| /******************************************************************************* |
| * Copyright (c) 2005, 2006 IBM Corporation 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: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jdt.internal.ui.text.java; |
| |
| import java.io.IOException; |
| import java.io.StringReader; |
| import java.io.StringWriter; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.LinkedHashMap; |
| import java.util.LinkedHashSet; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.Map.Entry; |
| |
| import javax.xml.parsers.DocumentBuilder; |
| import javax.xml.parsers.DocumentBuilderFactory; |
| import javax.xml.parsers.ParserConfigurationException; |
| import javax.xml.transform.OutputKeys; |
| import javax.xml.transform.Transformer; |
| import javax.xml.transform.TransformerException; |
| import javax.xml.transform.TransformerFactory; |
| import javax.xml.transform.dom.DOMSource; |
| import javax.xml.transform.stream.StreamResult; |
| |
| import org.eclipse.core.runtime.Assert; |
| import org.eclipse.core.runtime.CoreException; |
| import org.eclipse.core.runtime.IProgressMonitor; |
| import org.eclipse.core.runtime.IStatus; |
| import org.eclipse.core.runtime.NullProgressMonitor; |
| import org.eclipse.core.runtime.Preferences; |
| |
| |
| import org.eclipse.jdt.core.Flags; |
| import org.eclipse.jdt.core.IType; |
| import org.eclipse.jdt.core.ITypeHierarchy; |
| import org.eclipse.jdt.core.JavaModelException; |
| |
| import org.eclipse.jdt.internal.ui.JavaPlugin; |
| import org.eclipse.jdt.internal.ui.JavaUIException; |
| import org.eclipse.jdt.internal.ui.JavaUIStatus; |
| |
| 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; |
| |
| /** |
| * An LRU cache for code assist. |
| * |
| * @since 3.2 |
| */ |
| public final class ContentAssistHistory { |
| /** |
| * Persistence implementation. |
| * |
| * @since 3.2 |
| */ |
| private static final class ReaderWriter { |
| |
| private static final String NODE_ROOT= "history"; //$NON-NLS-1$ |
| private static final String NODE_LHS= "lhs"; //$NON-NLS-1$ |
| private static final String NODE_RHS= "rhs"; //$NON-NLS-1$ |
| private static final String ATTRIBUTE_NAME= "name"; //$NON-NLS-1$ |
| private static final String ATTRIBUTE_MAX_LHS= "maxLHS"; //$NON-NLS-1$ |
| private static final String ATTRIBUTE_MAX_RHS= "maxRHS"; //$NON-NLS-1$ |
| |
| public void store(ContentAssistHistory history, StreamResult result) throws CoreException { |
| try { |
| DocumentBuilderFactory factory= DocumentBuilderFactory.newInstance(); |
| DocumentBuilder builder= factory.newDocumentBuilder(); |
| Document document= builder.newDocument(); |
| |
| Element rootElement = document.createElement(NODE_ROOT); |
| rootElement.setAttribute(ATTRIBUTE_MAX_LHS, Integer.toString(history.fMaxLHS)); |
| rootElement.setAttribute(ATTRIBUTE_MAX_RHS, Integer.toString(history.fMaxRHS)); |
| document.appendChild(rootElement); |
| |
| for (Iterator leftHandSides= history.fLHSCache.keySet().iterator(); leftHandSides.hasNext();) { |
| String lhs= (String) leftHandSides.next(); |
| Element lhsElement= document.createElement(NODE_LHS); |
| lhsElement.setAttribute(ATTRIBUTE_NAME, lhs); |
| rootElement.appendChild(lhsElement); |
| |
| Set rightHandSides= (Set) history.fLHSCache.get(lhs); |
| for (Iterator rhsIterator= rightHandSides.iterator(); rhsIterator.hasNext();) { |
| String rhs= (String) rhsIterator.next(); |
| Element rhsElement= document.createElement(NODE_RHS); |
| rhsElement.setAttribute(ATTRIBUTE_NAME, rhs); |
| lhsElement.appendChild(rhsElement); |
| } |
| } |
| |
| Transformer transformer=TransformerFactory.newInstance().newTransformer(); |
| transformer.setOutputProperty(OutputKeys.METHOD, "xml"); //$NON-NLS-1$ |
| transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); //$NON-NLS-1$ |
| transformer.setOutputProperty(OutputKeys.INDENT, "no"); //$NON-NLS-1$ |
| DOMSource source = new DOMSource(document); |
| |
| transformer.transform(source, result); |
| } catch (TransformerException e) { |
