| using Lucene.Net.Support; |
| using System; |
| using System.Collections; |
| using System.Collections.Generic; |
| |
| namespace Lucene.Net.Index |
| { |
| /* |
| * 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. |
| */ |
| |
| /// <summary> |
| /// Flex API for access to fields and terms |
| /// <para/> |
| /// @lucene.experimental |
| /// </summary> |
| |
| public abstract class Fields : IEnumerable<string> |
| { |
| /// <summary> |
| /// Sole constructor. (For invocation by subclass |
| /// constructors, typically implicit.) |
| /// </summary> |
| protected Fields() |
| { |
| } |
| |
| /// <summary> |
| /// Returns an enumerator that will step through all field |
| /// names. This will not return <c>null</c>. |
| /// </summary> |
| public abstract IEnumerator<string> GetEnumerator(); |
| |
| IEnumerator IEnumerable.GetEnumerator() |
| { |
| return GetEnumerator(); |
| } |
| |
| /// <summary> |
| /// Get the <see cref="Terms"/> for this field. This will return |
| /// <c>null</c> if the field does not exist. |
| /// </summary> |
| public abstract Terms GetTerms(string field); |
| |
| /// <summary> |
| /// Gets the number of fields or -1 if the number of |
| /// distinct field names is unknown. If >= 0, |
| /// <see cref="GetEnumerator"/> will return as many field names. |
| /// <para/> |
| /// NOTE: This was size() in Lucene. |
| /// </summary> |
| public abstract int Count { get; } |
| |
| /// <summary> |
| /// Returns the number of terms for all fields, or -1 if this |
| /// measure isn't stored by the codec. Note that, just like |
| /// other term measures, this measure does not take deleted |
| /// documents into account. |
| /// </summary> |
| /// <seealso cref="Index.Terms.Count"></seealso> |
| [Obsolete("Iterate fields and add their Count instead. This method is only provided as a transition mechanism to access this statistic for 3.x indexes, which do not have this statistic per-field.")] |
| public virtual long UniqueTermCount |
| { |
| get |
| { |
| long numTerms = 0; |
| foreach (string field in this) |
| { |
| Terms terms = GetTerms(field); |
| if (terms != null) |
| { |
| long termCount = terms.Count; |
| if (termCount == -1) |
| { |
| return -1; |
| } |
| |
| numTerms += termCount; |
| } |
| } |
| return numTerms; |
| } |
| } |
| |
| /// <summary> |
| /// Zero-length <see cref="Fields"/> array. |
| /// </summary> |
| public static readonly Fields[] EMPTY_ARRAY = Arrays.Empty<Fields>(); |
| } |
| } |