looper/playback_process.cpp

#include <google/protobuf/descriptor.h>
#include <google/protobuf/wire_format_lite.h>
#include <ipc/common.pb.h>
#include <ipc/internal.pb.h>
#include "playback_process.hpp"
#include "playback_backend.hpp"
#include <functional>
#include "rpc.hpp"
#include "thirdparty/CRC.hpp"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <exception>
#include <thread>
#include <config.h>
#include <signal.h>
#include "backend.hpp"
#include "util.hpp"
#include "log.hpp"
#include <chrono>
#include <fmt/core.h>
#include <fmt/format.h>
#ifdef __WINDOWS__
#include <windows.h>
#endif
#ifdef __HAIKU__
#include <kernel/scheduler.h>
#endif
#include <google/protobuf/message.h>
#include "util.hpp"
using namespace google::protobuf;
int sndfd;
int rcvfd;
extern char *executable_path;
void print_field_descriptor(const google::protobuf::FieldDescriptor *fdesc, const google::protobuf::Message &msg, size_t level) {
    auto desc = msg.GetDescriptor();
    auto reflection = msg.GetReflection();
    static std::map<google::protobuf::FieldDescriptor::Label, const char*> labelNames = {
        {(google::protobuf::FieldDescriptor::Label)0, "(Error)"},
        {google::protobuf::FieldDescriptor::LABEL_OPTIONAL, "Optional"},
        {google::protobuf::FieldDescriptor::LABEL_REPEATED, "Repeated"},
        {google::protobuf::FieldDescriptor::LABEL_REQUIRED, "Required"}
    };
    DEBUG.writef_level(level, "- %s = %d", fdesc->full_name().c_str(), fdesc->number());
    level++;
    DEBUG.writef_level(level, "Type: %s (C++: %s)", fdesc->type_name(), fdesc->cpp_type_name());
    std::string value = "(None)";
    if (fdesc->has_default_value()) {
        FORMAT_CPP_TYPE_LOWERCASE(fdesc, value, fdesc->default_value_);
        DEBUG.writef_level(level, "Default value: %s", value.c_str());
    }
    DEBUG.writef_level(level, "Label: %s", labelNames.contains(fdesc->label()) ? labelNames[fdesc->label()] : labelNames[(google::protobuf::FieldDescriptor::Label)0]);
    DEBUG.writef_level(level, "Index: %d", fdesc->index());
    if (fdesc->type() == google::protobuf::FieldDescriptor::TYPE_MESSAGE || fdesc->type() == google::protobuf::FieldDescriptor::TYPE_GROUP) {
        const google::protobuf::Descriptor *desc = fdesc->message_type();
        DEBUG.writef_level(level, "Value: (Message)");
        const Message &out_msg = reflection->GetMessage(msg, fdesc);
        print_ipc_message(out_msg, level + 1);
        return;
    }
    if (fdesc->type() == google::protobuf::FieldDescriptor::TYPE_BYTES) {
        value = "(bytes)";
    } else {
        FORMAT_CPP_TYPE_TITLECASE(fdesc, value, reflection->Get, msg, fdesc);
    }
    DEBUG.writef_level(level, "Value: %s", value.c_str());
}
void print_ipc_message(const google::protobuf::Message &msg, size_t level) {
    const google::protobuf::Descriptor *msgdesc = msg.GetDescriptor();
    const google::protobuf::Reflection *reflect = msg.GetReflection();
    DEBUG.writef_level(level, "Message type: %s", msg.GetTypeName().c_str());
    std::vector<const FieldDescriptor *> descriptors;
    reflect->ListFields(msg, &descriptors);
    DEBUG.writef_level(level, "Message field count: %d", descriptors.size());
    for (auto field : descriptors) {
        print_field_descriptor(field, msg, level);
    }
    auto &unknown_fields = reflect->GetUnknownFields(msg);
    DEBUG.writef_level(level, "Unknown fields: %d", unknown_fields.field_count());
}
void show_command(const std::string &cmdid, const google::protobuf::Message &msg) {
	DEBUG.writefln("Command %s:", cmdid.c_str());
	print_ipc_message(msg);
}
RenderResponseOrError PlaybackProcessServiceImpl::Render(const RenderCommand *cmd) {
	RenderResponseOrError response;
	auto cur_backend = cur_backend_lock.lock();
    size_t maxlen = cmd->len();
    auto lock = render_ptr.lock();
    void *ptr = lock->get_byte_sized<void>(maxlen);
    size_t len = cur_backend->render(ptr, maxlen);
