1 files changed, 267 insertions, 0 deletions
diff --git a/debug/org.eclipse.cdt.debug.core/src/org/eclipse/cdt/debug/internal/core/CSettingsManager.java b/debug/org.eclipse.cdt.debug.core/src/org/eclipse/cdt/debug/internal/core/CSettingsManager.java
new file mode 100644
index 00000000000..96ee541ef12
--- /dev/null
+++ b/debug/org.eclipse.cdt.debug.core/src/org/eclipse/cdt/debug/internal/core/CSettingsManager.java
@@ -0,0 +1,267 @@
+/*******************************************************************************
+ * Copyright (c) 2007 Freescale Semiconductor 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:
+ *     Freescale Semiconductor - Initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.debug.internal.core;
+
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Set;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.transform.TransformerException;
+
+import org.eclipse.cdt.debug.core.CDebugUtils;
+import org.eclipse.cdt.debug.core.ICDTLaunchConfigurationConstants;
+import org.eclipse.cdt.debug.internal.core.model.CDebugTarget;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.debug.core.DebugPlugin;
+import org.eclipse.debug.core.ILaunchConfiguration;
+import org.eclipse.debug.core.ILaunchConfigurationWorkingCopy;
+import org.eclipse.debug.core.model.IDebugTarget;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+import org.xml.sax.InputSource;
+import org.xml.sax.SAXException;
+
+/**
+ * Settings manager
+ * 
+ * The settings manager stores a set of settings, 
+ * (key/value) pairs in the launch configuration so they exist across debug sessions.
+ * 
+ * All active settings are stored together in a single configuration entry 
+ * (ICDTLaunchConfigurationConstants.ATTR_DEBUGGER_FORMAT).
+ * 
+ * Every setting is identified by a string identifier. That string identifier can be used to 
+ * store an additional setting, to remove an exiting one or to retrieve a previously stored setting.
+ *
+ * The setting value consists of a String.
+ *
+ * Settings fade out automatically so clients do not necessarily need to delete old settings. This makes it 
+ * possible to build the string identifiers with names out of the user application, like function names or 
+ * variable names, without the danger of a constantly growing launch configuration.
+ * However it also causes that the settings manager must only be used for configurations and customizations for which
+ * always reasonable defaults exist.
+ *
+ * As cleanup policy the settings manager only keeps a certain number of settings and drops the 
+ * least recently used one when more settings are added. The least recently used order is maintained 
+ * across debug sessions. 
+ * 
+ */
+
+public class CSettingsManager {
+
+	/**
+	 * the name of the XML node for the list 
+	 */
+	private static final String CONTENT_LIST = "contentList"; //$NON-NLS-1$
+	
+	/**
+	 * the name of the XML node for every format entry 
+	 */
+	private static final String CONTENT = "content"; //$NON-NLS-1$
+	
+	/**
+	 * the attribute name used to identify the object to store the content for. 
+	 */
+	private static final String ATTR_CONTENT_ID = "id"; //$NON-NLS-1$
+	
+	/**
+	 * the attribute name of the actual content
+	 */
+	private static final String ATTR_CONTENT_VALUE = "val"; //$NON-NLS-1$
+
+	/**
+	 * Number defining how many settings are stored.
+	 * Whenever an additional setting is added when there are already MAX_USED_COUNT settings, the 
+	 * least recently used setting is dropped. 
+	 *
+	 * The actual value is chosen to be high enough for normal use cases, but still low enough to avoid that the launch configuration
+	 * gets arbitrarily large 
+	 */
+	private static int MAX_ELEMENT_COUNT = 100;
+
+	/**
+	 * the map used to actually store the format information
+	 * as key String are used, values are of type String too.
+	 * 
+	 * The map automatically is limited to MAX_ELEMENT_COUNT
+	 * elements, dropping the least recently used one
+	 * when more elements are added.
+	 */
+	private Map fContentMap = new LinkedHashMap(MAX_ELEMENT_COUNT, 0.75f, true) {
+		private static final long serialVersionUID = 1;
+		protected boolean removeEldestEntry(Map.Entry eldest) {
+			return size() > MAX_ELEMENT_COUNT;
+		}
+	};
+
+	/**
+	 * the debug target we store the values for
+	 */
+	private CDebugTarget fDebugTarget;
+	
+	/**
+	 * Store the value for the given id.
+	 * @param id used to identify the information. Different objects/topics should use different identifiers.
+	 * @param value content to be stored
+	 */
+	public synchronized void putValue( String id, String value ) {
+		fContentMap.put(id, value);
+	}
+	/**
+	 * remove the stored format for the given id.
+	 * @param id used to identify the formatting information. Different objects/topics should use different identifiers.
+	 */
+	public synchronized void removeValue( String id ) {
+		fContentMap.remove( id );
+	}
+
+	/** Retrieve the value for the given id.
