ch.ethz.mxquery.sms.MMimpl
Class TokenBufferStore

java.lang.Object
  ch.ethz.mxquery.sms.MMimpl.FIFOStore
      ch.ethz.mxquery.sms.MMimpl.TokenBufferStore

All Implemented Interfaces:

Source, ActiveStore, AppendUpdate, StreamStore, MXQueryAppendUpdate

Direct Known Subclasses:

FTTokenBufferStore

public class TokenBufferStore
extends FIFOStore

Simple TokenBuffer to materialize a stream. Additional a index on the node id's is created to allow easy jumping between nodes.

Field Summary

int	level
static int	MAX_NODE_ID
int	myId
Token[]	tokenBuffer

Fields inherited from class ch.ethz.mxquery.sms.MMimpl.FIFOStore

iterator, readThread

Constructor Summary

TokenBufferStore(int id, WindowBuffer container)

TokenBufferStore(XDMIterator sourceStream, int id, WindowBuffer container)
Creates a new TokenBuffer for a stream with standard paras

Method Summary

void	buffer(Token tok, int event) Materialize the given token into the store instance
int	compare(Source store)
Source	copySource(Context ctx, java.util.Vector nestedPredCtxStack)
void	deleteItems(int olderThanItemId) Simple garbage collection; deletes all nodes that are older than the parameter
Token	get(int tokenId) Returns the Token for a given token id
Token	get(int tokenId, int maxNodeId) Returns the token for a given tokenId.
int	getAttributePosFromNodeId(java.lang.String attrName, int nodeId)
int	getAttributePosFromTokenId(java.lang.String attrName, int activeTokenId)
int	getMaxNodeId() Returns the current materialized nodeId
int	getMaxTokenId() Returns the current materialized tokenId
int	getMyId() Returns the store id (mostly for debugging)
int	getNodeIdFromTokenId(int tokenId) Returns the NodeId for the given Token Id; The first node has the id = 0.
int	getNodeIdFromTokenId(int minNodeId, int tokenId) Like getNodeIdFromPosition(int position) but we give a additional information that makes the search for the right nodeId faster.
int	getSize()
int	getTokenIdForNode(int nodeId) Returns the position for a given NodePosition.
java.lang.String	getURI() Returns the URI of the source.
boolean	hasNode(int node) Checks if a node exists
void	newItem() Specify the beginning of a new item
void	printBuffer()
void	setContext(Context context) Sets the context of the source stream.
void	setIterator(XDMIterator it) For pull stores, add the iterator from which they should pull their data
void	start() Start the gathering of the active store

Methods inherited from class ch.ethz.mxquery.sms.MMimpl.FIFOStore

getCurrentTokenId, getIterator, setContainer

Methods inherited from class java.lang.Object

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

Field Detail

MAX_NODE_ID

public static final int MAX_NODE_ID

See Also:

Constant Field Values

level

public int level

tokenBuffer

public Token[] tokenBuffer

myId

public int myId

Constructor Detail

TokenBufferStore

public TokenBufferStore(XDMIterator sourceStream,
                        int id,
                        WindowBuffer container)

Creates a new TokenBuffer for a stream with standard paras

Parameters:

sourceStream - Source Stream

TokenBufferStore

public TokenBufferStore(int id,
                        WindowBuffer container)

Method Detail

start

public void start()

Description copied from interface: ActiveStore

Start the gathering of the active store

setIterator

public void setIterator(XDMIterator it)

Description copied from interface: StreamStore

For pull stores, add the iterator from which they should pull their data

Specified by:

setIterator in interface StreamStore

Overrides:

setIterator in class FIFOStore

setContext

public void setContext(Context context)
                throws MXQueryException

Sets the context of the source stream. This is especially necassary if the window iterator is used for external variables

Specified by:

setContext in interface MXQueryAppendUpdate

Overrides:

setContext in class FIFOStore

Parameters:

context -

Throws:

MXQueryException

getTokenIdForNode

public int getTokenIdForNode(int nodeId)
                      throws MXQueryException

Returns the position for a given NodePosition. If the node id is higher than the availabe source nodes the latest position is returned

Specified by:

getTokenIdForNode in interface MXQueryAppendUpdate

Overrides:

getTokenIdForNode in class FIFOStore

Parameters:

nodeId -

Returns:

the token id

Throws:

MXQueryException

hasNode

public boolean hasNode(int node)
                throws MXQueryException

Checks if a node exists

Specified by:

hasNode in interface MXQueryAppendUpdate

Overrides:

hasNode in class FIFOStore

Parameters:

node - a node id

Returns:

true if the node for the given id exists

Throws:

MXQueryException

getNodeIdFromTokenId

public int getNodeIdFromTokenId(int tokenId)
                         throws MXQueryException

Returns the NodeId for the given Token Id; The first node has the id = 0. If the position is not reachable, the last node id is returned.