    if (len == 0) {
    	DEBUG.writeln("Didn't get any audio when rendering");
    }
    auto output = new RenderResponse();
    output->set_data((const char*)ptr, len);
    output->set_len(len);
    response.set_allocated_output(output);
	return response;
}
PropertyDataOrError PlaybackProcessServiceImpl::Get(const GetProperty *request) {
	PropertyDataOrError response;
	auto cur_backend = cur_backend_lock.get_unsafe();
    PropertyData *data = new PropertyData();
    ErrorResponse *err_maybe = nullptr;
    switch (request->id()) {
    	case PropertyId::PlaybackRate: {
     		DoubleProperty property;
       		property.set_value(cur_backend->get_rate());
         	data->mutable_value()->PackFrom(property);
     	} break;
        case PropertyId::StreamIdProperty: {
            StreamId id;
            id.set_id(cur_backend->get_stream_idx());
            data->mutable_value()->PackFrom(id);
        } break;
        case PropertyId::FilenameProperty: {
            StringProperty prop;
            prop.set_value(std::filesystem::path(cur_backend->get_current_file().value_or("None")).filename().string());
            data->mutable_value()->PackFrom(prop);
        } break;
        case PropertyId::BackendId: {
            StringProperty prop;
            prop.set_value(cur_backend->get_id());
            data->mutable_value()->PackFrom(prop);
        } break;
        case PropertyId::BackendName: {
            StringProperty prop;
            prop.set_value(cur_backend->get_name());
            data->mutable_value()->PackFrom(prop);
        }
        case PropertyId::FilePathProperty: {
            StringProperty path;
            path.set_value(cur_backend->get_current_file().value_or(""));
            data->mutable_value()->PackFrom(path);
        } break;
        case PropertyId::SpecProperty: {
            AudioSpec spec;
            SDL_AudioSpec sdl_spec = cur_backend->get_spec();
            audio_data_t sample_spec = sdl_to_sample_spec(sdl_spec.format);
            DEBUG.writefln("Sample_spec.size: %d", sample_spec.size);
            spec.set_bits(sample_spec.size * 8);
            spec.set_channel_count(sdl_spec.channels);
            spec.set_endian(sample_spec.endian ? EndianID::BIG : EndianID::LITTLE);
            spec.set_format_type(sample_spec.is_float ? FormatType::FLOAT : sample_spec.is_signed ? FormatType::SIGNED : FormatType::UNSIGNED);
            spec.set_sample_rate(sdl_spec.freq);
            data->mutable_value()->PackFrom(spec);
        } break;
        case PropertyId::StreamsProperty: {
            auto full_streams = cur_backend->get_streams();
            if (request->has_idx()) {
                size_t idx = (size_t)request->idx();
                Stream stream;
                if (idx >= full_streams.size()) {
                    ErrorResponse *err = new ErrorResponse();
                    err->set_id("invalid_index");
                    err->set_desc("An attempt to access an array element outside the boundaries of that array was detected.");
                    err->set_fatal(false);
                    err_maybe = err;
                    break;
                }
                auto backend_stream = full_streams[idx];
                stream.set_id(backend_stream.id);
                stream.set_len(backend_stream.length);
                stream.set_title(backend_stream.name);
                data->mutable_value()->PackFrom(stream);
            } else {
                StreamList out_streams;
                for (auto backend_stream : full_streams) {
                    Stream stream = *out_streams.add_streams();
                    stream.set_id(backend_stream.id);
                    stream.set_len(backend_stream.length);
                    stream.set_title(backend_stream.name);
                }
                data->mutable_value()->PackFrom(out_streams);
            }
