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arangodb/arangod/Aql/AggregateBlock.h

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C++

////////////////////////////////////////////////////////////////////////////////
/// @brief AQL AggregateBlock
///
/// @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 Jan Steemann
/// @author Copyright 2014, triagens GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGODB_AQL_AGGREGATE_BLOCK_H
#define ARANGODB_AQL_AGGREGATE_BLOCK_H 1
#include "Basics/Common.h"
#include "Aql/ExecutionBlock.h"
#include "Aql/ExecutionNode.h"
namespace triagens {
namespace utils {
class AqlTransaction;
}
namespace aql {
class AqlItemBlock;
class ExecutionEngine;
// -----------------------------------------------------------------------------
// --SECTION-- AggregatorGroup
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief details about the current group
///////////////////////////////////////////////////////////////////////////////
struct AggregatorGroup {
std::vector<AqlValue> groupValues;
std::vector<TRI_document_collection_t const*> collections;
std::vector<AqlItemBlock*> groupBlocks;
size_t firstRow;
size_t lastRow;
size_t groupLength;
bool rowsAreValid;
bool const count;
AggregatorGroup () = delete;
explicit AggregatorGroup (bool);
~AggregatorGroup ();
void initialize (size_t capacity);
void reset ();
void setFirstRow (size_t value) {
firstRow = value;
rowsAreValid = true;
}
void setLastRow (size_t value) {
lastRow = value;
rowsAreValid = true;
}
void addValues (AqlItemBlock const* src,
RegisterId groupRegister);
};
// -----------------------------------------------------------------------------
// --SECTION-- SortedAggregateBlock
// -----------------------------------------------------------------------------
class SortedAggregateBlock : public ExecutionBlock {
public:
SortedAggregateBlock (ExecutionEngine*,
AggregateNode const*);
~SortedAggregateBlock ();
int initialize () override;
private:
int getOrSkipSome (size_t atLeast,
size_t atMost,
bool skipping,
AqlItemBlock*& result,
size_t& skipped) override;
////////////////////////////////////////////////////////////////////////////////
/// @brief writes the current group data into the result
////////////////////////////////////////////////////////////////////////////////
void emitGroup (AqlItemBlock const* cur,
AqlItemBlock* res,
size_t row);
private:
////////////////////////////////////////////////////////////////////////////////
/// @brief pairs, consisting of out register and in register
////////////////////////////////////////////////////////////////////////////////
std::vector<std::pair<RegisterId, RegisterId>> _aggregateRegisters;
////////////////////////////////////////////////////////////////////////////////
/// @brief details about the current group
////////////////////////////////////////////////////////////////////////////////
AggregatorGroup _currentGroup;
////////////////////////////////////////////////////////////////////////////////
/// @brief the optional register that contains the input expression values for
/// each group
////////////////////////////////////////////////////////////////////////////////
RegisterId _expressionRegister;
////////////////////////////////////////////////////////////////////////////////
/// @brief the optional register that contains the values for each group
/// if no values should be returned, then this has a value of MaxRegisterId
/// this register is also used for counting in case WITH COUNT INTO var is used
////////////////////////////////////////////////////////////////////////////////
RegisterId _groupRegister;
////////////////////////////////////////////////////////////////////////////////
/// @brief list of variables names for the registers
////////////////////////////////////////////////////////////////////////////////
std::vector<std::string> _variableNames;
};
// -----------------------------------------------------------------------------
// --SECTION-- HashedAggregateBlock
// -----------------------------------------------------------------------------
class HashedAggregateBlock : public ExecutionBlock {
public:
HashedAggregateBlock (ExecutionEngine*,
AggregateNode const*);
~HashedAggregateBlock ();
int initialize () override;
private:
int getOrSkipSome (size_t atLeast,
size_t atMost,
bool skipping,
AqlItemBlock*& result,
size_t& skipped) override;
private:
////////////////////////////////////////////////////////////////////////////////
/// @brief pairs, consisting of out register and in register
////////////////////////////////////////////////////////////////////////////////
std::vector<std::pair<RegisterId, RegisterId>> _aggregateRegisters;
////////////////////////////////////////////////////////////////////////////////
/// @brief the optional register that contains the values for each group
/// if no values should be returned, then this has a value of MaxRegisterId
/// this register is also used for counting in case WITH COUNT INTO var is used
////////////////////////////////////////////////////////////////////////////////
RegisterId _groupRegister;
////////////////////////////////////////////////////////////////////////////////
/// @brief hasher for a vector of AQL values
////////////////////////////////////////////////////////////////////////////////
struct GroupKeyHash {
GroupKeyHash (triagens::arango::AqlTransaction* trx,
std::vector<TRI_document_collection_t const*>& colls)
: _trx(trx),
_colls(colls),
_num(colls.size()) {
}
size_t operator() (std::vector<AqlValue> const& value) const;
triagens::arango::AqlTransaction* _trx;
std::vector<TRI_document_collection_t const*>& _colls;
size_t const _num;
};
////////////////////////////////////////////////////////////////////////////////
/// @brief comparator for a vector of AQL values
////////////////////////////////////////////////////////////////////////////////
struct GroupKeyEqual {
GroupKeyEqual (triagens::arango::AqlTransaction* trx,
std::vector<TRI_document_collection_t const*>& colls)
: _trx(trx),
_colls(colls) {
}
bool operator() (std::vector<AqlValue> const&,
std::vector<AqlValue> const&) const;
triagens::arango::AqlTransaction* _trx;
std::vector<TRI_document_collection_t const*>& _colls;
};
};
} // namespace triagens::aql
} // namespace triagens
#endif
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