org.openiot.gsn.vsensor.ChartVirtualSensor.java Source code

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Here is the source code for org.openiot.gsn.vsensor.ChartVirtualSensor.java

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/**
*    Copyright (c) 2011-2014, OpenIoT
*   
*    This file is part of OpenIoT.
*
*    OpenIoT is free software: you can redistribute it and/or modify
*    it under the terms of the GNU Lesser General Public License as published by
*    the Free Software Foundation, version 3 of the License.
*
*    OpenIoT is distributed in the hope that it will be useful,
*    but WITHOUT ANY WARRANTY; without even the implied warranty of
*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*    GNU Lesser General Public License for more details.
*
*    You should have received a copy of the GNU Lesser General Public License
*    along with OpenIoT.  If not, see <http://www.gnu.org/licenses/>.
*
*     Contact: OpenIoT mailto: info@openiot.eu
 * @author Ali Salehi
 * @author Mehdi Riahi
*/

package org.openiot.gsn.vsensor;

import org.openiot.gsn.beans.DataTypes;
import org.openiot.gsn.beans.StreamElement;
import org.openiot.gsn.utils.ParamParser;

import java.io.IOException;
import java.io.Serializable;
import java.util.Date;
import java.util.HashMap;
import java.util.TreeMap;

import org.apache.commons.io.output.ByteArrayOutputStream;
import org.apache.log4j.Logger;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.data.general.SeriesException;
import org.jfree.data.time.FixedMillisecond;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;

/**
 * The plot should be introduced in the init-param part of the configuration
 * file in which this virtual sensor is used. The paramter name is PLOT and the
 * value should have the following syntax
 * INPUT_STREAM_VAR_NAME:CHART_NAME[TYPE@SIZE]{WIDTH;HEIGHT} The typcal values
 * for width and height are 640 and 480. The Size means how many values the
 * system should use for plotting the diagram. <br>
 * VERY IMPORTANT : THIS A GENERAL PLOT DRAWING VIRTUAL SENSOR AND NOT
 * MEMORY/CPU FRIENDLY. ONE CAN USE THIS VIRTUAL SENSOR AS A STARTING POINT FOR
 * WRITING MORE ADVANCED AND OPTIMIZED CHART DRAWING PACKAGES. <br>
 * VERY IMPORTANT : IN THIS IMPLEMENTATION, THE LARGER THE SIZE OF THE HISTORY
 * USED FOR DRAWING, THE BIGGER THE OUTPUT PLOT SIZE (IN KILOBYTES) AND THE
 * HIGHER PROCESSING TIME.
 * 
 */
public class ChartVirtualSensor extends AbstractVirtualSensor {

    private final transient Logger logger = Logger.getLogger(this.getClass());

    /**
     * The <code>GENERATE_COUNT</code> represents after how many inputs, the
     * virtual sensor should generate data. By default it set to 1 meaning that
     * for each stream element received, the virtual sensor plots a new diagram.
     * If you want to make the virtual sensor plot after receiving each K stream
     * elements, set <code>GENERATE_COUNT</code> to K.
     */
    private final int GENERATE_COUNT = 4;

    private long counter = 0;

    private final HashMap<String, ChartInfo> input_stream_name_to_ChartInfo_map = new HashMap<String, ChartInfo>();

    private int counter_pref = 0;

    public boolean initialize() {
        /**
         * TODO : Checking if the user provides the arguements currectly. TODO :
         * This can now plot only for one input stream value.
         */
        TreeMap<String, String> params = getVirtualSensorConfiguration().getMainClassInitialParams();
        ChartInfo chartInfo = new ChartInfo();
        chartInfo.setInputStreamName(params.get("input-stream"));

        chartInfo.setPlotTitle(params.get("title"));
        chartInfo.setType(params.get("type"));
        chartInfo.setHeight(ParamParser.getInteger(params.get("height"), 480));
        chartInfo.setWidth(ParamParser.getInteger(params.get("width"), 640));
        chartInfo.setVerticalAxisTitle(params.get("vertical-axis"));
        chartInfo.setHistorySize(ParamParser.getInteger(params.get("history-size"), 10));
        input_stream_name_to_ChartInfo_map.put(chartInfo.getInputStreamName(), chartInfo);
        chartInfo.initialize();
        return true;
    }

