src/xalanc/PlatformSupport/XalanDOMStringPool.hpp

/*
 * 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.
 */
#if !defined(XALANDOMSTRINGPOOL_HEADER_GUARD_1357924680)
#define XALANDOMSTRINGPOOL_HEADER_GUARD_1357924680



// Base include file.  Must be first.
#include <xalanc/PlatformSupport/PlatformSupportDefinitions.hpp>



#include <xalanc/PlatformSupport/ArenaAllocator.hpp>
#include <xalanc/PlatformSupport/DOMStringHelper.hpp>
#include <xalanc/PlatformSupport/XalanDOMStringAllocator.hpp>
#include <xalanc/PlatformSupport/XalanDOMStringHashTable.hpp>



namespace XALAN_CPP_NAMESPACE {



class XALAN_PLATFORMSUPPORT_EXPORT XalanDOMStringPool
{
public:

    enum { eDefaultBlockSize = 32,
           eDefaultBucketCount = XalanDOMStringHashTable::eDefaultBucketCount,
           eDefaultBucketSize = XalanDOMStringHashTable::eDefaultBucketSize };

    typedef XalanDOMStringAllocator         AllocatorType;

    typedef AllocatorType::size_type                    block_size_type;
    typedef size_t                                      bucket_count_type;
    typedef XalanDOMStringHashTable::bucket_size_type   bucket_size_type;

    /**
     * Create a string pool.
     *
     * @param theBlockSize The block size for the allocator.
     * @param theBucketCount The number of buckets to use for the hash table.  This should be a prime number for best results.
     * @param theBucketSize The initial size of each bucket in the hash table.
     */
    explicit
    XalanDOMStringPool(
            MemoryManager&  theManager,
            block_size_type     theBlockSize = eDefaultBlockSize,
            bucket_count_type   theBucketCount = eDefaultBucketCount,
            bucket_size_type    theBucketSize = eDefaultBucketSize);

    static XalanDOMStringPool*
    create(
            MemoryManager&  theManager,
            block_size_type     theBlockSize = eDefaultBlockSize,
            bucket_count_type   theBucketCount = eDefaultBucketCount,
            bucket_size_type    theBucketSize = eDefaultBucketSize);


    virtual
    ~XalanDOMStringPool();

    /**
     * Clear the pool.
     *
     */
    virtual void
    clear();

    /**
     * Get the number of strings in the pool
     *
     * @return the size of the pool.
     */
    virtual size_t
    size() const;

    /**
     * Get a pooled string.  If the string is not pooled, it is added.
     *
     * @param theString The string to pool.
     * @return a const reference to the pooled string.
     */
    virtual const XalanDOMString&
    get(const XalanDOMString&   theString);

    /**
     * Get a pooled string.  If the string is not pooled, it is added.
     *
     * @param theString The string to pool.
     * @param theLength The length of the string.  If XalanDOMString::npos, the string is assumed to be null-terminated.
     * @return a const reference to the pooled string.
     */
    virtual const XalanDOMString&
    get(
            const XalanDOMChar*         theString,
            XalanDOMString::size_type   theLength = XalanDOMString::npos);

    /**
     * Get a reference to the pool's hash table.  Useful for diagnostic
     * purposes.
     *
     * @return a const reference to the hash table.
     */
    const XalanDOMStringHashTable&
    getHashTable() const
    {
        return m_hashTable;
    }

    MemoryManager&
    getMemoryManager()
    {
        return m_hashTable.getMemoryManager();
    }

    const MemoryManager&
    getMemoryManager() const
    {
        return m_hashTable.getMemoryManager();
    }

private:

    // Not implemented, for now...
    XalanDOMStringPool(const XalanDOMStringPool&);

    XalanDOMStringPool&
    operator=(const XalanDOMStringPool&);

    bool
    operator==(const XalanDOMStringPool&) const;

    // Data members...
    AllocatorType                   m_stringAllocator;

    size_t                          m_stringCount;

    XalanDOMStringHashTable         m_hashTable;

    static const XalanDOMString     s_emptyString;
};



}



#endif  // !defined(XALANDOMSTRINGPOOL_HEADER_GUARD_1357924680)