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arangodb/arangod/Aql/Aggregator.h

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////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 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 ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGOD_AQL_AGGREGATOR_H
#define ARANGOD_AQL_AGGREGATOR_H 1
#include "Basics/Common.h"
#include "Aql/AqlValue.h"
#include "Basics/Exceptions.h"
#include "Basics/JsonHelper.h"
#include "Utils/AqlTransaction.h"
struct TRI_document_collection_t;
namespace triagens {
namespace arango {
class AqlTransaction;
}
namespace aql {
struct Aggregator {
explicit Aggregator(triagens::arango::AqlTransaction* trx) : trx(trx) { }
virtual ~Aggregator() = default;
virtual char const* name() const = 0;
virtual void reset() = 0;
virtual void reduce(AqlValue const&, struct TRI_document_collection_t const*) = 0;
virtual AqlValue stealValue() = 0;
static Aggregator* fromTypeString(triagens::arango::AqlTransaction*, std::string const&);
static Aggregator* fromJson(triagens::arango::AqlTransaction*, triagens::basics::Json const&,
char const*);
static bool isSupported(std::string const&);
triagens::arango::AqlTransaction* trx;
};
struct AggregatorLength final : public Aggregator {
explicit AggregatorLength(triagens::arango::AqlTransaction* trx) : Aggregator(trx), count(0) { }
AggregatorLength(triagens::arango::AqlTransaction* trx, uint64_t initialCount) : Aggregator(trx), count(initialCount) { }
char const* name() const override final {
return "LENGTH";
}
void reset() override final;
void reduce(AqlValue const&, struct TRI_document_collection_t const*) override final;
AqlValue stealValue() override final;
uint64_t count;
};
struct AggregatorMin final : public Aggregator {
explicit AggregatorMin(triagens::arango::AqlTransaction* trx) : Aggregator(trx), value(), coll(nullptr) { }
~AggregatorMin();
char const* name () const override final {
return "MIN";
}
void reset() override final;
void reduce(AqlValue const&, struct TRI_document_collection_t const*) override final;
AqlValue stealValue() override final;
AqlValue value;
struct TRI_document_collection_t const* coll;
};
struct AggregatorMax final : public Aggregator {
explicit AggregatorMax(triagens::arango::AqlTransaction* trx) : Aggregator(trx), value(), coll(nullptr) { }
~AggregatorMax();
char const* name () const override final {
return "MAX";
}
void reset() override final;
void reduce(AqlValue const&, struct TRI_document_collection_t const*) override final;
AqlValue stealValue() override final;
AqlValue value;
struct TRI_document_collection_t const* coll;
};
struct AggregatorSum final : public Aggregator {
explicit AggregatorSum(triagens::arango::AqlTransaction* trx) : Aggregator(trx), sum(0.0), invalid(false) { }
~AggregatorSum();
char const* name () const override final {
return "SUM";
}
void reset() override final;
void reduce(AqlValue const&, struct TRI_document_collection_t const*) override final;
AqlValue stealValue() override final;
double sum;
bool invalid;
};
struct AggregatorAverage final : public Aggregator {
explicit AggregatorAverage(triagens::arango::AqlTransaction* trx) : Aggregator(trx), count(0), sum(0.0), invalid(false) { }
~AggregatorAverage();
char const* name () const override final {
return "AVERAGE";
}
void reset() override final;
void reduce(AqlValue const&, struct TRI_document_collection_t const*) override final;
AqlValue stealValue() override final;
uint64_t count;
double sum;
bool invalid;
};
} // namespace triagens::aql
} // namespace triagens
#endif