/*
 * Copyright 2020 Alibaba Group Holding Limited.
 *
 * 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.alibaba.graphscope.gremlin.plugin;

import com.alibaba.graphscope.gremlin.Utils;
import com.codahale.metrics.Timer;

import java.util.concurrent.TimeUnit;

// collect metrics per gremlin query
public class MetricsCollector {
    private final Timer.Context timeContext;
    private long startMillis;
    private long elapsedMillis;

    public MetricsCollector(Timer timer) {
        this.timeContext = timer.time();
    }

    public long getStartMillis() {
        return this.startMillis;
    }

    public long getElapsedMillis() {
        return this.elapsedMillis;
    }

    public void stop() {
        this.startMillis =
                TimeUnit.NANOSECONDS.toMillis(
                        Utils.getFieldValue(Timer.Context.class, timeContext, "startTime"));
        this.elapsedMillis = TimeUnit.NANOSECONDS.toMillis(timeContext.stop());
    }
}
