Bug 42044

This is the source code for a CompositeLogger that logs to a default logger, and
 the XmlLogger. This needs the environment variable ANT_LOG_PREFIX to be set
(there's no better way I can think of)


/*******************************************************************************
 * Copyright 2007 Ketan Padegaonkar http://ketan.padegaonkar.name
 * 
 * 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
 * 
 *     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 name.padegaonkar.ketan.ant.logger;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.PrintStream;
import java.util.ArrayList;
import java.util.Iterator;

import org.apache.tools.ant.BuildEvent;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.BuildLogger;
import org.apache.tools.ant.DefaultLogger;
import org.apache.tools.ant.XmlLogger;

/**
 * @author Ketan Padegaonkar
 */
public class CompositeAntLogger implements BuildLogger {

        private ArrayList       loggers;
        private String          logPrefix;
        private PrintStream     out;

        public CompositeAntLogger() {
                checkLogPrefix();
                createLoggers();
        }

        public void setEmacsMode(boolean emacsMode) {
                for (Iterator iterator = loggers.iterator(); iterator.hasNext();) {
                        BuildLogger logger = (BuildLogger) iterator.next();
                        logger.setEmacsMode(emacsMode);
                }
        }

        public void buildFinished(BuildEvent event) {
                for (Iterator iterator = loggers.iterator(); iterator.hasNext();) {
                        BuildLogger logger = (BuildLogger) iterator.next();
                        logger.buildFinished(event);
                }
        }

        public void buildStarted(BuildEvent event) {
                for (Iterator iterator = loggers.iterator(); iterator.hasNext();) {
                        BuildLogger logger = (BuildLogger) iterator.next();
                        logger.buildStarted(event);
                }
        }

        public void messageLogged(BuildEvent event) {
                for (Iterator iterator = loggers.iterator(); iterator.hasNext();) {
                        BuildLogger logger = (BuildLogger) iterator.next();
                        logger.messageLogged(event);
                }

        }

        public void targetFinished(BuildEvent event) {
                for (Iterator iterator = loggers.iterator(); iterator.hasNext();) {
                        BuildLogger logger = (BuildLogger) iterator.next();
                        logger.targetFinished(event);
                }
        }

        public void targetStarted(BuildEvent event) {
                for (Iterator iterator = loggers.iterator(); iterator.hasNext();) {
                        BuildLogger logger = (BuildLogger) iterator.next();
                        logger.targetStarted(event);
                }
        }

        public void taskFinished(BuildEvent event) {
                for (Iterator iterator = loggers.iterator(); iterator.hasNext();) {
                        BuildLogger logger = (BuildLogger) iterator.next();
                        logger.taskFinished(event);
                }
        }

        public void taskStarted(BuildEvent event) {
                for (Iterator iterator = loggers.iterator(); iterator.hasNext();) {
                        BuildLogger logger = (BuildLogger) iterator.next();
                        logger.taskStarted(event);
                }
        }

        public void setMessageOutputLevel(int level) {
                for (Iterator iterator = loggers.iterator(); iterator.hasNext();) {
                        BuildLogger logger = (BuildLogger) iterator.next();
                        logger.setMessageOutputLevel(level);
                }
        }

        public void setOutputPrintStream(PrintStream output) {
                // do nothing
        }

        public void setErrorPrintStream(PrintStream err) {
                // do nothing
        }

        private void createLoggers() {
                loggers = new ArrayList();
                try {
                        loggers.add(createDefaultLogger());
                        loggers.add(createXmlLogger());
                } catch (FileNotFoundException e) {
                        throw new BuildException("The loggers could not open the
file", e);
                }
        }

        private void checkLogPrefix() {
                logPrefix = System.getenv("ANT_LOG_PREFIX");
                if (logPrefix == null || logPrefix.trim().length() == 0)
                        throw new BuildException("You need to set the
environment variable ANT_LOG_PREFIX.");
        }

        private DefaultLogger createDefaultLogger() throws FileNotFoundException {
                DefaultLogger logger = new DefaultLogger();
                out = new PrintStream(new FileOutputStream(logPrefix + ".txt"));
                logger.setOutputPrintStream(out);
                logger.setErrorPrintStream(out);
                return logger;
        }

        private XmlLogger createXmlLogger() throws FileNotFoundException {
                XmlLogger logger = new XmlLogger();
                out = new PrintStream(new FileOutputStream(logPrefix + ".xml"));
                logger.setOutputPrintStream(out);
                logger.setErrorPrintStream(out);
                return logger;
        }
}

Created attachment 21851 [details]
lsof output for various cases of logging 

lsof output indicating number of pipes used for each combination of: 3 apache versions (2.2.6, 2.2.8 unpatched, 2.2.8 patched) by 3 config cases (T+E logs in main config, T+E in 1 VH, t+E in 2 VHs).

Please ignore recent attachment - it went to the wrong bug... sorry.

(why oh why does bugzilla go to a random bug after posting?)