content: package org.apache.lucene.search.spans;
  
  /**
   * 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.
   */
  
  import java.io.IOException;
  
  import java.util.List;
  import java.util.Collection;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.Set;
  
  import org.apache.lucene.index.IndexReader;
  import org.apache.lucene.index.Term;
  import org.apache.lucene.util.PriorityQueue;
  import org.apache.lucene.util.ToStringUtils;
  import org.apache.lucene.search.Query;
  
  /** Matches the union of its clauses.*/
  public class SpanOrQuery extends SpanQuery implements Cloneable {
    private List<SpanQuery> clauses;
    private String field;
  
    /** Construct a SpanOrQuery merging the provided clauses. */
    public SpanOrQuery(SpanQuery... clauses) {
  
      // copy clauses array into an ArrayList
      this.clauses = new ArrayList<SpanQuery>(clauses.length);
      for (int i = 0; i < clauses.length; i++) {
        addClause(clauses[i]);
      }
    }
  
    /** Adds a clause to this query */
    public final void addClause(SpanQuery clause) {
      if (field == null) {
        field = clause.getField();
      } else if (!clause.getField().equals(field)) {
        throw new IllegalArgumentException("Clauses must have same field.");
      }
      this.clauses.add(clause);
    }
    
    /** Return the clauses whose spans are matched. */
    public SpanQuery[] getClauses() {
      return clauses.toArray(new SpanQuery[clauses.size()]);
    }
  
    @Override
    public String getField() { return field; }
  
    @Override
    public void extractTerms(Set<Term> terms) {
      for(final SpanQuery clause: clauses) {
        clause.extractTerms(terms);
      }
    }
    
    @Override
    public Object clone() {
      int sz = clauses.size();
      SpanQuery[] newClauses = new SpanQuery[sz];
  
      for (int i = 0; i < sz; i++) {
        newClauses[i] = (SpanQuery) clauses.get(i).clone();
      }
      SpanOrQuery soq = new SpanOrQuery(newClauses);
      soq.setBoost(getBoost());
      return soq;
    }
  
    @Override
    public Query rewrite(IndexReader reader) throws IOException {
      SpanOrQuery clone = null;
      for (int i = 0 ; i < clauses.size(); i++) {
        SpanQuery c = clauses.get(i);
        SpanQuery query = (SpanQuery) c.rewrite(reader);
        if (query != c) {                     // clause rewrote: must clone
          if (clone == null)
            clone = (SpanOrQuery) this.clone();
          clone.clauses.set(i,query);
        }
      }
      if (clone != null) {
        return clone;                        // some clauses rewrote
      } else {
        return this;                         // no clauses rewrote
      }
    }
  
    @Override
    public String toString(String field) {
      StringBuilder buffer = new StringBuilder();
      buffer.append("spanOr([");
      Iterator<SpanQuery> i = clauses.iterator();
      while (i.hasNext()) {
        SpanQuery clause = i.next();
        buffer.append(clause.toString(field));
        if (i.hasNext()) {
          buffer.append(", ");
        }
      }
      buffer.append("])");
      buffer.append(ToStringUtils.boost(getBoost()));
      return buffer.toString();
    }
  
    @Override
    public boolean equals(Object o) {
      if (this == o) return true;
      if (o == null || getClass() != o.getClass()) return false;
  
      final SpanOrQuery that = (SpanOrQuery) o;
  
      if (!clauses.equals(that.clauses)) return false;
      if (!clauses.isEmpty() && !field.equals(that.field)) return false;
  
      return getBoost() == that.getBoost();
    }
  
    @Override
    public int hashCode() {
      int h = clauses.hashCode();
      h ^= (h << 10) | (h >>> 23);
      h ^= Float.floatToRawIntBits(getBoost());
      return h;
    }
  
  
    private class SpanQueue extends PriorityQueue<Spans> {
      public SpanQueue(int size) {
        initialize(size);
      }
  
      @Override
      protected final boolean lessThan(Spans spans1, Spans spans2) {
        if (spans1.doc() == spans2.doc()) {
          if (spans1.start() == spans2.start()) {
            return spans1.end() < spans2.end();
          } else {
            return spans1.start() < spans2.start();
          }
        } else {
          return spans1.doc() < spans2.doc();
        }
      }
    }
  
    @Override
    public Spans getSpans(final IndexReader reader) throws IOException {
      if (clauses.size() == 1)                      // optimize 1-clause case
        return (clauses.get(0)).getSpans(reader);
  
      return new Spans() {
          private SpanQueue queue = null;
  
          private boolean initSpanQueue(int target) throws IOException {
            queue = new SpanQueue(clauses.size());
            Iterator<SpanQuery> i = clauses.iterator();
            while (i.hasNext()) {
              Spans spans = i.next().getSpans(reader);
              if (   ((target == -1) && spans.next())
                  || ((target != -1) && spans.skipTo(target))) {
                queue.add(spans);
              }
            }
            return queue.size() != 0;
          }
  
          @Override
          public boolean next() throws IOException {
            if (queue == null) {
              return initSpanQueue(-1);
            }
  
            if (queue.size() == 0) { // all done
              return false;
            }
  
            if (top().next()) { // move to next
              queue.updateTop();
              return true;
            }
  
            queue.pop();  // exhausted a clause
            return queue.size() != 0;
          }
  
          private Spans top() { return queue.top(); }
  
          @Override
          public boolean skipTo(int target) throws IOException {
            if (queue == null) {
              return initSpanQueue(target);
            }
    
            boolean skipCalled = false;
            while (queue.size() != 0 && top().doc() < target) {
              if (top().skipTo(target)) {
                queue.updateTop();
              } else {
                queue.pop();
              }
              skipCalled = true;
            }
    
            if (skipCalled) {
              return queue.size() != 0;
            }
            return next();
          }
  
          @Override
          public int doc() { return top().doc(); }
          @Override
          public int start() { return top().start(); }
          @Override
          public int end() { return top().end(); }
  
        @Override
        public Collection<byte[]> getPayload() throws IOException {
          ArrayList<byte[]> result = null;
          Spans theTop = top();
          if (theTop != null && theTop.isPayloadAvailable()) {
            result = new ArrayList<byte[]>(theTop.getPayload());
          }
          return result;
        }
  
        @Override
        public boolean isPayloadAvailable() {
          Spans top = top();
          return top != null && top.isPayloadAvailable();
        }
  
        @Override
        public String toString() {
            return "spans("+SpanOrQuery.this+")@"+
              ((queue == null)?"START"
               :(queue.size()>0?(doc()+":"+start()+"-"+end()):"END"));
          }
  
        };
    }
  
  }
  