Package org.apache.uima.cas.impl

Class FSClassRegistry

java.lang.Object

org.apache.uima.cas.impl.FSClassRegistry

public abstract class FSClassRegistry
extends Object

There is one **class** instance of this per UIMA core class loader. The class loader is the loader for the UIMA core classes, not any UIMA extension class loader - **Builtin** JCas Types are loaded and shared among all type systems, once, when this class is loaded. There are no instances of this class. - The type system impl instances at commit time initialize parts of their Impl from data in this class - Some of the data kept in this class in static values, is constructed when the type system is committed The class instance is shared - by multiple type systems - by multiple CASes (in a CAS pool, for instance, when these CASes are sharing the same type system). - by all views of those CASes. - by multiple different pipelines, built using the same merged type system instance - by non-built-in JCas classes, loaded under possibly different extension class loaders PEAR support Multiple PEAR contexts can be used. - hierarchy (each is parent of kind below -- UIMA core class loader (built-ins, not redefinable by user JCas classes) --- a new limitation of UIMA V3 to allow sharing of built-in JCas classes, which also have custom impl, and don't fit the model used for PEAR Trampolines -- outer (non Pear) class loader (optional, known as base extension class loader) --- possible multiple, for different AE pipelines -- Within PEAR class loader - when running within a PEAR, operations which return Feature Structures potentially return JCas instances of classes loaded from the Pear's class loader. - These instances share the same int[] and Object[] and _typeImpl and _casView refs with the outer class loader's FS Timing / life cycle Built-in classes loaded and initialized at first type system commit time. non-pear classes loaded and initialized at type system commit time (if not already loaded) - special checks for conformability if some types loaded later, due to requirements for computing feature offsets at load time pear classes loaded and initialized at first entry to Pear, for a given type system and class loader. At typeSystemCommit time, this class is created and initialized: - The built-in JCas types are loaded - The user-defined non-PEAR JCas classes are loaded (not lazy, but eager), provided the type system is a new one. (If the type system is "equal" to an existing committed one, that one is used instead). -- User classes defined with the name of UIMA types, but which are not JCas definitions, are not used as JCas types. This permits uses cases where users define a class which (perhaps at a later integration time) has the same name as a UIMA type, but is not a JCas class. -- These classes, once loaded, remain loaded because of Java's design, unless the ClassLoader used to load them is Garbage Collected. --- The ClassLoader used is the CAS's JCasClassLoader, set from the UIMA Extension class loader if specified. Assigning slots for features: - each type being loaded runs static final initializers to set for (a subset of) all features the offset in the int or ref storage arrays for those values. - These call a static method in JCasRegistry: register[Int/Ref]Feature, which assigns the next available slot via accessing/updating a thread local instance of TypeSystemImpl.SlotAllocate.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	FSClassRegistry.JCasClassInfo	One instance per JCas class defined for it, per class loader - per class loader, because different JCas class definitions for the same name are possible, per class loader Kept in maps, per class loader.

Constructor Summary

Constructors

Constructor	Description
FSClassRegistry()

Method Summary

Modifier and Type	Method	Description
static FSClassRegistry.JCasClassInfo	createJCasClassInfo(TypeImpl ti, ClassLoader cl, MethodHandles.Lookup lookup)
static FSClassRegistry.JCasClassInfo	getOrCreateJCasClassInfo(TypeImpl ti, ClassLoader cl, Map<String,FSClassRegistry.JCasClassInfo> type2jcci, MethodHandles.Lookup lookup)	For a particular type name, get the JCasClassInfo - by fetching the cached value - by loading the class - return null if no JCas class for this name only called for non-Pear callers
static void	log_registered_classloaders(Level aLogLevel)	For internal use only!
static void	unregister_jcci_classloader(ClassLoader cl)	For internal use only!

Methods inherited from class java.lang.Object

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

Constructor Details

FSClassRegistry

public FSClassRegistry()

Method Details

getOrCreateJCasClassInfo

public static FSClassRegistry.JCasClassInfo getOrCreateJCasClassInfo(TypeImpl ti,
 ClassLoader cl,
 Map<String,FSClassRegistry.JCasClassInfo> type2jcci,
 MethodHandles.Lookup lookup)

For a particular type name, get the JCasClassInfo - by fetching the cached value - by loading the class - return null if no JCas class for this name only called for non-Pear callers

Parameters:

ti - -

cl - -

type2jcci - -

lookup - -

Returns:

- jcci or null, if no JCas class for this type was able to be loaded

createJCasClassInfo

public static FSClassRegistry.JCasClassInfo createJCasClassInfo(TypeImpl ti,
 ClassLoader cl,
 MethodHandles.Lookup lookup)

unregister_jcci_classloader

public static void unregister_jcci_classloader(ClassLoader cl)

For internal use only!

log_registered_classloaders

public static void log_registered_classloaders(Level aLogLevel)

For internal use only!