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Posted to notifications@freemarker.apache.org by dd...@apache.org on 2017/03/18 10:05:32 UTC
incubator-freemarker git commit: Cleaned up DefaultObjectWrapper TCCL
singleton caching
Repository: incubator-freemarker
Updated Branches:
refs/heads/3 dceec32ed -> c04f5b517
Cleaned up DefaultObjectWrapper TCCL singleton caching
Project: http://git-wip-us.apache.org/repos/asf/incubator-freemarker/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-freemarker/commit/c04f5b51
Tree: http://git-wip-us.apache.org/repos/asf/incubator-freemarker/tree/c04f5b51
Diff: http://git-wip-us.apache.org/repos/asf/incubator-freemarker/diff/c04f5b51
Branch: refs/heads/3
Commit: c04f5b5173046463cb8e9f14bd73d9c3fd045768
Parents: dceec32
Author: ddekany <dd...@apache.org>
Authored: Sat Mar 18 11:05:27 2017 +0100
Committer: ddekany <dd...@apache.org>
Committed: Sat Mar 18 11:05:27 2017 +0100
----------------------------------------------------------------------
.../core/model/impl/DefaultObjectWrapper.java | 179 +++++++++++--------
.../DefaultObjectWrapperTCCLSingletonUtil.java | 129 +++++++++++++
.../model/impl/RestrictedObjectWrapper.java | 29 ++-
.../freemarker/core/model/impl/_ModelAPI.java | 95 ----------
4 files changed, 260 insertions(+), 172 deletions(-)
----------------------------------------------------------------------
http://git-wip-us.apache.org/repos/asf/incubator-freemarker/blob/c04f5b51/src/main/java/org/apache/freemarker/core/model/impl/DefaultObjectWrapper.java
----------------------------------------------------------------------
diff --git a/src/main/java/org/apache/freemarker/core/model/impl/DefaultObjectWrapper.java b/src/main/java/org/apache/freemarker/core/model/impl/DefaultObjectWrapper.java
index da6c675..3e31739 100644
--- a/src/main/java/org/apache/freemarker/core/model/impl/DefaultObjectWrapper.java
+++ b/src/main/java/org/apache/freemarker/core/model/impl/DefaultObjectWrapper.java
@@ -1281,11 +1281,27 @@ public class DefaultObjectWrapper implements RichObjectWrapper {
* a singleton that is also in use elsewhere.
*/
public DefaultObjectWrapper build() {
- return _ModelAPI.getDefaultObjectWrapperSubclassSingleton(
+ return DefaultObjectWrapperTCCLSingletonUtil.getSingleton(
this, INSTANCE_CACHE, INSTANCE_CACHE_REF_QUEUE, ConstructorInvoker.INSTANCE);
}
/**
+ * Calls {@link ExtendableBuilder#hashCodeForCacheKey(ExtendableBuilder)}.
+ */
+ @Override
+ public int hashCode() {
+ return hashCodeForCacheKey(this);
+ }
+
+ /**
+ * Calls {@link ExtendableBuilder#equalsForCacheKey(ExtendableBuilder, Object)}.
+ */
+ @Override
+ public boolean equals(Object obj) {
+ return equalsForCacheKey(this, obj);
+ }
+
+ /**
* For unit testing only
*/
static Map<ClassLoader, Map<Builder, WeakReference<DefaultObjectWrapper>>> getInstanceCache() {
@@ -1293,7 +1309,7 @@ public class DefaultObjectWrapper implements RichObjectWrapper {
}
private static class ConstructorInvoker
- implements _ModelAPI._ConstructorInvoker<DefaultObjectWrapper, Builder> {
+ implements DefaultObjectWrapperTCCLSingletonUtil._ConstructorInvoker<DefaultObjectWrapper, Builder> {
private static final ConstructorInvoker INSTANCE = new ConstructorInvoker();
@@ -1318,10 +1334,10 @@ public class DefaultObjectWrapper implements RichObjectWrapper {
private final Version incompatibleImprovements;
- ClassIntrospector.Builder classIntrospectorBuilder;
+ // Can't be final because deep cloning must replace it
+ private ClassIntrospector.Builder classIntrospectorBuilder;
// Properties and their *defaults*:
- private boolean simpleMapWrapper;
private int defaultDateType = TemplateDateModel.UNKNOWN;
private ObjectWrapper outerIdentity;
private boolean strict;
@@ -1335,37 +1351,37 @@ public class DefaultObjectWrapper implements RichObjectWrapper {
/**
* @param incompatibleImprovements
- * Sets which of the non-backward-compatible improvements should be enabled. Not {@code null}. This version number
- * is the same as the FreeMarker version number with which the improvements were implemented.
