org.corpus_tools.salt.core.impl

Class GraphTraverserModule

java.lang.Object

org.corpus_tools.salt.core.impl.GraphTraverserModule

public class GraphTraverserModule
extends Object

Handles the traversal of a graph.

Author:

Florian Zipser

Field Summary

Fields

Modifier and Type	Field and Description
protected SGraph	graph

Constructor Summary

Constructors

Constructor and Description
GraphTraverserModule()

Method Summary

Methods

Modifier and Type	Method and Description
SGraph	getGraph()
void	setGraph(SGraph graph)
void	traverse(List<? extends SNode> startNodes, SGraph.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.
void	traverse(List<SNode> startNodes, SGraph.GRAPH_TRAVERSE_TYPE traverseType, String traverseId, GraphTraverseHandler traverseHandler) Traverses a graph in the given order traverseType and starts traversing with the given startNodes.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

graph

protected SGraph graph

Constructor Detail

GraphTraverserModule

public GraphTraverserModule()

Method Detail

getGraph

public SGraph getGraph()

setGraph

public void setGraph(SGraph graph)

traverse

public void traverse(List<SNode> startNodes,
            SGraph.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

public void traverse(List<? extends SNode> startNodes,
            SGraph.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.