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arangodb/arangod/Aql/TraversalNode.h

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C++

////////////////////////////////////////////////////////////////////////////////
/// 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 Michael Hackstein
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGOD_AQL_TRAVERSAL_NODE_H
#define ARANGOD_AQL_TRAVERSAL_NODE_H 1
#include "Aql/ExecutionNode.h"
#include "Aql/Condition.h"
#include "Aql/Graphs.h"
#include "VocBase/Traverser.h"
namespace arangodb {
namespace aql {
class SimpleTraverserExpression
: public arangodb::traverser::TraverserExpression {
public:
arangodb::aql::AstNode* compareToNode;
arangodb::aql::Expression* expression;
SimpleTraverserExpression(bool isEdgeAccess,
arangodb::aql::AstNodeType comparisonType,
arangodb::aql::AstNode const* varAccess,
arangodb::aql::AstNode* compareToNode)
: arangodb::traverser::TraverserExpression(isEdgeAccess, comparisonType,
varAccess),
compareToNode(compareToNode),
expression(nullptr) {}
SimpleTraverserExpression(arangodb::aql::Ast* ast, arangodb::basics::Json const& j);
~SimpleTraverserExpression();
void toJson(arangodb::basics::Json& json, TRI_memory_zone_t* zone) const;
void toVelocyPack(arangodb::velocypack::Builder&) const;
};
/// @brief class TraversalNode
class TraversalNode : public ExecutionNode {
friend class ExecutionBlock;
friend class TraversalCollectionBlock;
friend class RedundantCalculationsReplacer;
/// @brief constructor with a vocbase and a collection name
public:
TraversalNode(ExecutionPlan* plan, size_t id, TRI_vocbase_t* vocbase,
AstNode const* direction, AstNode const* start,
AstNode const* graph);
TraversalNode(ExecutionPlan* plan, arangodb::basics::Json const& base);
~TraversalNode() {
delete _condition;
for (auto& it : _expressions) {
for (auto& it2 : it.second) {
delete it2;
}
}
}
/// @brief Internal constructor to clone the node.
private:
TraversalNode(ExecutionPlan* plan, size_t id, TRI_vocbase_t* vocbase,
std::vector<std::string> const& edgeColls,
Variable const* inVariable, std::string const& vertexId,
std::vector<TRI_edge_direction_e> directions, uint64_t minDepth,
uint64_t maxDepth);
public:
/// @brief return the type of the node
NodeType getType() const override final { return TRAVERSAL; }
/// @brief export to VelocyPack
void toVelocyPackHelper(arangodb::velocypack::Builder&,
bool) const override final;
/// @brief clone ExecutionNode recursively
ExecutionNode* clone(ExecutionPlan* plan, bool withDependencies,
bool withProperties) const override final;
/// @brief the cost of a traversal node
double estimateCost(size_t&) const override final;
/// @brief Test if this node uses an in variable or constant
bool usesInVariable() const { return _inVariable != nullptr; }
/// @brief getVariablesUsedHere
std::vector<Variable const*> getVariablesUsedHere() const override final {
std::vector<Variable const*> result;
for (auto const& condVar : _conditionVariables) {
result.emplace_back(condVar);
}
if (usesInVariable()) {
result.emplace_back(_inVariable);
}
return result;
}
/// @brief getVariablesUsedHere
void getVariablesUsedHere(
std::unordered_set<Variable const*>& result) const override final {
for (auto const& condVar : _conditionVariables) {
result.emplace(condVar);
}
if (usesInVariable()) {
result.emplace(_inVariable);
}
}
/// @brief getVariablesSetHere
std::vector<Variable const*> getVariablesSetHere() const override final {
std::vector<Variable const*> vars;
if (_vertexOutVariable != nullptr) {
vars.emplace_back(_vertexOutVariable);
}
if (_edgeOutVariable != nullptr) {
vars.emplace_back(_edgeOutVariable);
}
if (_pathOutVariable != nullptr) {
vars.emplace_back(_pathOutVariable);
}
return vars;
}
/// @brief return the database
TRI_vocbase_t* vocbase() const { return _vocbase; }
