Copyright (c) 2016-present, RxJava Contributors.
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.
/**
 * Copyright (c) 2016-present, RxJava Contributors.
 *
 * 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 io.reactivex.disposables;

import java.util.*;

import io.reactivex.annotations.NonNull;
import io.reactivex.exceptions.*;
import io.reactivex.internal.disposables.DisposableContainer;
import io.reactivex.internal.functions.ObjectHelper;
import io.reactivex.internal.util.*;

A disposable container that can hold onto multiple other disposables and
offers O(1) add and removal complexity.
/**
 * A disposable container that can hold onto multiple other disposables and
 * offers O(1) add and removal complexity.
 */
public final class CompositeDisposable implements Disposable, DisposableContainer {

    OpenHashSet<Disposable> resources;

    volatile boolean disposed;

    
Creates an empty CompositeDisposable.
/**
     * Creates an empty CompositeDisposable.
     */
    public CompositeDisposable() {
    }

    
Creates a CompositeDisposables with the given array of initial elements.
Params:
disposables – the array of Disposables to start with
Throws:
NullPointerException – if disposables or any of its array items is null/**
     * Creates a CompositeDisposables with the given array of initial elements.
     * @param disposables the array of Disposables to start with
     * @throws NullPointerException if {@code disposables} or any of its array items is null
     */
    public CompositeDisposable(@NonNull Disposable... disposables) {
        ObjectHelper.requireNonNull(disposables, "disposables is null");
        this.resources = new OpenHashSet<Disposable>(disposables.length + 1);
        for (Disposable d : disposables) {
            ObjectHelper.requireNonNull(d, "A Disposable in the disposables array is null");
            this.resources.add(d);
        }
    }

    
Creates a CompositeDisposables with the given Iterable sequence of initial elements.
Params:
disposables – the Iterable sequence of Disposables to start with
Throws:
NullPointerException – if disposables or any of its items is null/**
     * Creates a CompositeDisposables with the given Iterable sequence of initial elements.
     * @param disposables the Iterable sequence of Disposables to start with
     * @throws NullPointerException if {@code disposables} or any of its items is null
     */
    public CompositeDisposable(@NonNull Iterable<? extends Disposable> disposables) {
        ObjectHelper.requireNonNull(disposables, "disposables is null");
        this.resources = new OpenHashSet<Disposable>();
        for (Disposable d : disposables) {
            ObjectHelper.requireNonNull(d, "A Disposable item in the disposables sequence is null");
            this.resources.add(d);
        }
    }

    @Override
    public void dispose() {
        if (disposed) {
            return;
        }
        OpenHashSet<Disposable> set;
        synchronized (this) {
            if (disposed) {
                return;
            }
            disposed = true;
            set = resources;
            resources = null;
        }

        dispose(set);
    }

    @Override
    public boolean isDisposed() {
        return disposed;
    }

    
Adds a disposable to this container or disposes it if the
container has been disposed.
Params:
disposable – the disposable to add, not null
Throws:
NullPointerException – if disposable is null
Returns:
true if successful, false if this container has been disposed/**
     * Adds a disposable to this container or disposes it if the
     * container has been disposed.
     * @param disposable the disposable to add, not null
     * @return true if successful, false if this container has been disposed
     * @throws NullPointerException if {@code disposable} is null
     */
    @Override
    public boolean add(@NonNull Disposable disposable) {
        ObjectHelper.requireNonNull(disposable, "disposable is null");
        if (!disposed) {
            synchronized (this) {
                if (!disposed) {
                    OpenHashSet<Disposable> set = resources;
                    if (set == null) {
                        set = new OpenHashSet<Disposable>();
                        resources = set;
                    }
                    set.add(disposable);
                    return true;
                }
            }
        }
        disposable.dispose();
        return false;
    }

