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org.ogema.resourcemanager.impl.ElementInfo Maven / Gradle / Ivy
/**
* Copyright 2011-2018 Fraunhofer-Gesellschaft zur Förderung der angewandten Wissenschaften e.V.
*
* Licensed 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.ogema.resourcemanager.impl;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;
import java.util.PriorityQueue;
import java.util.concurrent.Callable;
import org.ogema.core.administration.RegisteredAccessModeRequest;
import org.ogema.core.application.ApplicationManager;
import org.ogema.core.model.Resource;
import org.ogema.core.resourcemanager.AccessMode;
import static org.ogema.core.resourcemanager.AccessMode.EXCLUSIVE;
import static org.ogema.core.resourcemanager.AccessMode.READ_ONLY;
import static org.ogema.core.resourcemanager.AccessMode.SHARED;
import org.ogema.core.resourcemanager.AccessModeListener;
import org.ogema.core.resourcemanager.AccessPriority;
import org.ogema.resourcemanager.impl.timeseries.DefaultRecordedData;
import org.ogema.resourcetree.TreeElement;
import org.ogema.resourcetree.listeners.InternalValueChangedListenerRegistration;
import org.slf4j.LoggerFactory;
/**
* Info elemnt set on {@link TreeElement}, adding info on resource demands,
* existing locks and listener registrations. TreeElement and ElementInfo have a
* n:1 relationship since a TreeElement shares its ElementInfo with its
* referencing nodes.
*
* (This class is not thread safe - read / write operations are synchronized
* in ResourceBase) - obsolete: synchronisation is done internally
*
* @author jlapp
*/
public class ElementInfo {
final ResourceDBManager man;
private final Object referencesLock = new Object();
// TreeElements which have a reference to this element.
private List references;
private final Object listenersLock = new Object();
private Collection listeners;
static final int INITIAL_ACCESSREQUESTS_QUEUE_SIZE = 5;
private final Object accessLock = new Object();
PriorityQueue accessRequests;
public ElementInfo(ResourceDBManager man, TreeElement el) {
//System.out.printf("NEW ELEMENTINFO %s: %s (%s)%n", this, el.getPath(), el.getLocation());
Objects.requireNonNull(man);
Objects.requireNonNull(el);
this.man = man;
}
private Collection getListeners(Class type) {
synchronized (listenersLock) {
if (listeners == null) {
return Collections.emptyList();
}
Collection listenersOfRequestedType = new ArrayList<>();
for (Object listener : listeners) {
if (type.isAssignableFrom(listener.getClass())) {
listenersOfRequestedType.add(type.cast(listener));
}
}
return listenersOfRequestedType;
}
}
private void addListener(Object listener) {
synchronized (listenersLock) {
if (listeners == null) {
listeners = new ArrayList<>(3);
}
for (Object l : listeners) {
if (listener.equals(l)) {
return;
}
}
listeners.add(listener);
}
}
@SuppressWarnings("unchecked")
private T removeListener(T listener) {
synchronized (listenersLock) {
if (listeners == null) {
return null;
}
Iterator it = listeners.iterator();
while (it.hasNext()) {
Object l = it.next();
if (listener.equals(l)) {
it.remove();
return (T) l;
}
}
}
return null;
}
public Collection getResourceListeners() {
return getListeners(InternalValueChangedListenerRegistration.class);
}
public void addResourceListener(InternalValueChangedListenerRegistration l) {
addListener(l);
}
/*
* Removes a matching ResourceListenerRegistration and returns the
* originally registered object, or null if no such registration is found.
