1 files changed, 278 insertions, 0 deletions
diff --git a/target_explorer/plugins/org.eclipse.tm.te.runtime.services/src/org/eclipse/tm/te/runtime/services/AbstractServiceManager.java b/target_explorer/plugins/org.eclipse.tm.te.runtime.services/src/org/eclipse/tm/te/runtime/services/AbstractServiceManager.java
new file mode 100644
index 000000000..167803720
--- /dev/null
+++ b/target_explorer/plugins/org.eclipse.tm.te.runtime.services/src/org/eclipse/tm/te/runtime/services/AbstractServiceManager.java
@@ -0,0 +1,278 @@
+/*******************************************************************************
+ * Copyright (c) 2011 Wind River Systems, Inc. and others. All rights reserved.
+ * This program and the accompanying materials are made available under the terms
+ * of the Eclipse Public License v1.0 which accompanies this distribution, and is
+ * available at http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ * Wind River Systems - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.tm.te.runtime.services;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.eclipse.core.runtime.Assert;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IConfigurationElement;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Platform;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.tm.te.runtime.activator.CoreBundleActivator;
+import org.eclipse.tm.te.runtime.services.interfaces.IService;
+
+/**
+ * Abstract service manager implementation.
+ */
+public abstract class AbstractServiceManager<ServiceClass extends IService> {
+
+	// map for all services per id
+	private Map<String, List<ServiceProxy>> services = new HashMap<String, List<ServiceProxy>>();
+
+	/**
+	 * Proxy to provide lazy loading of contributing plug-ins.
+	 */
+	protected class ServiceProxy {
+
+		private IConfigurationElement configElement = null;
+		public String clazz;
+		private ServiceClass service = null;
+		private List<Class<? extends ServiceClass>> serviceTypes = new ArrayList<Class<? extends ServiceClass>>();
+
+		/**
+		 * Constructor.
+		 */
+		protected ServiceProxy(IConfigurationElement configElement) {
+			Assert.isNotNull(configElement);
+			this.configElement = configElement;
+
+			// Read the class attribute. If null, check for the class sub element
+			clazz = configElement.getAttribute("class"); //$NON-NLS-1$
+			if (clazz == null) {
+				IConfigurationElement[] children = configElement.getChildren("class"); //$NON-NLS-1$
+				// Single element definition assumed (see extension point schema)
+				if (children.length > 0) {
+					clazz = children[0].getAttribute("class"); //$NON-NLS-1$
+				}
+			}
+		}
+
+		/**
+		 * Add a type to the proxy. Types are used unless the proxy is instantiated to provide lazy
+		 * loading of services. After instantiated, a service will be identified only by its type
+		 * and implementing or extending interfaces or super-types.
+		 *
+		 * @param serviceType The type to add.
+		 */
+		public void addType(Class<? extends ServiceClass> serviceType) {
+			assert serviceType != null;
+			if (service == null && serviceTypes != null && !serviceTypes.contains(serviceType)) {
+				serviceTypes.add(serviceType);
+			}
+		}
+
+		/**
+		 * Return the real service instance for this proxy.
+		 */
+		@SuppressWarnings("unchecked")
+		protected ServiceClass getService(boolean unique) {
+			if ((service == null || unique) && configElement != null) {
+				try {
+					Object service = configElement.createExecutableExtension("class"); //$NON-NLS-1$
+					if (service instanceof IService) {
+						if (unique) {
+							return (ServiceClass) service;
+						}
+						else if (service instanceof IService) {
+							this.service = (ServiceClass)service;
+						}
+						else {
+							IStatus status = new Status(IStatus.ERROR, CoreBundleActivator.getUniqueIdentifier(), "Service '" + service.getClass().getName() + "' not of type IService."); //$NON-NLS-1$ //$NON-NLS-2$
+							Platform.getLog(CoreBundleActivator.getContext().getBundle())
+							                .log(status);
+						}
+					}
+				}
+				catch (CoreException e) {
+					IStatus status = new Status(IStatus.ERROR, CoreBundleActivator.getUniqueIdentifier(), "Cannot create service '" + clazz + "'.", e); //$NON-NLS-1$ //$NON-NLS-2$
+					Platform.getLog(CoreBundleActivator.getContext().getBundle()).log(status);
+				}
+				if (serviceTypes != null) {
+					serviceTypes.clear();
+				}
+				serviceTypes = null;
+			}
+			return service;
+		}
+
+		/**
+		 * Check whether this proxy holds a service that is suitable for the given type.
+		 *
+		 * @param serviceType The service type
+		 * @return
+		 */
+		protected boolean isMatching(Class<? extends ServiceClass> serviceType) {
+			if (service != null) {
+				return serviceType.isInstance(service);
+			}
+			else if (configElement != null) {
+				if (serviceType.getClass().getName().equals(clazz)) {
+					return true;
+				}
+				for (Class<? extends ServiceClass> type : serviceTypes) {
+					if (type.equals(serviceType)) {
+						return true;
+					}
+				}
+			}
+			return false;
+		}
+
+		public boolean equals(ServiceClass service) {
+			return clazz.equals(service.getClass());
+		}
+
+		public boolean equals(ServiceProxy proxy) {
+			return clazz.equals(proxy.clazz);
+		}
+	}
+
+	/**
+	 * Constructor.
