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arangodb/arangod/Aql/EnumerateCollectionBlock.h

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////////////////////////////////////////////////////////////////////////////////
/// @brief AQL EnumerateCollectionBlock
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2010-2014 triagens GmbH, Cologne, Germany
///
/// Licensed 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.
///
/// Copyright holder is triAGENS GmbH, Cologne, Germany
///
/// @author Max Neunhoeffer
/// @author Copyright 2014, triagens GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGODB_AQL_ENUMERATE_COLLECTION_BLOCK_H
#define ARANGODB_AQL_ENuMERATE_COLLECTION_BLOCK_H 1
#include "Aql/Collection.h"
#include "Aql/ExecutionBlock.h"
#include "Aql/ExecutionNode.h"
struct TRI_doc_mptr_copy_t;
namespace triagens {
namespace aql {
class AqlItemBlock;
struct CollectionScanner;
class ExecutionEngine;
// -----------------------------------------------------------------------------
// --SECTION-- EnumerateCollectionBlock
// -----------------------------------------------------------------------------
class EnumerateCollectionBlock : public ExecutionBlock {
public:
EnumerateCollectionBlock (ExecutionEngine* engine,
EnumerateCollectionNode const* ep);
~EnumerateCollectionBlock ();
////////////////////////////////////////////////////////////////////////////////
/// @brief initialize fetching of documents
////////////////////////////////////////////////////////////////////////////////
void initializeDocuments ();
////////////////////////////////////////////////////////////////////////////////
/// @brief continue fetching of documents
////////////////////////////////////////////////////////////////////////////////
bool moreDocuments (size_t hint);
////////////////////////////////////////////////////////////////////////////////
/// @brief initialize, here we fetch all docs from the database
////////////////////////////////////////////////////////////////////////////////
int initialize () override;
////////////////////////////////////////////////////////////////////////////////
/// @brief initializeCursor
////////////////////////////////////////////////////////////////////////////////
int initializeCursor (AqlItemBlock* items, size_t pos) override;
////////////////////////////////////////////////////////////////////////////////
/// @brief getSome
////////////////////////////////////////////////////////////////////////////////
AqlItemBlock* getSome (size_t atLeast, size_t atMost) override final;
////////////////////////////////////////////////////////////////////////////////
// skip between atLeast and atMost, returns the number actually skipped . . .
// will only return less than atLeast if there aren't atLeast many
// things to skip overall.
////////////////////////////////////////////////////////////////////////////////
size_t skipSome (size_t atLeast, size_t atMost) override final;
// -----------------------------------------------------------------------------
// --SECTION-- private variables
// -----------------------------------------------------------------------------
private:
////////////////////////////////////////////////////////////////////////////////
/// @brief collection
////////////////////////////////////////////////////////////////////////////////
Collection* _collection;
////////////////////////////////////////////////////////////////////////////////
/// @brief collection scanner
////////////////////////////////////////////////////////////////////////////////
CollectionScanner* _scanner;
////////////////////////////////////////////////////////////////////////////////
/// @brief document buffer
////////////////////////////////////////////////////////////////////////////////
std::vector<TRI_doc_mptr_copy_t> _documents;
////////////////////////////////////////////////////////////////////////////////
/// @brief current position in _documents
////////////////////////////////////////////////////////////////////////////////
size_t _posInDocuments;
////////////////////////////////////////////////////////////////////////////////
/// @brief whether or not we're doing random iteration
////////////////////////////////////////////////////////////////////////////////
bool const _random;
////////////////////////////////////////////////////////////////////////////////
/// @brief whether or not the enumerated documents need to be stored
////////////////////////////////////////////////////////////////////////////////
bool _mustStoreResult;
};
} // namespace triagens::aql
} // namespace triagens
#endif
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