_fail);

    pa_operation_unref(o);
    pa_threaded_mainloop_unlock(p->mainloop);

    return 0;

unlock_and_fail:

    if (o) {
        pa_operation_cancel(o);
        pa_operation_unref(o);
    }

    pa_threaded_mainloop_unlock(p->mainloop);
    return -1;
}

int pa_simple_flush(pa_simple *p, int *rerror) {
    pa_operation *o = NULL;

    pa_assert(p);

    pa_threaded_mainloop_lock(p->mainloop);
    CHECK_DEAD_GOTO(p, rerror, unlock_and_fail);

    o = pa_stream_flush(p->stream, success_cb, p);
    CHECK_SUCCESS_GOTO(p, rerror, o, unlock_and_fail);

    p->operation_success = 0;
    while (pa_operation_get_state(o) == PA_OPERATION_RUNNING) {
        pa_threaded_mainloop_wait(p->mainloop);
        CHECK_DEAD_GOTO(p, rerror, unlock_and_fail);
    }
    CHECK_SUCCESS_GOTO(p, rerror, p->operation_success, unlock_and_fail);

    pa_operation_unref(o);
    pa_threaded_mainloop_unlock(p->mainloop);

    return 0;

unlock_and_fail:

    if (o) {
        pa_operation_cancel(o);
        pa_operation_unref(o);
    }

    pa_threaded_mainloop_unlock(p->mainloop);
    return -1;
}

pa_usec_t pa_simple_get_latency(pa_simple *p, int *rerror) {
    pa_usec_t t;

    pa_assert(p);

    pa_threaded_mainloop_lock(p->mainloop);

    for (;;) {
        int negative;

        CHECK_DEAD_GOTO(p, rerror, unlock_and_fail);

        if (pa_stream_get_latency(p->stream, &t, &negative) >= 0) {
            if (p->direction == PA_STREAM_RECORD) {
                pa_usec_t already_read;

                /* pa_simple_read() calls pa_stream_peek() to get the next
                 * chunk of audio. If the next chunk is larger than what the
                 * pa_simple_read() caller wanted, the leftover data is stored
                 * in p->read_data until pa_simple_read() is called again.
                 * pa_stream_drop() won't be called until the whole chunk has
                 * been consumed, which means that pa_stream_get_latency() will
                 * return too large values, because the whole size of the
                 * partially read chunk is included in the latency. Therefore,
                 * we need to subtract the already-read amount from the
                 * latency. */
                already_read = pa_bytes_to_usec(p->read_index, pa_stream_get_sample_spec(p->stream));

                if (!negative) {
                    if (t > already_read)
                        t -= already_read;
                    else
                        t = 0;
                }
            }

            /* We don't have a way to report negative latencies from
             * pa_simple_get_latency(). If the latency is negative, let's
             * report zero. */
            if (negative)
                t = 0;

            break;
        }

        CHECK_SUCCESS_GOTO(p, rerror, pa_context_errno(p->context) == PA_ERR_NODATA, unlock_and_fail);

        /* Wait until latency data is available again */
        pa_threaded_mainloop_wait(p->mainloop);
    }

    pa_threaded_mainloop_unlock(p->mainloop);

    return t;

unlock_and_fail:

    pa_threaded_mainloop_unlock(p->mainloop);
    return (pa_usec_t) -1;
}