summaryrefslogtreecommitdiff
path: root/libjava/classpath/java/util/logging/MemoryHandler.java
diff options
context:
space:
mode:
authorupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
committerupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
commit554fd8c5195424bdbcabf5de30fdc183aba391bd (patch)
tree976dc5ab7fddf506dadce60ae936f43f58787092 /libjava/classpath/java/util/logging/MemoryHandler.java
downloadcbb-gcc-4.6.4-554fd8c5195424bdbcabf5de30fdc183aba391bd.tar.bz2
cbb-gcc-4.6.4-554fd8c5195424bdbcabf5de30fdc183aba391bd.tar.xz
obtained gcc-4.6.4.tar.bz2 from upstream website;upstream
verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository.
Diffstat (limited to 'libjava/classpath/java/util/logging/MemoryHandler.java')
-rw-r--r--libjava/classpath/java/util/logging/MemoryHandler.java345
1 files changed, 345 insertions, 0 deletions
diff --git a/libjava/classpath/java/util/logging/MemoryHandler.java b/libjava/classpath/java/util/logging/MemoryHandler.java
new file mode 100644
index 000000000..e5c258bbf
--- /dev/null
+++ b/libjava/classpath/java/util/logging/MemoryHandler.java
@@ -0,0 +1,345 @@
+/* MemoryHandler.java -- a class for buffering log messages in a memory buffer
+ Copyright (C) 2002, 2004 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath 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 for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING. If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library. Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module. An independent module is a module which is not derived from
+or based on this library. If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so. If you do not wish to do so, delete this
+exception statement from your version. */
+
+package java.util.logging;
+
+/**
+ * A <code>MemoryHandler</code> maintains a circular buffer of
+ * log records.
+ *
+ * <p><strong>Configuration:</strong> Values of the subsequent
+ * <code>LogManager</code> properties are taken into consideration
+ * when a <code>MemoryHandler</code> is initialized.
+ * If a property is not defined, or if it has an invalid
+ * value, a default is taken without an exception being thrown.
+ *
+ * <ul>
+ * <li><code>java.util.MemoryHandler.level</code> - specifies
+ * the initial severity level threshold. Default value:
+ * <code>Level.ALL</code>.</li>
+ * <li><code>java.util.MemoryHandler.filter</code> - specifies
+ * the name of a Filter class. Default value: No Filter.</li>
+ * <li><code>java.util.MemoryHandler.size</code> - specifies the
+ * maximum number of log records that are kept in the circular
+ * buffer. Default value: 1000.</li>
+ * <li><code>java.util.MemoryHandler.push</code> - specifies the
+ * <code>pushLevel</code>. Default value:
+ * <code>Level.SEVERE</code>.</li>
+ * <li><code>java.util.MemoryHandler.target</code> - specifies the
+ * name of a subclass of {@link Handler} that will be used as the
+ * target handler. There is no default value for this property;
+ * if it is not set, the no-argument MemoryHandler constructor
+ * will throw an exception.</li>
+ * </ul>
+ *
+ * @author Sascha Brawer (brawer@acm.org)
+ */
+public class MemoryHandler
+ extends Handler
+{
+ /**
+ * The storage area used for buffering the unpushed log records in
+ * memory.
+ */
+ private final LogRecord[] buffer;
+
+
+ /**
+ * The current position in the circular buffer. For a new
+ * MemoryHandler, or immediately after {@link #push()} was called,
+ * the value of this variable is zero. Each call to {@link
+ * #publish(LogRecord)} will store the published LogRecord into
+ * <code>buffer[position]</code> before position is incremented by
+ * one. If position becomes greater than the size of the buffer, it
+ * is reset to zero.
+ */
+ private int position;
+
+
+ /**
+ * The number of log records which have been published, but not
+ * pushed yet to the target handler.
