@doc.e.dub/csound-browser/src/mains/vanilla.main.js

[](https://www.npmjs.com/package/@csound/browser) [](h

import * as Comlink from "comlink";
import { logVANMain as log } from "@root/logger";
import { api as API } from "@root/libcsound";
import VanillaWorker from "@root/workers/vanilla.worker";
import { isEmpty } from "ramda";
import { csoundApiRename, fetchPlugins, makeProxyCallback, stopableStates } from "@root/utils";
import { IPCMessagePorts, messageEventHandler } from "@root/mains/messages.main";
import { EventPromises } from "@utils/event-promises";
import { PublicEventAPI } from "@root/events";
import {
  clearFsLastmods,
  persistentFilesystem,
  syncPersistentStorage,
} from "@root/filesystem/persistent-fs";

class VanillaWorkerMainThread {
  constructor({
    audioContext,
    audioWorker,
    wasmDataURI,
    audioContextIsProvided,
    inputChannelCount,
    outputChannelCount,
  }) {
    this.ipcMessagePorts = new IPCMessagePorts();
    this.eventPromises = new EventPromises();
    this.publicEvents = new PublicEventAPI(this);
    audioWorker.ipcMessagePorts = this.ipcMessagePorts;

    audioWorker.csoundWorkerMain = this;
    this.audioWorker = audioWorker;
    this.audioContextIsProvided = audioContextIsProvided;
    this.wasmDataURI = wasmDataURI;

    if (audioContextIsProvided) {
      this.sampleRate = audioContext.sampleRate;
    }
    if (inputChannelCount) {
      this.inputChannelCount = inputChannelCount;
    }

    if (outputChannelCount) {
      this.outputChannelCount = outputChannelCount;
    }

    this.exportApi = {};
    this.csoundInstance = undefined;
    this.currentPlayState = undefined;
    // this.messageCallbacks = [];
    this.midiPortStarted = false;
    this.onPlayStateChange = this.onPlayStateChange.bind(this);
  }

  async terminateInstance() {
    if (this.csoundWorker) {
      this.csoundWorker.terminate();
      delete this.csoundWorker;
    }
    if (this.audioWorker && this.audioWorker.terminateInstance) {
      await this.audioWorker.terminateInstance();
      delete this.audioWorker.terminateInstance;
    }
    if (this.proxyPort) {
      this.proxyPort[Comlink.releaseProxy]();
      delete this.proxyPort;
    }
    if (this.publicEvents) {
      this.publicEvents.terminateInstance();
    }
    Object.keys(this.exportApi).forEach((key) => delete this.exportApi[key]);
    Object.keys(this).forEach((key) => delete this[key]);
  }

  get api() {
    return this.exportApi;
  }

  handleMidiInput({ data: payload }) {
    this.ipcMessagePorts.csoundMainRtMidiPort.postMessage &&
      this.ipcMessagePorts.csoundMainRtMidiPort.postMessage(payload);
  }

  async prepareRealtimePerformance() {
    if (!this.csoundInstance) {
      console.error(`fatal error: csound instance not found?`);
      return;
    }

    this.audioWorker.sampleRate = await this.exportApi.getSr(this.csoundInstance);
    this.audioWorker.isRequestingInput = (
      await this.exportApi.getInputName(this.csoundInstance)
    ).includes("adc");
    this.audioWorker.isRequestingMidi = await this.exportApi._isRequestingRtMidiInput(
      this.csoundInstance,
    );
    this.audioWorker.outputsCount = await this.exportApi.getNchnls(this.csoundInstance);
    // TODO fix upstream: await this.exportApi.csoundGetNchnlsInput(this.csound);

    this.audioWorker.inputsCount = this.audioWorker.isRequestingInput ? 1 : 0;
    // if (this.audioWorker.scriptProcessorNode) {
    //   this.audioWorker.softwareBufferSize *= 2;
    // }

    log(`vars for rtPerf set`)();
  }

  async onPlayStateChange(newPlayState) {
    if (!this.publicEvents || newPlayState === this.currentPlayState) {
      // prevent error after termination
      return;
    }
    this.currentPlayState = newPlayState;

    switch (newPlayState) {
      case "realtimePerformanceStarted": {
        log(`event: realtimePerformanceStarted from worker, now preparingRT..`)();
        await this.prepareRealtimePerformance();
        break;
      }

      case "realtimePerformanceEnded": {
        log(`event: realtimePerformanceEnded`)();
        // a noop if the stop promise already exists
        this.eventPromises.createStopPromise();
        clearFsLastmods();
        syncPersistentStorage(await this.getWorkerFs());
        this.midiPortStarted = false;
        this.publicEvents.triggerRealtimePerformanceEnded(this);
        await this.eventPromises.releaseStopPromises();
        break;
      }
      case "realtimePerformancePaused": {
        this.publicEvents.triggerRealtimePerformancePaused(this);
        break;
      }
      case "realtimePerformanceResumed": {
        this.publicEvents.triggerRealtimePerformanceResumed(this);
        break;
      }
      case "renderStarted": {
        await this.eventPromises.releaseStartPromises();
        this.publicEvents.triggerRenderStarted(this);
        break;
      }
      case "renderEnded": {
        log(`event: renderEnded received, beginning cleanup`)();
        syncPersistentStorage(await this.getWorkerFs());
        clearFsLastmods();
        this.publicEvents.triggerRenderEnded(this);
        await this.eventPromises.releaseStopPromises();
        break;
      }

      default: {
        break;
      }
    }

    // forward the message from worker to the audioWorker
    await this.audioWorker.onPlayStateChange(newPlayState);
  }