| throw createException(e, JavaTextMessages.ContentAssistHistory_serialize_error); |
| } catch (ParserConfigurationException e) { |
| throw createException(e, JavaTextMessages.ContentAssistHistory_serialize_error); |
| } |
| } |
| |
| public ContentAssistHistory load(InputSource source) throws CoreException { |
| Element root; |
| try { |
| DocumentBuilder parser = DocumentBuilderFactory.newInstance().newDocumentBuilder(); |
| root = parser.parse(source).getDocumentElement(); |
| } catch (SAXException e) { |
| throw createException(e, JavaTextMessages.ContentAssistHistory_deserialize_error); |
| } catch (ParserConfigurationException e) { |
| throw createException(e, JavaTextMessages.ContentAssistHistory_deserialize_error); |
| } catch (IOException e) { |
| throw createException(e, JavaTextMessages.ContentAssistHistory_deserialize_error); |
| } |
| |
| if (root == null || !root.getNodeName().equalsIgnoreCase(NODE_ROOT)) |
| return null; |
| |
| int maxLHS= parseNaturalInt(root.getAttribute(ATTRIBUTE_MAX_LHS), DEFAULT_TRACKED_LHS); |
| int maxRHS= parseNaturalInt(root.getAttribute(ATTRIBUTE_MAX_RHS), DEFAULT_TRACKED_RHS); |
| |
| ContentAssistHistory history= new ContentAssistHistory(maxLHS, maxRHS); |
| |
| NodeList list= root.getChildNodes(); |
| int length= list.getLength(); |
| for (int i= 0; i < length; ++i) { |
| Node lhsNode= list.item(i); |
| if (lhsNode.getNodeType() == Node.ELEMENT_NODE) { |
| Element lhsElement= (Element) lhsNode; |
| if (lhsElement.getNodeName().equalsIgnoreCase(NODE_LHS)) { |
| String lhs= lhsElement.getAttribute(ATTRIBUTE_NAME); |
| if (lhs != null) { |
| Set cache= history.getCache(lhs); |
| NodeList children= lhsElement.getChildNodes(); |
| int nRHS= children.getLength(); |
| for (int j= 0; j < nRHS; j++) { |
| Node rhsNode= children.item(j); |
| if (rhsNode.getNodeType() == Node.ELEMENT_NODE) { |
| Element rhsElement= (Element) rhsNode; |
| if (rhsElement.getNodeName().equalsIgnoreCase(NODE_RHS)) { |
| String rhs= rhsElement.getAttribute(ATTRIBUTE_NAME); |
| if (rhs != null) { |
| cache.add(rhs); |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| return history; |
| } |
| |
| private int parseNaturalInt(String attribute, int defaultValue) { |
| try { |
| int integer= Integer.parseInt(attribute); |
| if (integer > 0) |
| return integer; |
| return defaultValue; |
| } catch (NumberFormatException e) { |
| return defaultValue; |
| } |
| } |
| |
| private JavaUIException createException(Exception e, String message) { |
| return new JavaUIException(JavaUIStatus.createError(IStatus.ERROR, message, e)); |
| } |
| } |
| |
| /** |
| * Most recently used variant with capped size that only counts |
| * {@linkplain #put(Object, Object) put} as access. This is implemented by always removing an |
| * element before it gets put back. |
| * |
| * @since 3.2 |
| */ |
| private static final class MRUMap extends LinkedHashMap { |
| private static final long serialVersionUID= 1L; |
| private final int fMaxSize; |
| |
| /** |
| * Creates a new <code>MRUMap</code> with the given size. |
| * |
| * @param maxSize the maximum size of the cache, must be > 0 |
| */ |
| public MRUMap(int maxSize) { |
| Assert.isLegal(maxSize > 0); |
| fMaxSize= maxSize; |
| } |
| |
| /* |
| * @see java.util.HashMap#put(java.lang.Object, java.lang.Object) |
| */ |
| public Object put(Object key, Object value) { |
| Object object= remove(key); |
| super.put(key, value); |
| return object; |
| } |
| |
| /* |
| * @see java.util.LinkedHashMap#removeEldestEntry(java.util.Map.Entry) |
| */ |
| protected boolean removeEldestEntry(Entry eldest) { |
| return size() > fMaxSize; |
| } |
| } |
| |
| /** |
| * Most recently used variant with capped size that orders the elements by addition. |
| * This is implemented by always removing an element before it gets added back. |
| * |
| * @since 3.2 |
| */ |
| private static final class MRUSet extends LinkedHashSet { |
| private static final long serialVersionUID= 1L; |
| private final int fMaxSize; |
| |
| /** |
| * Creates a new <code>MRUSet</code> with the given size. |
