org.infinispan.interceptors.InterceptorChain Maven / Gradle / Ivy
package org.infinispan.interceptors;
import org.infinispan.commands.VisitableCommand;
import org.infinispan.commons.CacheException;
import org.infinispan.commons.util.InfinispanCollections;
import org.infinispan.commons.util.ReflectionUtil;
import org.infinispan.commons.CacheConfigurationException;
import org.infinispan.context.InvocationContext;
import org.infinispan.factories.annotations.Inject;
import org.infinispan.factories.annotations.Start;
import org.infinispan.factories.annotations.Stop;
import org.infinispan.factories.components.ComponentMetadataRepo;
import org.infinispan.factories.scopes.Scope;
import org.infinispan.factories.scopes.Scopes;
import org.infinispan.interceptors.base.CommandInterceptor;
import org.infinispan.util.logging.Log;
import org.infinispan.util.logging.LogFactory;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.locks.ReentrantLock;
/**
* Knows how to build and manage an chain of interceptors. Also in charge with invoking methods on the chain.
*
* @author [email protected]
* @author Galder Zamarreño
* @since 4.0
*/
@Scope(Scopes.NAMED_CACHE)
public class InterceptorChain {
private static final Log log = LogFactory.getLog(InterceptorChain.class);
/**
* reference to the first interceptor in the chain
*/
private volatile CommandInterceptor firstInChain;
final ReentrantLock lock = new ReentrantLock();
final ComponentMetadataRepo componentMetadataRepo;
/**
* Constructs an interceptor chain having the supplied interceptor as first.
*/
public InterceptorChain(ComponentMetadataRepo componentMetadataRepo) {
this.componentMetadataRepo = componentMetadataRepo;
}
@Start
private void printChainInfo() {
if (log.isDebugEnabled()) {
log.debugf("Interceptor chain size: %d", size());
log.debugf("Interceptor chain is: %s", toString());
}
}
private void validateCustomInterceptor(Class i) {
if ((!ReflectionUtil.getAllMethodsShallow(i, Inject.class).isEmpty() ||
!ReflectionUtil.getAllMethodsShallow(i, Start.class).isEmpty() ||
!ReflectionUtil.getAllMethodsShallow(i, Stop.class).isEmpty()) &&
componentMetadataRepo.findComponentMetadata(i.getName()) == null) {
log.customInterceptorExpectsInjection(i.getName());
}
}
/**
* Ensures that the interceptor of type passed in isn't already added
*
* @param clazz type of interceptor to check for
*/
private void assertNotAdded(Class clazz) {
if (containsInterceptorType(clazz))
throw new CacheConfigurationException("Detected interceptor of type [" + clazz.getName() + "] being added to the interceptor chain " + System.identityHashCode(this) + " more than once!");
}
/**
* Inserts the given interceptor at the specified position in the chain (o based indexing).
*
* @throws IllegalArgumentException if the position is invalid (e.g. 5 and there are only 2 interceptors in the
* chain)
*/
public void addInterceptor(CommandInterceptor interceptor, int position) {
final ReentrantLock lock = this.lock;
lock.lock();
try {
Class interceptorClass = interceptor.getClass();
assertNotAdded(interceptorClass);
validateCustomInterceptor(interceptorClass);
if (position == 0) {
interceptor.setNext(firstInChain);
firstInChain = interceptor;
return;
}
if (firstInChain == null) return;
CommandInterceptor it = firstInChain;
int index = 0;
while (it != null) {
if (++index == position) {
interceptor.setNext(it.getNext());
it.setNext(interceptor);
return;
}
it = it.getNext();
}
throw new IllegalArgumentException("Invalid index: " + index + " !");
} finally {
lock.unlock();
}
}
/**
* Removes the interceptor at the given postion.
