org.htrace.impl.LocalFileSpanReceiver.java Source code

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Here is the source code for org.htrace.impl.LocalFileSpanReceiver.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.htrace.impl;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.htrace.HTraceConfiguration;
import org.htrace.Span;
import org.htrace.SpanReceiver;
import org.mortbay.util.ajax.JSON;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

/**
 * Writes the spans it receives to a local file.
 * A production LocalFileSpanReceiver should use a real CSV format.
 */
public class LocalFileSpanReceiver implements SpanReceiver {
    public static final Log LOG = LogFactory.getLog(LocalFileSpanReceiver.class);
    public static final String PATH_KEY = "local-file-span-receiver.path";
    public static final String CAPACITY_KEY = "local-file-span-receiver.capacity";
    // default capacity for the executors blocking queue
    public static final int CAPACITY_DEFAULT = 5000;
    // default timeout duration when calling executor.awaitTermination()
    public static final long EXECUTOR_TERMINATION_TIMEOUT_DURATION_DEFAULT = 60;
    private String file;
    private FileWriter fwriter;
    private BufferedWriter bwriter;
    private Map<String, Object> values;
    private ExecutorService executor;
    private long executorTerminationTimeoutDuration;

    public LocalFileSpanReceiver() {
    }

    @Override
    public void configure(HTraceConfiguration conf) {
        this.executorTerminationTimeoutDuration = EXECUTOR_TERMINATION_TIMEOUT_DURATION_DEFAULT;
        int capacity = conf.getInt(CAPACITY_KEY, CAPACITY_DEFAULT);
        this.file = conf.get(PATH_KEY);
        if (file == null || file.isEmpty()) {
            throw new IllegalArgumentException("must configure " + PATH_KEY);
        }
        this.executor = new ThreadPoolExecutor(1, 1, 0, TimeUnit.SECONDS,
                new LinkedBlockingQueue<Runnable>(capacity));
        try {
            this.fwriter = new FileWriter(this.file, true);
        } catch (IOException ioe) {
            throw new RuntimeException(ioe);
        }
        this.bwriter = new BufferedWriter(fwriter);
        this.values = new LinkedHashMap<String, Object>();
    }

    private class WriteSpanRunnable implements Runnable {
        public final Span span;

        public WriteSpanRunnable(Span span) {
            this.span = span;
        }

        @Override
        public void run() {
            try {
                values.put("TraceID", span.getTraceId());
                values.put("SpanID", span.getSpanId());
                values.put("ParentID", span.getParentId());
                values.put("ProcessID", span.getProcessId());
                values.put("Start", span.getStartTimeMillis());
                values.put("Stop", span.getStopTimeMillis());
                values.put("Description", span.getDescription());
                values.put("KVAnnotations", span.getKVAnnotations());
                values.put("TLAnnotations", span.getTimelineAnnotations());
                bwriter.write(JSON.toString(values));
                bwriter.newLine();
                bwriter.flush();
                values.clear();
            } catch (IOException e) {
                LOG.error("Error when writing to file: " + file, e);
            }
        }
    }

    @Override
    public void receiveSpan(Span span) {
        executor.submit(new WriteSpanRunnable(span));
    }

    @Override
    public void close() throws IOException {
        executor.shutdown();
        try {
            if (!executor.awaitTermination(this.executorTerminationTimeoutDuration, TimeUnit.SECONDS)) {
                LOG.warn("Was not able to process all remaining spans to write upon closing in: "
                        + this.executorTerminationTimeoutDuration + "s");
            }
        } catch (InterruptedException e1) {
            LOG.warn("Thread interrupted when terminating executor.", e1);
        }

        try {
            fwriter.close();
        } catch (IOException e) {
            LOG.error("Error closing filewriter for file: " + file, e);
        }
        try {
            bwriter.close();
        } catch (IOException e) {
            LOG.error("Error closing bufferedwriter for file: " + file, e);
        }
    }
}