    public void dataAvailable(String inputStreamName, StreamElement streamElement) {
        if (logger.isDebugEnabled())
            logger.debug(new StringBuilder("data received under the name *").append(inputStreamName)
                    .append("* to the ChartVS.").toString());
        /**
         * Finding the appropriate ChartInfo object for this input stream.
         */
        ChartInfo chartInfo = input_stream_name_to_ChartInfo_map.get(inputStreamName);
        /**
         * If there is not chartInfo configured for this input stream, the virtual
         * sensor doesn't produce any values. Note that if this virtual sensor is
         * intended to produce output other than plots (e.g., if output of this
         * virtual sensor also container integers), then one might comment the
         * following line.
         */

        if (chartInfo == null) {
            logger.warn(
                    "ChartVS drops the input because there is no chart specification defined for the specific input.");
            return;
        }
        /**
         * Sending the data to the chartInfo.
         */
        chartInfo.addData(streamElement);
        /**
         * counter checks to see if it's the time to do the plotting or not.
         */

        if (++counter % GENERATE_COUNT != 0)
            return;
        /**
         * Creating the stream element(s) for output. For creating a stream
         * element one need to provide the field names (in the form of string
         * array) and their types (in the form of integer array). This virtual
         * sensor just produces plots therefore the output is in the form of
         * binary data thus we set the type of the output stream element to
         * Types.Binary.
         */

        String[] fieldNames = input_stream_name_to_ChartInfo_map.keySet().toArray(new String[] {});
        Byte[] fieldTypes = new Byte[fieldNames.length];
        Serializable[] charts = new Serializable[fieldNames.length];
        for (int i = 0; i < fieldTypes.length; i++) {
            /**
             * We set the type of the output stream element to Types.Binary because
             * we are producing images.
             */
            fieldTypes[i] = DataTypes.BINARY;
        }
        /**
         * Creating an stream element with the specified fieldnames, fieldtypes
         * and using the current time as the timestamp of the stream element.
         */

        /**
         * In here our stream element's relation contains just one row of data and
         * it's filled using the binary data which contains the plots. Note that
         * this virtual sensor plots one diagram for each InputStreamName. Also
         * Note that, each InputStreamName can have one or more variables inside
         * it's stream elements's relation thus having one plot for several
         * variables.
         */

        for (int i = 0; i < fieldNames.length; i++) {
            ChartInfo chart = input_stream_name_to_ChartInfo_map.get(fieldNames[i]);
            charts[i] = chart.writePlot().toByteArray();
        }
        StreamElement output = new StreamElement(fieldNames, fieldTypes, charts, System.currentTimeMillis());

        /**
         * Informing container about existance of a stream element.
         */
        dataProduced(output);
        /**
         * For debugging purposes.
         */
        if (logger.isDebugEnabled())
            logger.debug(new StringBuilder().append("Data received under the name: ").append(inputStreamName)
                    .toString());
    }

    public void dispose() {

    }

}

/**
 * This class represents a chart. The class is initialized using a String with a
 * predefined syntax. The class acts as a proxy between the Virtual Sensor and
 * the JFreeChart library which is used for plotting diagrams.
 */

class ChartInfo {

    private static final String SYNTAX = "INPUT_STREAM_VAR_NAME:CHART_NAME:VERTICAL_AXIS_TITLE [TYPE@SIZE] {WIDTH;HEIGHT}";

    private final transient Logger logger = Logger.getLogger(this.getClass());

    private String plotTitle;

    private int width;

    private int height;

    private int historySize;

    private String type;

    private String rowData;

    private String inputStreamName;

    private TimeSeriesCollection dataCollectionForTheChart;

    private HashMap<String, TimeSeries> dataForTheChart = new HashMap<String, TimeSeries>();

    private ByteArrayOutputStream byteArrayOutputStream;

    private JFreeChart chart;

    private boolean changed = true;

    private boolean ready = false;

    private String verticalAxisTitle;