*
* @throws IllegalArgumentException if the position is invalid (e.g. 5 and there are only 2 interceptors in the
* chain)
*/
public void removeInterceptor(int position) {
final ReentrantLock lock = this.lock;
lock.lock();
try {
if (firstInChain == null) return;
if (position == 0) {
firstInChain = firstInChain.getNext();
return;
}
CommandInterceptor it = firstInChain;
int index = 0;
while (it != null) {
if (++index == position) {
if (it.getNext() == null) return; //nothing to remove
it.setNext(it.getNext().getNext());
return;
}
it = it.getNext();
}
throw new IllegalArgumentException("Invalid position: " + position + " !");
} finally {
lock.unlock();
}
}
/**
* Returns the number of interceptors in the chain.
*/
public int size() {
int size = 0;
CommandInterceptor it = firstInChain;
while (it != null) {
size++;
it = it.getNext();
}
return size;
}
/**
* Returns an unmofiable list with all the interceptors in sequence. If first in chain is null an empty list is
* returned.
*/
public List asList() {
if (firstInChain == null) return InfinispanCollections.emptyList();
List retval = new LinkedList();
CommandInterceptor tmp = firstInChain;
do {
retval.add(tmp);
tmp = tmp.getNext();
}
while (tmp != null);
return Collections.unmodifiableList(retval);
}
/**
* Removes all the occurences of supplied interceptor type from the chain.
*/
public void removeInterceptor(Class clazz) {
final ReentrantLock lock = this.lock;
lock.lock();
try {
if (isFirstInChain(clazz)) {
firstInChain = firstInChain.getNext();
}
CommandInterceptor it = firstInChain.getNext();
CommandInterceptor prevIt = firstInChain;
while (it != null) {
if (it.getClass() == clazz) {
prevIt.setNext(it.getNext());
}
prevIt = it;
it = it.getNext();
}
} finally {
lock.unlock();
}
}
protected boolean isFirstInChain(Class clazz) {
return firstInChain.getClass() == clazz;
}
/**
* Adds a new interceptor in list after an interceptor of a given type.
*
* @return true if the interceptor was added; i.e. the afterInterceptor exists
*/
public boolean addInterceptorAfter(CommandInterceptor toAdd, Class afterInterceptor) {
final ReentrantLock lock = this.lock;
lock.lock();
try {
Class interceptorClass = toAdd.getClass();
assertNotAdded(interceptorClass);
validateCustomInterceptor(interceptorClass);
CommandInterceptor it = firstInChain;
while (it != null) {
if (it.getClass().equals(afterInterceptor)) {
toAdd.setNext(it.getNext());
it.setNext(toAdd);
return true;
}
it = it.getNext();
}
return false;
} finally {
lock.unlock();
}
}
public boolean addInterceptorBefore(CommandInterceptor toAdd, Class beforeInterceptor, boolean isCustom) {
if (isCustom) validateCustomInterceptor(toAdd.getClass());
return addInterceptorBefore(toAdd, beforeInterceptor);
}
/**
* Adds a new interceptor in list after an interceptor of a given type.
*
* @return true if the interceptor was added; i.e. the afterInterceptor exists
*/
public boolean addInterceptorBefore(CommandInterceptor toAdd, Class beforeInterceptor) {
final ReentrantLock lock = this.lock;
lock.lock();
try {
Class interceptorClass = toAdd.getClass();
assertNotAdded(interceptorClass);
validateCustomInterceptor(interceptorClass);
if (firstInChain.getClass().equals(beforeInterceptor)) {
toAdd.setNext(firstInChain);
firstInChain = toAdd;
return true;
}
CommandInterceptor it = firstInChain;
while (it.getNext() != null) {
if (it.getNext().getClass().equals(beforeInterceptor)) {
toAdd.setNext(it.getNext());
it.setNext(toAdd);
return true;
}
it = it.getNext();
}
return false;
} finally {
lock.unlock();
}
}
/**
* Replaces an existing interceptor of the given type in the interceptor chain with a new interceptor instance passed as parameter.
