indexquery.java

jxta_src_2.41b jxta 2.41b 最新版源码 from www.jxta.org

package net.jxta.impl.xindice.core.indexer;

/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xindice" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999-2001, The dbXML
 * Group, L.L.C., http://www.dbxmlgroup.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * $Id: IndexQuery.java,v 1.1 2003/01/28 21:09:08 akhil Exp $
 */

import net.jxta.impl.xindice.core.data.*;
import java.util.*;

/**
 * IndexQuery represents the most primitive form of index querying.
 * Instances of this object should be created by QueryResolvers and
 * cached in Query instances.
 */

public class IndexQuery {
   // No Operator
   public static final int ANY = 0;   // Any And All Matches
   
   // Singleton Operators
   public static final int EQ = 1;    // Equal To
   public static final int NEQ = -1;  // Not Equal To
   public static final int GT = 2;    // Greater Than
   public static final int LEQ = -2;  // Less Than Or Equal To
   public static final int LT = 3;    // Less Than
   public static final int GEQ = -3;  // Greater Than Or Equal To
   
   // Range Operators
   public static final int BW = 4;    // Between (Inclusive)
   public static final int NBW = -4;  // Not Between (Inclusive)
   public static final int BWX = 5;   // Between (Exclusive)
   public static final int NBWX = -5; // Not Between (Exclusive)
   
   // Set Operators
   public static final int IN = 6;    // In The Set
   public static final int NIN = -6;  // Not In The Set
   
   // Other operators
   public static final int SW = 7;    // Starts-with
   public static final int NSW = -7;  // Not Starts-with
   
   public static final int EW = 8;    // Ends-with
   public static final int NEW = -8;  // Not Ends-with

   protected int op;
   protected Value[] vals;
   
   public IndexQuery() {
      op = ANY;
   }
   
   public IndexQuery(int op, Value[] vals) {
      this.op = op;
      this.vals = vals;
   }
   
   public IndexQuery(Value[] vals) {
      this(IN, vals);
   }

   public IndexQuery(int op, Value val1) {
      this.op = op;
      if ( op == SW || op == NSW ) {
         byte[] b = new byte[val1.getLength()+1];
         System.arraycopy(val1.getData(), 0, b, 0, b.length-1);
         b[b.length-1] = 127; // TODO: Must fix this
         Value val2 = new Value(b);
         vals = new Value[] { val1, val2 };
      }
      else
         vals = new Value[] { val1 };
   }
      
   public IndexQuery(Value val1) {
      this(EQ, val1);
   }
   
   public IndexQuery(int op, Value val1, Value val2) {
      this.op = op;
      vals = new Value[] { val1, val2 };
   }
   
   public IndexQuery(Value val1, Value val2) {
      this(IN, val1, val2);
   }
   
   public IndexQuery(int op, String val1) {
      this(op, new Value(val1));
   }
   
   public IndexQuery(String val1) {
      this(new Value(val1));
   }
   
   public IndexQuery(int op, String val1, String val2) {
      this(op, new Value(val1), new Value(val2));
   }
   
   public IndexQuery(String val1, String val2) {
      this(new Value(val1), new Value(val2));
   }
   
   /**
    * getOperator returns the operator associated with this query.
    *
    * @return The operator
    */
   public int getOperator() {
      return op;
   }
   
   /**
    * getValue returns one of the Values associated with this query.
    *
    * @param index The Value index
    * @return The request Value
    */
   public final Value getValue(int index) {
      return vals[index];
   }

   /**
    * getValues returns the Values associated with this query.
    *
    * @return The Value set
    */
   public Value[] getValues() {
      return vals;
   }
   
   /**
    * getLength returns the length of the Value set associated with
    * this query.
    *
    * @return The Value set length
    */
   public final int getLength() {
      return vals.length;
   }
   
   
   /**
    * testValue tests the specified value for validity against this
    * IndexQuery.  The helper classes in org.apache.xindice.core.indexer.helpers
    * should be used for optimized performance.
    *
    * @param value The Value to compare
    * @return Whether or not the value matches
    */
   public boolean testValue(Value value) {
      switch ( op ) {
         // No Comparison (Any)
         case ANY:
            return true;
            
         // Singleton Comparisons
         case EQ:
            return value.equals(vals[0]);
         case NEQ:
            return !value.equals(vals[0]);
         case GT:
            return value.compareTo(vals[0]) > 0;
         case LEQ:
            return value.compareTo(vals[0]) <= 0;
         case LT:
            return value.compareTo(vals[0]) < 0;
         case GEQ:
            return value.compareTo(vals[0]) >= 0;
            
         // Range Comparisons
         case BW:
            return value.compareTo(vals[0]) >= 0 && value.compareTo(vals[1]) <= 0;
         case NBW:
            return value.compareTo(vals[0]) <= 0 || value.compareTo(vals[1]) >= 0;
         case BWX:
            return value.compareTo(vals[0]) > 0 && value.compareTo(vals[1]) < 0;
         case NBWX:
            return value.compareTo(vals[0]) < 0 || value.compareTo(vals[1]) > 0;
            
         // Set Comparisons
         case IN:
         case NIN:
            return Arrays.binarySearch(vals, value)>= 0 ? op == IN
                                                        : op == NIN;
            
         // Other comparisons
         case SW:
         case NSW:
            return value.startsWith(vals[0]) ? op == SW
                                             : op == NSW;
         
         case EW:
         case NEW:
            return value.endsWith(vals[0]) ? op == EW
                                           : op == NEW;
         
      }
      return false;
   }

   /**
    * testValue tests the specified value for validity against this
    * IndexQuery.  The helper classes in org.apache.xindice.core.indexer.helpers
    * should be used for optimized performance.
    *
    * @param value The Value to compare
    * @return Whether or not the value matches
    */
   public final boolean testValue(String value) {
      return testValue(new Value(value));
   }
}