- *
- * <p>For new projects, it's recommended to set this to the FreeMarker version that's used during the development.
- * For released products that are still actively developed it's a low risk change to increase the 3rd
- * version number further as FreeMarker is updated, but of course you should always check the list of effects
- * below. Increasing the 2nd or 1st version number possibly mean substantial changes with higher risk of breaking
- * the application, but again, see the list of effects below.
- *
- * <p>The reason it's separate from {@link Configuration#setIncompatibleImprovements(Version)} is that
- * {@link ObjectWrapper} objects are often shared among multiple {@link Configuration}-s, so the two version
- * numbers are technically independent. But it's recommended to keep those two version numbers the same.
- *
- * <p>The changes enabled by {@code incompatibleImprovements} are:
- * <ul>
- * <li>
- * <p>3.0.0: No changes; this is the starting point, the version used in older projects.
- * </li>
- * </ul>
- *
- * <p>Note that the version will be normalized to the lowest version where the same incompatible
- * {@link DefaultObjectWrapper} improvements were already present, so {@link #getIncompatibleImprovements()} might returns
- * a lower version than what you have specified.
+ * Sets which of the non-backward-compatible improvements should be enabled. Not {@code null}. This
+ * version number is the same as the FreeMarker version number with which the improvements were
+ * implemented.
+ * <p>
+ * For new projects, it's recommended to set this to the FreeMarker version that's used during the
+ * development. For released products that are still actively developed it's a low risk change to
+ * increase the 3rd version number further as FreeMarker is updated, but of course you should always
+ * check the list of effects below. Increasing the 2nd or 1st version number possibly mean substantial
+ * changes with higher risk of breaking the application, but again, see the list of effects below.
+ * <p>
+ * The reason it's separate from {@link Configuration#setIncompatibleImprovements(Version)} is that
+ * {@link ObjectWrapper} objects are often shared among multiple {@link Configuration}-s, so the two
+ * version numbers are technically independent. But it's recommended to keep those two version numbers
+ * the same.
+ * <p>
+ * The changes enabled by {@code incompatibleImprovements} are:
+ * <ul>
+ * <li><p>3.0.0: No changes; this is the starting point, the version used in older projects.</li>
+ * </ul>
+ * <p>
+ * Note that the version will be normalized to the lowest version where the same incompatible {@link
+ * DefaultObjectWrapper} improvements were already present, so {@link #getIncompatibleImprovements()}
+ * might returns a lower version than what you have specified.
* @param isIncompImprsAlreadyNormalized
- * Tells if the {@code incompatibleImprovements} parameter contains an <em>already normalized</em> value.
- * This parameter meant to be {@code true} when the class that extends {@link DefaultObjectWrapper} needs to
- * add additional breaking versions over those of {@link DefaultObjectWrapper}. Thus, if this parameter is
- * {@code true}, the versions where {@link DefaultObjectWrapper} had breaking changes must be already
- * factored into the {@code incompatibleImprovements} parameter value, as no more normalization will happen.
- * (You can use {@link DefaultObjectWrapper#normalizeIncompatibleImprovementsVersion(Version)} to discover
- * those.)
+ * Tells if the {@code incompatibleImprovements} parameter contains an <em>already normalized</em>
+ * value. This parameter meant to be {@code true} when the class that extends {@link
+ * DefaultObjectWrapper} needs to add additional breaking versions over those of {@link
+ * DefaultObjectWrapper}. Thus, if this parameter is {@code true}, the versions where {@link
+ * DefaultObjectWrapper} had breaking changes must be already factored into the {@code
+ * incompatibleImprovements} parameter value, as no more normalization will happen. (You can use {@link
+ * DefaultObjectWrapper#normalizeIncompatibleImprovementsVersion(Version)} to discover those.)
