source: trunk/EventBenchConsole/src/de/ugoe/cs/eventbench/windows/LogPreprocessor.java

package de.ugoe.cs.eventbench.windows;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;

import org.apache.commons.codec.binary.Base64;

import de.ugoe.cs.util.FileTools;
import de.ugoe.cs.util.StringTools;
import de.ugoe.cs.util.console.Console;

/**
 * <p>
 * Pre-processes log files generated by the EventBench's MFCUsageMonitor. It
 * decodes Base64 encoding into UTF-16. It removes all lines of the log file,
 * that do not start with the prefix "UL:", end everything before the prefix and
 * the prefix itself.
 * </p>
 * 
 * @author Steffen Herbold
 * @version 1.0
 */
public class LogPreprocessor {

        /**
         * <p>
         * Internal flag that monitors whether there is an open session-node in the
         * XML file to ensure that there is a closing session-node for each opening
         * session node and, thereby, ensure that the XML file is well formed.
         * </p>
         */
        private boolean sessionOpen = false;

        /**
         * <p>
         * Internal flag that monitors whether a message node is longer than one
         * line, as the prefix handling is different in this case.
         * </p>
         */
        private boolean msgIncomplete = false;

        /**
         * <p>
         * Flag that marks whether the log file is Base64 encoded.
         * </p>
         */
        private boolean base64;

        /**
         * <p>
         * Constructor. Creates a new LogPreprocessor that does not decode Base64.
         * </p>
         */
        public LogPreprocessor() {
                this(false);
        }

        /**
         * <p>
         * Constructor. Creates a new LogPreprocessor.
         * </p>
         * 
         * @param base64
         *            if true, Base64 will be decoded.
         */
        public LogPreprocessor(boolean base64) {
                this.base64 = base64;
        }

        /**
         * <p>
         * Pre-processes a single log file.
         * </p>
         * 
         * @param source
         *            name and path of the source file
         * @param target
         *            name and path of the target file
         * @throws IOException
         *             thrown if there is a problem with reading from or writing to
         *             the source, respectively target file
         * @throws FileNotFoundException
         *             thrown if the source file is not found
         */
        public void convertToXml(String source, String target) throws IOException,
                        FileNotFoundException {
                OutputStreamWriter targetFile = new OutputStreamWriter(
                                new FileOutputStream(target), "UTF-8");
                targetFile.write("<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
                                + StringTools.ENDLINE);
                targetFile.write("<log>" + StringTools.ENDLINE);
                processFile(source, targetFile);
                if (sessionOpen) {
                        targetFile.write(" </session>" + StringTools.ENDLINE);
                }
                targetFile.write("</log>");
                targetFile.close();
        }

        /**
         * <p>
         * Pre-processes all files in a given source folder.
         * </p>
         * 
         * @param path
         *            path of the source folder
         * @param target
         *            name and path of the target file
         * @throws IOException
         *             thrown if there is a problem with reading from or writing to
         *             the source, respectively target file
         * @throws FileNotFoundException
         *             thrown if the source file is not found
         */
        public void convertDirToXml(String path, String target) throws IOException,
                        FileNotFoundException {
                OutputStreamWriter targetFile = new OutputStreamWriter(
                                new FileOutputStream(target), "UTF-8");
                targetFile.write("<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
                                + StringTools.ENDLINE);
                targetFile.write("<log>" + StringTools.ENDLINE);
                File folder = new File(path);
                if (!folder.isDirectory()) {
                        throw new IOException(path + " is not a directory");
                }
                String absolutPath = folder.getAbsolutePath();
                for (String filename : folder.list()) {
                        String source = absolutPath + "/" + filename;
                        Console.traceln("Processing file: " + source);
                        processFile(source, targetFile);
                }

                if (sessionOpen) {
                        targetFile.write(" </session>" + StringTools.ENDLINE);
                }
                targetFile.write("</log>");
                targetFile.close();
        }

        /**
         * <p>
         * Internal function that pre-processes a log file.
         * </p>
         * 
         * @param source
         *            name and path of the source file
         * @param target
         *            name and path of the target file
         * @throws IOException
         *             thrown if there is a problem with reading from or writing to
         *             the source, respectively target file
         * @throws FileNotFoundException
         *             thrown if the source file is not found
         */
        private void processFile(String source, OutputStreamWriter targetFile)
                        throws FileNotFoundException, IOException {
                String[] lines = FileTools.getLinesFromFile(source, false);
                String incompleteLine = "";
                for (String currentLine : lines) {
                        if (currentLine.contains("UL: <session>")) {
                                if (sessionOpen) {
                                        targetFile.write(" </session>" + StringTools.ENDLINE);
                                        targetFile.write(" <session>" + StringTools.ENDLINE);
                                } else {
                                        targetFile.write(" <session>" + StringTools.ENDLINE);
                                        sessionOpen = true;
                                }
                        } else if (currentLine.contains("UL: </session>")) {
                                if (sessionOpen) {
                                        targetFile.write(" </session>" + StringTools.ENDLINE);
                                        sessionOpen = false;
                                }
                        } else if (msgIncomplete || currentLine.contains("UL: ")) {

                                String currentContent;
                                String actualLine;
                                if (msgIncomplete) {
                                        actualLine = currentLine;
                                } else {
                                        String[] splitResult = currentLine.split("UL: ");
                                        actualLine = splitResult[1];
                                }
                                if (base64) {
                                        Base64 decoder = new Base64();
                                        byte[] decoded = decoder.decode(actualLine);
                                        currentContent = new String(decoded, "UTF-16LE");
                                        if( currentContent.length()!=0 ) {
                                                currentContent = currentContent.substring(0,
                                                                currentContent.length() - 1);
                                        }
                                } else {
                                        currentContent = actualLine;
                                }
                                if (msgIncomplete) {
                                        incompleteLine += currentContent;
                                        if (incompleteLine.contains("</msg>")) {
                                                msgIncomplete = false;
                                                targetFile.write(incompleteLine + StringTools.ENDLINE);
                                                incompleteLine = "";
                                        }
                                } else {
                                        if (currentContent.contains("<msg") && sessionOpen) {
                                                if (currentContent.contains("</msg>")) {
                                                        targetFile.write("  " + currentContent
                                                                        + StringTools.ENDLINE);
                                                } else {
                                                        msgIncomplete = true;
                                                        incompleteLine += currentContent;
                                                }
                                        }
                                }
                        }
                }
        }

}