org.corpus_tools.salt.core.impl.GraphTraverserModule Class Reference

Handles the traversal of a graph. More...

Classes
class	Traverser
	A threadable class, which traverses the graph and invokes methods of the given callback handler during the traversal.

Public Member Functions
SGraph	getGraph ()
void	setGraph (SGraph graph)
void	traverse (List< SNode > startNodes, GRAPH_TRAVERSE_TYPE traverseType, String traverseId, GraphTraverseHandler traverseHandler)
	Traverses a graph in the given order traverseType and starts traversing with the given startNodes. More...
void	traverse (List<? extends SNode > startNodes, GRAPH_TRAVERSE_TYPE traverseType, String traverseId, GraphTraverseHandler traverseHandler, boolean isCycleSafe)
	Traverses a graph in the given order traverseType and starts traversing with the given startNodes. More...

Protected Attributes
SGraph	graph = null

Detailed Description

Handles the traversal of a graph.

Author

Florian Zipser

Member Function Documentation

traverse() [1/2]

void org.corpus_tools.salt.core.impl.GraphTraverserModule.traverse	(	List< SNode >	startNodes,
		GRAPH_TRAVERSE_TYPE	traverseType,
		String	traverseId,
		GraphTraverseHandler	traverseHandler
	)

Traverses a graph in the given order traverseType and starts traversing with the given startNodes.

When a node is reached, first this method will invoke the method GraphTraverseHandler#checkConstraint(GRAPH_TRAVERSE_TYPE, String, SRelation, SNode, long) of the given callback handler traverseHandler, second the method GraphTraverseHandler#nodeReached(GRAPH_TRAVERSE_TYPE, String, SNode, SRelation, SNode, long) is invoked. When a node was left, the method GraphTraverseHandler#nodeLeft(GRAPH_TRAVERSE_TYPE, String, SNode, SRelation, SNode, long) is invoked. When calling these methods, the traverseId will be passed, so that the callback handler knows which traversal is meant. This is helpful, in case of a single callback handler is used for more than one traversal at the same time. This method throws a SaltInvalidModelException in case of the graph contains a cycle. A cycle means a path containing the same node twice. Cycle safe breadth first traversing could consume a lot of memory because the algorithm keeps a map of all visited Nodes for every start node.

Parameters

startNodes	list of nodes at which the traversal shall start
traverseType	type of traversing
traverseId	identification for callback handler, in case of more than one traversal is running at the same time with the same callback handler
traverseHandler	callback handler, on which the three methods will be invoked

traverse() [2/2]

void org.corpus_tools.salt.core.impl.GraphTraverserModule.traverse	(	List<? extends SNode >	startNodes,
		GRAPH_TRAVERSE_TYPE	traverseType,
		String	traverseId,
		GraphTraverseHandler	traverseHandler,
		boolean	isCycleSafe
	)

Traverses a graph in the given order traverseType and starts traversing with the given startNodes.

When a node is reached, first this method will invoke the method GraphTraverseHandler#checkConstraint(GRAPH_TRAVERSE_TYPE, String, SRelation, SNode, long) of the given callback handler traverseHandler, second the method GraphTraverseHandler#nodeReached(GRAPH_TRAVERSE_TYPE, String, SNode, SRelation, SNode, long) is invoked. When a node was left, the method GraphTraverseHandler#nodeLeft(GRAPH_TRAVERSE_TYPE, String, SNode, SRelation, SNode, long) is invoked. When calling these methods, the traverseId will be passed, so that the callback handler knows which traversal is meant. This is helpful, in case of a single callback handler is used for more than one traversal at the same time. This method throws a SaltInvalidModelException in case of the graph contains a cycle. A cycle means a path containing the same node twice. Cycle safe breadth first traversing could consume a lot of memory because the algorithm keeps a map of all visited Nodes for every start node.

Parameters

startNodes	list of nodes at which the traversal shall start
traverseType	type of traversing
traverseId	identification for callback handler, in case of more than one traversal is running at the same time with the same callback handler
traverseHandler	callback handler, on which the three methods will be invoked
isCycleSafe	if this value is false, this method does not take care about cycles. This can invoke endless loops.