Code streamlining.

Change-Id: I773eb373e6397260af6fd3815f1b16815500dabd

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/IPDOMVisitor.java

@@ -8,20 +8,17 @@
  * Contributors:
  * 	   QNX - Initial API and implementation
  *******************************************************************************/
-
 package org.eclipse.cdt.core.dom;
 
 import org.eclipse.core.runtime.CoreException;
 
 /**
  * @author Doug Schaefer
- *
  */
 public interface IPDOMVisitor {
-
 	/**
-	 * Walk the nodes in a PDOM. Return true to visit the children of
+	 * Walks the nodes in a PDOM. Returns true to visit the children of
-	 * this node, or false to skip to the next sibling of this node.
+	 * the node, or false to skip to the next sibling of this node.
 	 * Throw CoreException to stop the visit.
 	 *  
 	 * @param node being visited
@@ -36,5 +33,4 @@ public interface IPDOMVisitor {
 	 * @throws CoreException
 	 */
 	public void leave(IPDOMNode node) throws CoreException;
-	
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/db/BTree.java

@@ -47,7 +47,7 @@ public class BTree {
 	/**
 	 * Constructor.
 	 * 
-	 * @param db the database containing the btree
+	 * @param db the database containing the B-tree
 	 * @param rootPointer offset into database of the pointer to the root node
 	 */
 	public BTree(Database db, long rootPointer, int degree, IBTreeComparator cmp) {
@@ -157,7 +157,7 @@ public class BTree {
 			}
 		}
 
-		// Binary search to find the insert point.
+		// Binary search to find the insertion point.
 		int lower= 0; 
 		int upper= MAX_RECORDS - 1;
 		while (lower < upper && getRecord(chunk, node, upper - 1) == 0) {
@@ -165,7 +165,7 @@ public class BTree {
 		}
 
 		while (lower < upper) {
-			int middle= (lower + upper) / 2;
+    		int middle= (lower + upper) >>> 1;
 			long checkRec= getRecord(chunk, node, middle);
 			if (checkRec == 0) {
 				upper= middle;
@@ -414,7 +414,7 @@ public class BTree {
 	}
 
 	/**
-	 * Merge node 'src' onto the right side of node 'dst' using node
+	 * Merges node 'src' onto the right side of node 'dst' using node
 	 * 'keyProvider' as the source of the median key. Bounds checking is not
 	 * performed.
 	 * @param src the key to merge into dst
@@ -446,7 +446,7 @@ public class BTree {
 	}
 
 	/**
-	 * Insert the key and (its predecessor) child at the left side of the specified node. Bounds checking
+	 * Inserts the key and (its predecessor) child at the left side of the specified node. Bounds checking
 	 * is not performed.
 	 * @param node the node to prepend to
 	 * @param key the new leftmost (least) key
@@ -459,7 +459,7 @@ public class BTree {
 	}
 
 	/**
-	 * Insert the key and (its successor) child at the right side of the specified node. Bounds
+	 * Inserts the key and (its successor) child at the right side of the specified node. Bounds
 	 * checking is not performed.
 	 * @param node
 	 * @param key
@@ -471,7 +471,7 @@ public class BTree {
 	}
 
 	/**
-	 * Overwrite a section of the specified node (dst) with the specified section of the source
+	 * Overwrites a section of the specified node (dst) with the specified section of the source
 	 * node. Bounds checking is not performed. To allow just copying of the final child (which has
 	 * no corresponding key) the routine behaves as though there were a corresponding key existing
 	 * with value zero.<p>
@@ -500,7 +500,7 @@ public class BTree {
 	}
 
 	/**
-	 * Delete a section of node content - (key, (predecessor)child) pairs. Bounds checking
+	 * Deletes a section of node content - (key, (predecessor)child) pairs. Bounds checking
 	 * is not performed. To allow deletion of the final child (which has no corresponding key)
 	 * the routine behaves as though there were a corresponding key existing with value zero.<p>
 	 * Content is deleted and remaining content is moved leftward the appropriate amount.
@@ -522,7 +522,7 @@ public class BTree {
 	}
 
