| /* |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| package org.apache.royale.compiler.internal.scopes; |
| |
| import org.apache.royale.compiler.definitions.IDefinition; |
| import org.apache.royale.compiler.internal.definitions.DefinitionBase; |
| import org.apache.royale.compiler.scopes.IDefinitionSet; |
| |
| /** |
| * An implementation of {@link IMutableDefinitionSet} set that can hold |
| * only a small and fixed number -- currently 2 -- of definitions. |
| * <p> |
| * Note that this class simply stores its two definitions |
| * in two fields and does not require a separate array. |
| * <p> |
| * 95% of definition sets contain only a single definition, |
| * which is why {@link DefinitionBase} implements {@link IDefinitionSet} |
| * to make a single definition act as a set of size 1. |
| * Most of the other 5% of definition sets contain only two |
| * definitions, typically for a getter/setter pair, |
| * and can use {@link SmallDefinitionSet}; this class is for them. |
| * Less than 1% of definitions sets contain more than 2 definitions |
| * and must use {@link LargeDefinitionSet}. |
| */ |
| public class SmallDefinitionSet implements IMutableDefinitionSet |
| { |
| private static final int MAX_SIZE = 2; |
| |
| /** |
| * Constructor. |
| */ |
| public SmallDefinitionSet(IDefinition definition0, IDefinition definition1) |
| { |
| assert definition0 != null && definition1 != null; |
| this.definition0 = definition0; |
| this.definition1 = definition1; |
| } |
| |
| // Storage for two definitions. |
| private IDefinition definition0; |
| private IDefinition definition1; |
| |
| @Override |
| public boolean isEmpty() |
| { |
| return definition0 == null && definition1 == null; |
| } |
| |
| @Override |
| public int getSize() |
| { |
| int size = 0; |
| if (definition0 != null) |
| size++; |
| if (definition1 != null) |
| size++; |
| return size; |
| } |
| |
| @Override |
| public int getMaxSize() |
| { |
| return MAX_SIZE; |
| } |
| |
| @Override |
| public IDefinition getDefinition(int i) |
| { |
| if (i == 0) |
| return definition0; |
| else if (i == 1) |
| return definition1; |
| |
| return null; |
| } |
| |
| @Override |
| public void addDefinition(IDefinition definition) |
| { |
| assert definition != null : "Can't add a null definition to a definition set"; |
| |
| if (definition0 == null) |
| definition0 = definition; |
| else if (definition1 == null) |
| definition1 = definition; |
| else |
| assert false : "SmallDefinitionSet is full"; |
| } |
| |
| @Override |
| public void removeDefinition(IDefinition definition) |
| { |
| assert definition != null : "Can't remove a null definition from a definition set"; |
| |
| if (definition1 == definition) |
| definition1 = null; |
| |
| if (definition0 == definition) |
| { |
| // We're removing definition #0, so move definition #1 down to be definition #0. |
| definition0 = definition1; |
| definition1 = null; |
| } |
| } |
| |
| @Override |
| public void replaceDefinition(int i, IDefinition newDefinition) |
| { |
| assert newDefinition != null : "Can't replace a definition in a definition set with null"; |
| |
| if (i == 0) |
| definition0 = newDefinition; |
| else if (i == 1) |
| definition1 = newDefinition; |
| else |
| assert false : "Invalid index " + i + " in SmallDefinitionSet"; |
| } |
| |
| /** |
| * For debugging only. |
| */ |
| @Override |
| public String toString() |
| { |
| StringBuffer sb = new StringBuffer(); |
| if (definition0 != null) |
| sb.append(definition0.toString()); |
| sb.append('\n'); |
| if (definition1 != null) |
| sb.append(definition1.toString()); |
| return sb.toString(); |
| } |
| } |