beagled/Lucene.Net/Index/TermDocs.cs

   1 /*
   2  * Copyright 2004 The Apache Software Foundation
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 using System;
  17 namespace Lucene.Net.Index
  18 {
  19
  20         /// <summary>TermDocs provides an interface for enumerating &lt;document, frequency&gt;
  21         /// pairs for a term.  <p> The document portion names each document containing
  22         /// the term.  Documents are indicated by number.  The frequency portion gives
  23         /// the number of times the term occurred in each document.  <p> The pairs are
  24         /// ordered by document number.
  25         /// </summary>
  26         /// <seealso cref="IndexReader#termDocs">
  27         /// </seealso>
  28
  29         public interface TermDocs
  30         {
  31                 /// <summary>Sets this to the data for a term.
  32                 /// The enumeration is reset to the start of the data for this term.
  33                 /// </summary>
  34                 void  Seek(Term term);
  35
  36                 /// <summary>Sets this to the data for the current term in a {@link TermEnum}.
  37                 /// This may be optimized in some implementations.
  38                 /// </summary>
  39                 void  Seek(TermEnum termEnum);
  40
  41                 /// <summary>Returns the current document number.  <p> This is invalid until {@link
  42                 /// #Next()} is called for the first time.
  43                 /// </summary>
  44                 int Doc();
  45
  46                 /// <summary>Returns the frequency of the term within the current document.  <p> This
  47                 /// is invalid until {@link #Next()} is called for the first time.
  48                 /// </summary>
  49                 int Freq();
  50
  51                 /// <summary>Moves to the next pair in the enumeration.  <p> Returns true iff there is
  52                 /// such a next pair in the enumeration.
  53                 /// </summary>
  54                 bool Next();
  55
  56                 /// <summary>Attempts to read multiple entries from the enumeration, up to length of
  57                 /// <i>docs</i>.  Document numbers are stored in <i>docs</i>, and term
  58                 /// frequencies are stored in <i>freqs</i>.  The <i>freqs</i> array must be as
  59                 /// long as the <i>docs</i> array.
  60                 ///
  61                 /// <p>Returns the number of entries read.  Zero is only returned when the
  62                 /// stream has been exhausted.
  63                 /// </summary>
  64                 int Read(int[] docs, int[] freqs);
  65
  66                 /// <summary>Skips entries to the first beyond the current whose document number is
  67                 /// greater than or equal to <i>target</i>. <p>Returns true iff there is such
  68                 /// an entry.  <p>Behaves as if written: <pre>
  69                 /// boolean skipTo(int target) {
  70                 /// do {
  71                 /// if (!next())
  72                 /// return false;
  73                 /// } while (target > doc());
  74                 /// return true;
  75                 /// }
  76                 /// </pre>
  77                 /// Some implementations are considerably more efficient than that.
  78                 /// </summary>
  79                 bool SkipTo(int target);
  80
  81                 /// <summary>Frees associated resources. </summary>
  82                 void  Close();
  83         }
  84 }