*/
protected ExtendableBuilder(Version incompatibleImprovements, boolean isIncompImprsAlreadyNormalized) {
_CoreAPI.checkVersionNotNullAndSupported(incompatibleImprovements);
@@ -1379,62 +1395,77 @@ public class DefaultObjectWrapper implements RichObjectWrapper {
}
/**
- * Properly implementing this method is important if the builder is used as a cache key; if you override
- * {@link ExtendableBuilder} and add new fields, don't forget to override it!
+ * Calculate a content-based hash that could be used when looking up the product object that {@link #build()}
+ * returns from a cache. If you override {@link ExtendableBuilder} and add new fields, don't forget to take
+ * those into account too!
+ *
+ * <p>{@link Builder#hashCode()} is delegated to this.
+ *
+ * @see #equalsForCacheKey(ExtendableBuilder, Object)
+ * @see #cloneForCacheKey()
*/
- // TODO Move this to Builder and a static helper method
- @Override
- public int hashCode() {
+ protected static int hashCodeForCacheKey(ExtendableBuilder<?, ?> builder) {
final int prime = 31;
int result = 1;
- result = prime * result + incompatibleImprovements.hashCode();
- result = prime * result + (simpleMapWrapper ? 1231 : 1237);
- result = prime * result + defaultDateType;
- result = prime * result + (outerIdentity != null ? outerIdentity.hashCode() : 0);
- result = prime * result + (strict ? 1231 : 1237);
- result = prime * result + (useModelCache ? 1231 : 1237);
- result = prime * result + (usePrivateCaches ? 1231 : 1237);
- result = prime * result + classIntrospectorBuilder.hashCode();
+ result = prime * result + builder.getIncompatibleImprovements().hashCode();
+ result = prime * result + builder.getDefaultDateType();
+ result = prime * result + (builder.getOuterIdentity() != null ? builder.getOuterIdentity().hashCode() : 0);
+ result = prime * result + (builder.isStrict() ? 1231 : 1237);
+ result = prime * result + (builder.getUseModelCache() ? 1231 : 1237);
+ result = prime * result + (builder.getUsePrivateCaches() ? 1231 : 1237);
+ result = prime * result + builder.classIntrospectorBuilder.hashCode();
return result;
}
/**
- * Two {@link ExtendableBuilder}-s are equal exactly if their classes are identical ({@code ==}), and their
- * field values are equal. Properly implementing this method is important if the builder is used as a cache key;
- * if you override {@link ExtendableBuilder} and add new fields, don't forget to override it!
+ * A content-based {@link Object#equals(Object)} that could be used to look up the product object that
+ * {@link #build()} returns from a cache. If you override {@link ExtendableBuilder} and add new fields, don't
+ * forget to take those into account too!
+ *
+ * <p>
+ * {@link Builder#equals(Object)} is delegated to this.
