components.ts

/**
 * @license
 * Copyright 2020 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { Firestore } from './database';
import { PersistenceSettings } from '../../../src/core/firestore_client';
import { Code, FirestoreError } from '../../../src/util/error';
import {
  MemoryOfflineComponentProvider,
  OfflineComponentProvider,
  OnlineComponentProvider
} from '../../../src/core/component_provider';
import { LocalStore } from '../../../src/local/local_store';
import { Deferred } from '../../../src/util/promise';
import { logDebug } from '../../../src/util/log';
import { SyncEngine } from '../../../src/core/sync_engine';
import { RemoteStore } from '../../../src/remote/remote_store';
import { Persistence } from '../../../src/local/persistence';
import { EventManager } from '../../../src/core/event_manager';
export const LOG_TAG = 'ComponentProvider';

// The components module manages the lifetime of dependencies of the Firestore
// client. Dependencies can be lazily constructed and only one exists per
// Firestore instance.

// Instance maps that ensure that only one component provider exists per
// Firestore instance.
const offlineComponentProviders = new Map<
  Firestore,
  Promise<OfflineComponentProvider>
>();
const onlineComponentProviders = new Map<
  Firestore,
  Promise<OnlineComponentProvider>
>();

export async function setOfflineComponentProvider(
  firestore: Firestore,
  persistenceSettings: PersistenceSettings,
  offlineComponentProvider: OfflineComponentProvider
): Promise<void> {
  const offlineDeferred = new Deferred<OfflineComponentProvider>();
  offlineComponentProviders.set(firestore, offlineDeferred.promise);

  const configuration = await firestore._getConfiguration();
  configuration.persistenceSettings = persistenceSettings;

  logDebug(LOG_TAG, 'Initializing OfflineComponentProvider');
  await offlineComponentProvider.initialize(configuration);
  firestore._setCredentialChangeListener(user =>
    // TODO(firestorexp): This should be a retryable IndexedDB operation
    firestore._queue.enqueueAndForget(() =>
      // TODO(firestorexp): Make sure handleUserChange is a no-op if user
      // didn't change
      offlineComponentProvider.localStore.handleUserChange(user)
    )
  );
  // When a user calls clearPersistence() in one client, all other clients
  // need to be terminated to allow the delete to succeed.
  offlineComponentProvider.persistence.setDatabaseDeletedListener(() =>
    firestore.delete()
  );
  offlineDeferred.resolve(offlineComponentProvider);
}

export async function setOnlineComponentProvider(
  firestore: Firestore,
  onlineComponentProvider: OnlineComponentProvider
): Promise<void> {
  const onlineDeferred = new Deferred<OnlineComponentProvider>();
  onlineComponentProviders.set(firestore, onlineDeferred.promise);

  const configuration = await firestore._getConfiguration();
  const offlineComponentProvider = await getOfflineComponentProvider(firestore);

  logDebug(LOG_TAG, 'Initializing OnlineComponentProvider');
  await onlineComponentProvider.initialize(
    offlineComponentProvider,
    configuration
  );
  // The CredentialChangeListener of the online component provider takes
  // precedence over the offline component provider.
  firestore._setCredentialChangeListener(user =>
    firestore._queue.enqueueAndForget(() =>
      onlineComponentProvider.remoteStore.handleCredentialChange(user)
    )
  );
  onlineDeferred.resolve(onlineComponentProvider);
}

function getOfflineComponentProvider(
  firestore: Firestore
): Promise<OfflineComponentProvider> {
  verifyNotTerminated(firestore);

  if (!offlineComponentProviders.has(firestore)) {
    logDebug(LOG_TAG, 'Using default OfflineComponentProvider');
    // eslint-disable-next-line @typescript-eslint/no-floating-promises
    setOfflineComponentProvider(
      firestore,
      { durable: false },
      new MemoryOfflineComponentProvider()
    );
  }
  return offlineComponentProviders.get(firestore)!;
}

function getOnlineComponentProvider(
  firestore: Firestore
): Promise<OnlineComponentProvider> {
  verifyNotTerminated(firestore);

  if (!onlineComponentProviders.has(firestore)) {
    logDebug(LOG_TAG, 'Using default OnlineComponentProvider');
    // eslint-disable-next-line @typescript-eslint/no-floating-promises
    setOnlineComponentProvider(firestore, new OnlineComponentProvider());
  }
  return onlineComponentProviders.get(firestore)!;
}

function verifyNotTerminated(firestore: Firestore): void {
  if (firestore._terminated) {
    throw new FirestoreError(
      Code.FAILED_PRECONDITION,
      'The client has already been terminated.'
    );
  }
}

export function getSyncEngine(firestore: Firestore): Promise<SyncEngine> {
  return getOnlineComponentProvider(firestore).then(
    components => components.syncEngine
  );
}

export function getRemoteStore(firestore: Firestore): Promise<RemoteStore> {
  return getOnlineComponentProvider(firestore).then(
    components => components.remoteStore
  );
}

export function getEventManager(firestore: Firestore): Promise<EventManager> {
  return getOnlineComponentProvider(firestore).then(
    components => components.eventManager
  );
}

export function getPersistence(firestore: Firestore): Promise<Persistence> {
  return getOfflineComponentProvider(firestore).then(
    components => components.persistence
  );
}

export function getLocalStore(firestore: Firestore): Promise<LocalStore> {
  return getOfflineComponentProvider(firestore).then(
    provider => provider.localStore
  );
}

/**
 * Removes all components associated with the provided instance. Must be called
 * when the Firestore instance is terminated.
 */
export async function removeComponents(firestore: Firestore): Promise<void> {
  const onlineComponentProviderPromise = onlineComponentProviders.get(
    firestore
  );
  if (onlineComponentProviderPromise) {
    logDebug(LOG_TAG, 'Removing OnlineComponentProvider');
    onlineComponentProviders.delete(firestore);
    await (await onlineComponentProviderPromise).terminate();
  }

  const offlineComponentProviderPromise = offlineComponentProviders.get(
    firestore
  );
  if (offlineComponentProviderPromise) {
    logDebug(LOG_TAG, 'Removing OfflineComponentProvider');
    offlineComponentProviders.delete(firestore);
    await (await offlineComponentProviderPromise).terminate();
  }
}