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Posted to dev@tomcat.apache.org by ma...@apache.org on 2021/11/04 10:53:14 UTC
[tomcat] branch 10.0.x updated: Provide a little more control over
resource caching
This is an automated email from the ASF dual-hosted git repository.
markt pushed a commit to branch 10.0.x
in repository https://gitbox.apache.org/repos/asf/tomcat.git
The following commit(s) were added to refs/heads/10.0.x by this push:
new 9425968 Provide a little more control over resource caching
9425968 is described below
commit 9425968c6a94cb85ec8e748cd16cc3e591040ab4
Author: Mark Thomas <ma...@apache.org>
AuthorDate: Thu Nov 4 10:52:06 2021 +0000
Provide a little more control over resource caching
---
java/org/apache/catalina/WebResourceRoot.java | 44 ++++++++++++++++++++++
.../apache/catalina/startup/ContextRuleSet.java | 8 ++++
java/org/apache/catalina/webresources/Cache.java | 17 +++++++++
.../catalina/webresources/MyCacheStrategy.java | 29 ++++++++++++++
.../apache/catalina/webresources/StandardRoot.java | 11 ++++++
webapps/docs/changelog.xml | 5 +++
6 files changed, 114 insertions(+)
diff --git a/java/org/apache/catalina/WebResourceRoot.java b/java/org/apache/catalina/WebResourceRoot.java
index 8d8092a..ae37893 100644
--- a/java/org/apache/catalina/WebResourceRoot.java
+++ b/java/org/apache/catalina/WebResourceRoot.java
@@ -431,10 +431,54 @@ public interface WebResourceRoot extends Lifecycle {
*/
void gc();
+ /**
+ * Obtain the current caching strategy.
+ * <p>
+ * The default implementation returns {@code null}. Sub-classes wishing to
+ * utilise a {@link CacheStrategy} should provide an appropriate
+ * implementation.
+ *
+ * @return the current caching strategy or {@code null} if no strategy has
+ * been configured
+ */
+ default CacheStrategy getCacheStrategy() {
+ return null;
+ }
+
+ /**
+ * Set the current caching strategy.
+ * <p>
+ * The default implementation is a NO-OP. Sub-classes wishing to utilise a
+ * {@link CacheStrategy} should provide an appropriate implementation.
+ *
+ * @param strategy The new strategy to use or {@code null} for no strategy
+ */
+ default void setCacheStrategy(CacheStrategy strategy) {
+ // NO-OP
+ }
+
enum ResourceSetType {
PRE,
RESOURCE_JAR,
POST,
CLASSES_JAR
}
+
+ /**
+ * Provides a mechanism to modify the caching behaviour.
+ */
+ interface CacheStrategy {
+
+ /**
+ * Should the result of looking up the resource at the given path be
+ * excluded from caching?