        } break;
        case PropertyId::TitleProperty: {
            StringProperty title;
            title.set_value(cur_backend->get_title().value_or(""));
            data->mutable_value()->PackFrom(title);
        } break;
        case PropertyId::PositionProperty: {
            DoubleProperty pos;
            pos.set_value(cur_backend->get_position());
            data->mutable_value()->PackFrom(pos);
        } break;
        case PropertyId::BackendSpecific: {
            if (!request->has_path()) {
                ErrorResponse *err = new ErrorResponse();
                err->set_id("param_missing");
                err->set_fatal(false);
                err->set_desc("Backend specific parameters require a path.");
                err_maybe = err;
                break;
            }
            auto output_maybe = cur_backend->get(request->path());
            if (output_maybe.has_value()) {
                data->mutable_value()->PackFrom(output_maybe.value());
            } else {
                ErrorResponse *err = new ErrorResponse;
                err->set_id("not_found");
                err->set_fatal(false);
                err->set_desc("The backend reported that the property was not found.");
                err_maybe = err;
            }
        } break;
        case PropertyId::LengthProperty: {
            DoubleProperty output;
            output.set_value(cur_backend->get_length());
            data->mutable_value()->PackFrom(output);
        } break;
        default: {
            ErrorResponse *err = new ErrorResponse();
            err->set_id("invalid_property");
            err->set_fatal(false);
            err->set_desc("The property requested was invalid or write-only");
            err_maybe = err;
        } break;
    }
    if (err_maybe != nullptr) {
        delete data;
        response.set_allocated_err(err_maybe);
    } else {
        response.set_allocated_output(data);
    }
    return response;
}
MaybeError PlaybackProcessServiceImpl::Set(const SetProperty *request) {
	MaybeError response;
    ErrorResponse *err_maybe = nullptr;
	auto cur_backend = cur_backend_lock.lock();
    switch (request->id()) {
    	case PropertyId::PlaybackRate: {
     		cur_backend->set_rate(resolve_any<DoubleProperty>(request->value())->value());
     	} break;
        case PropertyId::PositionProperty: {
            double value = resolve_any<DoubleProperty>(request->value())->value();
            cur_backend->seek(value);
        } break;
        case PropertyId::StreamIdProperty: {
            cur_backend->switch_stream(resolve_any<StreamId>(request->value())->id());
        } break;
        case PropertyId::BackendSpecific: {
            if (!request->has_path()) {
                ErrorResponse *err = new ErrorResponse();
                err->set_id("param_missing");
                err->set_fatal(false);
                err->set_desc("Backend specific parameters require a path.");
                err_maybe = err;
                break;
            }
            if (!cur_backend->set(request->path(), request->value())) {
                ErrorResponse *err = new ErrorResponse();
                err->set_id("not_found");
                err->set_fatal(false);
                err->set_desc("The backend reported that the property being set was invalid for it.");
                err_maybe = err;
            }
        } break;
        default: {
            ErrorResponse *err = new ErrorResponse();
            err->set_id("invalid_property");
            err->set_fatal(false);
            err->set_desc("The property requested was invalid or read-only");
            err_maybe = err;
        } break;
    }
    if (err_maybe != nullptr) {
        response.set_allocated_err(err_maybe);
    }
    return response;
}
ResetResponse PlaybackProcessServiceImpl::Reset(const ResetProperty *request) {
