A fault tree: nodes keyed by name, plus a designated top event. More...

#include <fault_tree.hpp>

Public Member Functions
void	addNode (Node node)
	Adds a node at the end of the node list. More...

bool	hasNode (const std::string &name) const
	Tests whether a node of this name has been added. More...

const Node &	node (const std::string &name) const
	Looks a node up by name. More...

const std::vector< Node > &	nodes () const
	All nodes, basic events and gates, in the order they were added. More...

std::size_t	size () const
	Number of nodes (basic events plus gates). More...

void	setTop (const std::string &name)
	Designates the top event. More...

const std::string &	top () const
	Name of the top event. More...

std::vector< std::string >	basicEventNames () const

void	setBasicEventProbability (const std::string &name, double probability)

void	validate () const

Private Member Functions
Node &	mutableNode (const std::string &name)
	Non-const lookup. Throws FaultTreeError when the name is unknown. More...

Private Attributes
std::vector< Node >	nodes_
	insertion order More...

std::unordered_map< std::string, std::size_t >	index_
	name to position in nodes_ More...

std::string	top_
	empty until setTop() More...

Detailed Description

A fault tree: nodes keyed by name, plus a designated top event.

Nodes are stored in the order they are added, and that order is what nodes() and basicEventNames() report. addNode() and setTop() check only the name. All structural rules are checked by validate(), which the .fta reader and the Quantifier constructor both call.

Definition at line 78 of file fault_tree.hpp.

Member Function Documentation

◆ addNode()

void faulttree::FaultTree::addNode ( Node node )

Adds a node at the end of the node list.

The inputs named in node.children do not have to exist yet.

Parameters

node	Node to store. `node.name` must be non-empty.

Exceptions

FaultTreeError if the name is empty or a node of that name already exists.

Note: Node references returned earlier by node(), and iterators into nodes(), can be invalidated, because the nodes live in one std::vector.

Definition at line 23 of file fault_tree.cpp.

References index_, faulttree::Node::name, node(), and nodes_.

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◆ basicEventNames()

std::vector< std::string > faulttree::FaultTree::basicEventNames ( ) const

Names of every basic event, in definition order (the order of the addNode() calls).

Definition at line 64 of file fault_tree.cpp.

References faulttree::Basic, faulttree::Node::name, node(), nodes_, and faulttree::Node::type.

Referenced by faulttree::Quantifier::basicEventNames().

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◆ hasNode()

bool faulttree::FaultTree::hasNode ( const std::string & name ) const

Tests whether a node of this name has been added.

Parameters

name	Node name, compared exactly.

Returns: True when the tree holds a node of that name.

Definition at line 32 of file fault_tree.cpp.

References index_.

Referenced by faulttree::Quantifier::isDefined(), setTop(), and validate().

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◆ mutableNode()

Node & faulttree::FaultTree::mutableNode ( const std::string & name )

private

Non-const lookup. Throws FaultTreeError when the name is unknown.

Definition at line 44 of file fault_tree.cpp.

References index_, and nodes_.

Referenced by setBasicEventProbability().

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◆ node()

const Node & faulttree::FaultTree::node ( const std::string & name ) const

Looks a node up by name.

Parameters

name	Node name, compared exactly.

Returns: The stored node.

Exceptions

FaultTreeError if no node of that name exists.

Definition at line 36 of file fault_tree.cpp.

References index_, and nodes_.

Referenced by addNode(), basicEventNames(), and validate().

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◆ nodes()

const std::vector< Node > & faulttree::FaultTree::nodes ( ) const

inline

All nodes, basic events and gates, in the order they were added.

Definition at line 103 of file fault_tree.hpp.

References nodes_.

Referenced by faulttree::Quantifier::build().

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◆ setBasicEventProbability()

void faulttree::FaultTree::setBasicEventProbability	(	const std::string &	name,
		double	probability
	)

Overrides a basic event's probability (the fixEvent operation the engine performs when a component failure is observed).

Parameters

name	Name of a basic event.
probability	New failure probability, in [0, 1].

Exceptions

FaultTreeError if the node is missing, is not a basic event, or the probability is outside [0, 1] (NaN is rejected too).

Definition at line 72 of file fault_tree.cpp.

References faulttree::Basic, mutableNode(), faulttree::Node::probability, and faulttree::Node::type.

Referenced by faulttree::Quantifier::setBasicEventProbability().

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◆ setTop()

void faulttree::FaultTree::setTop ( const std::string & name )

Designates the top event.

Parameters

name	Name of a node that has already been added.

Exceptions

FaultTreeError if no node of that name exists.

Definition at line 52 of file fault_tree.cpp.

References hasNode(), and top_.

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◆ size()

std::size_t faulttree::FaultTree::size ( ) const

inline

Number of nodes (basic events plus gates).

Definition at line 106 of file fault_tree.hpp.

References nodes_.

Referenced by faulttree::Quantifier::probabilityOf().

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◆ top()

const std::string & faulttree::FaultTree::top ( ) const

Name of the top event.

Exceptions

FaultTreeError if setTop() has not been called.

Definition at line 59 of file fault_tree.cpp.

References top_.

Referenced by faulttree::Quantifier::topEventProbability().

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◆ validate()

void faulttree::FaultTree::validate ( ) const

Structural check: every child resolves, no cycles, gates have the inputs their type requires, probabilities are in [0, 1], k is within range. Throws FaultTreeError describing the first problem found.

The checks, in order:

the tree is not empty and has a top event;
for each node in insertion order: a basic event has no inputs and a probability in [0, 1]; a NOT gate has exactly one input; AND, OR and K/N gates have at least one input; a K/N gate has 1 <= k <= number of inputs; every input names an existing node, is not the node itself, and is listed at most once in that gate;
the input graph has no cycle (iterative depth-first search, so deep trees do not grow the call stack).

An event that feeds several gates is valid. Nodes that cannot be reached from the top event are not reported.

Exceptions

FaultTreeError for the first violated rule.

Definition at line 88 of file fault_tree.cpp.

References faulttree::And, faulttree::Basic, faulttree::Node::children, hasNode(), index_, faulttree::Node::k, faulttree::KofN, faulttree::Node::name, node(), nodes_, faulttree::Not, faulttree::Or, faulttree::Node::probability, top_, and faulttree::Node::type.

Referenced by faulttree::Quantifier::Quantifier().

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Member Data Documentation

◆ index_

std::unordered_map<std::string, std::size_t> faulttree::FaultTree::index_

private

name to position in nodes_

Definition at line 153 of file fault_tree.hpp.

Referenced by addNode(), hasNode(), mutableNode(), node(), and validate().

◆ nodes_

std::vector<Node> faulttree::FaultTree::nodes_

private

insertion order

Definition at line 152 of file fault_tree.hpp.

Referenced by addNode(), basicEventNames(), mutableNode(), node(), nodes(), size(), and validate().

◆ top_

std::string faulttree::FaultTree::top_

private

empty until setTop()

Definition at line 154 of file fault_tree.hpp.

Referenced by setTop(), top(), and validate().

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

src/FaultTree/include/faulttree/fault_tree.hpp
src/FaultTree/src/fault_tree.cpp

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Member Function Documentation

◆ addNode()

◆ basicEventNames()

◆ hasNode()

◆ mutableNode()

◆ node()

◆ nodes()

◆ setBasicEventProbability()

◆ setTop()

◆ size()

◆ top()

◆ validate()

Member Data Documentation

◆ index_

◆ nodes_

◆ top_