+ */
+ private int numPublished;
+
+
+ /**
+ * The push level threshold for this <code>Handler</code>. When a
+ * record is published whose severity level is greater than or equal
+ * to the <code>pushLevel</code> of this <code>MemoryHandler</code>,
+ * the {@link #push()} method will be invoked for pushing the buffer
+ * contents to the target <code>Handler</code>.
+ */
+ private Level pushLevel;
+
+
+ /**
+ * The Handler to which log records are forwarded for actual
+ * publication.
+ */
+ private final Handler target;
+
+
+ /**
+ * Constructs a <code>MemoryHandler</code> for keeping a circular
+ * buffer of LogRecords; the initial configuration is determined by
+ * the <code>LogManager</code> properties described above.
+ */
+ public MemoryHandler()
+ {
+ this((Handler) LogManager.getInstanceProperty(
+ "java.util.logging.MemoryHandler.target",
+ Handler.class, /* default */ null),
+ LogManager.getIntPropertyClamped(
+ "java.util.logging.MemoryHandler.size",
+ /* default */ 1000,
+ /* minimum value */ 1,
+ /* maximum value */ Integer.MAX_VALUE),
+ LogManager.getLevelProperty(
+ "java.util.logging.MemoryHandler.push",
+ /* default push level */ Level.SEVERE));
+ }
+
+
+ /**
+ * Constructs a <code>MemoryHandler</code> for keeping a circular
+ * buffer of LogRecords, given some parameters. The values of the
+ * other parameters are taken from LogManager properties, as
+ * described above.
+ *
+ * @param target the target handler that will receive those
+ * log records that are passed on for publication.
+ *
+ * @param size the number of log records that are kept in the buffer.
+ * The value must be a at least one.
+ *
+ * @param pushLevel the push level threshold for this
+ * <code>MemoryHandler</code>. When a record is published whose
+ * severity level is greater than or equal to
+ * <code>pushLevel</code>, the {@link #push()} method will be
+ * invoked in order to push the bufffer contents to
+ * <code>target</code>.
+ *
+ * @throws java.lang.IllegalArgumentException if <code>size</code>
+ * is negative or zero. The GNU implementation also throws
+ * an IllegalArgumentException if <code>target</code> or
+ * <code>pushLevel</code> are <code>null</code>, but the
+ * API specification does not prescribe what should happen
+ * in those cases.
+ */
+ public MemoryHandler(Handler target, int size, Level pushLevel)
+ {
+ if ((target == null) || (size <= 0) || (pushLevel == null))
+ throw new IllegalArgumentException();
+
+ buffer = new LogRecord[size];
+ this.pushLevel = pushLevel;
+ this.target = target;
+
+ setLevel(LogManager.getLevelProperty(
+ "java.util.logging.MemoryHandler.level",
+ /* default value */ Level.ALL));
+
+ setFilter((Filter) LogManager.getInstanceProperty(
+ "java.util.logging.MemoryHandler.filter",
+ /* must be instance of */ Filter.class,
+ /* default value */ null));
+ }
+
+
+ /**
+ * Stores a <code>LogRecord</code> in a fixed-size circular buffer,
+ * provided the record passes all tests for being loggable. If the
+ * buffer is full, the oldest record will be discarded.
+ *
+ * <p>If the record has a severity level which is greater than or
+ * equal to the <code>pushLevel</code> of this
+ * <code>MemoryHandler</code>, the {@link #push()} method will be
+ * invoked for pushing the buffer contents to the target
+ * <code>Handler</code>.
+ *
+ * <p>Most applications do not need to call this method directly.
+ * Instead, they will use use a {@link Logger}, which will create
+ * LogRecords and distribute them to registered handlers.
+ *
+ * @param record the log event to be published.
+ */
+ public void publish(LogRecord record)
+ {
+ if (!isLoggable(record))
+ return;
+
+ buffer[position] = record;
+ position = (position + 1) % buffer.length;
+ numPublished = numPublished + 1;
+
+ if (record.getLevel().intValue() >= pushLevel.intValue())
+ push();
+ }
+
+
+ /**
+ * Pushes the contents of the memory buffer to the target
+ * <code>Handler</code> and clears the buffer. Note that
+ * the target handler will discard those records that do
+ * not satisfy its own severity level threshold, or that are
+ * not considered loggable by an installed {@link Filter}.
