Histogram.java

/*
 * Copyright (c) 2008, 2024, Jaroslav Bachorik <j.bachorik@btrace.io>.
 * All rights reserved.
 *
 * 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
 *
 *     https://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.
 */


import io.btrace.core.annotations.BTrace;
import io.btrace.core.annotations.OnMethod;
import io.btrace.core.annotations.OnTimer;
import io.btrace.core.annotations.Self;

import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;

import static io.btrace.core.BTraceUtils.*;

/**
 * This sample collects histogram of javax.swing.JComponets
 * created by traced app. The histogram is printed once
 * every 4 seconds.
 */
@BTrace
public class Histogram {
    private static Map<String, AtomicInteger> histo = Collections.newHashMap();

    @OnMethod(
            clazz = "javax.swing.JComponent",
            method = "<init>"
    )
    public static void onnewObject(@Self Object obj) {
        String cn = Reflective.name(classOf(obj));
        AtomicInteger ai = Collections.get(histo, cn);
        if (ai == null) {
            ai = Atomic.newAtomicInteger(1);
            Collections.put(histo, cn, ai);
        } else {
            Atomic.incrementAndGet(ai);
        }
    }

    @OnTimer(4000)
    public static void print() {
        if (Collections.size(histo) != 0) {
            printNumberMap("Component Histogram", histo);
        }
    }
}