+ *
+ * @see #hashCodeForCacheKey(ExtendableBuilder)
+ * @see #cloneForCacheKey()
*/
- // TODO Move this to Builder and a static helper method
- @Override
- public boolean equals(Object obj) {
- if (this == obj) return true;
- if (obj == null) return false;
- if (getClass() != obj.getClass()) return false;
- ExtendableBuilder other = (ExtendableBuilder) obj;
-
- if (!incompatibleImprovements.equals(other.incompatibleImprovements)) return false;
- if (simpleMapWrapper != other.simpleMapWrapper) return false;
- if (defaultDateType != other.defaultDateType) return false;
- if (outerIdentity != other.outerIdentity) return false;
- if (strict != other.strict) return false;
- if (useModelCache != other.useModelCache) return false;
- if (usePrivateCaches != other.usePrivateCaches) return false;
- return classIntrospectorBuilder.equals(other.classIntrospectorBuilder);
+ protected static boolean equalsForCacheKey(ExtendableBuilder<?, ?> thisBuilder, Object thatObj) {
+ if (thisBuilder == thatObj) return true;
+ if (thatObj == null) return false;
+ if (thisBuilder.getClass() != thatObj.getClass()) return false;
+ ExtendableBuilder<?, ?> thatBuilder = (ExtendableBuilder<?, ?>) thatObj;
+
+ if (!thisBuilder.getIncompatibleImprovements().equals(thatBuilder.getIncompatibleImprovements())) {
+ return false;
+ }
+ if (thisBuilder.getDefaultDateType() != thatBuilder.getDefaultDateType()) return false;
+ if (thisBuilder.getOuterIdentity() != thatBuilder.getOuterIdentity()) return false;
+ if (thisBuilder.isStrict() != thatBuilder.isStrict()) return false;
+ if (thisBuilder.getUseModelCache() != thatBuilder.getUseModelCache()) return false;
+ if (thisBuilder.getUsePrivateCaches() != thatBuilder.getUsePrivateCaches()) return false;
+ return thisBuilder.classIntrospectorBuilder.equals(thatBuilder.classIntrospectorBuilder);
}
/**
- * In case the builder is used as a cache key, this is used to clone it before it's actually used as a key; if
- * you override {@link ExtendableBuilder} and add new fields that needs deep cloning, don't forget to
- * override it! Calls {@link Object#clone()} internally (among others), so newly added fields are automatically
- * copied, but again, that's not enough if the field value is mutable.
+ * If the builder is used as a cache key, this is used to clone it before it's stored in the cache as a key, so
+ * that further changes in the original builder won't change the key (aliasing). It calls {@link Object#clone()}
+ * internally, so all fields are automatically copied, but it will also individually clone field values that are
+ * both mutable and has a content-based equals method (deep cloning).
+ * <p>
+ * If you extend {@link ExtendableBuilder} with new fields with mutable values that have a content-based equals
+ * method, and you will also cache product instances, you need to clone those values manually to prevent
+ * aliasing problems, so don't forget to override this method!
+ *
+ * @see #equalsForCacheKey(ExtendableBuilder, Object)
+ * @see #hashCodeForCacheKey(ExtendableBuilder)
*/
- // TODO Move this to Builder and DeepCloneableBuilder
- protected SelfT deepClone() {
+ protected SelfT cloneForCacheKey() {
try {
@SuppressWarnings("unchecked") SelfT clone = (SelfT) super.clone();
- clone.classIntrospectorBuilder = (ClassIntrospector.Builder) classIntrospectorBuilder.clone();
+ ((ExtendableBuilder<?, ?>) clone).classIntrospectorBuilder = (ClassIntrospector.Builder)
+ classIntrospectorBuilder.clone();
return clone;
} catch (CloneNotSupportedException e) {
- throw new RuntimeException("Failed to deepClone ExtendableBuilder", e);
+ throw new RuntimeException("Failed to deepClone Builder", e);
}
}
http://git-wip-us.apache.org/repos/asf/incubator-freemarker/blob/c04f5b51/src/main/java/org/apache/freemarker/core/model/impl/DefaultObjectWrapperTCCLSingletonUtil.java
----------------------------------------------------------------------
diff --git a/src/main/java/org/apache/freemarker/core/model/impl/DefaultObjectWrapperTCCLSingletonUtil.java b/src/main/java/org/apache/freemarker/core/model/impl/DefaultObjectWrapperTCCLSingletonUtil.java
new file mode 100644
index 0000000..3945770
--- /dev/null
+++ b/src/main/java/org/apache/freemarker/core/model/impl/DefaultObjectWrapperTCCLSingletonUtil.java
@@ -0,0 +1,129 @@
+/*
+ * 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.freemarker.core.model.impl;
+
+import java.lang.ref.Reference;
+import java.lang.ref.ReferenceQueue;
+import java.lang.ref.WeakReference;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+import org.apache.freemarker.core.util.BuilderBase;
+
+/**
+ * Utility method for caching {@link DefaultObjectWrapper} (and subclasses) sigletons per Thread Context Class
+ * Loader.
+ */
+// [FM3] Maybe generalize and publish this functionality
+final class DefaultObjectWrapperTCCLSingletonUtil {
+
+ private DefaultObjectWrapperTCCLSingletonUtil() {
+ // Not meant to be instantiated
+ }
+
+ /**
+ * Contains the common parts of the singleton management for {@link DefaultObjectWrapper} and {@link DefaultObjectWrapper}.