  async csoundPause() {
    if (this.audioWorker && typeof this.audioWorker.workletProxy !== "undefined") {
      await this.audioWorker.workletProxy.pause();
    }
    this.onPlayStateChange("realtimePerformancePaused");
  }

  async csoundResume() {
    if (this.audioWorker && typeof this.audioWorker.workletProxy !== "undefined") {
      await this.audioWorker.workletProxy.resume();
    }
    this.onPlayStateChange("realtimePerformanceResumed");
  }

  async initialize({ withPlugins }) {
    if (typeof this.audioWorker.initIframe === "function") {
      await this.audioWorker.initIframe();
    }

    if (withPlugins && !isEmpty(withPlugins)) {
      withPlugins = await fetchPlugins(withPlugins);
    }
    log(`vanilla.main: initialize`)();
    clearFsLastmods();
    this.csoundWorker = this.csoundWorker || new Worker(VanillaWorker());

    this.ipcMessagePorts.mainMessagePort.addEventListener("message", messageEventHandler(this));
    this.ipcMessagePorts.mainMessagePort.start();

    const proxyPort = Comlink.wrap(this.csoundWorker);
    this.proxyPort = proxyPort;
    this.csoundInstance = await proxyPort.initialize(
      Comlink.transfer(
        {
          wasmDataURI: this.wasmDataURI,
          messagePort: this.ipcMessagePorts.workerMessagePort,
          requestPort: this.ipcMessagePorts.csoundWorkerFrameRequestPort,
          audioInputPort: this.ipcMessagePorts.csoundWorkerAudioInputPort,
          rtmidiPort: this.ipcMessagePorts.csoundWorkerRtMidiPort,
          fsPort: this.ipcMessagePorts.workerFilesystemPort,
          // these values are only set if the user provided them
          // during init or by passing audioContext
          sampleRate: this.sampleRate,
          inputChannelCount: this.inputChannelCount,
          outputChannelCount: this.outputChannelCount,
          withPlugins,
        },
        [
          this.ipcMessagePorts.workerMessagePort,
          this.ipcMessagePorts.csoundWorkerFrameRequestPort,
          this.ipcMessagePorts.csoundWorkerAudioInputPort,
          this.ipcMessagePorts.csoundWorkerRtMidiPort,
          this.ipcMessagePorts.workerFilesystemPort,
        ],
      ),
    );

    this.exportApi.pause = this.csoundPause.bind(this);
    this.exportApi.resume = this.csoundResume.bind(this);
    this.exportApi.terminateInstance = this.terminateInstance.bind(this);
    this.exportApi.fs = persistentFilesystem;

    // sync/getWorkerFs is only for internal usage
    this.getWorkerFs = makeProxyCallback(
      proxyPort,
      this.csoundInstance,
      "getWorkerFs",
      this.currentPlayState,
    );
    this.getWorkerFs = this.getWorkerFs.bind(this);

    this.exportApi.getAudioContext = async () => this.audioWorker.audioContext;

    this.exportApi.getNode = async () => {
      const maybeNode = this.audioWorker.audioWorkletNode;
      if (maybeNode) {
        return maybeNode;
      } else {
        const node = await new Promise((resolve) => {
          this.exportApi.once("onAudioNodeCreated", resolve);
        });
        return node;
      }
    };

    this.exportApi = this.publicEvents.decorateAPI(this.exportApi);
    this.exportApi.enableAudioInput = () =>
      console.warn(
        `enableAudioInput was ignored: please use -iadc option before calling start with useWorker=true`,
      );

    // the default message listener
    this.exportApi.addListener("message", console.log);

    for (const apiK of Object.keys(API)) {
      const reference = API[apiK];
      const proxyCallback = makeProxyCallback(
        proxyPort,
        this.csoundInstance,
        apiK,
        this.currentPlayState,
      );
      switch (apiK) {
        case "csoundCreate": {
          break;
        }

        case "csoundStart": {
          const csoundStart = async function () {
            this.eventPromises.createStartPromise();

            const startResult = await proxyCallback({
              csound: this.csoundInstance,
            });
            await this.eventPromises.waitForStart();

            return startResult;
          };

          csoundStart.toString = () => reference.toString();
          this.exportApi.start = csoundStart.bind(this);
          break;
        }

        case "csoundStop": {
          const csoundStop = async function () {
            if (this.eventPromises.isWaitingToStop()) {
              return -1;
            } else {
              this.eventPromises.createStopPromise();
              this.ipcMessagePorts.mainMessagePort.postMessage({
                newPlayState:
                  this.currentPlayState === "renderStarted"
                    ? "renderEnded"
                    : "realtimePerformanceEnded",
              });
              await this.eventPromises.waitForStop();
              return 0;
            }
          };
          this.exportApi.stop = csoundStop.bind(this);
          csoundStop.toString = () => reference.toString();
          break;
        }

        case "csoundReset": {
          const csoundReset = async () => {
            // no start = noReset
            if (!this.currentPlayState) {
              return;
            }
            if (stopableStates.has(this.currentPlayState)) {
              await this.exportApi.stop();
            } else if (this.eventPromises.isWaitingToStop()) {
              await this.eventPromises.waitForStop();
            }
            const resetResult = await proxyCallback([]);
            if (!this.audioContextIsProvided) {
              await this.audioWorker.terminateInstance();
              delete this.audioWorker.audioContext;
            }
            this.ipcMessagePorts.restartAudioWorkerPorts();
            return resetResult;
          };
          this.exportApi.reset = csoundReset.bind(this);
          csoundReset.toString = () => reference.toString();
          break;
        }

        default: {
          proxyCallback.toString = () => reference.toString();
          this.exportApi[csoundApiRename(apiK)] = proxyCallback;
          break;
        }
      }
    }
    log(`exportAPI generated`)();
  }
}

export default VanillaWorkerMainThread;