| * |
| * @param maxSize the maximum size of the cache, must be > 0 |
| */ |
| public MRUSet(int maxSize) { |
| Assert.isLegal(maxSize > 0); |
| fMaxSize= maxSize; |
| } |
| |
| /* |
| * @see java.util.HashSet#add(java.lang.Object) |
| */ |
| public boolean add(Object o) { |
| if (remove(o)) { |
| super.add(o); |
| return false; |
| } |
| |
| if (size() >= fMaxSize) |
| remove(this.iterator().next()); |
| |
| super.add(o); |
| return true; |
| } |
| } |
| |
| /** |
| * A ranking of the most recently selected types. |
| * |
| * @since 3.2 |
| */ |
| public static final class RHSHistory { |
| private final LinkedHashMap fHistory; |
| private List fList; |
| |
| RHSHistory(LinkedHashMap history) { |
| fHistory= history; |
| } |
| |
| /** |
| * Returns the rank of a type in the history in [0.0, 1.0]. The rank of the most |
| * recently selected type is 1.0, the rank of any type that is not remembered is zero. |
| * |
| * @param type the fully qualified type name to get the rank for |
| * @return the rank of <code>type</code> |
| */ |
| public float getRank(String type) { |
| if (fHistory == null) |
| return 0.0F; |
| Integer integer= (Integer) fHistory.get(type); |
| return integer == null ? 0.0F : integer.floatValue() / fHistory.size(); |
| } |
| |
| /** |
| * Returns the size of the history. |
| * |
| * @return the size of the history |
| */ |
| public int size() { |
| return fHistory == null ? 0 : fHistory.size(); |
| } |
| |
| /** |
| * Returns the list of remembered types ordered by recency. The first element is the |
| * <i>least</i>, the last element the <i>most</i> recently remembered type. |
| * |
| * @return the list of remembered types as fully qualified type names (element type: |
| * {@link String}) |
| */ |
| public List getTypes() { |
| if (fHistory == null) |
| return Collections.EMPTY_LIST; |
| if (fList == null) { |
| fList= Collections.unmodifiableList(new ArrayList(fHistory.keySet())); |
| } |
| return fList; |
| } |
| } |
| |
| private static final RHSHistory EMPTY_HISTORY= new RHSHistory(null); |
| private static final int DEFAULT_TRACKED_LHS= 100; |
| private static final int DEFAULT_TRACKED_RHS= 10; |
| |
| private static final Set UNCACHEABLE; |
| static { |
| Set uncacheable= new HashSet(); |
| uncacheable.add("java.lang.Object"); //$NON-NLS-1$ |
| uncacheable.add("java.lang.Comparable"); //$NON-NLS-1$ |
| uncacheable.add("java.io.Serializable"); //$NON-NLS-1$ |
| uncacheable.add("java.io.Externalizable"); //$NON-NLS-1$ |
| UNCACHEABLE= Collections.unmodifiableSet(uncacheable); |
| } |
| |
| private final LinkedHashMap/*<IType, MRUSet<IType>>*/ fLHSCache; |
| private final int fMaxLHS; |
| private final int fMaxRHS; |
| |
| /** |
| * Creates a new history. |
| * |
| * @param maxLHS the maximum number of tracked left hand sides (> 0) |
| * @param maxRHS the maximum number of tracked right hand sides per left hand side(> 0) |
| */ |
| public ContentAssistHistory(int maxLHS, int maxRHS) { |
| Assert.isLegal(maxLHS > 0); |
| Assert.isLegal(maxRHS > 0); |
| fMaxLHS= maxLHS; |
| fMaxRHS= maxRHS; |
| fLHSCache= new MRUMap(fMaxLHS); |
| } |
| |
| /** |
| * Creates a new history, equivalent to |
| * <code>ContentAssistHistory(DEFAULT_TRACKED_LHS, DEFAULT_TRACKED_RHS})</code>. |
| */ |
| public ContentAssistHistory() { |
| this(DEFAULT_TRACKED_LHS, DEFAULT_TRACKED_RHS); |
| } |
| |
| /** |
| * Remembers the selection of a right hand side type (proposal type) for a certain left hand side (expected |
| * type) in content assist. |
| * |
| * @param lhs the left hand side / expected type |
| * @param rhs the selected right hand side |
| */ |
| public void remember(IType lhs, IType rhs) { |
| Assert.isLegal(lhs != null); |
| Assert.isLegal(rhs != null); |
| |
| try { |
| if (!isCacheableRHS(rhs)) |
| return; |
| ITypeHierarchy hierarchy= rhs.newSupertypeHierarchy(getProgressMonitor()); |
| if (hierarchy.contains(lhs)) { |
| // TODO remember for every member of the LHS hierarchy or not? Yes for now. |
| IType[] allLHSides= hierarchy.getAllSupertypes(lhs); |