+ *
+ * @param dowConstructorInvoker Creates a <em>new</em> read-only object wrapper of the desired
+ * {@link DefaultObjectWrapper} subclass.
+ */
+ static <
+ ObjectWrapperT extends DefaultObjectWrapper,
+ BuilderT extends DefaultObjectWrapper.ExtendableBuilder<ObjectWrapperT, BuilderT>>
+ ObjectWrapperT getSingleton(
+ BuilderT builder,
+ Map<ClassLoader, Map<BuilderT, WeakReference<ObjectWrapperT>>> instanceCache,
+ ReferenceQueue<ObjectWrapperT> instanceCacheRefQue,
+ _ConstructorInvoker<ObjectWrapperT, BuilderT> dowConstructorInvoker) {
+ // DefaultObjectWrapper can't be cached across different Thread Context Class Loaders (TCCL), because the result of
+ // a class name (String) to Class mappings depends on it, and the staticModels and enumModels need that.
+ // (The ClassIntrospector doesn't have to consider the TCCL, as it only works with Class-es, not class
+ // names.)
+ ClassLoader tccl = Thread.currentThread().getContextClassLoader();
+
+ Reference<ObjectWrapperT> instanceRef;
+ Map<BuilderT, WeakReference<ObjectWrapperT>> tcclScopedCache;
+ synchronized (instanceCache) {
+ tcclScopedCache = instanceCache.get(tccl);
+ if (tcclScopedCache == null) {
+ tcclScopedCache = new HashMap<>();
+ instanceCache.put(tccl, tcclScopedCache);
+ instanceRef = null;
+ } else {
+ instanceRef = tcclScopedCache.get(builder);
+ }
+ }
+
+ ObjectWrapperT instance = instanceRef != null ? instanceRef.get() : null;
+ if (instance != null) { // cache hit
+ return instance;
+ }
+ // cache miss
+
+ builder = builder.cloneForCacheKey(); // prevent any aliasing issues
+ instance = dowConstructorInvoker.invoke(builder);
+
+ synchronized (instanceCache) {
+ instanceRef = tcclScopedCache.get(builder);
+ ObjectWrapperT concurrentInstance = instanceRef != null ? instanceRef.get() : null;
+ if (concurrentInstance == null) {
+ tcclScopedCache.put(builder, new WeakReference<>(instance, instanceCacheRefQue));
+ } else {
+ instance = concurrentInstance;
+ }
+ }
+
+ removeClearedReferencesFromCache(instanceCache, instanceCacheRefQue);
+
+ return instance;
+ }
+
+ private static <
+ ObjectWrapperT extends DefaultObjectWrapper, BuilderT extends DefaultObjectWrapper.ExtendableBuilder>
+ void removeClearedReferencesFromCache(
+ Map<ClassLoader, Map<BuilderT, WeakReference<ObjectWrapperT>>> instanceCache,
+ ReferenceQueue<ObjectWrapperT> instanceCacheRefQue) {
+ Reference<? extends ObjectWrapperT> clearedRef;
+ while ((clearedRef = instanceCacheRefQue.poll()) != null) {
+ synchronized (instanceCache) {
+ findClearedRef: for (Map<BuilderT, WeakReference<ObjectWrapperT>> tcclScopedCache : instanceCache.values()) {
+ for (Iterator<WeakReference<ObjectWrapperT>> it2 = tcclScopedCache.values().iterator(); it2.hasNext(); ) {
+ if (it2.next() == clearedRef) {
+ it2.remove();
+ break findClearedRef;
+ }
+ }
+ }
+ } // sync
+ } // while poll
+ }
+
+ /**
+ * For internal use only; don't depend on this, there's no backward compatibility guarantee at all!
+ * Used when the builder delegates the product creation to something else (typically, an instance cache). Calling
+ * {@link BuilderBase#build()} would be infinite recursion in such cases.