+	 */
+	protected AbstractServiceManager() {
+		loadServices();
+	}
+
+	/**
+	 * @param element
+	 * @return
+	 */
+	protected ServiceProxy getServiceProxy(IConfigurationElement element) {
+		return new ServiceProxy(element);
+	}
+
+	/**
+	 * Returns all id's of the registered services.
+	 *
+	 * @return The list of id's of the registered services.
+	 */
+	public String[] getIds() {
+		return services.keySet().toArray(new String[services.keySet().size()]);
+	}
+
+	/**
+	 * Get a service for the id that implements at least the needed service type. If an interface
+	 * type is given, the service with the highest implementation is returned. This may result in a
+	 * random selection depending on the extension registration order, especially when a service
+	 * interface is implemented two times in different hierarchy paths. If a class type is given, if
+	 * available, the service of exactly that class is returned. Otherwise the highest
+	 * implementation is returned.
+	 *
+	 * @param id The id for which a service is needed.
+	 * @param serviceType The service type the service should at least implement or extend.
+	 * @return The service or <code>null</code>.
+	 */
+	public ServiceClass getService(String id, Class<? extends ServiceClass> serviceType) {
+		return getService(id, serviceType, false);
+	}
+
+	/**
+	 * Get a service for the id that implements at least the needed service type. If an interface
+	 * type is given, the service with the highest implementation is returned. This may result in a
+	 * random selection depending on the extension registration order, especially when a service
+	 * interface is implemented two times in different hierarchy paths. If a class type is given, if
+	 * available, the service of exactly that class is returned. Otherwise the highest
+	 * implementation is returned.
+	 *
+	 * @param id The id for which a service is needed.
+	 * @param serviceType The service type the service should at least implement or extend.
+	 * @param unique <code>true</code> if a new instance of the service is needed.
+	 *
+	 * @return The service or <code>null</code>.
+	 */
+	public ServiceClass getService(String id, Class<? extends ServiceClass> serviceType, boolean unique) {
+		assert serviceType != null;
+		if (id == null) {
+			id = ""; //$NON-NLS-1$
+		}
+		List<ServiceProxy> proxies = services.get(id);
+		if (proxies != null && !proxies.isEmpty()) {
+			List<ServiceProxy> candidates = new ArrayList<ServiceProxy>();
+			boolean isInterface = serviceType.isInterface();
+			for (ServiceProxy proxy : proxies) {
+				if (proxy.isMatching(serviceType)) {
+					if (!isInterface && proxy.equals(serviceType)) {
+						ServiceClass service = proxy.getService(unique);
+						service.setId(id);
+						return service;
+					}
+					candidates.add(proxy);
+				}
+			}
+			ServiceClass service = null;
+			if (!candidates.isEmpty()) {
+				service = candidates.get(0).getService(unique);
+				service.setId(id);
+			}
+
+			return service;
+		}
+		return null;
+	}
+
+	/**
+	 * Get a service list for the id that implements at least the needed service type.
+	 *
+	 * @param id The id for which a service is needed.
+	 * @param serviceType The service type the service should at least implement or extend.
+	 * @param unique <code>true</code> if a new instance of the service is needed.
+	 * @return The service list or empty list.
+	 */
+	public IService[] getServices(String id, Class<? extends ServiceClass> serviceType, boolean unique) {
+		assert serviceType != null;
+		if (id == null) {
+			id = ""; //$NON-NLS-1$
+		}
+		List<ServiceProxy> proxies = services.get(id);
+		List<IService> services = new ArrayList<IService>();
+		if (proxies != null && !proxies.isEmpty()) {
+			List<ServiceProxy> candidates = new ArrayList<ServiceProxy>();
+			for (ServiceProxy proxy : proxies) {
+				if (proxy.isMatching(serviceType)) {
+					candidates.add(proxy);
+				}
+			}
+			for (ServiceProxy serviceProxy : candidates) {
+				IService service = serviceProxy.getService(unique);
+				service.setId(id);
+				services.add(service);
+			}
+		}
+		return services.toArray(new IService[services.size()]);
+	}
+
+	/*
+	 * Add a service proxy to the list of available services.
+	 */
+	protected boolean addService(String id, ServiceProxy proxy) {
+		assert services != null && id != null && proxy != null;
+		List<ServiceProxy> proxies = services.get(id);
+		if (proxies == null) {
+			proxies = new ArrayList<ServiceProxy>();
+			services.put(id, proxies);
+		}
+		assert proxies != null;
+		if (proxies.isEmpty() || !proxies.contains(proxy)) {
+			return proxies.add(proxy);
+		}
+		return false;
+	}
+
+	/**
+	 * Loads the contributed services into proxies (lazy loading!!) and adds them to this manager;
+	 */
+	protected abstract void loadServices();
+}