    public ChartInfo() {
        byteArrayOutputStream = new ByteArrayOutputStream(64 * 1024); // Grows
        // as
        // needed
        byteArrayOutputStream.reset();
        dataCollectionForTheChart = new TimeSeriesCollection();
        rowData = "";
    }

    public void setWidth(int width) {
        if (!ready)
            this.width = width;
    }

    public void setHeight(int height) {
        if (!ready)
            this.height = height;
    }

    public void setHistorySize(int history) {
        if (!ready)
            historySize = history;
    }

    public void setVerticalAxisTitle(String title) {
        if (!ready)
            verticalAxisTitle = title;
    }

    public void setType(String type) {
        if (!ready)
            this.type = type;
    }

    public void setPlotTitle(String plotTitle) {
        if (!ready)
            this.plotTitle = plotTitle;
    }

    public void setInputStreamName(String inputStreamName) {
        if (!ready)
            this.inputStreamName = inputStreamName;
    }

    public void initialize() {
        if (!ready) {
            chart = ChartFactory.createTimeSeriesChart(plotTitle, "Time", verticalAxisTitle,
                    dataCollectionForTheChart, true, true, false);
            chart.setBorderVisible(true);
            ready = true;
            if (logger.isDebugEnabled())
                logger.debug("The Chart Virtual Sensor is ready.");
        }
    }

    /**
     * This method adds the specified stream elements to the timeSeries of the
     * appropriate plot.
     * 
     * @param streamElement
     */
    public synchronized void addData(StreamElement streamElement) {
        for (int i = 0; i < streamElement.getFieldNames().length; i++) {
            TimeSeries timeSeries = dataForTheChart.get(streamElement.getFieldNames()[i]);
            if (timeSeries == null) {
                dataForTheChart.put(streamElement.getFieldNames()[i],
                        timeSeries = new TimeSeries(streamElement.getFieldNames()[i],
                                org.jfree.data.time.FixedMillisecond.class));
                timeSeries.setMaximumItemCount(historySize);
                dataCollectionForTheChart.addSeries(timeSeries);
            }
            try {
                timeSeries.addOrUpdate(new FixedMillisecond(new Date(streamElement.getTimeStamp())),
                        Double.parseDouble(streamElement.getData()[i].toString()));
            } catch (SeriesException e) {
                logger.warn(e.getMessage(), e);
            }

        }
        changed = true;
    }

    /**
     * Plots the chart and sends it in the form of ByteArrayOutputStream to
     * outside.
     * 
     * @return Returns the byteArrayOutputStream.
     */
    public synchronized ByteArrayOutputStream writePlot() {
        if (!changed)
            return byteArrayOutputStream;
        byteArrayOutputStream.reset();
        try {
            ChartUtilities.writeChartAsPNG(byteArrayOutputStream, chart, width, height, false, 8);

        } catch (IOException e) {
            logger.warn(e.getMessage(), e);
        }
        return byteArrayOutputStream;
    }

    public boolean equals(Object obj) {
        if (obj == null && !(obj instanceof ChartInfo))
            return false;
        return (obj.hashCode() == hashCode());
    }

    int cachedHashCode = -1;

    public int hashCode() {
        if (rowData != null && cachedHashCode == -1)
            cachedHashCode = rowData.hashCode();
        return cachedHashCode;
    }

    /**
     * @return Returns the inputStreamName.
     */
    public String getInputStreamName() {
        return inputStreamName;
    }

    public String toString() {
        StringBuffer buffer = new StringBuffer();
        try {
            if (plotTitle != null)
                buffer.append("Plot-Title : ").append(plotTitle).append("\n");
            if (inputStreamName != null) {
                buffer.append("Input-Stream Name : ").append(inputStreamName).append("\n");
            }
            buffer.append("Width : ").append(width).append("\n");
            buffer.append("Height : ").append(height).append("\n");
            if (type != null)
                buffer.append("Type : ").append(type).append("\n");
            buffer.append("History-size : ").append(historySize).append("\n");
        } catch (Exception e) {
            buffer.insert(0,
                    "ERROR : Till now the ChartVirtualSensor instance could understand the followings : \n");
        }
        return buffer.toString();
    }
}