+ *
+ * <p>In case of an I/O failure, the {@link ErrorManager} of the
+ * target <code>Handler</code> will be notified, but the caller of
+ * this method will not receive an exception.
+ */
+ public void push()
+ {
+ int i;
+
+ if (numPublished < buffer.length)
+ {
+ for (i = 0; i < position; i++)
+ target.publish(buffer[i]);
+ }
+ else
+ {
+ for (i = position; i < buffer.length; i++)
+ target.publish(buffer[i]);
+ for (i = 0; i < position; i++)
+ target.publish(buffer[i]);
+ }
+
+ numPublished = 0;
+ position = 0;
+ }
+
+
+ /**
+ * Forces any data that may have been buffered by the target
+ * <code>Handler</code> to the underlying output device, but
+ * does <em>not</em> push the contents of the circular memory
+ * buffer to the target handler.
+ *
+ * <p>In case of an I/O failure, the {@link ErrorManager} of the
+ * target <code>Handler</code> will be notified, but the caller of
+ * this method will not receive an exception.
+ *
+ * @see #push()
+ */
+ public void flush()
+ {
+ target.flush();
+ }
+
+
+ /**
+ * Closes this <code>MemoryHandler</code> and its associated target
+ * handler, discarding the contents of the memory buffer. However,
+ * any data that may have been buffered by the target
+ * <code>Handler</code> is forced to the underlying output device.
+ *
+ * <p>As soon as <code>close</code> has been called,
+ * a <code>Handler</code> should not be used anymore. Attempts
+ * to publish log records, to flush buffers, or to modify the
+ * <code>Handler</code> in any other way may throw runtime
+ * exceptions after calling <code>close</code>.</p>
+ *
+ * <p>In case of an I/O failure, the <code>ErrorManager</code> of
+ * the associated target <code>Handler</code> will be informed, but
+ * the caller of this method will not receive an exception.</p>
+ *
+ * @throws SecurityException if a security manager exists and
+ * the caller is not granted the permission to control
+ * the logging infrastructure.
+ *
+ * @see #push()
+ */
+ public void close()
+ throws SecurityException
+ {
+ push();
+
+ /* This will check for LoggingPermission("control"). If the
+ * current security context does not grant this permission,
+ * push() has been executed, but this does not impose a
+ * security risk.
+ */
+ target.close();
+ }
+
+
+
+ /**
+ * Returns the push level threshold for this <code>Handler</code>.
+ * When a record is published whose severity level is greater
+ * than or equal to the <code>pushLevel</code> of this
+ * <code>MemoryHandler</code>, the {@link #push()} method will be
+ * invoked for pushing the buffer contents to the target
+ * <code>Handler</code>.
+ *
+ * @return the push level threshold for automatic pushing.
+ */
+ public Level getPushLevel()
+ {
+ return pushLevel;
+ }
+
+
+ /**
+ * Sets the push level threshold for this <code>Handler</code>.
+ * When a record is published whose severity level is greater
+ * than or equal to the <code>pushLevel</code> of this
+ * <code>MemoryHandler</code>, the {@link #push()} method will be
+ * invoked for pushing the buffer contents to the target
+ * <code>Handler</code>.
+ *
+ * @param pushLevel the push level threshold for automatic pushing.
+ *
+ * @exception SecurityException if a security manager exists and
+ * the caller is not granted the permission to control
+ * the logging infrastructure.
+ *
+ * @exception NullPointerException if <code>pushLevel</code> is
+ * <code>null</code>.
+ */
+ public void setPushLevel(Level pushLevel)
+ {
+ LogManager.getLogManager().checkAccess();
+
+ /* Throws a NullPointerException if pushLevel is null. */
+ pushLevel.getClass();
+
+ this.pushLevel = pushLevel;
+ }
+}