+ */
+ public interface _ConstructorInvoker<ProductT, BuilderT> {
+
+ ProductT invoke(BuilderT builder);
+ }
+
+}
http://git-wip-us.apache.org/repos/asf/incubator-freemarker/blob/c04f5b51/src/main/java/org/apache/freemarker/core/model/impl/RestrictedObjectWrapper.java
----------------------------------------------------------------------
diff --git a/src/main/java/org/apache/freemarker/core/model/impl/RestrictedObjectWrapper.java b/src/main/java/org/apache/freemarker/core/model/impl/RestrictedObjectWrapper.java
index eeec18f..e456dc6 100644
--- a/src/main/java/org/apache/freemarker/core/model/impl/RestrictedObjectWrapper.java
+++ b/src/main/java/org/apache/freemarker/core/model/impl/RestrictedObjectWrapper.java
@@ -19,6 +19,11 @@
package org.apache.freemarker.core.model.impl;
+import java.lang.ref.ReferenceQueue;
+import java.lang.ref.WeakReference;
+import java.util.Map;
+import java.util.WeakHashMap;
+
import org.apache.freemarker.core.Version;
import org.apache.freemarker.core.model.TemplateHashModel;
import org.apache.freemarker.core.model.TemplateModel;
@@ -31,8 +36,8 @@ import org.apache.freemarker.core.model.TemplateModelException;
*/
public class RestrictedObjectWrapper extends DefaultObjectWrapper {
- protected RestrictedObjectWrapper(Builder builder) {
- super(builder, true);
+ protected RestrictedObjectWrapper(Builder builder, boolean finalizeConstruction) {
+ super(builder, finalizeConstruction);
}
/**
@@ -62,14 +67,32 @@ public class RestrictedObjectWrapper extends DefaultObjectWrapper {
public static final class Builder extends ExtendableBuilder<RestrictedObjectWrapper, Builder> {
+ private final static Map<ClassLoader, Map<Builder, WeakReference<RestrictedObjectWrapper>>>
+ INSTANCE_CACHE = new WeakHashMap<>();
+
+ private final static ReferenceQueue<RestrictedObjectWrapper> INSTANCE_CACHE_REF_QUEUE = new ReferenceQueue<>();
+
public Builder(Version incompatibleImprovements) {
super(incompatibleImprovements, false);
}
@Override
public RestrictedObjectWrapper build() {
- return new RestrictedObjectWrapper(this);
+ return DefaultObjectWrapperTCCLSingletonUtil.getSingleton(
+ this, INSTANCE_CACHE, INSTANCE_CACHE_REF_QUEUE, ConstructorInvoker.INSTANCE);
+ }
+
+ private static class ConstructorInvoker
+ implements DefaultObjectWrapperTCCLSingletonUtil._ConstructorInvoker<RestrictedObjectWrapper, Builder> {
+
+ private static final ConstructorInvoker INSTANCE = new ConstructorInvoker();
+
+ @Override
+ public RestrictedObjectWrapper invoke(Builder builder) {
+ return new RestrictedObjectWrapper(builder, true);
+ }
}
+
}
}
http://git-wip-us.apache.org/repos/asf/incubator-freemarker/blob/c04f5b51/src/main/java/org/apache/freemarker/core/model/impl/_ModelAPI.java
----------------------------------------------------------------------
diff --git a/src/main/java/org/apache/freemarker/core/model/impl/_ModelAPI.java b/src/main/java/org/apache/freemarker/core/model/impl/_ModelAPI.java
index 6e09e9b..fecb0b0 100644
--- a/src/main/java/org/apache/freemarker/core/model/impl/_ModelAPI.java
+++ b/src/main/java/org/apache/freemarker/core/model/impl/_ModelAPI.java
@@ -19,20 +19,13 @@
package org.apache.freemarker.core.model.impl;
-import java.lang.ref.Reference;
-import java.lang.ref.ReferenceQueue;
-import java.lang.ref.WeakReference;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.Iterator;
import java.util.List;
-import java.util.Map;
import org.apache.freemarker.core.model.TemplateModelException;
-import org.apache.freemarker.core.util.BuilderBase;
import org.apache.freemarker.core.util._CollectionUtil;
/**
@@ -125,93 +118,5 @@ public class _ModelAPI {
return constrDesc.invokeConstructor(ow, packedArgs);
}
-
- /**
- * Contains the common parts of the singleton management for {@link DefaultObjectWrapper} and {@link DefaultObjectWrapper}.