| for (int i= 0; i < allLHSides.length; i++) |
| rememberInternal(allLHSides[i], rhs); |
| rememberInternal(lhs, rhs); |
| } |
| } catch (JavaModelException x) { |
| JavaPlugin.log(x); |
| } |
| } |
| |
| /** |
| * Returns the {@link RHSHistory history} of the types that have been selected most recently as |
| * right hand sides for the given type. |
| * |
| * @param lhs the fully qualified type name of an expected type for which right hand sides are |
| * requested, or <code>null</code> |
| * @return the right hand side history for the given type |
| */ |
| public RHSHistory getHistory(String lhs) { |
| MRUSet rhsCache= (MRUSet) fLHSCache.get(lhs); |
| if (rhsCache != null) { |
| int count= rhsCache.size(); |
| LinkedHashMap history= new LinkedHashMap((int) (count / 0.75)); |
| int rank= 1; |
| for (Iterator it= rhsCache.iterator(); it.hasNext(); rank++) { |
| String type= (String) it.next(); |
| history.put(type, new Integer(rank)); |
| } |
| return new RHSHistory(history); |
| } |
| return EMPTY_HISTORY; |
| } |
| |
| /** |
| * Returns a read-only map from {@link IType} to {@link RHSHistory}, where each value is the |
| * history for the key type (see {@link #getHistory(String)}. |
| * |
| * @return the set of remembered right hand sides ordered by least recent selection |
| */ |
| public Map getEntireHistory() { |
| HashMap map= new HashMap((int) (fLHSCache.size() / 0.75)); |
| for (Iterator it= fLHSCache.entrySet().iterator(); it.hasNext();) { |
| Entry entry= (Entry) it.next(); |
| String lhs= (String) entry.getKey(); |
| map.put(lhs, getHistory(lhs)); |
| } |
| return Collections.unmodifiableMap(map); |
| } |
| |
| private void rememberInternal(IType lhs, IType rhs) throws JavaModelException { |
| if (isCacheableLHS(lhs)) |
| getCache(lhs.getFullyQualifiedName()).add(rhs.getFullyQualifiedName()); |
| } |
| |
| private boolean isCacheableLHS(IType type) throws JavaModelException { |
| return !Flags.isFinal(type.getFlags()) && !UNCACHEABLE.contains(type.getFullyQualifiedName()); |
| } |
| |
| private boolean isCacheableRHS(IType type) throws JavaModelException { |
| return !type.isInterface() && !Flags.isAbstract(type.getFlags()); |
| } |
| |
| private Set getCache(String lhs) { |
| MRUSet rhsCache= (MRUSet) fLHSCache.get(lhs); |
| if (rhsCache == null) { |
| rhsCache= new MRUSet(fMaxRHS); |
| fLHSCache.put(lhs, rhsCache); |
| } |
| |
| return rhsCache; |
| } |
| |
| private IProgressMonitor getProgressMonitor() { |
| return new NullProgressMonitor(); |
| } |
| |
| /** |
| * Stores the history as XML document into the given preferences. |
| * |
| * @param history the history to store |
| * @param preferences the preferences to store the history into |
| * @param key the key under which to store the history |
| * @throws CoreException if serialization fails |
| * @see #load(Preferences, String) on how to restore a history stored by this method |
| */ |
| public static void store(ContentAssistHistory history, Preferences preferences, String key) throws CoreException { |
| StringWriter writer= new StringWriter(); |
| new ReaderWriter().store(history, new StreamResult(writer)); |
| preferences.setValue(key, writer.toString()); |
| } |
| |
| /** |
| * Loads a history from an XML encoded preference value. |
| * |
| * @param preferences the preferences to retrieve the history from |
| * @param key the key under which the history is stored |
| * @return the deserialized history, or <code>null</code> if there is nothing stored under the |
| * given key |
| * @throws CoreException if deserialization fails |
| * @see #store(ContentAssistHistory, Preferences, String) on how to store a history such that it |
| * can be read by this method |
| */ |
| public static ContentAssistHistory load(Preferences preferences, String key) throws CoreException { |
| String value= preferences.getString(key); |
| if (value != null && value.length() > 0) { |
| return new ReaderWriter().load(new InputSource(new StringReader(value))); |
| } |
| return null; |
| } |
| } |