Move SLC Support

[gpl/argeo-slc.git] / org.argeo.slc.support / src / org / argeo / slc / log4j / SlcExecutionAppender.java

diff --git a/org.argeo.slc.support/src/org/argeo/slc/log4j/SlcExecutionAppender.java b/org.argeo.slc.support/src/org/argeo/slc/log4j/SlcExecutionAppender.java
new file mode 100644 (file)
index 0000000..190a0b6
--- /dev/null
+++ b/org.argeo.slc.support/src/org/argeo/slc/log4j/SlcExecutionAppender.java
@@ -0,0 +1,165 @@
+/*
+ * Copyright (C) 2007-2012 Argeo GmbH
+ *
+ * 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 org.argeo.slc.log4j;
+
+import java.util.Date;
+import java.util.concurrent.BlockingQueue;
+
+import org.apache.log4j.AppenderSkeleton;
+import org.apache.log4j.Level;
+import org.apache.log4j.Logger;
+import org.apache.log4j.spi.LoggingEvent;
+import org.argeo.slc.core.execution.ExecutionThread;
+import org.argeo.slc.core.execution.ProcessThreadGroup;
+import org.argeo.slc.execution.ExecutionStep;
+
+/** Not meant to be used directly in standard log4j config */
+public class SlcExecutionAppender extends AppenderSkeleton {
+
+       private Boolean disabled = false;
+
+       private String level = null;
+
+       private Level log4jLevel = null;
+
+       /** Marker to prevent stack overflow */
+       private ThreadLocal<Boolean> dispatching = new ThreadLocal<Boolean>() {
+
+               @Override
+               protected Boolean initialValue() {
+                       return false;
+               }
+       };
+
+       // private Layout layout = null;
+       // private String pattern = "%m - %c%n";
+       private Boolean onlyExecutionThread = false;
+
+       public void init() {
+               // if (layout != null)
+               // setLayout(layout);
+               // else
+               // setLayout(new PatternLayout(pattern));
+               Logger.getRootLogger().addAppender(this);
+       }
+
+       @Override
+       protected void append(LoggingEvent event) {
+               if (disabled)
+                       return;
+
+               if (dispatching.get())
+                       return;
+
+               if (level != null && !level.trim().equals("")) {
+                       if (log4jLevel == null || !log4jLevel.toString().equals(level))
+                               try {
+                                       log4jLevel = Level.toLevel(level);
+                               } catch (Exception e) {
+                                       System.err
+                                                       .println("Log4j level could not be set for level '"
+                                                                       + level + "', resetting it to null.");
+                                       e.printStackTrace();
+                                       level = null;
+                               }
+
+                       if (log4jLevel != null
+                                       && !event.getLevel().isGreaterOrEqual(log4jLevel)) {
+                               return;
+                       }
+               }
+
+               // Check whether we are within an executing process
+               Thread currentThread = Thread.currentThread();
+               if (currentThread.getThreadGroup() instanceof ProcessThreadGroup) {
+                       if (onlyExecutionThread
+                                       && !(currentThread instanceof ExecutionThread))
+                               return;
+
+                       final String type;
+                       if (event.getLevel().equals(Level.ERROR)
+                                       || event.getLevel().equals(Level.FATAL))
+                               type = ExecutionStep.ERROR;
+                       else if (event.getLevel().equals(Level.WARN))
+                               type = ExecutionStep.WARNING;
+                       else if (event.getLevel().equals(Level.INFO))
+                               type = ExecutionStep.INFO;
+                       else if (event.getLevel().equals(Level.DEBUG))
+                               type = ExecutionStep.DEBUG;
+                       else if (event.getLevel().equals(Level.TRACE))
+                               type = ExecutionStep.TRACE;
+                       else
+                               type = ExecutionStep.INFO;
+
+                       ExecutionStep step = new ExecutionStep(event.getLoggerName(),
+                                       new Date(event.getTimeStamp()), type, event.getMessage()
+                                                       .toString());
+
+                       try {
+                               dispatching.set(true);
+                               BlockingQueue<ExecutionStep> steps = ((ProcessThreadGroup) currentThread
+                                               .getThreadGroup()).getSteps();
+                               if (steps.remainingCapacity() == 0) {
+                                       stdOut("WARNING: execution steps queue is full, skipping step: "
+                                                       + step);
+                                       // FIXME understand why it block indefinitely: the queue
+                                       // should be emptied by the logging thread
+                               } else {
+                                       steps.add(step);
+                               }
+                       } finally {
+                               dispatching.set(false);
+                       }
+               }
+       }
+
+       public void destroy() throws Exception {
+               Logger.getRootLogger().removeAppender(this);
+       }
+
+       public void close() {
+       }
+
+       public boolean requiresLayout() {
+               return false;
+       }
+
+       // public void setLayout(Layout layout) {
+       // this.layout = layout;
+       // }
+
+       /** For development purpose, since using regular logging is not easy here */
+       static void stdOut(Object obj) {
+               System.out.println(obj);
+       }
+
+       // public void setPattern(String pattern) {
+       // this.pattern = pattern;
+       // }
+
+       public void setOnlyExecutionThread(Boolean onlyExecutionThread) {
+               this.onlyExecutionThread = onlyExecutionThread;
+       }
+
+       public void setDisabled(Boolean disabled) {
+               this.disabled = disabled;
+       }
+
+       public void setLevel(String level) {
+               this.level = level;
+       }
+
+}