*/
public InternalValueChangedListenerRegistration removeResourceListener(InternalValueChangedListenerRegistration reg) {
final InternalValueChangedListenerRegistration old = removeListener(reg);
if (old != null)
old.dispose();
return old;
}
public void fireResourceChanged(final ConnectedResource r, long time, boolean valueChanged) {
if (!r.isActive()) {
return;
}
DefaultRecordedData d = man.getExistingRecordedData(r.getTreeElement());
if (d != null) {
d.update(time);
}
for (InternalValueChangedListenerRegistration reg : getListeners(InternalValueChangedListenerRegistration.class)) {
if (reg instanceof ResourceListenerRegistration && ((ResourceListenerRegistration) reg).isAbandoned()) {
removeListener(reg);
}
else {
reg.queueResourceChangedEvent(r, valueChanged);
}
}
}
/**
* call this after adding sub resources or references to register existing
* listeners on all newly reachable elements
*/
public void updateListenerRegistrations() {
for (InternalValueChangedListenerRegistration reg : getListeners(InternalValueChangedListenerRegistration.class)) {
if (reg instanceof ResourceListenerRegistration)
if (((ResourceListenerRegistration) reg).isAbandoned()) {
removeListener(reg);
}
else {
((ResourceListenerRegistration) reg).performRegistration();
}
else {
// TODO check: ok?
this.addResourceListener(reg);
// reg.performRegistration();
}
}
}
/**
* call this when a TreeElement is no longer reachable via a formerly valild
* path.
*
* @param oldPath remove all resource listeners that where registered for
* this path but are no longer valid for this TreeElement.
* @return list of removed listener registrations.
*/
public List invalidateListenerRegistrations(String oldPath) {
List invalidRegs = new ArrayList<>();
for (InternalValueChangedListenerRegistration reg : getListeners(InternalValueChangedListenerRegistration.class)) {
if (reg instanceof ResourceListenerRegistration && ((ResourceListenerRegistration) reg).isAbandoned()) {
removeListener(reg);
continue;
}
if (oldPath.startsWith("/")){
oldPath = oldPath.substring(1);
}
if (oldPath.startsWith(reg.getResource().getPath())) {
removeListener(reg);
invalidRegs.add(reg);
}
}
return invalidRegs;
}
/**
* adds a reference poining to this ElementInfo's tree element. the reference
* is the actual link element, not the 'reference parent' of this element.
* @param reference the reference element
*/
public void addReference(TreeElement reference) {
//System.out.printf("ADD REFERENCE %s: %s%n", this, reference);
if (!reference.isReference()) {
throw new IllegalArgumentException("not a reference: " + reference);
}
synchronized (referencesLock) {
if (references == null) {
references = new ArrayList<>(3);
}
/* XXX references must be deleted in the correct order:
in case of a reference to a reference insert that element before the
element it references...
*/
boolean inserted = false;
for (int i = 0; i < references.size(); i++) {
TreeElement listEl = references.get(i);
if (listEl == reference) {
inserted = true;
break;
}
if (reference.isReference() && reference.getReference() == listEl) {
references.add(i, reference);
inserted = true;
break;
}
}
if (!inserted) {
references.add(reference);
}
}
}
public void removeReference(TreeElement referenceElement, TreeElement target) {
//System.out.printf("REMOVE REFERENCE %s: %s%n", this, referenceElement);
boolean removed = false;
synchronized (referencesLock) {
if (references != null) {
removed = references.remove(referenceElement);
}
}
if (!removed) {
//FIXME
LoggerFactory.getLogger(getClass()).warn("suspicious removeReference call on {}", referenceElement);
}
//System.out.printf("REFERENCES %s: %s%n", this, references);
}
public Collection getReferences(String path, boolean transitive) {
synchronized (referencesLock) {
if (references == null) {
return Collections.emptyList();
}
Collection rval = new ArrayList<>(references.size());
for (TreeElement e: references) {
if (transitive) {
TreeElement p = e;
while (p.isReference()) {
if (p.getReference().getPath().equals(path)) {
rval.add(e);
break;
}
p = p.getReference();
}
}
else {
if (e.isReference() && e.getReference().getPath().equals(path)) {
rval.add(e);
}
}
}
return rval;
}
}
AccessModeRequest addAccessModeRequest(Resource res, ApplicationManager app, AccessMode mode, AccessPriority priority) {
synchronized (accessLock) {
if (accessRequests == null) {
accessRequests = new PriorityQueue<>(INITIAL_ACCESSREQUESTS_QUEUE_SIZE);
}
AccessModeRequest newReq = new AccessModeRequest(res, this, app, mode, priority);
//remove previous request by the same app
for (Iterator it = accessRequests.iterator(); it.hasNext();) {
AccessModeRequest r = it.next();
if (r.getApplicationManager() == app) {
it.remove();
}
}
if (mode != AccessMode.READ_ONLY) {
accessRequests.add(newReq);
} else { //READ_ONLY requests are not stored (treated as 'no request').
