lucene-java-3.5.0/lucene/src/java/org/apache/lucene/search/spans/SpanNotQuery.java

   1 package org.apache.lucene.search.spans;
   2
   3 /**
   4  * Licensed to the Apache Software Foundation (ASF) under one or more
   5  * contributor license agreements.  See the NOTICE file distributed with
   6  * this work for additional information regarding copyright ownership.
   7  * The ASF licenses this file to You under the Apache License, Version 2.0
   8  * (the "License"); you may not use this file except in compliance with
   9  * the License.  You may obtain a copy of the License at
  10  *
  11  *     http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  */
  19
  20 import org.apache.lucene.index.IndexReader;
  21 import org.apache.lucene.index.Term;
  22 import org.apache.lucene.search.Query;
  23 import org.apache.lucene.util.ToStringUtils;
  24
  25 import java.io.IOException;
  26 import java.util.ArrayList;
  27 import java.util.Collection;
  28 import java.util.Set;
  29
  30 /** Removes matches which overlap with another SpanQuery. */
  31 public class SpanNotQuery extends SpanQuery implements Cloneable {
  32   private SpanQuery include;
  33   private SpanQuery exclude;
  34
  35   /** Construct a SpanNotQuery matching spans from <code>include</code> which
  36    * have no overlap with spans from <code>exclude</code>.*/
  37   public SpanNotQuery(SpanQuery include, SpanQuery exclude) {
  38     this.include = include;
  39     this.exclude = exclude;
  40
  41     if (!include.getField().equals(exclude.getField()))
  42       throw new IllegalArgumentException("Clauses must have same field.");
  43   }
  44
  45   /** Return the SpanQuery whose matches are filtered. */
  46   public SpanQuery getInclude() { return include; }
  47
  48   /** Return the SpanQuery whose matches must not overlap those returned. */
  49   public SpanQuery getExclude() { return exclude; }
  50
  51   @Override
  52   public String getField() { return include.getField(); }
  53
  54   @Override
  55   public void extractTerms(Set<Term> terms) { include.extractTerms(terms); }
  56
  57   @Override
  58   public String toString(String field) {
  59     StringBuilder buffer = new StringBuilder();
  60     buffer.append("spanNot(");
  61     buffer.append(include.toString(field));
  62     buffer.append(", ");
  63     buffer.append(exclude.toString(field));
  64     buffer.append(")");
  65     buffer.append(ToStringUtils.boost(getBoost()));
  66     return buffer.toString();
  67   }
  68
  69   @Override
  70   public Object clone() {
  71     SpanNotQuery spanNotQuery = new SpanNotQuery((SpanQuery)include.clone(),(SpanQuery) exclude.clone());
  72     spanNotQuery.setBoost(getBoost());
  73     return  spanNotQuery;
  74   }
  75
  76   @Override
  77   public Spans getSpans(final IndexReader reader) throws IOException {
  78     return new Spans() {
  79         private Spans includeSpans = include.getSpans(reader);
  80         private boolean moreInclude = true;
  81
  82         private Spans excludeSpans = exclude.getSpans(reader);
  83         private boolean moreExclude = excludeSpans.next();
  84
  85         @Override
  86         public boolean next() throws IOException {
  87           if (moreInclude)                        // move to next include
  88             moreInclude = includeSpans.next();
  89
  90           while (moreInclude && moreExclude) {
  91
  92             if (includeSpans.doc() > excludeSpans.doc()) // skip exclude
  93               moreExclude = excludeSpans.skipTo(includeSpans.doc());
  94
  95             while (moreExclude                    // while exclude is before
  96                    && includeSpans.doc() == excludeSpans.doc()
  97                    && excludeSpans.end() <= includeSpans.start()) {
  98               moreExclude = excludeSpans.next();  // increment exclude
  99             }
 100
 101             if (!moreExclude                      // if no intersection
 102                 || includeSpans.doc() != excludeSpans.doc()