	ResetResponse response;
	auto cur_backend = cur_backend_lock.lock();
    auto path = request->path();
    std::optional<uint64_t> idx = {};
    if (request->has_idx()) {
        idx = request->idx();
    }
    auto output = cur_backend->reset(path);
    if (output.has_value()) {
        PropertyDataOrError *real_output = new PropertyDataOrError();
        PropertyData *data = new PropertyData();
        data->mutable_value()->PackFrom(output.value());
        data->set_id(PropertyId::BackendSpecific);
        data->clear_idx();
        real_output->set_allocated_output(data);
        response.set_allocated_value(real_output);
    }
    return response;
}
MaybeError PlaybackProcessServiceImpl::Quit(const QuitCmd *request) {
	if (process == nullptr) return MaybeError();
    process->done = true;
    cur_backend_lock.get_unsafe()->cleanup();
    return MaybeError();
}
PropertyList PlaybackProcessServiceImpl::GetPropertyList(const GetPropertyListCommand *cmd) {
	std::vector<Property> list;
	{
		list = cur_backend_lock.lock()->get_property_list();
	}
	PropertyList output;
	for (auto el : list) {
		output.add_list()->CopyFrom(el);
	}
	return output;
}
MaybeError PlaybackProcessServiceImpl::Init(const InitCommand *cmd) {
	MaybeError ret;
	MaybeError *response = &ret;
    auto lock = cur_backend_lock.lock();
    render_ptr.lock().set(new DynPtr(), true);
    lock.clear();
    auto filename = cmd->filename();

    if (!std::filesystem::exists(filename)) {
    	ErrorResponse *maybe_error = response->mutable_err();
        maybe_error->set_desc("File not found");
        maybe_error->set_id("not_found");
        maybe_error->set_fatal(true);
        process->done = true;
        return ret;
    }
    auto idx = cmd->idx();
    for (auto &backend : PlaybackBackendHelper()) {
        DEBUG.writefln("Trying backend: %s", backend.second->get_name().c_str());
        try {
            backend.second->init(filename.c_str(), idx);
        } catch (std::exception e) {
            DEBUG.writeln("Cleaning up backend.");
            backend.second->cleanup();
            continue;
        }
        lock.set(backend.second, false);
        DEBUG.writefln("Using backend: %s", backend.second->get_name().c_str());
        break;
    }
    if (!cur_backend_lock.has_value()) {
        ErrorResponse *maybe_error = response->mutable_err();
        maybe_error->set_desc("Couldn't find a backend.");
        maybe_error->set_id("no_backend_for_file");
        maybe_error->set_fatal(true);
        process->done = true;
        DEBUG.writefln("Couldn't find any backend.");
        return ret;
    }
    return ret;
}

void init_logging_subprocess(PlaybackProcess *proc) {
    Looper::Log::init_logging();
}
PlaybackStream deserialize_stream(Stream serialized) {
    PlaybackStream stream;
    stream.id = serialized.id();
    stream.length = serialized.len();
    stream.name = serialized.title();
    return stream;
}
Stream serialize_stream(PlaybackStream stream, std::optional<Stream*> stream_ptr = {}) {
    Stream serialized;
    serialized.set_id(stream.id);
    serialized.set_len(stream.length);
    serialized.set_title(stream.name);
    if (stream_ptr.has_value()) {
        *(stream_ptr.value()) = serialized;
    }
    return serialized;
}
std::vector<PlaybackStream> deserialize_stream_list(StreamList list) {
    int len = list.streams_size();
    std::vector<PlaybackStream> output;
    output.reserve(len);
    for (int i = 0; i < len; i++) {
        Stream stream = list.streams(i);
        output.push_back(deserialize_stream(stream));
    }
    return output;
}
StreamList serialize_stream_list(std::vector<PlaybackStream> streams) {
    StreamList list;
    for (auto input : streams) {
        Stream *stream = list.add_streams();
        serialize_stream(input, stream);
    }
    return list;
}
PlaybackProcess::PlaybackProcess(PlaybackProcess *parent) {