*
* @param replacingInterceptor the interceptor to add to the interceptor chain
* @param toBeReplacedInterceptorType the type of interceptor that should be swapped with the new one
* @return true if the interceptor was replaced
*/
public boolean replaceInterceptor(CommandInterceptor replacingInterceptor, Class toBeReplacedInterceptorType) {
final ReentrantLock lock = this.lock;
lock.lock();
try {
Class interceptorClass = replacingInterceptor.getClass();
assertNotAdded(interceptorClass);
validateCustomInterceptor(interceptorClass);
if (firstInChain.getClass().equals(toBeReplacedInterceptorType)) {
replacingInterceptor.setNext(firstInChain.getNext());
firstInChain = replacingInterceptor;
return true;
}
CommandInterceptor it = firstInChain;
CommandInterceptor previous = firstInChain;
while (it.getNext() != null) {
CommandInterceptor current = it.getNext();
if (current.getClass().equals(toBeReplacedInterceptorType)) {
replacingInterceptor.setNext(current.getNext());
previous.setNext(replacingInterceptor);
return true;
}
previous = current;
it = current;
}
return false;
} finally {
lock.unlock();
}
}
/**
* Appends at the end.
*/
public void appendInterceptor(CommandInterceptor ci, boolean isCustom) {
Class interceptorClass = ci.getClass();
if (isCustom) validateCustomInterceptor(interceptorClass);
assertNotAdded(interceptorClass);
// Called when building interceptor chain and so concurrent start calls are protected already
if (firstInChain == null) {
firstInChain = ci;
} else {
CommandInterceptor it = firstInChain;
while (it.hasNext()) it = it.getNext();
it.setNext(ci);
}
// make sure we nullify the "next" pointer in the last interceptors.
ci.setNext(null);
}
/**
* Walks the command through the interceptor chain. The received ctx is being passed in.
*/
public Object invoke(InvocationContext ctx, VisitableCommand command) {
try {
return command.acceptVisitor(ctx, firstInChain);
} catch (CacheException e) {
if (e.getCause() instanceof InterruptedException)
Thread.currentThread().interrupt();
throw e;
} catch (RuntimeException e) {
throw e;
} catch (Throwable t) {
throw new CacheException(t);
}
}
/**
* @return the first interceptor in the chain.
*/
public CommandInterceptor getFirstInChain() {
return firstInChain;
}
/**
* Mainly used by unit tests to replace the interceptor chain with the starting point passed in.
*
* @param interceptor interceptor to be used as the first interceptor in the chain.
*/
public void setFirstInChain(CommandInterceptor interceptor) {
this.firstInChain = interceptor;
}
/**
* Returns all interceptors which extend the given command interceptor.
*/
public List getInterceptorsWhichExtend(Class interceptorClass) {
List result = new LinkedList();
for (CommandInterceptor interceptor : asList()) {
boolean isSubclass = interceptorClass.isAssignableFrom(interceptor.getClass());
if (isSubclass) {
result.add(interceptor);
}
}
return result;
}
/**
* Returns all the interceptors that have the fully qualified name of their class equal with the supplied class
* name.
*/
public List getInterceptorsWithClass(Class clazz) {
// Called when building interceptor chain and so concurrent start calls are protected already
CommandInterceptor iterator = firstInChain;
List result = new ArrayList(2);
while (iterator != null) {
if (iterator.getClass() == clazz) result.add(iterator);
iterator = iterator.getNext();
}
return result;
}
public String toString() {
StringBuilder sb = new StringBuilder();
CommandInterceptor i = firstInChain;
while (i != null) {
sb.append("\n\t>> ");
sb.append(i.getClass().getName());
i = i.getNext();
}
return sb.toString();
}
/**
* Checks whether the chain contains the supplied interceptor instance.
*/
public boolean containsInstance(CommandInterceptor interceptor) {
CommandInterceptor it = firstInChain;
while (it != null) {
if (it == interceptor) return true;
it = it.getNext();
}
return false;
}
public boolean containsInterceptorType(Class interceptorType) {
return containsInterceptorType(interceptorType, false);
}
public boolean containsInterceptorType(Class interceptorType, boolean alsoMatchSubClasses) {
// Called when building interceptor chain and so concurrent start calls are protected already
CommandInterceptor it = firstInChain;
while (it != null) {
if (alsoMatchSubClasses) {
if (interceptorType.isAssignableFrom(it.getClass())) return true;
} else {
if (it.getClass().equals(interceptorType)) return true;
}
it = it.getNext();
}
return false;
}
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