Copyright 2018 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.
/**
 * Copyright 2018 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 com.netflix.concurrency.limits.limit;

import com.netflix.concurrency.limits.Limit;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.TimeUnit;
import java.util.function.Consumer;

public class TracingLimitDecorator implements Limit {
    private static final Logger LOG = LoggerFactory.getLogger(TracingLimitDecorator.class);
    
    private final Limit delegate;

    public static TracingLimitDecorator wrap(Limit delegate) {
        return new TracingLimitDecorator(delegate);
    }
    
    public TracingLimitDecorator(Limit delegate) {
        this.delegate = delegate;
    }
    
    @Override
    public int getLimit() {
        return delegate.getLimit();
    }

    @Override
    public void onSample(long startTime, long rtt, int inflight, boolean didDrop) {
        LOG.debug("maxInFlight={} minRtt={} ms",
                inflight,
                TimeUnit.NANOSECONDS.toMicros(rtt) / 1000.0);
        delegate.onSample(startTime, rtt, inflight, didDrop);
    }

    @Override
    public void notifyOnChange(Consumer<Integer> consumer) {
        delegate.notifyOnChange(consumer);
    }
}