 103                 || includeSpans.end() <= excludeSpans.start())
 104               break;                              // we found a match
 105
 106             moreInclude = includeSpans.next();    // intersected: keep scanning
 107           }
 108           return moreInclude;
 109         }
 110
 111         @Override
 112         public boolean skipTo(int target) throws IOException {
 113           if (moreInclude)                        // skip include
 114             moreInclude = includeSpans.skipTo(target);
 115
 116           if (!moreInclude)
 117             return false;
 118
 119           if (moreExclude                         // skip exclude
 120               && includeSpans.doc() > excludeSpans.doc())
 121             moreExclude = excludeSpans.skipTo(includeSpans.doc());
 122
 123           while (moreExclude                      // while exclude is before
 124                  && includeSpans.doc() == excludeSpans.doc()
 125                  && excludeSpans.end() <= includeSpans.start()) {
 126             moreExclude = excludeSpans.next();    // increment exclude
 127           }
 128
 129           if (!moreExclude                      // if no intersection
 130                 || includeSpans.doc() != excludeSpans.doc()
 131                 || includeSpans.end() <= excludeSpans.start())
 132             return true;                          // we found a match
 133
 134           return next();                          // scan to next match
 135         }
 136
 137         @Override
 138         public int doc() { return includeSpans.doc(); }
 139         @Override
 140         public int start() { return includeSpans.start(); }
 141         @Override
 142         public int end() { return includeSpans.end(); }
 143
 144       // TODO: Remove warning after API has been finalized
 145       @Override
 146       public Collection<byte[]> getPayload() throws IOException {
 147         ArrayList<byte[]> result = null;
 148         if (includeSpans.isPayloadAvailable()) {
 149           result = new ArrayList<byte[]>(includeSpans.getPayload());
 150         }
 151         return result;
 152       }
 153
 154       // TODO: Remove warning after API has been finalized
 155       @Override
 156       public boolean isPayloadAvailable() {
 157         return includeSpans.isPayloadAvailable();
 158       }
 159
 160       @Override
 161       public String toString() {
 162           return "spans(" + SpanNotQuery.this.toString() + ")";
 163         }
 164
 165       };
 166   }
 167
 168   @Override
 169   public Query rewrite(IndexReader reader) throws IOException {
 170     SpanNotQuery clone = null;
 171
 172     SpanQuery rewrittenInclude = (SpanQuery) include.rewrite(reader);
 173     if (rewrittenInclude != include) {
 174       clone = (SpanNotQuery) this.clone();
 175       clone.include = rewrittenInclude;
 176     }
 177     SpanQuery rewrittenExclude = (SpanQuery) exclude.rewrite(reader);
 178     if (rewrittenExclude != exclude) {
 179       if (clone == null) clone = (SpanNotQuery) this.clone();
 180       clone.exclude = rewrittenExclude;
 181     }
 182
 183     if (clone != null) {
 184       return clone;                        // some clauses rewrote
 185     } else {
 186       return this;                         // no clauses rewrote
 187     }
 188   }
 189
 190     /** Returns true iff <code>o</code> is equal to this. */
 191   @Override
 192   public boolean equals(Object o) {
 193     if (this == o) return true;
 194     if (!(o instanceof SpanNotQuery)) return false;
 195
 196     SpanNotQuery other = (SpanNotQuery)o;
 197     return this.include.equals(other.include)
 198             && this.exclude.equals(other.exclude)
 199             && this.getBoost() == other.getBoost();
 200   }
 201
 202   @Override
 203   public int hashCode() {
 204     int h = include.hashCode();
 205     h = (h<<1) | (h >>> 31);  // rotate left
 206     h ^= exclude.hashCode();
 207     h = (h<<1) | (h >>> 31);  // rotate left
 208     h ^= Float.floatToRawIntBits(getBoost());
 209     return h;
 210   }
 211
 212 }