/// @brief return the vertex out variable
Variable const* vertexOutVariable() const { return _vertexOutVariable; }
/// @brief checks if the vertex out variable is used
bool usesVertexOutVariable() const { return _vertexOutVariable != nullptr; }
/// @brief set the vertex out variable
void setVertexOutput(Variable const* outVar) { _vertexOutVariable = outVar; }
/// @brief return the edge out variable
Variable const* edgeOutVariable() const { return _edgeOutVariable; }
/// @brief checks if the edge out variable is used
bool usesEdgeOutVariable() const { return _edgeOutVariable != nullptr; }
/// @brief set the edge out variable
void setEdgeOutput(Variable const* outVar) { _edgeOutVariable = outVar; }
/// @brief checks if the path out variable is used
bool usesPathOutVariable() const { return _pathOutVariable != nullptr; }
/// @brief return the path out variable
Variable const* pathOutVariable() const { return _pathOutVariable; }
/// @brief set the path out variable
void setPathOutput(Variable const* outVar) { _pathOutVariable = outVar; }
/// @brief return the in variable
Variable const* inVariable() const { return _inVariable; }
std::string const getStartVertex() const { return _vertexId; }
/// @brief Fill the traversal options with all values known to this node or
/// with default values.
void fillTraversalOptions(arangodb::traverser::TraverserOptions& opts) const;
std::vector<std::string> const edgeColls() const { return _edgeColls; }
/// @brief remember the condition to execute for early traversal abortion.
void setCondition(Condition* condition);
/// @brief return the condition for the node
Condition* condition() const { return _condition; }
/// @brief which variable? -1 none, 0 Edge, 1 Vertex, 2 path
int checkIsOutVariable(size_t variableId) const;
/// @brief check whether an access is inside the specified range
bool isInRange(uint64_t thisIndex, bool isEdge) const {
if (isEdge) {
return (thisIndex < _maxDepth);
}
return (thisIndex <= _maxDepth);
}
/// @brief check whecher min..max actualy span a range
bool isRangeValid() const { return _maxDepth >= _minDepth; }
/// @brief Remember a simple comparator filter
void storeSimpleExpression(bool isEdgeAccess, size_t indexAccess,
AstNodeType comparisonType,
AstNode const* varAccess, AstNode* compareToNode);
/// @brief Returns a regerence to the simple traverser expressions
std::unordered_map<
size_t, std::vector<arangodb::traverser::TraverserExpression*>> const*
expressions() const {
return &_expressions;
}
private:
/// @brief the database
TRI_vocbase_t* _vocbase;
/// @brief vertex output variable
Variable const* _vertexOutVariable;
/// @brief vertex output variable
Variable const* _edgeOutVariable;
/// @brief vertex output variable
Variable const* _pathOutVariable;
/// @brief input variable only used if _vertexId is unused
Variable const* _inVariable;
/// @brief input vertexId only used if _inVariable is unused
std::string _vertexId;
/// @brief input graphJson only used for serialisation & info
arangodb::basics::Json _graphJson;
/// @brief The minimal depth included in the result
uint64_t _minDepth;
/// @brief The maximal depth searched and included in the result
uint64_t _maxDepth;
/// @brief The directions edges are followed
std::vector<TRI_edge_direction_e> _directions;
/// @brief the edge collection cid
std::vector<std::string> _edgeColls;
/// @brief our graph...
Graph const* _graphObj;
/// @brief early abort traversal conditions:
Condition* _condition;
/// @brief variables that are inside of the condition
std::vector<Variable const*> _conditionVariables;
/// @brief store a simple comparator filter
/// one vector of TraverserExpressions per matchdepth (size_t)
std::unordered_map<size_t,
std::vector<arangodb::traverser::TraverserExpression*>>
_expressions;
};
} // namespace arangodb::aql
} // namespace arangodb
#endif