    
Atomically adds the given array of Disposables to the container or
disposes them all if the container has been disposed.
Params:
disposables – the array of Disposables
Throws:
NullPointerException – if disposables or any of its array items is null
Returns:
true if the operation was successful, false if the container has been disposed/**
     * Atomically adds the given array of Disposables to the container or
     * disposes them all if the container has been disposed.
     * @param disposables the array of Disposables
     * @return true if the operation was successful, false if the container has been disposed
     * @throws NullPointerException if {@code disposables} or any of its array items is null
     */
    public boolean addAll(@NonNull Disposable... disposables) {
        ObjectHelper.requireNonNull(disposables, "disposables is null");
        if (!disposed) {
            synchronized (this) {
                if (!disposed) {
                    OpenHashSet<Disposable> set = resources;
                    if (set == null) {
                        set = new OpenHashSet<Disposable>(disposables.length + 1);
                        resources = set;
                    }
                    for (Disposable d : disposables) {
                        ObjectHelper.requireNonNull(d, "A Disposable in the disposables array is null");
                        set.add(d);
                    }
                    return true;
                }
            }
        }
        for (Disposable d : disposables) {
            d.dispose();
        }
        return false;
    }

    
Removes and disposes the given disposable if it is part of this
container.
Params:
disposable – the disposable to remove and dispose, not null
Returns:
true if the operation was successful/**
     * Removes and disposes the given disposable if it is part of this
     * container.
     * @param disposable the disposable to remove and dispose, not null
     * @return true if the operation was successful
     */
    @Override
    public boolean remove(@NonNull Disposable disposable) {
        if (delete(disposable)) {
            disposable.dispose();
            return true;
        }
        return false;
    }

    
Removes (but does not dispose) the given disposable if it is part of this
container.
Params:
disposable – the disposable to remove, not null
Throws:
NullPointerException – if disposable is null
Returns:
true if the operation was successful/**
     * Removes (but does not dispose) the given disposable if it is part of this
     * container.
     * @param disposable the disposable to remove, not null
     * @return true if the operation was successful
     * @throws NullPointerException if {@code disposable} is null
     */
    @Override
    public boolean delete(@NonNull Disposable disposable) {
        ObjectHelper.requireNonNull(disposable, "disposables is null");
        if (disposed) {
            return false;
        }
        synchronized (this) {
            if (disposed) {
                return false;
            }

            OpenHashSet<Disposable> set = resources;
            if (set == null || !set.remove(disposable)) {
                return false;
            }
        }
        return true;
    }

    
Atomically clears the container, then disposes all the previously contained Disposables.
/**
     * Atomically clears the container, then disposes all the previously contained Disposables.
     */
    public void clear() {
        if (disposed) {
            return;
        }
        OpenHashSet<Disposable> set;
        synchronized (this) {
            if (disposed) {
                return;
            }

            set = resources;
            resources = null;
        }

        dispose(set);
    }

    
Returns the number of currently held Disposables.
Returns:
the number of currently held Disposables/**
     * Returns the number of currently held Disposables.
     * @return the number of currently held Disposables
     */
    public int size() {
        if (disposed) {
            return 0;
        }
        synchronized (this) {
            if (disposed) {
                return 0;
            }
            OpenHashSet<Disposable> set = resources;
            return set != null ? set.size() : 0;
        }
    }

    
Dispose the contents of the OpenHashSet by suppressing non-fatal
Throwables till the end.
Params:
set – the OpenHashSet to dispose elements of/**
     * Dispose the contents of the OpenHashSet by suppressing non-fatal
     * Throwables till the end.
     * @param set the OpenHashSet to dispose elements of
     */
    void dispose(OpenHashSet<Disposable> set) {
        if (set == null) {
            return;
        }
        List<Throwable> errors = null;
        Object[] array = set.keys();
        for (Object o : array) {
            if (o instanceof Disposable) {
                try {
                    ((Disposable) o).dispose();
                } catch (Throwable ex) {
                    Exceptions.throwIfFatal(ex);
                    if (errors == null) {
                        errors = new ArrayList<Throwable>();
                    }
                    errors.add(ex);
                }
            }
        }
        if (errors != null) {
            if (errors.size() == 1) {
                throw ExceptionHelper.wrapOrThrow(errors.get(0));
            }
            throw new CompositeException(errors);
        }
    }
}