| /* |
| * Copyright (C) 2020 The Android Open Source Project |
| * |
| * 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. |
| */ |
| |
| package android.car.vms; |
| |
| import android.annotation.NonNull; |
| import android.util.ArrayMap; |
| import android.util.ArraySet; |
| import android.util.SparseBooleanArray; |
| |
| import com.android.internal.annotations.GuardedBy; |
| |
| import java.util.Collections; |
| import java.util.Map; |
| import java.util.Objects; |
| import java.util.Set; |
| import java.util.function.Consumer; |
| import java.util.stream.Collectors; |
| import java.util.stream.Stream; |
| |
| /** |
| * Internal utility for computing subscription updates. |
| * |
| * @hide |
| */ |
| public final class VmsSubscriptionHelper { |
| private final Consumer<Set<VmsAssociatedLayer>> mUpdateHandler; |
| |
| private final Object mLock = new Object(); |
| |
| @GuardedBy("mLock") |
| private final Set<VmsLayer> mLayerSubscriptions = new ArraySet<>(); |
| |
| @GuardedBy("mLock") |
| private final Map<VmsLayer, SparseBooleanArray> mPublisherSubscriptions = new ArrayMap<>(); |
| |
| @GuardedBy("mLock") |
| private boolean mPendingUpdate; |
| |
| /** |
| * Constructor for subscription helper. |
| * |
| * @param updateHandler Consumer of subscription updates. |
| */ |
| public VmsSubscriptionHelper(@NonNull Consumer<Set<VmsAssociatedLayer>> updateHandler) { |
| mUpdateHandler = Objects.requireNonNull(updateHandler, "updateHandler cannot be null"); |
| } |
| |
| /** |
| * Adds a subscription to a layer. |
| */ |
| public void subscribe(@NonNull VmsLayer layer) { |
| Objects.requireNonNull(layer, "layer cannot be null"); |
| synchronized (mLock) { |
| if (mLayerSubscriptions.add(layer)) { |
| mPendingUpdate = true; |
| } |
| publishSubscriptionUpdate(); |
| } |
| } |
| |
| /** |
| * Adds a subscription to a specific provider of a layer. |
| */ |
| public void subscribe(@NonNull VmsLayer layer, int providerId) { |
| Objects.requireNonNull(layer, "layer cannot be null"); |
| synchronized (mLock) { |
| SparseBooleanArray providerIds = mPublisherSubscriptions.computeIfAbsent(layer, |
| ignored -> new SparseBooleanArray()); |
| if (!providerIds.get(providerId)) { |
| providerIds.put(providerId, true); |
| mPendingUpdate = true; |
| } |
| publishSubscriptionUpdate(); |
| } |
| } |
| |
| /** |
| * Removes a subscription to a layer. |
| */ |
| public void unsubscribe(@NonNull VmsLayer layer) { |
| Objects.requireNonNull(layer, "layer cannot be null"); |
| synchronized (mLock) { |
| if (mLayerSubscriptions.remove(layer)) { |
| mPendingUpdate = true; |
| } |
| publishSubscriptionUpdate(); |
| } |
| } |
| |
| /** |
| * Removes a subscription to the specific provider of a layer. |
| */ |
| public void unsubscribe(@NonNull VmsLayer layer, int providerId) { |
| Objects.requireNonNull(layer, "layer cannot be null"); |
| synchronized (mLock) { |
| SparseBooleanArray providerIds = mPublisherSubscriptions.get(layer); |
| if (providerIds != null && providerIds.get(providerId)) { |
| providerIds.delete(providerId); |
| if (providerIds.size() == 0) { |
| mPublisherSubscriptions.remove(layer); |
| } |
| mPendingUpdate = true; |
| } |
| publishSubscriptionUpdate(); |
| } |
| } |
| |
| /** |
| * Gets the current set of subscriptions. |
| */ |
| @NonNull |
| public Set<VmsAssociatedLayer> getSubscriptions() { |
| return Stream.concat( |
| mLayerSubscriptions.stream().map( |
| layer -> new VmsAssociatedLayer(layer, Collections.emptySet())), |
| mPublisherSubscriptions.entrySet().stream() |
| .filter(entry -> !mLayerSubscriptions.contains(entry.getKey())) |
| .map(VmsSubscriptionHelper::toAssociatedLayer)) |
| .collect(Collectors.toSet()); |
| } |
| |
| private void publishSubscriptionUpdate() { |
| synchronized (mLock) { |
| if (mPendingUpdate) { |
| mUpdateHandler.accept(getSubscriptions()); |
| } |
| mPendingUpdate = false; |
| } |
| } |
| |
| private static VmsAssociatedLayer toAssociatedLayer( |
| Map.Entry<VmsLayer, SparseBooleanArray> entry) { |
| SparseBooleanArray providerIdArray = entry.getValue(); |
| Set<Integer> providerIds = new ArraySet<>(providerIdArray.size()); |
| for (int i = 0; i < providerIdArray.size(); i++) { |
| providerIds.add(providerIdArray.keyAt(i)); |
| } |
| return new VmsAssociatedLayer(entry.getKey(), providerIds); |
| } |
| } |