Package org.apache.flink.cep.nfa.compiler

Class NFACompiler

java.lang.Object

org.apache.flink.cep.nfa.compiler.NFACompiler

public class NFACompiler
extends Object

Compiler class containing methods to compile a Pattern into a NFA or a NFACompiler.NFAFactory.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	NFACompiler.NFAFactory<T>	Factory interface for NFA.

Field Summary

Fields

Modifier and Type	Field	Description
protected static final String	ENDING_STATE_NAME

Constructor Summary

Constructors

Constructor	Description
NFACompiler()

Method Summary

Modifier and Type	Method	Description
static boolean	canProduceEmptyMatches(Pattern<?,?> pattern)	Verifies if the provided pattern can possibly generate empty match.
static <T> NFACompiler.NFAFactory<T>	compileFactory(Pattern<T,?> pattern, boolean timeoutHandling)	Compiles the given pattern into a NFACompiler.NFAFactory.

Methods inherited from class java.lang.Object

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

Field Details

ENDING_STATE_NAME

protected static final String ENDING_STATE_NAME

See Also:

• Constant Field Values

Constructor Details

NFACompiler

public NFACompiler()

Method Details

compileFactory

public static <T> NFACompiler.NFAFactory<T> compileFactory(Pattern<T,?> pattern,
 boolean timeoutHandling)

Compiles the given pattern into a NFACompiler.NFAFactory. The NFA factory can be used to create multiple NFAs.

Type Parameters:

T - Type of the input events

Parameters:

pattern - Definition of sequence pattern

timeoutHandling - True if the NFA shall return timed out event patterns

Returns:

Factory for NFAs corresponding to the given pattern

canProduceEmptyMatches

public static boolean canProduceEmptyMatches(Pattern<?,?> pattern)

Verifies if the provided pattern can possibly generate empty match. Example of patterns that can possibly generate empty matches are: A*, A?, A* B? etc.

Parameters:

pattern - pattern to check

Returns:

true if empty match could potentially match the pattern, false otherwise