--- /dev/null
+package org.simantics.structural.synchronization.protocol;
+
+import gnu.trove.map.hash.THashMap;
+import gnu.trove.set.hash.THashSet;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Map;
+
+import org.simantics.databoard.util.URIStringUtils;
+
+/**
+ * <p>A partial implementation of SynchronizationEventHandler that contains all generic
+ * logic for synchronization that is not domain specific.
+ *
+ * <p>It is assumed that the current state of the simulator is stored in some tree-like
+ * data structure and Component is the class that refers to currently instantiated components.
+ *
+ * @author Hannu Niemistö
+ */
+public abstract class AbstractSynchronizationEventHandler<Component, ConnectionResolvedCallback> implements SynchronizationEventHandler {
+ /**
+ * Returns the root of the current configuration. It must not be null.
+ */
+ protected abstract Component getConfigurationRoot();
+
+ /**
+ * Returns the parent of the component. It may be null, if the component
+ * is the configuration root or if it is detached or just created.
+ */
+ protected abstract Component getParent(Component component);
+
+ /**
+ * Returns the map of current children of the component. The method may assume
+ * that the caller will not modify the map directly.
+ */
+ protected abstract Map<String, Component> getChildMap(Component component);
+
+ /**
+ * Sets the children of the component. The method may assume that all components
+ * in the newChildMap are detached (i.e. do not have a parent).
+ */
+ protected abstract void setChildMap(Component component, THashMap<String, Component> newChildMap);
+
+ /**
+ * <p>Detaches the component from its parent. After calling this method
+ * getParent(component) and getChildMap(parent).get(name) should return null where
+ * parent is the old parent of the component and name the name of the component.
+ *
+ * <p>It is important that after detaching, the method {@link #getComponentByUid}
+ * still returns the component.
+ */
+ protected abstract void detachFromParent(Component component);
+
+ /**
+ * Try to find the component by given uid. If it is not found, returns null.
+ */
+ protected abstract Component getComponentByUid(String uid);
+
+ /**
+ * Creates a new component with the given uid. The method may
+ * assume that there is no existing component with the same uid.
+ * After the method returns, getComponentByUid must return the
+ * same component with the given uid.
+ */
+ protected abstract Component createComponent(String uid);
+
+ /**
+ * Removes the component. The method may assume that the component
+ * has already been detached from its parent.
+ */
+ protected abstract void removeComponent(Component component);
+
+ /**
+ * Calls connectionResolvedCallback with the result of resolving the given connection point
+ * of the given component. The method is called only for components whose updating is completed.
+ */
+ protected abstract void resolveConnectionPointLocally(Component component, String connectionPointName,
+ ConnectionResolvedCallback connectionResolvedCallback);
+
+ /**
+ * <p>Updates the component based on the given name, type, properties and connections.
+ *
+ * <p>When updating has been finished (this may happen after this method has been finished)
+ * the method {@link #componentUpdated} must be called.
+ *
+ * <p>The method may use {@link resolveReference} to resolve connection point references.
+ */
+ protected abstract void updateComponent(Component component, String name,
+ String typeId, Collection<SerializedVariable> properties,
+ Collection<Connection> connections);
+
+ /**
+ * The component that synchronizer is currently updating.
+ * If currentComponent=null, beginComponent method is not yet called
+ * or endComponent is called matching the first beginComponent call.
+ */
+ private Component currentComponent;
+
+ /**
+ * The set of components which or whose children may still be
+ * updated by calling beginComponent during this synchronization.
+ */
+ private THashSet<Component> mayBeUpdated = new THashSet<Component>();
+
+ /**
+ * The key set of this map contains all components in {@link #mayBeUpdated} and additionally
+ * components whose updating has began by beginComponent call, but that are not yet completely
+ * updated (for example because they are waiting other unresolved components).
+ */
+ private THashMap<Component, ArrayList<PendingResolve<Component, ConnectionResolvedCallback>>> pendingResolves =
+ new THashMap<Component, ArrayList<PendingResolve<Component, ConnectionResolvedCallback>>>();
+
+ /**
+ * This set contains all components that currently have no parents and will be removed
+ * at the end of synchronization.
