--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/util/logging/MemoryHandler.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,270 @@
+/*
+ * Copyright 2000-2004 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.util.logging;
+
+/**
+ * <tt>Handler</tt> that buffers requests in a circular buffer in memory.
+ * <p>
+ * Normally this <tt>Handler</tt> simply stores incoming <tt>LogRecords</tt>
+ * into its memory buffer and discards earlier records. This buffering
+ * is very cheap and avoids formatting costs. On certain trigger
+ * conditions, the <tt>MemoryHandler</tt> will push out its current buffer
+ * contents to a target <tt>Handler</tt>, which will typically publish
+ * them to the outside world.
+ * <p>
+ * There are three main models for triggering a push of the buffer:
+ * <ul>
+ * <li>
+ * An incoming <tt>LogRecord</tt> has a type that is greater than
+ * a pre-defined level, the <tt>pushLevel</tt>.
+ * <li>
+ * An external class calls the <tt>push</tt> method explicitly.
+ * <li>
+ * A subclass overrides the <tt>log</tt> method and scans each incoming
+ * <tt>LogRecord</tt> and calls <tt>push</tt> if a record matches some
+ * desired criteria.
+ * </ul>
+ * <p>
+ * <b>Configuration:</b>
+ * By default each <tt>MemoryHandler</tt> is initialized using the following
+ * LogManager configuration properties. If properties are not defined
+ * (or have invalid values) then the specified default values are used.
+ * If no default value is defined then a RuntimeException is thrown.
+ * <ul>
+ * <li> java.util.logging.MemoryHandler.level
+ * specifies the level for the <tt>Handler</tt>
+ * (defaults to <tt>Level.ALL</tt>).
+ * <li> java.util.logging.MemoryHandler.filter
+ * specifies the name of a <tt>Filter</tt> class to use
+ * (defaults to no <tt>Filter</tt>).
+ * <li> java.util.logging.MemoryHandler.size
+ * defines the buffer size (defaults to 1000).
+ * <li> java.util.logging.MemoryHandler.push
+ * defines the <tt>pushLevel</tt> (defaults to <tt>level.SEVERE</tt>).
+ * <li> java.util.logging.MemoryHandler.target
+ * specifies the name of the target <tt>Handler </tt> class.
+ * (no default).
+ * </ul>
+ *
+ * @since 1.4
+ */
+
+public class MemoryHandler extends Handler {
+ private final static int DEFAULT_SIZE = 1000;
+ private Level pushLevel;
+ private int size;
+ private Handler target;
+ private LogRecord buffer[];
+ int start, count;
+
+ // Private method to configure a ConsoleHandler from LogManager
+ // properties and/or default values as specified in the class
+ // javadoc.
+ private void configure() {
+ LogManager manager = LogManager.getLogManager();
+ String cname = getClass().getName();
+
+ pushLevel = manager.getLevelProperty(cname +".push", Level.SEVERE);
+ size = manager.getIntProperty(cname + ".size", DEFAULT_SIZE);
+ if (size <= 0) {
+ size = DEFAULT_SIZE;
+ }
+ setLevel(manager.getLevelProperty(cname +".level", Level.ALL));
+ setFilter(manager.getFilterProperty(cname +".filter", null));
+ setFormatter(manager.getFormatterProperty(cname +".formatter", new SimpleFormatter()));
+ }
+
+ /**
+ * Create a <tt>MemoryHandler</tt> and configure it based on
+ * <tt>LogManager</tt> configuration properties.
+ */
+ public MemoryHandler() {
+ sealed = false;
+ configure();
+ sealed = true;
+
+ String name = "???";
+ try {
+ LogManager manager = LogManager.getLogManager();
+ name = manager.getProperty("java.util.logging.MemoryHandler.target");
+ Class clz = ClassLoader.getSystemClassLoader().loadClass(name);
+ target = (Handler) clz.newInstance();
+ } catch (Exception ex) {
+ throw new RuntimeException("MemoryHandler can't load handler \"" + name + "\"" , ex);
+ }
+ init();
+ }
+
+ // Initialize. Size is a count of LogRecords.
+ private void init() {
+ buffer = new LogRecord[size];
+ start = 0;
+ count = 0;
+ }
+
+ /**
+ * Create a <tt>MemoryHandler</tt>.
+ * <p>
+ * The <tt>MemoryHandler</tt> is configured based on <tt>LogManager</tt>
+ * properties (or their default values) except that the given <tt>pushLevel</tt>
+ * argument and buffer size argument are used.
+ *
+ * @param target the Handler to which to publish output.
