com.johncroth.histo.logging.LogHistogramParser.java Source code

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Here is the source code for com.johncroth.histo.logging.LogHistogramParser.java

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/**
 * Perfutil -- https://github.com/dzhaughnroth/Dzh-perfutil 
 * (C) 2011 John Charles Roth
 *
 * Perfutil is free software, licensed under the terms of the GNU GPL 
 * Version 2 or, at your option, any later version. You should have 
 * received a copy of the license with this file. See the above web address
 * for more information, or contact the Free Software Foundation, Boston, MA. 
 * It is distributed WITHOUT WARRANTY; without even the implied warranty of 
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 */
package com.johncroth.histo.logging;

import static com.johncroth.histo.logging.LogHistogramWriter.COUNT;
import static com.johncroth.histo.logging.LogHistogramWriter.END;
import static com.johncroth.histo.logging.LogHistogramWriter.MESSAGE_START_LINE;
import static com.johncroth.histo.logging.LogHistogramWriter.RECORDER;
import static com.johncroth.histo.logging.LogHistogramWriter.START;
import static com.johncroth.histo.logging.LogHistogramWriter.WEIGHT;

import java.io.BufferedReader;
import java.io.Reader;

import org.json.simple.JSONObject;
import org.json.simple.JSONValue;

import com.johncroth.histo.core.LogHistogram;
import com.johncroth.histo.util.Notifier;

/** 
 * Records each type of event into a {@link LogHistogram} for later aggregation.
 */

public class LogHistogramParser extends Notifier<LogHistogramParser.Listener> {

    public enum EventType {
        IGNORED, ERROR, INTERVAL_READ
    }

    public static interface Listener {
        void lineParsed(EventType type, String line, Object detail);
    }

    protected void notifyListeners(EventType type, String line, Object detail) {
        for (Listener l : currentListeners()) {
            l.lineParsed(type, line, detail);
        }
    }

    public void parse(Reader reader) throws Exception {
        BufferedReader r = new BufferedReader(reader);
        boolean expectingJson = false;
        String line = r.readLine();
        while (line != null) {
            EventType type = EventType.IGNORED;
            Object detail = null;
            if (line.startsWith(MESSAGE_START_LINE)) {
                if (expectingJson) {
                    type = EventType.ERROR;
                    detail = "Duplicate message start.";
                    notifyListeners(type, line, detail);
                }
                expectingJson = true;
            } else {
                if (expectingJson) {
                    try {
                        Object jv = JSONValue.parseWithException(line);
                        RecordedInterval<LogHistogramRecorder> ri = parseIntervalJson((JSONObject) jv);
                        type = EventType.INTERVAL_READ;
                        detail = ri;
                    } catch (Exception e) {
                        type = EventType.ERROR;
                        detail = e;
                    }
                    expectingJson = false;
                }
            }
            if (!expectingJson) {
                notifyListeners(type, line, detail);
            }
            line = r.readLine();
        }

    }

    LogHistogram parseHistogramJson(JSONObject jo) {
        LogHistogram result = new LogHistogram();
        for (Object key : jo.keySet()) {
            int iKey = Integer.parseInt(String.valueOf(key));
            JSONObject joBucket = (JSONObject) jo.get(key);
            long c = (Long) joBucket.get(COUNT);
            double w = (Double) joBucket.get(WEIGHT);
            result.setBucket(iKey, c, w);
        }
        return result;
    }

    LogHistogramRecorder parseRecorderJson(JSONObject jo) {
        LogHistogramRecorder result = new LogHistogramRecorder();
        for (Object o : jo.keySet()) {
            String metric = (String) o;
            LogHistogram hist = parseHistogramJson((JSONObject) jo.get(o));
            result.getHistogramMap().put(metric, hist);
        }
        return result;
    }

    RecordedInterval<LogHistogramRecorder> parseIntervalJson(JSONObject jo) {
        long start = (Long) jo.get(START);
        long end = (Long) jo.get(END);
        LogHistogramRecorder rec = parseRecorderJson((JSONObject) jo.get(RECORDER));
        RecordedInterval<LogHistogramRecorder> result = new RecordedInterval<LogHistogramRecorder>(rec, start, end);
        return result;
    }

}