 	/**
-	 * Visit all nodes beginning when the visitor comparator
+	 * Visits all nodes beginning when the visitor comparator
 	 * returns >= 0 until the visitor visit returns falls.
 	 * 
 	 * @param visitor
@@ -539,9 +539,7 @@ public class BTree {
 		if (node == 0) {
 			return true;
 		}
-		if (visitor instanceof IBTreeVisitor2) {
+		visitor.preNode(node);
-			((IBTreeVisitor2) visitor).preNode(node);
-		}
 
 		try {
 			Chunk chunk = db.getChunk(node);
@@ -553,7 +551,7 @@ public class BTree {
 				upper--;
 			}
 			while (lower < upper) {
-				int middle= (lower + upper) / 2;
+				int middle= (lower + upper) >>> 1;
 				long checkRec = getRecord(chunk, node, middle);
 				if (checkRec == 0) {
 					upper= middle;
@@ -587,25 +585,14 @@ public class BTree {
 			}
 			return accept(getChild(chunk, node, i), visitor);
 		} finally {
-			if (visitor instanceof IBTreeVisitor2) {
+			visitor.postNode(node);
-				((IBTreeVisitor2) visitor).postNode(node);
 		}
 	}
-	}
-
-	/*
-	 * TODO: It would be good to move these into IBTreeVisitor and eliminate
-	 * IBTreeVisitor2 if this is acceptable.
-	 */
-	private interface IBTreeVisitor2 extends IBTreeVisitor {
-		void preNode(long node) throws CoreException;
-		void postNode(long node) throws CoreException;
-	}
 
 	/**
-	 * Debugging method for checking B-tree invariants
+	 * Debugging method for checking B-tree invariants.
-	 * @return the empty String if B-tree invariants hold, otherwise
+	 *
-	 * a human readable report
+	 * @return the empty String if B-tree invariants hold, otherwise a human readable report
 	 * @throws CoreException
 	 */
 	public String getInvariantsErrorReport() throws CoreException {
@@ -618,7 +605,7 @@ public class BTree {
 	 * A B-tree visitor for checking some B-tree invariants.
 	 * Note ordering invariants are not checked here.
 	 */
-	private class InvariantsChecker implements IBTreeVisitor2 {
+	private class InvariantsChecker implements IBTreeVisitor {
 		boolean valid = true;
 		String msg = ""; //$NON-NLS-1$
 		Integer leafDepth;

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/db/IBTreeVisitor.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2005, 2012 QNX Software Systems and others.
+ * Copyright (c) 2005, 2015 QNX Software Systems 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
@@ -20,21 +20,33 @@ import org.eclipse.core.runtime.CoreException;
  */
 public interface IBTreeVisitor {
 	/**
-	 * Compare the record against an internally held key. The comparison must be
+	 * Compares the record against an internally held key. The comparison must be
-	 * compatible with the one used for the btree.
+	 * compatible with the one used for the B-tree.
 	 * Used for visiting.
 	 * 
 	 * @param record
 	 * @return -1 if record < key, 0 if record == key, 1 if record > key
-	 * @throws CoreException
 	 */
-	public abstract int compare(long record) throws CoreException;
+	public int compare(long record) throws CoreException;
 
 	/**
-	 * Visit a given record and return whether to continue or not.
+	 * Visits a given record and returns whether to continue or not.
-
+	 *
-	 * @return <code>true</code> to continue the visit, <code>false</code> to abort it.
+	 * @return {@code true} to continue the visit, {@code false} to abort it.
-	 * @throws CoreException
 	 */
-	public abstract boolean visit(long record) throws CoreException;	
+	public boolean visit(long record) throws CoreException;	
+
+	/**
+	 * Called before visiting a node.
+	 *
+	 * @param record the node being visited
+	 */
+	public default void preNode(long record) throws CoreException {}
+
+	/**
+	 * Called after visiting a node.
+	 *
+	 * @param record the node being visited
+	 */
+	public default void postNode(long record) throws CoreException {}
 }