+ * @param size the number of log records to buffer (must be greater than zero)
+ * @param pushLevel message level to push on
+ *
+ * @throws IllegalArgumentException is size is <= 0
+ */
+ public MemoryHandler(Handler target, int size, Level pushLevel) {
+ if (target == null || pushLevel == null) {
+ throw new NullPointerException();
+ }
+ if (size <= 0) {
+ throw new IllegalArgumentException();
+ }
+ sealed = false;
+ configure();
+ sealed = true;
+ this.target = target;
+ this.pushLevel = pushLevel;
+ this.size = size;
+ init();
+ }
+
+ /**
+ * Store a <tt>LogRecord</tt> in an internal buffer.
+ * <p>
+ * If there is a <tt>Filter</tt>, its <tt>isLoggable</tt>
+ * method is called to check if the given log record is loggable.
+ * If not we return. Otherwise the given record is copied into
+ * an internal circular buffer. Then the record's level property is
+ * compared with the <tt>pushLevel</tt>. If the given level is
+ * greater than or equal to the <tt>pushLevel</tt> then <tt>push</tt>
+ * is called to write all buffered records to the target output
+ * <tt>Handler</tt>.
+ *
+ * @param record description of the log event. A null record is
+ * silently ignored and is not published
+ */
+ public synchronized void publish(LogRecord record) {
+ if (!isLoggable(record)) {
+ return;
+ }
+ int ix = (start+count)%buffer.length;
+ buffer[ix] = record;
+ if (count < buffer.length) {
+ count++;
+ } else {
+ start++;
+ start %= buffer.length;
+ }
+ if (record.getLevel().intValue() >= pushLevel.intValue()) {
+ push();
+ }
+ }
+
+ /**
+ * Push any buffered output to the target <tt>Handler</tt>.
+ * <p>
+ * The buffer is then cleared.
+ */
+ public synchronized void push() {
+ for (int i = 0; i < count; i++) {
+ int ix = (start+i)%buffer.length;
+ LogRecord record = buffer[ix];
+ target.publish(record);
+ }
+ // Empty the buffer.
+ start = 0;
+ count = 0;
+ }
+
+ /**
+ * Causes a flush on the target <tt>Handler</tt>.
+ * <p>
+ * Note that the current contents of the <tt>MemoryHandler</tt>
+ * buffer are <b>not</b> written out. That requires a "push".
+ */
+ public void flush() {
+ target.flush();
+ }
+
+ /**
+ * Close the <tt>Handler</tt> and free all associated resources.
+ * This will also close the target <tt>Handler</tt>.
+ *
+ * @exception SecurityException if a security manager exists and if
+ * the caller does not have <tt>LoggingPermission("control")</tt>.
+ */
+ public void close() throws SecurityException {
+ target.close();
+ setLevel(Level.OFF);
+ }
+
+ /**
+ * Set the <tt>pushLevel</tt>. After a <tt>LogRecord</tt> is copied
+ * into our internal buffer, if its level is greater than or equal to
+ * the <tt>pushLevel</tt>, then <tt>push</tt> will be called.
+ *
+ * @param newLevel the new value of the <tt>pushLevel</tt>
+ * @exception SecurityException if a security manager exists and if
+ * the caller does not have <tt>LoggingPermission("control")</tt>.
+ */
+ public void setPushLevel(Level newLevel) throws SecurityException {
+ if (newLevel == null) {
+ throw new NullPointerException();
+ }
+ LogManager manager = LogManager.getLogManager();
+ checkAccess();
+ pushLevel = newLevel;
+ }
+
+ /**
+ * Get the <tt>pushLevel</tt>.
+ *
+ * @return the value of the <tt>pushLevel</tt>
+ */
+ public synchronized Level getPushLevel() {
+ return pushLevel;
+ }
+
+ /**
+ * Check if this <tt>Handler</tt> would actually log a given
+ * <tt>LogRecord</tt> into its internal buffer.
+ * <p>
+ * This method checks if the <tt>LogRecord</tt> has an appropriate level and
+ * whether it satisfies any <tt>Filter</tt>. However it does <b>not</b>
+ * check whether the <tt>LogRecord</tt> would result in a "push" of the
+ * buffer contents. It will return false if the <tt>LogRecord</tt> is Null.
+ * <p>
+ * @param record a <tt>LogRecord</tt>
+ * @return true if the <tt>LogRecord</tt> would be logged.
+ *
+ */
+ public boolean isLoggable(LogRecord record) {
+ return super.isLoggable(record);
+ }
+}