Package org.apache.iotdb.db.metadata.mtree.traverser

Class Traverser

java.lang.Object

org.apache.iotdb.db.metadata.mtree.traverser.Traverser

Direct Known Subclasses:

CollectorTraverser, CounterTraverser, MeasurementGroupByLevelCounter

public abstract class Traverser
extends java.lang.Object

This class defines the main traversal framework and declares some methods for result process extension. This class could be extended to implement concrete tasks.
Currently, the tasks are classified into two type:

1. counter: to count the node num or measurement num that matches the path pattern
2. collector: to collect customized results of the matched node or measurement

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	isInTemplate
protected boolean	isPrefixMatch
protected boolean	isPrefixStart
protected java.lang.String[]	nodes
protected boolean	shouldTraverseTemplate
protected int	startIndex
protected int	startLevel
protected IMNode	startNode
protected IMTreeStore	store
protected java.util.Map<java.lang.Integer,Template>	templateMap
protected java.util.Deque<IMNode>	traverseContext

Constructor Summary

Constructors

Constructor	Description
Traverser(IMNode startNode, org.apache.iotdb.commons.path.PartialPath path, IMTreeStore store)	To traverse subtree under root.sg, e.g., init Traverser(root, "root.sg.**")

Method Summary

Modifier and Type	Method	Description
protected org.apache.iotdb.commons.path.PartialPath	getCurrentPartialPath(IMNode currentNode)
protected java.lang.String[]	getCurrentPathNodes(IMNode currentNode)
protected IMNode	getStorageGroupNodeInTraversePath(IMNode currentNode)
protected Template	getUpperTemplate(IMNode node)
protected abstract boolean	processFullMatchedMNode(IMNode node, int idx, int level)	full match: root.sg.d full match root.sg.**(pattern)
protected abstract boolean	processInternalMatchedMNode(IMNode node, int idx, int level)	internal match: root.sg internal match root.sg.**(pattern)
protected void	processMultiLevelWildcard(IMNode node, int idx, int level)
protected void	processNameMatch(IMNode node, int idx, int level)
protected void	processOneLevelWildcard(IMNode node, int idx, int level)
void	setPrefixMatch(boolean isPrefixMatch)
void	setTemplateMap(java.util.Map<java.lang.Integer,Template> templateMap)
void	traverse()	The interface to start the traversal.
protected void	traverse(IMNode node, int idx, int level)	The recursive method for MTree traversal.

Methods inherited from class java.lang.Object

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

Field Detail

store

protected IMTreeStore store

startNode

protected IMNode startNode

nodes

protected java.lang.String[] nodes

startIndex

protected int startIndex

startLevel

protected int startLevel

isPrefixStart

protected boolean isPrefixStart

traverseContext

protected java.util.Deque<IMNode> traverseContext

isInTemplate

protected boolean isInTemplate

shouldTraverseTemplate

protected boolean shouldTraverseTemplate

templateMap

protected java.util.Map<java.lang.Integer,Template> templateMap

isPrefixMatch

protected boolean isPrefixMatch

Constructor Detail

Traverser

public Traverser(IMNode startNode,
                 org.apache.iotdb.commons.path.PartialPath path,
                 IMTreeStore store)
          throws org.apache.iotdb.commons.exception.MetadataException

To traverse subtree under root.sg, e.g., init Traverser(root, "root.sg.**")

Parameters:

startNode - denote which tree to traverse by passing its root

path - use wildcard to specify which part to traverse

Throws:

org.apache.iotdb.commons.exception.MetadataException

Method Detail

traverse

public void traverse()
              throws org.apache.iotdb.commons.exception.MetadataException

The interface to start the traversal. The node process should be defined before traversal by overriding or implement concerned methods.

Throws:

org.apache.iotdb.commons.exception.MetadataException

traverse

protected void traverse(IMNode node,
                        int idx,
                        int level)
                 throws org.apache.iotdb.commons.exception.MetadataException

The recursive method for MTree traversal. If the node matches nodes[idx], then do some operation and traverse the children with nodes[idx+1].

Parameters:

node - current node that match the targetName in given path

idx - the index of targetName in given path

level - the level of current node in MTree

Throws:

org.apache.iotdb.commons.exception.MetadataException - some result process may throw MetadataException

processInternalMatchedMNode

protected abstract boolean processInternalMatchedMNode(IMNode node,
                                                       int idx,
                                                       int level)
                                                throws org.apache.iotdb.commons.exception.MetadataException

internal match: root.sg internal match root.sg.**(pattern)

Returns:

whether this branch of recursive traversal should stop; if true, stop

Throws:

org.apache.iotdb.commons.exception.MetadataException

processFullMatchedMNode

protected abstract boolean processFullMatchedMNode(IMNode node,
                                                   int idx,
                                                   int level)
                                            throws org.apache.iotdb.commons.exception.MetadataException

full match: root.sg.d full match root.sg.**(pattern)

Returns:

whether this branch of recursive traversal should stop; if true, stop

Throws:

org.apache.iotdb.commons.exception.MetadataException

processMultiLevelWildcard

protected void processMultiLevelWildcard(IMNode node,
                                         int idx,
                                         int level)
                                  throws org.apache.iotdb.commons.exception.MetadataException

Throws:

org.apache.iotdb.commons.exception.MetadataException

processOneLevelWildcard

protected void processOneLevelWildcard(IMNode node,
                                       int idx,
                                       int level)
                                throws org.apache.iotdb.commons.exception.MetadataException

Throws:

org.apache.iotdb.commons.exception.MetadataException

processNameMatch

protected void processNameMatch(IMNode node,
                                int idx,
                                int level)
                         throws org.apache.iotdb.commons.exception.MetadataException

Throws:

org.apache.iotdb.commons.exception.MetadataException

getUpperTemplate

protected Template getUpperTemplate(IMNode node)

setTemplateMap

public void setTemplateMap(java.util.Map<java.lang.Integer,Template> templateMap)

setPrefixMatch

public void setPrefixMatch(boolean isPrefixMatch)

getCurrentPartialPath

protected org.apache.iotdb.commons.path.PartialPath getCurrentPartialPath(IMNode currentNode)

Parameters:

currentNode - the node need to get the full path of

Returns:

full path from traverse start node to the current node

getCurrentPathNodes

protected java.lang.String[] getCurrentPathNodes(IMNode currentNode)

getStorageGroupNodeInTraversePath

protected IMNode getStorageGroupNodeInTraversePath(IMNode currentNode)

Returns:

the storage group node in the traverse path