Parameters:

tokenId -

Returns:

the node id >=0

Throws:

MXQueryException

getNodeIdFromTokenId

public int getNodeIdFromTokenId(int minNodeId,
                                int tokenId)
                         throws MXQueryException

Like getNodeIdFromPosition(int position) but we give a additional information that makes the search for the right nodeId faster.

Specified by:

getNodeIdFromTokenId in interface MXQueryAppendUpdate

Overrides:

getNodeIdFromTokenId in class FIFOStore

Parameters:

minNodeId -

tokenId -

Returns:

the nodeId

Throws:

MXQueryException

printBuffer

public void printBuffer()

get

public Token get(int tokenId)
          throws MXQueryException

Returns the Token for a given token id

Specified by:

get in interface StreamStore

Specified by:

get in interface MXQueryAppendUpdate

Overrides:

get in class FIFOStore

Parameters:

tokenId -

Returns:

the token for this Id

Throws:

MXQueryException

get

public Token get(int tokenId,
                 int maxNodeId)
          throws MXQueryException

Returns the token for a given tokenId. If the token is corresponds to a higher nodeId than maxNodeId, the END_SEQUENCE token is returned.

Specified by:

get in interface MXQueryAppendUpdate

Overrides:

get in class FIFOStore

Parameters:

tokenId - Token Id

maxNodeId - Max Token Id

Returns:

the token, or END_SEQENCE if out of range

Throws:

MXQueryException

getMaxNodeId

public int getMaxNodeId()

Returns the current materialized nodeId

Returns:

the node id of the last materialized node

getMaxTokenId

public int getMaxTokenId()

Returns the current materialized tokenId

Returns:

the token id of the last materialized node

getSize

public int getSize()

Overrides:

getSize in class FIFOStore

deleteItems

public void deleteItems(int olderThanItemId)
                 throws MXQueryException

Simple garbage collection; deletes all nodes that are older than the parameter

Specified by:

deleteItems in interface AppendUpdate

Overrides:

deleteItems in class FIFOStore

Parameters:

olderThanItemId -

Throws:

MXQueryException

getAttributePosFromTokenId

public int getAttributePosFromTokenId(java.lang.String attrName,
                                      int activeTokenId)
                               throws MXQueryException

Overrides:

getAttributePosFromTokenId in class FIFOStore

Throws:

MXQueryException

getAttributePosFromNodeId

public int getAttributePosFromNodeId(java.lang.String attrName,
                                     int nodeId)
                              throws MXQueryException

Overrides:

getAttributePosFromNodeId in class FIFOStore

Throws:

MXQueryException

getMyId

public int getMyId()

Description copied from interface: StreamStore

Returns the store id (mostly for debugging)

Specified by:

getMyId in interface StreamStore

Overrides:

getMyId in class FIFOStore

Returns:

id of the store given at creation time

buffer

public void buffer(Token tok,
                   int event)

Description copied from interface: StreamStore

Materialize the given token into the store instance

Specified by:

buffer in interface StreamStore

Overrides:

buffer in class FIFOStore

newItem

public void newItem()

Description copied from interface: StreamStore

Specify the beginning of a new item

Specified by:

newItem in interface StreamStore

Overrides:

newItem in class FIFOStore

compare

public int compare(Source store)

Specified by:

compare in interface Source

Overrides:

compare in class FIFOStore

copySource

public Source copySource(Context ctx,
                         java.util.Vector nestedPredCtxStack)
                  throws MXQueryException

Specified by:

copySource in interface Source

Overrides:

copySource in class FIFOStore

Throws:

MXQueryException

getURI

public java.lang.String getURI()

Description copied from interface: Source

Returns the URI of the source.

Specified by:

getURI in interface Source

Overrides:

getURI in class FIFOStore

Returns:

a String representing the URI/Identifier of this source