newReq.setAvailableMode(READ_ONLY);
if (accessRequests.isEmpty()) {
return newReq;
}
}
AccessMode topMode = accessRequests.peek().getRequiredAccessMode();
AccessMode availableMode = topMode == AccessMode.EXCLUSIVE
? READ_ONLY : AccessMode.SHARED;
for (AccessModeRequest r : accessRequests) {
if (r == accessRequests.peek()) {
r.setAvailableMode(r.getRequiredAccessMode());
} else {
r.setAvailableMode(availableMode);
}
}
return newReq;
}
}
public List getAccessRequests(ApplicationManager app) {
synchronized (accessLock) {
if (accessRequests == null) {
return Collections.emptyList();
}
List rval = new ArrayList<>(accessRequests.size());
for (AccessModeRequest r : accessRequests) {
if (r.getApplicationManager() == app) {
rval.add(r);
}
}
return rval;
}
}
public AccessMode getAccessMode(ApplicationManager app) {
AccessModeRequest top;
synchronized (accessLock) {
if (accessRequests == null || accessRequests.isEmpty()) {
return SHARED;
}
top = accessRequests.peek();
}
if (top.getRequiredAccessMode() == EXCLUSIVE) {
if (top.getApplicationManager() == app) {
return EXCLUSIVE;
}
else {
return READ_ONLY;
}
}
else {
return SHARED;
}
}
public AccessPriority getAccessPriority(ApplicationManager app) {
synchronized (accessLock) {
if (accessRequests == null) {
return AccessPriority.PRIO_LOWEST;
}
for (AccessModeRequest r : accessRequests) {
if (r.getApplicationManager() == app) {
return r.getPriority();
}
}
}
return AccessPriority.PRIO_LOWEST;
}
public void addAccessModeListener(AccessModeListener l, Resource res, ApplicationManager app) {
addListener(new AccessModeListenerRegistration(app, res, l));
}
public boolean removeAccessModeListener(AccessModeListener l, Resource res, ApplicationManager app) {
final AccessModeListenerRegistration reg = removeListener(new AccessModeListenerRegistration(app, res, l));
if (reg != null)
reg.dispose();
return reg != null;
}
public void fireAccessModeChanged(ApplicationManager app, final Resource r, final boolean requestedModeAvailable) {
for (AccessModeListenerRegistration reg : getListeners(AccessModeListenerRegistration.class)) {
final AccessModeListener l = reg.listener.get();
if (l == null) {
removeListener(reg);
}
else {
if (reg.app == app && reg.res.equals(r)) {
app.submitEvent(createAccessModeChangedCallback(reg, l, r));
}
}
}
}
private Callable createAccessModeChangedCallback(final AccessModeListenerRegistration reg, final AccessModeListener l, final Resource r) {
return new Callable() {
@Override
public Void call() throws Exception {
if (reg.isActive())
l.accessModeChanged(r);
return null;
}
};
}
public void transferListeners(TreeElement target) {
ElementInfo targetElementInfo = man.getElementInfo(target);
for (InternalValueChangedListenerRegistration reg : getResourceListeners()) {
if (!(reg instanceof ResourceListenerRegistration) || !((ResourceListenerRegistration) reg).isRecursive()) {
targetElementInfo.addListener(reg);
}
}
targetElementInfo.addAccessModeListeners(this);
}
private void addAccessModeListeners(ElementInfo other) {
synchronized (listenersLock) {
if (listeners == null){
listeners = new ArrayList<>();
}
Collection otherListeners = other.getListeners(AccessModeListenerRegistration.class);
for (AccessModeListenerRegistration amlr: otherListeners){
if (!listeners.contains(amlr)){
listeners.add(amlr);
}
}
}
}
}
