xercesc/util/Hashers.hpp

0001 /*
0002  * Licensed to the Apache Software Foundation (ASF) under one or more
0003  * contributor license agreements.  See the NOTICE file distributed with
0004  * this work for additional information regarding copyright ownership.
0005  * The ASF licenses this file to You under the Apache License, Version 2.0
0006  * (the "License"); you may not use this file except in compliance with
0007  * the License.  You may obtain a copy of the License at
0008  *
0009  *      http://www.apache.org/licenses/LICENSE-2.0
0010  *
0011  * Unless required by applicable law or agreed to in writing, software
0012  * distributed under the License is distributed on an "AS IS" BASIS,
0013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0014  * See the License for the specific language governing permissions and
0015  * limitations under the License.
0016  */
0017
0018 /*
0019  * $Id$
0020  */
0021
0022 #if !defined(XERCESC_INCLUDE_GUARD_HASHERS_HPP)
0023 #define XERCESC_INCLUDE_GUARD_HASHERS_HPP
0024
0025 #include <xercesc/util/XMLString.hpp>
0026
0027 XERCES_CPP_NAMESPACE_BEGIN
0028
0029 //
0030 // Common hashers. Only widely-used hashers should be placed here.
0031 //
0032
0033 /**
0034  * Hasher for keys that are const XMLCh*.
0035  */
0036 struct StringHasher
0037 {
0038   /**
0039    * Returns a hash value based on the key
0040    *
0041    * @param key the key to be hashed
0042    * @param mod the modulus the hasher should use
0043    */
0044   XMLSize_t getHashVal(const void* key, XMLSize_t mod) const
0045   {
0046     return XMLString::hash ((const XMLCh*)key, mod);
0047   }
0048
0049   /**
0050    * Compares two keys and determines if they are semantically equal
0051    *
0052    * @param key1 the first key to be compared
0053    * @param key2 the second key to be compared
0054    *
0055    * @return true if they are equal
0056    */
0057   bool equals(const void *const key1, const void *const key2) const
0058   {
0059     return XMLString::equals ((const XMLCh*)key1, (const XMLCh*)key2);
0060   }
0061 };
0062
0063 /**
0064  * Hasher for keys that are pointers.
0065  */
0066 struct PtrHasher
0067 {
0068   /**
0069    * Returns a hash value based on the key
0070    *
0071    * @param key the key to be hashed
0072    * @param mod the modulus the hasher should use
0073    */
0074   XMLSize_t getHashVal(const void* key, XMLSize_t mod) const
0075   {
0076     return ((XMLSize_t)key) % mod;
0077   }
0078
0079   /**
0080    * Compares two keys and determines if they are semantically equal
0081    *
0082    * @param key1 the first key to be compared
0083    * @param key2 the second key to be compared
0084    *
0085    * @return true if they are equal
0086    */
0087   bool equals(const void *const key1, const void *const key2) const
0088   {
0089     return key1 == key2;
0090   }
0091 };
0092
0093 XERCES_CPP_NAMESPACE_END
0094
0095 #endif