ltk/org.eclipse.statet.ltk.core/src/org/eclipse/statet/ltk/model/core/impl/AbstractModelManager.java

/*=============================================================================#
 # Copyright (c) 2009, 2020 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.ltk.model.core.impl;

import java.util.List;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.Job;

import org.eclipse.statet.jcommons.collections.CopyOnWriteIdentityListSet;
import org.eclipse.statet.jcommons.collections.ImCollections;
import org.eclipse.statet.jcommons.collections.ImIdentityList;

import org.eclipse.statet.ltk.core.LTK;
import org.eclipse.statet.ltk.core.WorkingContext;
import org.eclipse.statet.ltk.model.core.IElementChangedListener;
import org.eclipse.statet.ltk.model.core.IModelManager;
import org.eclipse.statet.ltk.model.core.elements.ISourceUnit;


public abstract class AbstractModelManager implements IModelManager {
	
	
	protected static class ContextItem {
		
		public final WorkingContext context;
		
		public final CopyOnWriteIdentityListSet<IElementChangedListener> listeners= new CopyOnWriteIdentityListSet<>();
		
		
		protected ContextItem(final WorkingContext context) {
			this.context= context;
		}
		
		
		@Override
		public final int hashCode() {
			return this.context.hashCode();
		}
		
		@Override
		public final boolean equals(final Object obj) {
			return (this == obj);
		}
		
	}
	
	private static final ImIdentityList<IElementChangedListener> NO_LISTENERS= ImCollections.emptyIdentityList();
	
	private class RefreshJob extends Job {
		
		
		private final List<ISourceUnit> list;
		
		private final int flags;
		
		
		public RefreshJob(final WorkingContext context, final int flags) {
			super("Model Refresh"); //$NON-NLS-1$
			setUser(false);
			setSystem(true);
			setPriority(DECORATE);
			
			this.list= LTK.getSourceUnitManager().getOpenSourceUnits(AbstractModelManager.this.typeId, context);
			this.flags= flags;
		}
		
		@Override
		protected IStatus run(final IProgressMonitor monitor) {
			for (final ISourceUnit su : this.list) {
				su.getModelInfo(null, this.flags, monitor);
			}
			return Status.OK_STATUS;
		}
		
	}
	
	
	private final String typeId;
	
	private final CopyOnWriteIdentityListSet<ContextItem> contexts= new CopyOnWriteIdentityListSet<>();
	
	
	public AbstractModelManager(final String typeId) {
		this.typeId= typeId;
	}
	
	
	public String getModelTypeId() {
		return this.typeId;
	}
	
	protected ContextItem getContextItem(final WorkingContext context, final boolean create) {
		while (true) {
			final ImIdentityList<ContextItem> contextItems= this.contexts.toList();
			for (final ContextItem contextItem : contextItems) {
				if (contextItem.context == context) {
					return contextItem;
				}
			}
			if (!create) {
				return null;
			}
			synchronized (this.contexts) {
				if (contextItems == this.contexts.toList()) {
					final ContextItem item= doCreateContextItem(context);
					this.contexts.add(item);
					return item;
				}
			}
		}
	}
	
	protected ContextItem doCreateContextItem(final WorkingContext context) {
		return new ContextItem(context);
	}
	
	@Override
	public void addElementChangedListener(final IElementChangedListener listener,
			final WorkingContext context) {
		final ContextItem contextItem= getContextItem(context, true);
		contextItem.listeners.add(listener);
	}
	
	@Override
	public void removeElementChangedListener(final IElementChangedListener listener,
			final WorkingContext context) {
		final ContextItem contextItem= getContextItem(context, false);
		if (contextItem != null) {
			contextItem.listeners.remove(listener);
		}
	}
	
	protected ImIdentityList<IElementChangedListener> getElementChangedListeners(final WorkingContext context) {
		final ContextItem contextItem= getContextItem(context, false);
		if (contextItem == null) {
			return NO_LISTENERS;
		}
		return contextItem.listeners.toList();
	}
	
	/**
	 * Refresh reuses existing ast
	 */
	@Override
	public void refresh(final WorkingContext context) {
		new RefreshJob(context, (MODEL_DEPENDENCIES | RECONCILE)).schedule();
	}
	
	@Override
	public void registerDependentUnit(final ISourceUnit su) {
	}
	
	@Override
	public void deregisterDependentUnit(final ISourceUnit su) {
	}
	
}