1 files changed, 188 insertions, 0 deletions
diff --git a/org.eclipse.jdt.core/search/org/eclipse/jdt/internal/core/nd/field/FieldOneToMany.java b/org.eclipse.jdt.core/search/org/eclipse/jdt/internal/core/nd/field/FieldOneToMany.java
new file mode 100644
index 000000000..8f95c681f
--- /dev/null
+++ b/org.eclipse.jdt.core/search/org/eclipse/jdt/internal/core/nd/field/FieldOneToMany.java
@@ -0,0 +1,188 @@
+/*******************************************************************************
+ * Copyright (c) 2015, 2016 Google, 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:
+ *   Stefan Xenos (Google) - Initial implementation
+ *******************************************************************************/
+package org.eclipse.jdt.internal.core.nd.field;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.eclipse.jdt.internal.core.nd.Nd;
+import org.eclipse.jdt.internal.core.nd.NdNode;
+import org.eclipse.jdt.internal.core.nd.RawGrowableArray;
+
+/**
+ * Holds the 1 side of a 1..n relationship between two objects. FieldNodePointer and FieldBackPointer fields always go
+ * together in pairs.
+ */
+public class FieldOneToMany<T extends NdNode> implements IDestructableField, IRefCountedField, IField {
+	private int offset;
+	public Class<T> targetType;
+	public final Class<? extends NdNode> localType;
+	private final RawGrowableArray backPointerArray;
+	FieldManyToOne<?> forwardPointer;
+
+	public interface Visitor<T> {
+		public void visit(int index, T toVisit);
+	}
+
+	@SuppressWarnings({ "rawtypes", "unchecked" })
+	private FieldOneToMany(Class<? extends NdNode> localType, FieldManyToOne<? extends NdNode> forwardPointer,
+			int inlineElements) {
+		this.localType = localType;
+
+		if (forwardPointer != null) {
+			if (forwardPointer.backPointer != null && forwardPointer.backPointer != this) {
+				throw new IllegalArgumentException(
+					"Attempted to construct a FieldBackPointer referring to a forward pointer that is already in use" //$NON-NLS-1$
+						+ " by another field"); //$NON-NLS-1$
+			}
+			forwardPointer.targetType = (Class)localType;
+			this.targetType = (Class)forwardPointer.localType;
+			forwardPointer.backPointer = this;
+		}
+		this.forwardPointer = forwardPointer;
+		this.backPointerArray = new RawGrowableArray(inlineElements);
+	}
+
+	/**
+	 * Creates a {@link FieldOneToMany} using the given builder. It will hold the many side of a one-to-many
+	 * relationship with nodeType. 
+	 * 
+	 * @param builder builder that is being used to construct the struct containing this field
+	 * @param forwardPointer field of the model object which holds the one side of this one-to-many relationship
+	 * @param inlineElementCount number of inline elements. If this is nonzero, space for this number elements is
+	 * preallocated and reserved in the header. The first few elements inserted will be stored here. For relationships
+	 * which will usually have more than a certain number of participants, using a small number of inline elements will
+	 * offer a performance improvement. For relationships that will normally be empty, this should be 0.
+	 * @return the newly constructed backpointer field
+	 */
+	public static <T extends NdNode, B extends NdNode> FieldOneToMany<T> create(StructDef<B> builder, 
+			FieldManyToOne<B> forwardPointer, int inlineElementCount) {
+		FieldOneToMany<T> result = new FieldOneToMany<T>(builder.getStructClass(), forwardPointer,
+				inlineElementCount);
+		builder.add(result);
+		builder.addDestructableField(result);
+		builder.addRefCountedField(result);
+		return result;
+	}
+
+	public static <T extends NdNode, B extends NdNode> FieldOneToMany<T> create(StructDef<B> builder, 
+			FieldManyToOne<B> forwardPointer) {
+		return create(builder, forwardPointer, 0);
+	}
+	
+	public void accept(Nd nd, long address, Visitor<T> visitor) {
+		int size = size(nd, address);
+
+		for (int idx = 0; idx < size; idx++) {
+			visitor.visit(idx, get(nd, address, idx));
+		}
+	}
+
+	public List<T> asList(Nd nd, long address) {
+		final List<T> result = new ArrayList<>(size(nd, address));
+
+		accept(nd, address, new Visitor<T>() {
+			@Override
+			public void visit(int index, T toVisit) {
+				result.add(toVisit);
+			}
+		});
+
+		return result;
+	}
+
+	public boolean isEmpty(Nd nd, long address) {
+		return this.backPointerArray.isEmpty(nd, address + this.offset);
+	}
+	
+	public int size(Nd nd, long address) {
+		return this.backPointerArray.size(nd, address + this.offset);
+	}
+
+	public T get(Nd nd, long address, int index) {
+		long nextPointer = this.backPointerArray.get(nd, address + this.offset, index);
+
+		return NdNode.load(nd, nextPointer, this.targetType);
+	}
+
+	/**
+	 * Removes the given index from the list. If another element is swapped into the removed element's
+	 * location, that element's index will be updated. The removed element itself will not be modified. The
+	 * caller is responsible for nulling out the pointer and updating its index if necessary.
+	 * <p>
+	 * Not intended to be called by clients. The normal way to remove something from a backpointer list is
+	 * by calling {@link FieldManyToOne#put}, which performs the appropriate removals automatically.
+	 */
+	void remove(Nd nd, long address, int index) {
+		long swappedElement = this.backPointerArray.remove(nd, address + this.offset, index);
+
+		if (swappedElement != 0) {
+			this.forwardPointer.adjustIndex(nd, swappedElement, index);
+		}
+	}
+
+	/**
+	 * Addss the given forward pointer to the list and returns the insertion index. This should not be invoked
+	 * directly by clients. The normal way to insert into a backpointer list is to assign a forward pointer.
+	 */
+	int add(Nd nd, long address, long value) {
+		return this.backPointerArray.add(nd, address + this.offset, value);
+	}
+
+	/**
+	 * Returns the record size of the back pointer list 
+	 */
+	public int getRecordSize() {
+		return this.backPointerArray.getRecordSize();
+	}
+
+	public void ensureCapacity(Nd nd, long address, int capacity) {
+		long arrayAddress = address + this.offset;
+		this.backPointerArray.ensureCapacity(nd, arrayAddress, capacity);
+	}
+
+	@Override
+	public void destruct(Nd nd, long address) {
+		long arrayAddress = address + this.offset;
+		int size = size(nd, address);
+
+		boolean isOwner = this.forwardPointer.pointsToOwner;
+		for (int idx = 0; idx < size; idx++) {
+			long target = this.backPointerArray.get(nd, arrayAddress, idx);
+
+			this.forwardPointer.clearedByBackPointer(nd, target);
+
+			if (isOwner) {
+				nd.scheduleDeletion(target);
+			}
+		}
+
+		this.backPointerArray.destruct(nd, arrayAddress);
+	}
+
+	public int getCapacity(Nd nd, long address) {
+		return this.backPointerArray.getCapacity(nd, address + this.offset);
+	}
+
+	@Override
+	public boolean hasReferences(Nd nd, long address) {
+		// If this field owns the objects it points to, don't treat the incoming pointers as ref counts
+		if (this.forwardPointer.pointsToOwner) {
+			return false;
+		}
+		return !isEmpty(nd, address);
+	}
+
+	@Override
+	public void setOffset(int offset) {
+		this.offset = offset;
+	}
+}