- *
- * @param dowConstructorInvoker Creates a <em>new</em> read-only object wrapper of the desired
- * {@link DefaultObjectWrapper} subclass.
- */
- // [FM3] Generalize and publish this functionality
- public static <
- ObjectWrapperT extends DefaultObjectWrapper,
- BuilderT extends DefaultObjectWrapper.ExtendableBuilder<ObjectWrapperT, BuilderT>>
- ObjectWrapperT getDefaultObjectWrapperSubclassSingleton(
- BuilderT builder,
- Map<ClassLoader, Map<BuilderT, WeakReference<ObjectWrapperT>>> instanceCache,
- ReferenceQueue<ObjectWrapperT> instanceCacheRefQue,
- _ConstructorInvoker<ObjectWrapperT, BuilderT> dowConstructorInvoker) {
- // DefaultObjectWrapper can't be cached across different Thread Context Class Loaders (TCCL), because the result of
- // a class name (String) to Class mappings depends on it, and the staticModels and enumModels need that.
- // (The ClassIntrospector doesn't have to consider the TCCL, as it only works with Class-es, not class
- // names.)
- ClassLoader tccl = Thread.currentThread().getContextClassLoader();
-
- Reference<ObjectWrapperT> instanceRef;
- Map<BuilderT, WeakReference<ObjectWrapperT>> tcclScopedCache;
- synchronized (instanceCache) {
- tcclScopedCache = instanceCache.get(tccl);
- if (tcclScopedCache == null) {
- tcclScopedCache = new HashMap<>();
- instanceCache.put(tccl, tcclScopedCache);
- instanceRef = null;
- } else {
- instanceRef = tcclScopedCache.get(builder);
- }
- }
-
- ObjectWrapperT instance = instanceRef != null ? instanceRef.get() : null;
- if (instance != null) { // cache hit
- return instance;
- }
- // cache miss
-
- builder = builder.deepClone(); // prevent any aliasing issues
- instance = dowConstructorInvoker.invoke(builder);
-
- synchronized (instanceCache) {
- instanceRef = tcclScopedCache.get(builder);
- ObjectWrapperT concurrentInstance = instanceRef != null ? instanceRef.get() : null;
- if (concurrentInstance == null) {
- tcclScopedCache.put(builder, new WeakReference<>(instance, instanceCacheRefQue));
- } else {
- instance = concurrentInstance;
- }
- }
-
- removeClearedReferencesFromCache(instanceCache, instanceCacheRefQue);
-
- return instance;
- }
- private static <
- ObjectWrapperT extends DefaultObjectWrapper, BuilderT extends DefaultObjectWrapper.ExtendableBuilder>
- void removeClearedReferencesFromCache(
- Map<ClassLoader, Map<BuilderT, WeakReference<ObjectWrapperT>>> instanceCache,
- ReferenceQueue<ObjectWrapperT> instanceCacheRefQue) {
- Reference<? extends ObjectWrapperT> clearedRef;
- while ((clearedRef = instanceCacheRefQue.poll()) != null) {
- synchronized (instanceCache) {
- findClearedRef: for (Map<BuilderT, WeakReference<ObjectWrapperT>> tcclScopedCache : instanceCache.values()) {
- for (Iterator<WeakReference<ObjectWrapperT>> it2 = tcclScopedCache.values().iterator(); it2.hasNext(); ) {
- if (it2.next() == clearedRef) {
- it2.remove();
- break findClearedRef;
- }
- }
- }
- } // sync
- } // while poll
- }
-
- /**
- * For internal use only; don't depend on this, there's no backward compatibility guarantee at all!
- * Used when the builder delegates the product creation to something else (typically, an instance cache). Calling
- * {@link BuilderBase#build()} would be infinite recursion in such cases.
- */
- public interface _ConstructorInvoker<ProductT, BuilderT> {
-
- ProductT invoke(BuilderT builder);
- }
-
}