+ *
+ * @param path The path to check against the strategy to see if the
+ * result should be cached
+ *
+ * @return {@code true} if the result should not be cached, otherwise
+ * {@code false}
+ */
+ boolean noCache(String path);
+ }
}
diff --git a/java/org/apache/catalina/startup/ContextRuleSet.java b/java/org/apache/catalina/startup/ContextRuleSet.java
index e230d54..4aa081e 100644
--- a/java/org/apache/catalina/startup/ContextRuleSet.java
+++ b/java/org/apache/catalina/startup/ContextRuleSet.java
@@ -168,6 +168,14 @@ public class ContextRuleSet implements RuleSet {
"setResources",
"org.apache.catalina.WebResourceRoot");
+ digester.addObjectCreate(prefix + "Context/Resources/CacheStrategy",
+ null, // MUST be specified in the element
+ "className");
+ digester.addSetProperties(prefix + "Context/Resources/CacheStrategy");
+ digester.addSetNext(prefix + "Context/Resources/CacheStrategy",
+ "setCacheStrategy",
+ "org.apache.catalina.WebResourceRoot$CacheStrategy");
+
digester.addObjectCreate(prefix + "Context/Resources/PreResources",
null, // MUST be specified in the element
"className");
diff --git a/java/org/apache/catalina/webresources/Cache.java b/java/org/apache/catalina/webresources/Cache.java
index b2ce23c..bf762d4 100644
--- a/java/org/apache/catalina/webresources/Cache.java
+++ b/java/org/apache/catalina/webresources/Cache.java
@@ -24,6 +24,7 @@ import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.catalina.WebResource;
+import org.apache.catalina.WebResourceRoot.CacheStrategy;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.res.StringManager;
@@ -45,6 +46,7 @@ public class Cache {
private long ttl = 5000;
private long maxSize = 10 * 1024 * 1024;
private int objectMaxSize = (int) maxSize/OBJECT_MAX_SIZE_FACTOR;
+ private CacheStrategy cacheStrategy;
private AtomicLong lookupCount = new AtomicLong(0);
private AtomicLong hitCount = new AtomicLong(0);
@@ -62,6 +64,13 @@ public class Cache {
return root.getResourceInternal(path, useClassLoaderResources);
}
+ CacheStrategy strategy = getCacheStrategy();
+ if (strategy != null) {
+ if (strategy.noCache(path)) {
+ return root.getResourceInternal(path, useClassLoaderResources);
+ }
+ }
+
lookupCount.incrementAndGet();
CachedResource cacheEntry = resourceCache.get(path);
@@ -261,6 +270,14 @@ public class Cache {
}
}
+ public CacheStrategy getCacheStrategy() {
+ return cacheStrategy;
+ }
+
+ public void setCacheStrategy(CacheStrategy cacheStrategy) {
+ this.cacheStrategy = cacheStrategy;
+ }
+
public long getTtl() {
return ttl;
}
diff --git a/java/org/apache/catalina/webresources/MyCacheStrategy.java b/java/org/apache/catalina/webresources/MyCacheStrategy.java
new file mode 100644
index 0000000..ac23782
--- /dev/null
+++ b/java/org/apache/catalina/webresources/MyCacheStrategy.java
@@ -0,0 +1,29 @@
+/*
+ * 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.catalina.webresources;
+
+import org.apache.catalina.WebResourceRoot.CacheStrategy;
+
+public class MyCacheStrategy implements CacheStrategy {
+
+
+ @Override
+ public boolean noCache(String path) {
+ System.out.println(path);
+ return true;
+ }
+}
diff --git a/java/org/apache/catalina/webresources/StandardRoot.java b/java/org/apache/catalina/webresources/StandardRoot.java
index 6238e39..ec28485 100644
--- a/java/org/apache/catalina/webresources/StandardRoot.java
+++ b/java/org/apache/catalina/webresources/StandardRoot.java
@@ -498,6 +498,17 @@ public class StandardRoot extends LifecycleMBeanBase implements WebResourceRoot
return cachingAllowed;
}
+
+ @Override
+ public CacheStrategy getCacheStrategy() {
+ return cache.getCacheStrategy();
+ }
+
+ @Override
+ public void setCacheStrategy(CacheStrategy strategy) {
+ cache.setCacheStrategy(strategy);
+ }
+
@Override
public long getCacheTtl() {
return cache.getTtl();
diff --git a/webapps/docs/changelog.xml b/webapps/docs/changelog.xml
index 49f0bf8..88d7c38 100644
--- a/webapps/docs/changelog.xml
+++ b/webapps/docs/changelog.xml
@@ -116,6 +116,11 @@
Add Javadoc comment which listeners must be nested whithin
<code>Server</code> elements only. (michaelo)
</docs>
+ <add>
+ Add support for custom caching strategies for web application resources.
+ This initial implementation allows control over whether or not a
+ resource is cached. (markt)
+ </add>
</changelog>
</subsection>
<subsection name="Coyote">
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