/**
 * Copyright 2014 Netflix, Inc.
 *
 * 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 rx.subscriptions;

import java.util.concurrent.TimeUnit;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Group;
import org.openjdk.jmh.annotations.GroupThreads;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Threads;

import rx.Subscription;
import rx.internal.util.SubscriptionList;

/**
 * Benchmark typical subscription list concurrent behavior.
 * <p>
 * gradlew benchmarks "-Pjmh=-f 1 -tu s -bm thrpt -wi 5 -i 5 -r 1 .*CompositeSubscriptionConcurrentPerf.*"
 * <p>
 * gradlew benchmarks "-Pjmh=-f 1 -tu ns -bm avgt -wi 5 -i 5 -r 1 .*CompositeSubscriptionConcurrentPerf.*"
 */
@BenchmarkMode(Mode.Throughput)
@OutputTimeUnit(TimeUnit.SECONDS)
@Threads(2)
@State(Scope.Group)
public class SubscriptionListConcurrentPerf {
    @Param({ "1", "1000", "100000" })
    public int loop;

    public final SubscriptionList csub = new SubscriptionList();
    @Param({ "1", "5", "10", "20" })
    public int count;

    public Subscription[] values;
    @Setup
    public void setup() {
        values = new Subscription[count * 2];
        for (int i = 0; i < count * 2; i++) {
            values[i] = new Subscription() {
                @Override
                public boolean isUnsubscribed() {
                    return false;
                }
                @Override
                public void unsubscribe() {

                }
            };
        }
    }

    @Group("g1")
    @GroupThreads(1)
    @Benchmark
    public void addClearT1() {
        SubscriptionList csub = this.csub;
        Subscription[] values = this.values;

        for (int i = loop; i > 0; i--) {
            for (int j = values.length - 1; j >= 0; j--) {
                csub.add(values[j]);
            }
            csub.clear();
        }
    }
    @Group("g1")
    @GroupThreads(1)
    @Benchmark
    public void addClearT2() {
        SubscriptionList csub = this.csub;
        Subscription[] values = this.values;

        for (int i = loop; i > 0; i--) {
            for (int j = values.length - 1; j >= 0; j--) {
                csub.add(values[j]);
            }
            csub.clear();
        }
    }
    @Group("g2")
    @GroupThreads(1)
    @Benchmark
    public void addClearHalfT1() {
        SubscriptionList csub = this.csub;
        Subscription[] values = this.values;
        int n = values.length;

        for (int i = loop; i > 0; i--) {
            for (int j = n / 2 - 1; j >= 0; j--) {
                csub.add(values[j]);
            }
            csub.clear();
        }
    }
    @Group("g2")
    @GroupThreads(1)
    @Benchmark
    public void addRemoveHalfT2() {
        SubscriptionList csub = this.csub;
        Subscription[] values = this.values;
        int n = values.length;

        for (int i = loop; i > 0; i--) {
            for (int j = n - 1; j >= n / 2; j--) {
                csub.add(values[j]);
            }
            csub.clear();
        }
    }
}