	other_process = parent;
	DEBUG.writeln("Playback backends: ");
    for (auto &backend : PlaybackBackendHelper()) {
    	DEBUG.writefln(" - %s", backend.second->get_id().c_str());
    }
    DEBUG.writeln("Host process address: (in-process)");
}
PlaybackProcess::PlaybackProcess(std::vector<std::string> args) {
#ifdef __HAIKU__
	set_thread_priority(find_thread(NULL), suggest_thread_priority(B_LIVE_AUDIO_MANIPULATION));
#endif
	SDL_InitSubSystem(SDL_INIT_AUDIO);
    done = false;
    is_playback_process = true;
    Looper::Log::init_logging();
    init_playback_backends();
    DEBUG.writeln("Playback backends: ");
    for (auto &backend : PlaybackBackendHelper()) {
    	DEBUG.writefln(" - %s", backend.second->get_id().c_str());
    }
    init_audio_data();
    send_fd = std::stoi(args[0]);
    recv_fd = std::stoi(args[1]);
    this->impl.process = this;
    done = true;
}
PlaybackProcess::PlaybackProcess(std::string filename, int idx) {
//	multi_process = Looper::Options::get_option<bool>("playback.multi_process", true);
    multi_process = true;
    done = false;
    this->done = false;
    if (multi_process) {
        int fd1[2];
        int fd2[2];
        if (pipe(fd1) < 0) {
            throw CustomException("Pipe creation failed!");
        }
        if (pipe(fd2) < 0) {
            throw CustomException("Pipe creation failed!");
        }
        std::vector<std::string> args;
        args.push_back(fmt::format("{}", fd1[1]));
        args.push_back(fmt::format("{}", fd2[0]));
        send_fd = fd2[1];
        recv_fd = fd1[0];
        pid = launch_self("playback", args);
    } else {
        this->impl.process = this;
        other_process = new PlaybackProcess(this);
    }
    done = true;
    DEBUG.writeln("Playback process started.");
    InitCommand cmd;
    cmd.set_filename(filename);
    cmd.set_idx(idx);
    RPCCall call;
    call.mutable_init()->CopyFrom(cmd);
    RPCResponse response = SendCommand(&call);
    if (response.has_err()) {
    	this->init_failed = true;
    	delete other_process;
     	other_process = nullptr;
     	auto err = response.err();
        throw CustomException(err.has_desc() ? err.desc() : err.id());
    }
}
bool PlaybackProcess::process_running() {
    if (is_playback_process) return true;
    if (other_process != nullptr) return true;
    if (!multi_process) return other_process != nullptr;
    return kill(pid, 0) == 0;
}
RPCResponse PlaybackProcess::handle_command(RPCCall &call) {
    SimpleAckResponse *ack = new SimpleAckResponse();
    RPCResponse resp;
    if (call.has_get()) {
        PropertyDataOrError output = impl.Get(&call.get());
        if (output.has_err()) {
            resp.mutable_err()->CopyFrom(output.err());
        } else {
            resp.mutable_data()->CopyFrom(output.output());
        }
    } else if (call.has_init()) {
        MaybeError output = impl.Init(&call.init());
        if (output.has_err()) {
            resp.mutable_err()->CopyFrom(output.err());
        } else {
            resp.set_allocated_ack(ack);
        }
    } else if (call.has_quit()) {
        MaybeError output = impl.Quit(&call.quit());
        if (output.has_err()) {
            resp.mutable_err()->CopyFrom(output.err());
        } else {
            resp.set_allocated_ack(ack);
        }
    } else if (call.has_set()) {
        MaybeError output = impl.Set(&call.set());
        if (output.has_err()) {
            resp.mutable_err()->CopyFrom(output.err());
        } else {
            resp.set_allocated_ack(ack);
        }
    } else if (call.has_reset()) {
        ResetResponse output = impl.Reset(&call.reset());
        resp.mutable_reset()->CopyFrom(output);
    } else if (call.has_render()) {
        RenderResponseOrError output = impl.Render(&call.render());
        if (output.has_err()) {
            resp.mutable_err()->CopyFrom(output.err());
        } else {
