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+<?php
+/**
+ * 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 log4php
+ */
+
+/**
+ * Abstract class that defines output logs strategies.
+ *
+ * @version $Revision: 1374777 $
+ * @package log4php
+ */
+abstract class LoggerAppender extends LoggerConfigurable {
+
+ /**
+ * Set to true when the appender is closed. A closed appender will not
+ * accept any logging requests.
+ * @var boolean
+ */
+ protected $closed = false;
+
+ /**
+ * The first filter in the filter chain.
+ * @var LoggerFilter
+ */
+ protected $filter;
+
+ /**
+ * The appender's layout. Can be null if the appender does not use
+ * a layout.
+ * @var LoggerLayout
+ */
+ protected $layout;
+
+ /**
+ * Appender name. Used by other components to identify this appender.
+ * @var string
+ */
+ protected $name;
+
+ /**
+ * Appender threshold level. Events whose level is below the threshold
+ * will not be logged.
+ * @var LoggerLevel
+ */
+ protected $threshold;
+
+ /**
+ * Set to true if the appender requires a layout.
+ *
+ * True by default, appenders which do not use a layout should override
+ * this property to false.
+ *
+ * @var boolean
+ */
+ protected $requiresLayout = true;
+
+ /**
+ * Default constructor.
+ * @param string $name Appender name
+ */
+ public function __construct($name = '') {
+ $this->name = $name;
+
+ if ($this->requiresLayout) {
+ $this->layout = $this->getDefaultLayout();
+ }
+ }
+
+ public function __destruct() {
+ $this->close();
+ }
+
+ /**
+ * Returns the default layout for this appender. Can be overriden by
+ * derived appenders.
+ *
+ * @return LoggerLayout
+ */
+ public function getDefaultLayout() {
+ return new LoggerLayoutSimple();
+ }
+
+ /**
+ * Adds a filter to the end of the filter chain.
+ * @param LoggerFilter $filter add a new LoggerFilter
+ */
+ public function addFilter($filter) {
+ if ($this->filter === null) {
+ $this->filter = $filter;
+ } else {
+ $this->filter->addNext($filter);
+ }
+ }
+
+ /**
+ * Clears the filter chain by removing all the filters in it.
+ */
+ public function clearFilters() {
+ $this->filter = null;
+ }
+
+ /**
+ * Returns the first filter in the filter chain.
+ * The return value may be <i>null</i> if no is filter is set.
+ * @return LoggerFilter
+ */
+ public function getFilter() {
+ return $this->filter;
+ }
+
+ /**
+ * Returns the first filter in the filter chain.
+ * The return value may be <i>null</i> if no is filter is set.
+ * @return LoggerFilter
+ */
+ public function getFirstFilter() {
+ return $this->filter;
+ }
+
+ /**
+ * Performs threshold checks and invokes filters before delegating logging
+ * to the subclass' specific <i>append()</i> method.
+ * @see LoggerAppender::append()
+ * @param LoggerLoggingEvent $event
+ */
+ public function doAppend(LoggerLoggingEvent $event) {
+ if ($this->closed) {
+ return;
+ }
+
+ if (!$this->isAsSevereAsThreshold($event->getLevel())) {
+ return;
+ }
+
+ $filter = $this->getFirstFilter();
+ while ($filter !== null) {
+ switch ($filter->decide($event)) {
+ case LoggerFilter::DENY:
+ return;
+ case LoggerFilter::ACCEPT:
+ return $this->append($event);
+ case LoggerFilter::NEUTRAL:
+ $filter = $filter->getNext();
+ }
+ }
+ $this->append($event);
+ }
+
+ /**
+ * Sets the appender layout.
+ * @param LoggerLayout $layout
+ */
+ public function setLayout($layout) {
+ if ($this->requiresLayout()) {
+ $this->layout = $layout;
+ }
+ }
+
+ /**
+ * Returns the appender layout.
+ * @return LoggerLayout
+ */
+ public function getLayout() {
+ return $this->layout;
+ }
+
+ /**
+ * Configurators call this method to determine if the appender
+ * requires a layout.
+ *
+ * <p>If this method returns <i>true</i>, meaning that layout is required,
+ * then the configurator will configure a layout using the configuration
+ * information at its disposal. If this method returns <i>false</i>,
+ * meaning that a layout is not required, then layout configuration will be
+ * skipped even if there is available layout configuration
+ * information at the disposal of the configurator.</p>
+ *
+ * <p>In the rather exceptional case, where the appender
+ * implementation admits a layout but can also work without it, then
+ * the appender should return <i>true</i>.</p>
+ *
+ * @return boolean
+ */
+ public function requiresLayout() {
+ return $this->requiresLayout;
+ }
+
+ /**
+ * Retruns the appender name.
+ * @return string
+ */
+ public function getName() {
+ return $this->name;
+ }
+
+ /**
+ * Sets the appender name.
+ * @param string $name
+ */
+ public function setName($name) {
+ $this->name = $name;
+ }
+
+ /**
+ * Returns the appender's threshold level.
+ * @return LoggerLevel
+ */
+ public function getThreshold() {
+ return $this->threshold;
+ }
+
+ /**
+ * Sets the appender threshold.
+ *
+ * @param LoggerLevel|string $threshold Either a {@link LoggerLevel}
+ * object or a string equivalent.
+ * @see LoggerOptionConverter::toLevel()
+ */
+ public function setThreshold($threshold) {
+ $this->setLevel('threshold', $threshold);
+ }
+
+ /**
+ * Checks whether the message level is below the appender's threshold.
+ *
+ * If there is no threshold set, then the return value is always <i>true</i>.
+ *
+ * @param LoggerLevel $level
+ * @return boolean Returns true if level is greater or equal than
+ * threshold, or if the threshold is not set. Otherwise returns false.
+ */
+ public function isAsSevereAsThreshold($level) {
+ if ($this->threshold === null) {
+ return true;
+ }
+ return $level->isGreaterOrEqual($this->getThreshold());
+ }
+
+ /**
+ * Prepares the appender for logging.
+ *
+ * Derived appenders should override this method if option structure
+ * requires it.
+ */
+ public function activateOptions() {
+ $this->closed = false;
+ }
+
+ /**
+ * Forwards the logging event to the destination.
+ *
+ * Derived appenders should implement this method to perform actual logging.
+ *
+ * @param LoggerLoggingEvent $event
+ */
+ abstract protected function append(LoggerLoggingEvent $event);
+
+ /**
+ * Releases any resources allocated by the appender.
+ *
+ * Derived appenders should override this method to perform proper closing
+ * procedures.
+ */
+ public function close() {
+ $this->closed = true;
+ }
+
+ /** Triggers a warning for this logger with the given message. */
+ protected function warn($message) {
+ $id = get_class($this) . (empty($this->name) ? '' : ":{$this->name}");
+ trigger_error("log4php: [$id]: $message", E_USER_WARNING);
+ }
+
+}