+ */
+ private THashSet<Component> pendingRemoval = new THashSet<Component>();
+
+ private static class PendingResolve<Component, ConnectionResolvedCallback> {
+ public final Component component;
+ public final String connectionPoint;
+ public final ConnectionResolvedCallback connectionResolvedCallback;
+
+ public PendingResolve(Component component, String connectionPoint,
+ ConnectionResolvedCallback connectionResolvedCallback) {
+ this.component = component;
+ this.connectionPoint = connectionPoint;
+ this.connectionResolvedCallback = connectionResolvedCallback;
+ }
+
+ @Override
+ public String toString() {
+ return connectionPoint + "->" + connectionResolvedCallback;
+ }
+ }
+
+ @Override
+ public void beginSynchronization() {
+ currentComponent = null;
+ }
+
+ @Override
+ public void endSynchronization() {
+ if(currentComponent != null)
+ throw new SynchronizationException("beginComponent is called more often than endComponent at the end of synchronization.");
+
+ for(Component component : pendingRemoval)
+ removeComponent(component);
+ pendingRemoval.clear();
+ }
+
+ @Override
+ public void beginComponent(String name, String typeId,
+ Collection<SerializedVariable> properties,
+ Collection<Connection> connections, Collection<ChildInfo> children)
+ throws SynchronizationException {
+ if(currentComponent == null) {
+ currentComponent = getConfigurationRoot();
+ if(currentComponent == null)
+ throw new SynchronizationException("getConfiguration root returned null.");
+ }
+ else {
+ currentComponent = getChildMap(currentComponent).get(name);
+ if(currentComponent == null)
+ throw new SynchronizationException("Didn't find '"+name+"'. "
+ + "It should have been mentioned as a child in the parent beginComponent method.");
+ }
+
+ // Handle children
+ if(!getChildMap(currentComponent).isEmpty() || !children.isEmpty()){
+ THashMap<String, Component> newChildMap =
+ new THashMap<String, Component>();
+ for(ChildInfo info : children) {
+ // Detach from the existing configuration the children with
+ // the right uids or create new components if uid is unknown.
+ Component component = getComponentByUid(info.uid);
+ if(component == null)
+ component = createComponent(info.uid);
+ else {
+ pendingRemoval.remove(component);
+ detachFromParent(component);
+ }
+ newChildMap.put(info.name, component);
+ componentMayBeUpdated(component);
+ }
+
+ // Put old children not detached in the previous phase
+ // to the pending removal set. They might have been
+ // moved somewhere else.
+ Map<String, Component> oldChildMap = getChildMap(currentComponent);
+ for(Component component : oldChildMap.values()) {
+ detachFromParent(component);
+ pendingRemoval.add(component);
+ }
+ setChildMap(currentComponent, newChildMap);
+ }
+
+ // Update/create component itself
+ mayBeUpdated.remove(currentComponent);
+ updateComponent(currentComponent, name, typeId, properties, connections);
+ }
+
+ @Override
+ public void endComponent() {
+ if(currentComponent == null)
+ throw new SynchronizationException("endComponent is called more often than beginComponent.");
+
+ for(Component child : getChildMap(currentComponent).values())
+ if(mayBeUpdated.remove(child))
+ // clear pending status of components which will not change
+ // during synchronization
+ componentUpdated(child);
+
+ currentComponent = getParent(currentComponent);
+ }
+
+ private void componentMayBeUpdated(Component component) {
+ mayBeUpdated.add(component);
+ pendingResolves.put(component, new ArrayList<PendingResolve<Component, ConnectionResolvedCallback>>(2));
+ }
+
+ /**
+ * Signals that the component is updated so far that its connection may be resolved
+ * (with resolveConnectionPointLocally).
+ */
+ public void componentUpdated(Component component) {
+ ArrayList<PendingResolve<Component, ConnectionResolvedCallback>> resolves = pendingResolves.remove(component);
+ if(resolves != null)
+ for(PendingResolve<Component, ConnectionResolvedCallback> resolve : resolves) {
+ resolveConnectionPoint(resolve.component,
+ resolve.connectionPoint,
+ resolve.connectionResolvedCallback);
+ }
+ }
+
+ /**
+ * Resolves relative connection point reference starting from the given component and calls
+ * ConnectionResolvedCallback with the resolved reference.
+ */
+ public void resolveConnectionPoint(Component component, String connectionPoint, ConnectionResolvedCallback connectionResolvedCallback) {
+ int pos = 0;
+ while(true) {
+ char c = connectionPoint.charAt(pos++);
+ switch(c) {
+ case '.':
+ component = getParent(component);
+ break;
+ case '/': {
+ int endPos = pos;
+ while(true) {
+ c = connectionPoint.charAt(endPos);
+ if(c == '/' || c == '#')
+ break;
+ ++endPos;
+ }
+ String segment = URIStringUtils.unescape(connectionPoint.substring(pos, endPos));
+ pos = endPos;
+ component = getChildMap(component).get(segment);
+ if(component == null) {
+ String message = "Couldn't resolve " + connectionPoint +
+ ", because child " + segment + " does not exist.";
+ reportProblem(message);
+ return;
+ }
+ ArrayList<PendingResolve<Component, ConnectionResolvedCallback>> pendingList = pendingResolves.get(component);
+ if(pendingList != null) {
+ pendingList.add(
+ new PendingResolve<Component, ConnectionResolvedCallback>(
+ component, connectionPoint.substring(pos), connectionResolvedCallback));
+ return;
+ }
+ } break;
+ case '#': {
+ String segment = connectionPoint.substring(pos);
+ resolveConnectionPointLocally(component, segment, connectionResolvedCallback);
+ } return;
+ }
+ }
+ }
+}
Code Review / simantics / platform.git / blobdiff