+	 * @param id used to identify the formatting information. Different objects/topics should use different identifiers.
+	 * @return returns the entry information for the given id, or null if no such information is available.
+	 */
+	public synchronized String getValue( String id ) {
+		String entry= (String) fContentMap.get( id );
+		return entry;
+	}
+
+	/** constructor.
+	 * @param debugTarget
+	 */
+	public CSettingsManager( CDebugTarget debugTarget ) {
+		fDebugTarget = debugTarget;
+		initialize();
+	}
+	
+	/** get the string format of the current content.
+	 * Only stores entries which have been used in the last MAX_USED_COUNT debug sessions.
+	 * @return
+	 */
+	private String getMemento() {
+		Document document = null;
+		try {
+			document = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
+			Element node = document.createElement( CONTENT_LIST );
+			document.appendChild( node );
+			Set entrySet = fContentMap.entrySet();
+			Iterator it =  entrySet.iterator();
+			while ( it.hasNext() ) {
+				Map.Entry entry= (Map.Entry) it.next();
+				String id= (String)entry.getKey();
+				String value= (String)entry.getValue();
+				Element child = document.createElement( CONTENT );
+				child.setAttribute( ATTR_CONTENT_ID, id );
+				child.setAttribute( ATTR_CONTENT_VALUE, value );
+				node.appendChild( child );
+			}
+			return CDebugUtils.serializeDocument( document, false );
+		}
+		catch( ParserConfigurationException e ) {
+			DebugPlugin.log( e );
+		}
+		catch( IOException e ) {
+			DebugPlugin.log( e );
+		}
+		catch( TransformerException e ) {
+			DebugPlugin.log( e );
+		}
+		return null;
+	}
+
+	/** set the current state to the one given by the memento.
+	 * @param memento a string representation of the state to be loaded.
+	 * @throws CoreException
+	 */
+	private void initializeFromMemento( String memento ) throws CoreException {
+		try {
+			fContentMap.clear();
+			DocumentBuilder parser = DocumentBuilderFactory.newInstance().newDocumentBuilder();
+			StringReader reader = new StringReader( memento );
+			InputSource source = new InputSource( reader );
+			Element root = parser.parse( source ).getDocumentElement();
+			if ( root.getNodeName().equalsIgnoreCase( CONTENT_LIST ) ) {
+				NodeList list = root.getChildNodes();
+				int i = list.getLength() - 1; // backwards to keep least recent access order.
+				for( ; i >= 0; i-- ) {
+					Node node = list.item( i );
+					short type = node.getNodeType();
+					if ( type == Node.ELEMENT_NODE ) {
+						Element elem = (Element)node;
+						if ( elem.getNodeName().equalsIgnoreCase( CONTENT ) ) {
+							String id = elem.getAttribute( ATTR_CONTENT_ID );
+							String value= elem.getAttribute( ATTR_CONTENT_VALUE );
+							if ( id == null || id.length() == 0 ) {
+								DebugPlugin.logMessage( "unexpected entry in CSettingsManager.initializeFromMemento", null ); //$NON-NLS-1$
+								continue;
+							}
+							putValue( id, value );
+						}
+					}
+				}
+				return;
+			}
+			DebugPlugin.logMessage( "unexpected content", null ); //$NON-NLS-1$
+		}
+		catch( ParserConfigurationException e ) {
+			DebugPlugin.log( e );
+		}
+		catch( SAXException e ) {
+			DebugPlugin.log( e );
+		}
+		catch( IOException e ) {
+			DebugPlugin.log( e );
+		}
+	}
+
+	/**
+	 * read the stored format from the launch configuration
+	 */
+	private void initialize() {
+		ILaunchConfiguration config = getDebugTarget().getLaunch().getLaunchConfiguration();
+		try {
+			String memento = config.getAttribute( ICDTLaunchConfigurationConstants.ATTR_DEBUGGER_FORMAT, "" ); //$NON-NLS-1$
+			if ( memento != null && memento.trim().length() != 0 )
+				initializeFromMemento( memento );
+		}
+		catch( CoreException e ) {
+			DebugPlugin.log( e );
+		}
+	}
+
+	/**
+	 * store the current content in the launch configuration.
+	 */
+	public synchronized void save() {
+		ILaunchConfiguration config = getDebugTarget().getLaunch().getLaunchConfiguration();
+		try {
+			ILaunchConfigurationWorkingCopy wc = config.getWorkingCopy();
+			wc.setAttribute( ICDTLaunchConfigurationConstants.ATTR_DEBUGGER_FORMAT, getMemento() );
+			wc.doSave();
+		}
+		catch( CoreException e ) {
+			DebugPlugin.log( e );
+		}
+	}
+	
+	/**
+	 * accessor to the debug target
+	 */
+	IDebugTarget getDebugTarget() {
+		return fDebugTarget;
+	}
+}