83 lines
2.4 KiB
C++
83 lines
2.4 KiB
C++
/*
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* Copyright (c) 2001-2008
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* DecisionSoft Limited. All rights reserved.
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* Copyright (c) 2004-2008
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* Oracle. All rights reserved.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* $Id: ResultBufferImpl.hpp,v 1.5 2008/01/08 18:47:33 jpcs Exp $
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*/
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#ifndef _RESULTBUFFERIMPL_HPP
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#define _RESULTBUFFERIMPL_HPP
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#include <vector>
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#include <xqilla/framework/XQillaExport.hpp>
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#include <xqilla/runtime/Result.hpp>
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#include <xqilla/framework/ReferenceCounted.hpp>
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/** A buffer for lazily evaluated query results. This object is not thread safe */
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class XQILLA_API ResultBufferImpl : public ReferenceCounted
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{
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public:
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typedef RefCountPointer<ResultBufferImpl> Ptr;
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static const unsigned int UNLIMITED_COUNT;
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/**
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* Do not allocate this object from a memory manager!
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* It must be created using the heap.
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*/
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ResultBufferImpl(const Result &result, unsigned int readCount = UNLIMITED_COUNT);
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ResultBufferImpl(const Item::Ptr &item, unsigned int readCount = UNLIMITED_COUNT);
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~ResultBufferImpl();
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/// Creates a result that returns the same items as the one used to construct this buffer
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Result createResult();
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unsigned int getMaxReadCount() const { return _maxReadCount; }
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unsigned int incrementReadCount() { return ++_readCount; }
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private:
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ResultBufferImpl(const ResultBufferImpl &);
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ResultBufferImpl &operator=(const ResultBufferImpl &);
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Item::Ptr item(unsigned int index, DynamicContext *context);
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friend class BufferedResult;
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typedef std::vector<Item::Ptr> ItemList;
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unsigned int _refCount;
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Result _result;
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ItemList _items;
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unsigned int _readCount;
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unsigned int _maxReadCount;
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};
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class BufferedResult : public ResultImpl
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{
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public:
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BufferedResult(ResultBufferImpl *impl);
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Item::Ptr next(DynamicContext *context);
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std::string asString(DynamicContext *context, int indent) const;
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private:
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ResultBufferImpl::Ptr _impl;
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unsigned int _pos;
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};
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#endif
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