com.saxonica.ee.optim

Class MultithreadedForEach

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.instruct.Instruction

net.sf.saxon.expr.instruct.ForEach

com.saxonica.ee.optim.MultithreadedForEach

All Implemented Interfaces:

ContextMappingFunction, ContextOriginator, ContextSwitchingExpression, TailCallReturner, IdentityComparable

public class MultithreadedForEach
extends ForEach

This instruction represents an xsl:for-each instruction using more than one thread

Field Summary

Fields inherited from class net.sf.saxon.expr.instruct.ForEach

actionOp, containsTailCall, selectOp, threadsOp

Fields inherited from class net.sf.saxon.expr.Expression

EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, UPDATE_METHOD, WATCH_METHOD

Constructor Summary

Constructors

Constructor and Description
MultithreadedForEach(Expression select, Expression action, boolean containsTailCall, Expression threads)

Method Summary

Methods

Modifier and Type	Method and Description
Expression	copy() Copy an expression.
protected void	explainThreads(ExpressionPresenter out) Add the value of the saxon:threads attribute to the explain output
ExpressionCompiler	getExpressionCompiler() Return the compiler of the MultithreadedForEach expression.
int	getImplementationMethod() An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
SequenceIterator	iterate(XPathContext context) Return an Iterator to iterate over the values of the sequence.
TailCall	processLeavingTail(XPathContext context) ProcessLeavingTail: called to do the real work of this instruction.

Methods inherited from class net.sf.saxon.expr.instruct.ForEach

addToPathMap, checkPermittedContents, computeSpecialProperties, createsNewNodes, export, getAction, getActionExpression, getExpressionName, getInstructionNameCode, getItemType, getNumberOfThreadsExpression, getSelect, getSelectExpression, getStreamingAdjunct, getThreads, map, operands, optimize, promoteChildren, setAction, setActionExpression, setSelect, setSelectExpression, setThreads, toShortString, toString, typeCheck, unordered

Methods inherited from class net.sf.saxon.expr.instruct.Instruction

assembleParams, assembleTunnelParams, computeCardinality, dynamicError, evaluateAsString, evaluateItem, getConstructType, getInstructionName, getNetCost, getSourceLocator, isXSLT, main, process, toStreamingPattern

Methods inherited from class net.sf.saxon.expr.Expression

adoptChildExpression, checkedOperands, checkForUpdatingSubexpressions, clearStreamabilityData, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluatePendingUpdates, explain, getCardinality, getConfiguration, getCost, getDependencies, getEvaluationMethod, getHostLanguage, getIntegerBounds, getIntrinsicDependencies, getLocation, getObjectName, getPackageData, getParentExpression, getPosture, getPostureAndSweepIfKnown, getProperties, getProperty, getRetainedStaticContext, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStreamability, getSweep, getSystemId, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isCallOnSystemFunction, isIdentical, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterateEvents, makeStreamingAdjunct, markTailFunctionCalls, operandList, operandSparseList, optimizeChildren, optimizeForType, promote, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setFiltered, setFlattened, setLocation, setParentExpression, setPostureAndSweep, setRetainedStaticContext, setRetainedStaticContextLocally, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, suppressValidation, toPattern, typeCheckChildren, typeError

Methods inherited from class java.lang.Object

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

Constructor Detail

MultithreadedForEach

public MultithreadedForEach(Expression select,
                    Expression action,
                    boolean containsTailCall,
                    Expression threads)

Method Detail

copy

public Expression copy()

Copy an expression. This makes a deep copy.

Overrides:

copy in class ForEach

Returns:

the copy of the original expression

getImplementationMethod

public int getImplementationMethod()

An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process(). This method indicates which of these methods is provided. This implementation provides only the process() method natively.

Overrides:

getImplementationMethod in class ForEach

Returns:

the implementation method, for example Expression.ITERATE_METHOD or Expression.EVALUATE_METHOD or Expression.PROCESS_METHOD

processLeavingTail

public TailCall processLeavingTail(XPathContext context)
                            throws XPathException

Description copied from class: Instruction

ProcessLeavingTail: called to do the real work of this instruction. This method must be implemented in each subclass. The results of the instruction are written to the current Receiver, which can be obtained via the Controller.

Specified by:

processLeavingTail in interface TailCallReturner

Overrides:

processLeavingTail in class ForEach

Parameters:

context - The dynamic context of the transformation, giving access to the current node, the current variables, etc.

Returns:

null if the instruction has completed execution; or a TailCall indicating a function call or template call that is delegated to the caller, to be made after the stack has been unwound so as to save stack space.

Throws:

XPathException - if a dynamic error occurs during the evaluation of the instruction

iterate

public SequenceIterator iterate(XPathContext context)
                         throws XPathException

Return an Iterator to iterate over the values of the sequence.

Overrides:

iterate in class ForEach

Parameters:

context - supplies the context for evaluation

Returns:

a SequenceIterator that can be used to iterate over the result of the expression

Throws:

XPathException - if any dynamic error occurs evaluating the expression

getExpressionCompiler

public ExpressionCompiler getExpressionCompiler()

Return the compiler of the MultithreadedForEach expression. For this expression, the compiled code simply invokes the interpreter.

Overrides:

getExpressionCompiler in class ForEach

Returns:

the relevant ExpressionCompiler

explainThreads

protected void explainThreads(ExpressionPresenter out)

Add the value of the saxon:threads attribute to the explain output

Overrides:

explainThreads in class ForEach

Parameters:

out - the destination for explain output