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/*
 * Adapted from https://github.com/apache/commons-collections/blob/fce46cdcc6fa33ba9472921d4b3ec3f548d8cbcc/src/main/java/org/apache/commons/collections4/collection/SynchronizedCollection.java
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 io.sentry;

import com.jakewharton.nopen.annotation.Open;
import io.sentry.util.AutoClosableReentrantLock;
import java.io.Serializable;
import java.util.Collection;
import java.util.Iterator;
import org.jetbrains.annotations.NotNull;

/**
 * Decorates another {@link Collection} to synchronize its behaviour for a multi-threaded
 * environment.
 *
 * Iterators must be manually synchronized:
 *
 * 
 * synchronized (coll) {
 *   Iterator it = coll.iterator();
 *   // do stuff with iterator
 * }
 * 
 *
 * This class is Serializable from Commons Collections 3.1.
 *
 * @param  the type of the elements in the collection
 * @since 3.0
 */
@Open
class SynchronizedCollection implements Collection, Serializable {

  /** Serialization version */
  private static final long serialVersionUID = 2412805092710877986L;

  /** The collection to decorate */
  private final Collection collection;
  /** The object to lock on, needed for List/SortedSet views */
  final AutoClosableReentrantLock lock;

  /**
   * Factory method to create a synchronized collection.
   *
   * @param  the type of the elements in the collection
   * @param coll the collection to decorate, must not be null
   * @return a new synchronized collection
   * @throws NullPointerException if collection is null
   * @since 4.0
   */
  public static  SynchronizedCollection synchronizedCollection(final Collection coll) {
    return new SynchronizedCollection<>(coll);
  }

  // -----------------------------------------------------------------------
  /**
   * Constructor that wraps (not copies).
   *
   * @param collection the collection to decorate, must not be null
   * @throws NullPointerException if the collection is null
   */
  SynchronizedCollection(final Collection collection) {
    if (collection == null) {
      throw new NullPointerException("Collection must not be null.");
    }
    this.collection = collection;
    this.lock = new AutoClosableReentrantLock();
  }

  /**
   * Constructor that wraps (not copies).
   *
   * @param collection the collection to decorate, must not be null
   * @param lock the lock object to use, must not be null
   * @throws NullPointerException if the collection or lock is null
   */
  SynchronizedCollection(final Collection collection, final AutoClosableReentrantLock lock) {
    if (collection == null) {
      throw new NullPointerException("Collection must not be null.");
    }
    if (lock == null) {
      throw new NullPointerException("Lock must not be null.");
    }
    this.collection = collection;
    this.lock = lock;
  }

  /**
   * Gets the collection being decorated.
   *
   * @return the decorated collection
   */
  protected Collection decorated() {
    return collection;
  }

  // -----------------------------------------------------------------------

  @Override
  public boolean add(final E object) {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().add(object);
    }
  }

  @Override
  public boolean addAll(final Collection coll) {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().addAll(coll);
    }
  }

  @Override
  public void clear() {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      decorated().clear();
    }
  }

  @Override
  public boolean contains(final Object object) {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().contains(object);
    }
  }

  @Override
  public boolean containsAll(final Collection coll) {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().containsAll(coll);
    }
  }

  @Override
  public boolean isEmpty() {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().isEmpty();
    }
  }

  /**
   * Iterators must be manually synchronized.
   *
   * 
   * synchronized (coll) {
   *   Iterator it = coll.iterator();
   *   // do stuff with iterator
   * }
   * 
   *
   * @return an iterator that must be manually synchronized on the collection
   */
  @Override
  public Iterator iterator() {
    return decorated().iterator();
  }

  @Override
  public Object[] toArray() {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().toArray();
    }
  }

  @Override
  public  T[] toArray(final T[] object) {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().toArray(object);
    }
  }

  @Override
  public boolean remove(final Object object) {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().remove(object);
    }
  }

  @Override
  public boolean removeAll(final Collection coll) {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().removeAll(coll);
    }
  }

  @Override
  public boolean retainAll(final Collection coll) {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().retainAll(coll);
    }
  }

  @Override
  public int size() {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().size();
    }
  }

  @SuppressWarnings("UndefinedEquals")
  @Override
  public boolean equals(final Object object) {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      if (object == this) {
        return true;
      }
      return object == this || decorated().equals(object);
    }
  }

  @Override
  public int hashCode() {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().hashCode();
    }
  }

  @Override
  public String toString() {
    try (final @NotNull ISentryLifecycleToken ignored = lock.acquire()) {
      return decorated().toString();
    }
  }
}