            resp.mutable_render()->CopyFrom(output.output());
        }
    } else if (call.has_get_property_list()) {
    	PropertyList output = impl.GetPropertyList(&call.get_property_list());
     	resp.mutable_property_list()->CopyFrom(output);
    }
    if (!resp.has_ack()) {
        delete ack;
    }
    return resp;
}
void PlaybackProcess::run_playback_process() {
	while (true) {
        uint64_t len;
        blocking_read(recv_fd, &len, sizeof(len));
        std::string in_bytes = std::string(' ', len, std::allocator<char>());
        in_bytes.resize(len);
        blocking_read(recv_fd, in_bytes.data(), len);
        RPCCall call;
        if (!call.ParseFromString(in_bytes)) {
            throw std::exception();
        }
        RPCResponse resp = handle_command(call);
        std::string bytes = resp.SerializeAsString();
        len = bytes.length();
        ssize_t ret = -1;
        blocking_write(send_fd, &len, sizeof(len));
        blocking_write(send_fd, bytes.data(), bytes.length());
    }
}
int looper_run_playback_process(std::vector<std::string> args) {
    auto proc = PlaybackProcess(args);
    proc.run_playback_process();
    SDL_QuitSubSystem(SDL_INIT_AUDIO);
    return 0;
}
PropertyData PlaybackProcess::get_property(PropertyId property, std::optional<uint64_t> idx) {
    GetProperty get_property;
    get_property.set_id(property);
    if (idx.has_value()) {
        get_property.set_idx(idx.value());
    } else {
        get_property.clear_idx();
    }
    RPCCall call;
    call.mutable_get()->CopyFrom(get_property);
    RPCResponse output = SendCommand(&call);
    if (output.has_err()) {
        throw std::exception();
    }
    return output.data();
}
void PlaybackProcess::set_property(PropertyId id, PropertyData data, std::optional<uint64_t> idx) {
    SetProperty set_property;
    set_property.set_id(id);
    set_property.mutable_value()->CopyFrom(data.value());
    if (idx.has_value()) {
        set_property.set_idx(idx.value());
    } else {
        set_property.clear_idx();
    }
    RPCCall call;
    call.mutable_set()->CopyFrom(set_property);
    SendCommand(&call);
}
std::string PlaybackProcess::get_version_code() {
    return std::string(TAG) +
        #ifdef DEBUG_MODE
        std::string("-debugmode") +
        #endif
        std::string("-at") + std::string(__TIME__);
}
double PlaybackProcess::get_position() {
    return get_property_double(PropertyId::PositionProperty);
}
void PlaybackProcess::set_position(double value) {
    DoubleProperty *pos = new DoubleProperty();
    pos->set_value(value);
    set_property_value<DoubleProperty>(PropertyId::PositionProperty, pos);
    delete pos;
}
double PlaybackProcess::get_length() {
    return get_property_double(PropertyId::LengthProperty);
}
size_t PlaybackProcess::get_stream_idx() {
    StreamId *id = get_property_value<StreamId>(PropertyId::StreamIdProperty);
    size_t output = id->id();
    delete id;
    return output;
}
void PlaybackProcess::set_stream_idx(size_t idx) {
    StreamId *id = new StreamId();
    id->set_id(idx);
    set_property_value<StreamId>(PropertyId::StreamIdProperty, id);
    delete id;
}
std::string PlaybackProcess::get_title() {
    return get_property_string(PropertyId::TitleProperty);
}
std::string PlaybackProcess::get_file_path() {
    return get_property_string(PropertyId::FilePathProperty);
}
std::string PlaybackProcess::get_file_name() {
    return get_property_string(PropertyId::FilenameProperty);
}
RPCResponse PlaybackProcess::SendCommand(RPCCall *call) {
    if (multi_process) {
        std::lock_guard guard(ipc_mutex);
        uint64_t len;
        std::string str = call->SerializeAsString();
        len = str.length();
        blocking_write(send_fd, &len, sizeof(len));
        blocking_write(send_fd, str.data(), str.length());
        blocking_read(recv_fd, &len, sizeof(len));
        str.resize(len);
