1 files changed, 243 insertions, 0 deletions
diff --git a/qpid/java/broker-core/src/main/java/org/apache/qpid/server/logging/LogRecorder.java b/qpid/java/broker-core/src/main/java/org/apache/qpid/server/logging/LogRecorder.java
new file mode 100644
index 0000000000..dfffbdbb5f
--- /dev/null
+++ b/qpid/java/broker-core/src/main/java/org/apache/qpid/server/logging/LogRecorder.java
@@ -0,0 +1,243 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.apache.qpid.server.logging;
+
+import java.util.Iterator;
+import org.apache.log4j.Appender;
+import org.apache.log4j.Layout;
+import org.apache.log4j.Logger;
+import org.apache.log4j.spi.ErrorHandler;
+import org.apache.log4j.spi.Filter;
+import org.apache.log4j.spi.LoggingEvent;
+import org.apache.log4j.spi.ThrowableInformation;
+import org.apache.qpid.server.configuration.BrokerProperties;
+
+public class LogRecorder implements Appender, Iterable<LogRecorder.Record>
+{
+    private static final int DEFAULT_BUFFER_SIZE = 4096;
+    private ErrorHandler _errorHandler;
+    private Filter _filter;
+    private String _name;
+    private long _recordId;
+
+    private final int _bufferSize = Integer.getInteger(BrokerProperties.PROPERTY_LOG_RECORDS_BUFFER_SIZE, DEFAULT_BUFFER_SIZE);
+    private final int _mask = _bufferSize - 1;
+    private Record[] _records = new Record[_bufferSize];
+
+
+    public static class Record
+    {
+        private final long _id;
+        private final String _logger;
+        private final long _timestamp;
+        private final String _threadName;
+        private final String _level;
+        private final String _message;
+
+
+        public Record(long id, LoggingEvent event)
+        {
+            _id = id;
+            _logger = event.getLoggerName();
+            _timestamp = event.timeStamp;
+            _threadName = event.getThreadName();
+            _level = event.getLevel().toString();
+            StringBuilder message = new StringBuilder();
+            String renderedMessage = event.getRenderedMessage();
+            if (renderedMessage != null)
+            {
+                message.append(renderedMessage);
+            }
+            ThrowableInformation ti = event.getThrowableInformation();
+            if (ti != null)
+            {
+                Throwable t = ti.getThrowable();
+                if (t != null)
+                {
+                    if (message.length() > 0)
+                    {
+                        message.append(":");
+                    }
+                    String exceptionMessage = t.getMessage();
+                    if (exceptionMessage != null && !"".equals(exceptionMessage))
+                    {
+                        message.append(t.getMessage());
+                    }
+                    else
+                    {
+                        message.append(t.getClass().getName());
+                    }
+                }
+            }
+            _message = message.toString();
+        }
+
+        public long getId()
+        {
+            return _id;
+        }
+
+        public long getTimestamp()
+        {
+            return _timestamp;
+        }
+
+        public String getThreadName()
+        {
+            return _threadName;
+        }
+
+        public String getLevel()
+        {
+            return _level;
+        }
+
+        public String getMessage()
+        {
+            return _message;
+        }
+
+        public String getLogger()
+        {
+            return _logger;
+        }
+    }
+
+    public LogRecorder()
+    {
+        Logger.getRootLogger().addAppender(this);
+    }
+
+    @Override
+    public void addFilter(Filter filter)
+    {
+        _filter = filter;
+    }
+
+    @Override
+    public void clearFilters()
+    {
+        _filter = null;
+    }
+
+    @Override
+    public void close()
+    {
+    }
+
+    public void closeLogRecorder()
+    {
+        Logger.getRootLogger().removeAppender(this);
+    }
+
+    @Override
+    public synchronized void doAppend(LoggingEvent loggingEvent)
+    {
+        _records[((int) (_recordId & _mask))] = new Record(_recordId, loggingEvent);
+        _recordId++;
+    }
+
+    @Override
+    public ErrorHandler getErrorHandler()
+    {
+        return _errorHandler;
+    }
+
+    @Override
+    public Filter getFilter()
+    {
+        return _filter;
+    }
+
+    @Override
+    public Layout getLayout()
+    {
+        return null;
+    }
+
+    @Override
+    public String getName()
+    {
+        return _name;
+    }
+
+    @Override
+    public boolean requiresLayout()
+    {
+        return false;
+    }
+
+    @Override
+    public void setErrorHandler(ErrorHandler errorHandler)
+    {
+        _errorHandler = errorHandler;
+    }
+
+    @Override
+    public void setLayout(Layout layout)
+    {
+
+    }
+
+    @Override
+    public void setName(String name)
+    {
+        _name = name;
+    }
+
+    @Override
+    public Iterator<Record> iterator()
+    {
+        return new RecordIterator(Math.max(_recordId-_bufferSize, 0l));
+    }
+
+    private class RecordIterator implements Iterator<Record>
+    {
+        private long _id;
+
+        public RecordIterator(long currentRecordId)
+        {
+            _id = currentRecordId;
+        }
+
+        @Override
+        public boolean hasNext()
+        {
+            return _id < _recordId;
+        }
+
+        @Override
+        public Record next()
+        {
+            Record record = _records[((int) (_id & _mask))];
+            while(_id < _recordId-_bufferSize)
+            {
+                _id = _recordId-_bufferSize;
+                record = _records[((int) (_id & _mask))];
+            }
+            _id++;
+            return record;
+        }
+
+        @Override
+        public void remove()
+        {
+            throw new UnsupportedOperationException();
+        }
+    }
+}