| package org.apache.lucene.facet.taxonomy.writercache; |
| |
| import org.apache.lucene.facet.taxonomy.FacetLabel; |
| |
| /* |
| * 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. |
| */ |
| |
| /** |
| * Abstract class for storing Label->Ordinal mappings in a taxonomy. |
| * |
| * @lucene.experimental |
| */ |
| public abstract class LabelToOrdinal { |
| |
| /** How many ordinals we've seen. */ |
| protected int counter; |
| |
| /** Returned by {@link #getOrdinal} when the label isn't |
| * recognized. */ |
| public static final int INVALID_ORDINAL = -2; |
| |
| /** Default constructor. */ |
| public LabelToOrdinal() { |
| } |
| |
| /** |
| * return the maximal Ordinal assigned so far |
| */ |
| public int getMaxOrdinal() { |
| return this.counter; |
| } |
| |
| /** |
| * Returns the next unassigned ordinal. The default behavior of this method |
| * is to simply increment a counter. |
| */ |
| public int getNextOrdinal() { |
| return this.counter++; |
| } |
| |
| /** |
| * Adds a new label if its not yet in the table. |
| * Throws an {@link IllegalArgumentException} if the same label with |
| * a different ordinal was previoulsy added to this table. |
| */ |
| public abstract void addLabel(FacetLabel label, int ordinal); |
| |
| /** |
| * Returns the ordinal assigned to the given label, |
| * or {@link #INVALID_ORDINAL} if the label cannot be found in this table. |
| */ |
| public abstract int getOrdinal(FacetLabel label); |
| |
| } |