        blocking_read(recv_fd, str.data(), len);
        RPCResponse resp;
        resp.ParseFromString(str);
        return resp;
    } else {
        return handle_command(*call);
    }
}
PlaybackStream PlaybackProcess::get_playback_stream(size_t idx) {
    auto *stream = get_property_value<Stream>(PropertyId::StreamsProperty, idx);
    PlaybackStream output = deserialize_stream(*stream);
    delete stream;
    return output;
}
std::string PlaybackProcess::get_backend_id() {
    return get_property_string(PropertyId::BackendId);
}
std::string PlaybackProcess::get_backend_name() {
    return get_property_string(PropertyId::BackendName);
}
std::vector<PlaybackStream> PlaybackProcess::get_playback_streams() {
    auto *list = get_property_value<StreamList>(PropertyId::StreamsProperty);
    auto output = deserialize_stream_list(*list);
    delete list;
    return output;
}
bool PlaybackProcess::set_property(std::string path, google::protobuf::Any value) {
	SetProperty set_property;
	set_property.set_id(PropertyId::BackendSpecific);
	set_property.mutable_value()->CopyFrom(value);
	set_property.set_path(path);
	RPCCall call;
	call.mutable_set()->CopyFrom(set_property);
	RPCResponse output = SendCommand(&call);
	if (output.has_err()) {
		return false;
	}
	return true;
}
std::optional<google::protobuf::Any> PlaybackProcess::get_property(std::string path) {
	GetProperty get_property;
	get_property.set_id(PropertyId::BackendSpecific);
	get_property.set_path(path);
	RPCCall call;
	call.mutable_get()->CopyFrom(get_property);
	RPCResponse output = SendCommand(&call);
	if (output.has_err()) {
		return {};
	}
	return output.data().value();
}
size_t PlaybackProcess::render(void *buf, size_t maxlen) {
    RenderCommand rend_cmd = RenderCommand();
    rend_cmd.set_len(maxlen);
    RPCResponse response;
    RPCCall call;
    call.mutable_render()->CopyFrom(rend_cmd);
    response = SendCommand(&call);
    if (response.has_err()) {
    	ERROR.writefln("Error rendering audio: %s", response.err().id().c_str());
        return 0;
    } else {
    	std::string data = response.render().data();
    	if (data.length() == 0) {
	    	WARNING.writeln("Rendering audio didn't produce anything!");
		}
		if (data.length() != response.render().len()) {
			WARNING.writefln("Rendering audio size mismatch: Intended != Provided\nIntended: %d\nProvided: %d", response.render().len(), data.length());
		}
        memcpy(buf, data.data(), data.length());
        return data.length();
    }
}
AudioSpec *PlaybackProcess::get_audio_spec() {
    return get_property_value<AudioSpec>(PropertyId::SpecProperty);
}
PlaybackProcess::~PlaybackProcess() {
	if (init_failed || !process_running()) {
		done = true;
		return;
	}
    QuitCmd quit_cmd;
    RPCCall call;
    call.mutable_quit()->CopyFrom(quit_cmd);
    SendCommand(&call);
    done = true;
    if (multi_process) kill(pid, SIGHUP);
}
void PlaybackProcess::threadfunc() {
    while (!process_running()) {
        std::this_thread::yield();
        if (done) return;
    }
    while (true) {
        if (!process_running()) {
            done = true;
            started.notify_all();
        }
        if (done) {
            return;
        }
        std::this_thread::yield();
    }
}
double PlaybackProcess::get_cached_rate() {
	return get_property_double(PropertyId::PlaybackRate);
}
void PlaybackProcess::set_rate(double value) {
	set_property_double(PropertyId::PlaybackRate, value);
}
std::vector<Property> PlaybackProcess::get_property_list() {
	RPCCall call;
	GetPropertyListCommand cmd;
	call.mutable_get_property_list()->CopyFrom(cmd);
	RPCResponse resp = SendCommand(&call);
	if (resp.has_property_list()) {
		std::vector<Property> output;
		for (size_t i = 0; i < resp.property_list().list_size(); i++) {
			output.push_back(resp.property_list().list(i));
		}
		return output;
	} else {
		return std::vector<Property>();
	}
}