ch.ethz.mxquery.bindings
Class WindowIterator

java.lang.Object
  ch.ethz.mxquery.model.Iterator
      ch.ethz.mxquery.model.Window
          ch.ethz.mxquery.bindings.WindowIterator

All Implemented Interfaces:

IndexIterator, XDMIterator, Traversable

Direct Known Subclasses:

WindowEmptySequenceIterator, WindowSequenceIterator, WindowTokenIterator

public abstract class WindowIterator
extends Window

Implements the WindowInterface and provides the functionalities the WindowItem- and the WindowSequence-Iterator have in common

Field Summary

Fields inherited from class ch.ethz.mxquery.model.Window

END_OF_STREAM_NODE, END_OF_STREAM_POSITION

Fields inherited from interface ch.ethz.mxquery.model.XDMIterator

EXPR_CATEGORY_SEQUENTIAL, EXPR_CATEGORY_SIMPLE, EXPR_CATEGORY_UPDATING, EXPR_CATEGORY_VACUOUS, EXPR_PARAM_CHEAPEVAL, EXPR_PARAM_VARIABLE, EXPR_PARAM_WINDOW, EXPR_PARAM_XDMGEN

Constructor Summary

WindowIterator(WindowBuffer mat, int windowId)

Method Summary

void	destroyWindow() Deregister a window in the window buffer (and gives the items free for garbage collection if their are not used by other windows).
boolean	equals(java.lang.Object other)
abstract int	getStartNode() Returns the first node id of the window
Source	getStore()
int	getWindowId() Every window has a unique id given by the buffer the window is working on.
int	hashCode()
boolean	isWindowInUse() If a window is not in use it is a schema for other windows.
void	setContext(Context context)
void	setWindowInUse(boolean windowInUse) Specifies if a window can be used again.

Methods inherited from class ch.ethz.mxquery.model.Window

getEndPosition, getNewEarlyParallelWindowInterface, getNewEarlyWindowInterface, getNewItemWindow, getNewWindow, getNextWindowStartPosition, getPosition, getUnderlyingWindow, increasePosition, isExprParameter, isWindow, jumpToNextAttribute, setPosition

Methods inherited from class ch.ethz.mxquery.model.Iterator

addPredicates, close, copy, copyInts, copyIterators, copyQNames, copyStrings, copyTypeInfos, getAllSubIters, getAllSubItersRecursive, getContext, getExpressionCategoryType, getLoc, getPendingUpdateList, getPredicates, getStaticType, getSubIters, hasPredicates, isConstModePreserve, isOpen, isResettable, removePredicates, reset, setConstModePreserve, setContext, setLoc, setOrderByExpr, setParam, setResettable, setReturnExpr, setSubIters, setSubIters, setSubIters, setWhereExpr, traverse, traverseIteratorTree

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface ch.ethz.mxquery.model.IndexIterator

getItem, hasItem, hasNextItem, nextItem

Methods inherited from interface ch.ethz.mxquery.model.XDMIterator

next

Constructor Detail

WindowIterator

public WindowIterator(WindowBuffer mat,
                      int windowId)

Method Detail

getStartNode

public abstract int getStartNode()

Description copied from class: Window

Returns the first node id of the window

Specified by:

getStartNode in class Window

Returns:

returns the first node id of this window

destroyWindow

public void destroyWindow()

Deregister a window in the window buffer (and gives the items free for garbage collection if their are not used by other windows). Important: Never use a window again after destroying it!

Specified by:

destroyWindow in class Window

equals

public boolean equals(java.lang.Object other)

Specified by:

equals in class Window

getWindowId

public int getWindowId()

Description copied from class: Window

Every window has a unique id given by the buffer the window is working on.

Specified by:

getWindowId in class Window

Returns:

the identifier of this window

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

setContext

public void setContext(Context context)
                throws MXQueryException

Throws:

MXQueryException

isWindowInUse

public boolean isWindowInUse()

Description copied from class: Window

If a window is not in use it is a schema for other windows. E.g. a LET/FOR/FORSEQ binds a window to a variable the window is not in use yet. But in the moment the first variable reference is using the window the window is in used

Specified by:

isWindowInUse in class Window

Returns:

true if the window is use, false otherwise

setWindowInUse

public void setWindowInUse(boolean windowInUse)

Description copied from class: Window

Specifies if a window can be used again. This method is normally only used by the variable iterator. Be carefully with it, as it is mainly responsible to allow proper garbage collection.

Specified by:

setWindowInUse in class Window

getStore

public Source getStore()

Specified by:

getStore in class Window