taco::TreeNode Class Reference

TreeNode is the base class of all tree structures in TDB (e.g., parsing tree, logical plan, physical plan, query execution state). More...

#include <utils/tree/TreeNode.h>

Inheritance diagram for taco::TreeNode:

Public Member Functions
template<class ... UniquePtrs>
	TreeNode (NodeTag tag, UniquePtrs &&...input)
virtual	~TreeNode ()
	TreeNode (TreeNode &&)=default
TreeNode &	operator= (TreeNode &&)=default
	TreeNode (const TreeNode &)=delete
TreeNode &	operator= (const TreeNode &)=delete
constexpr NodeTag	get_tag () const
TreeNode *	get_input (size_t i) const
template<class Node >
Node *	get_input_as (size_t i) const
std::string	to_string () const
void	node_to_string (std::string &buf, int indent) const
	Prints the node contents to a string buffer. More...
const char *	node_name () const
virtual void	node_properties_to_string (std::string &buf, int indent) const =0

Static Public Member Functions
static void	append_indent (std::string &buf, int indent)

Private Attributes
NodeTag	m_tag
std::vector< std::unique_ptr< TreeNode > >	m_input

Static Private Attributes
static constexpr const int	TO_STRING_INDENT_SIZE = 4

Detailed Description

TreeNode is the base class of all tree structures in TDB (e.g., parsing tree, logical plan, physical plan, query execution state).

Each TreeNode can have zero or more inputs, and it owns the objects by storing a unique_ptr to it. TreeNode constructors constructors and destructors should only allocate/deallocate memory and perform initialization that may not generate an error (e.g., initializing fields with trivial constructors). Any initialization that may generate an error must be done in a separate function call, that communicates the error to the caller through the return value. Similarly, clean-up of a node that may produce some error must be done in a separate function other than the destructor with a return status.

A TreeNode object is owned by another TreeNode or some function scope that has a unique_ptr to it. As a result, a TreeNode object may only be explicitly moved as a unique_ptr or referenced through a raw pointer. It may not be shallow copied and the copy constructor and the copy assignment operator is deleted. The owner of a node is responsible to keep it alive while there are references to the object. That being said, the most common pattern is to never delete objects unless the entire tree goes is being deleted. If you need to update an input without changing the inputs of the input, most likely you'll have to replace the entire subtree anyway (since we do not allow shallow copies). The original node will be deleted when the entire tree is deleted.

Each TreeNode object is associated with a tag (NodeTag). It identifies the type of the TreeNode object. We use the tag rather than RTTI to cast or identify TreeNode – that will probably be more flexible and faster at the cost of an additional 8-byte overhead (2 bytes + padding) per node.

Constructor & Destructor Documentation

TreeNode() [1/3]

template<class ... UniquePtrs>

taco::TreeNode::TreeNode ( NodeTag  tag, UniquePtrs &&...  input  )

inline

~TreeNode()

virtual taco::TreeNode::~TreeNode ( )

inlinevirtual

TreeNode() [2/3]

taco::TreeNode::TreeNode ( TreeNode &&  )

default

TreeNode() [3/3]

taco::TreeNode::TreeNode ( const TreeNode &  )

delete

Member Function Documentation

append_indent()

void taco::TreeNode::append_indent ( std::string &  buf, int  indent  )

static

get_input()

TreeNode* taco::TreeNode::get_input ( size_t  i ) const

inline

get_input_as()

template<class Node >

Node* taco::TreeNode::get_input_as ( size_t  i ) const

inline

get_tag()

constexpr NodeTag taco::TreeNode::get_tag ( ) const

inlineconstexpr

node_name()

const char* taco::TreeNode::node_name ( ) const

inline

node_properties_to_string()

virtual void taco::TreeNode::node_properties_to_string ( std::string &  buf, int  indent  ) const

pure virtual

Implemented in taco::TempTable, taco::TableScan, taco::TableInsert, taco::TableDelete, taco::Sort, taco::Selection, taco::Projection, taco::Limit, taco::IndexScan, taco::CartesianProduct, taco::Aggregation, taco::Variable, taco::UnaryOperator, taco::OrOperator, taco::Literal, taco::FuncCallOperator, taco::Cast, taco::BinaryOperator, taco::AndOperator, taco::TempTableState, taco::TableScanState, taco::TableInsertState, taco::TableDeleteState, taco::SortState, taco::SelectionState, taco::ProjectionState, taco::LimitState, taco::IndexScanState, taco::CartesianProductState, and taco::AggregationState.

node_to_string()

void taco::TreeNode::node_to_string	(	std::string &	buf,
		int	indent
	)		const

Prints the node contents to a string buffer.

No indentation is added on the first line, and all subsequent lines have an indentation of at least indent * INDENT_SIZE spaces.

operator=() [1/2]

TreeNode& taco::TreeNode::operator= ( const TreeNode &  )

delete

operator=() [2/2]

TreeNode& taco::TreeNode::operator= ( TreeNode &&  )

default

to_string()

std::string taco::TreeNode::to_string ( ) const

inline

Member Data Documentation

m_input

std::vector<std::unique_ptr<TreeNode> > taco::TreeNode::m_input

private

m_tag

NodeTag taco::TreeNode::m_tag

private

TO_STRING_INDENT_SIZE

constexpr const int taco::TreeNode::TO_STRING_INDENT_SIZE = 4

staticconstexprprivate

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The documentation for this class was generated from the following files:

• utils/tree/TreeNode.h
• utils/tree/TreeNode.cpp