org.mozilla.javascript
Class ClassCache

java.lang.Object
  |
  +--org.mozilla.javascript.ClassCache

public class ClassCache

extends java.lang.Object

Cache of generated classes and data structures to access Java runtime from JavaScript.

Since:

Rhino 1.5 Release 5

Author:

Igor Bukanov

Constructor Summary

ClassCache()

Method Summary

boolean	associate(ScriptableObject topScope) Associate ClassCache object with the given top-level scope.
void	clearCaches() Empty caches of generated Java classes and Java reflection information.
static ClassCache	get(Scriptable scope) Search for ClassCache object in the given scope.
boolean	isCachingEnabled() Check if generated Java classes and Java reflection information is cached.
int	newClassSerialNumber() Internal engine method to return serial number for generated classes to ensure name uniqueness.
void	setCachingEnabled(boolean enabled) Set whether to cache some values.
void	setInvokerOptimizationEnabled(boolean enabled) To optimize invocation of reflected Java methods, the engine generates special glue classes that will call the methods directly.

Methods inherited from class java.lang.Object

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

Constructor Detail

ClassCache

public ClassCache()

Method Detail

get

public static ClassCache get(Scriptable scope)

Search for ClassCache object in the given scope. The method first calls ScriptableObject.getTopLevelScope(Scriptable scope) to get the top most scope and then tries to locate associated ClassCache object in the prototype chain of the top scope.

Parameters:

scope - scope to search for ClassCache object.

Returns:

previously associated ClassCache object or a new instance of ClassCache if no ClassCache object was found.

See Also:

associate(ScriptableObject topScope)

associate

public boolean associate(ScriptableObject topScope)

Associate ClassCache object with the given top-level scope. The ClassCache object can only be associated with the given scope once.

Parameters:

topScope - scope to associate this ClassCache object with.

Returns:

true if no prevous ClassCache objects were embedded into the scope and this ClassCache were successfully associated or false otherwise.

See Also:

get(Scriptable scope)

clearCaches

public void clearCaches()

Empty caches of generated Java classes and Java reflection information.

isCachingEnabled

public final boolean isCachingEnabled()

Check if generated Java classes and Java reflection information is cached.

setCachingEnabled

public void setCachingEnabled(boolean enabled)

Set whether to cache some values.

By default, the engine will cache generated classes and results of Class.getMethods() and similar calls. This can speed execution dramatically, but increases the memory footprint. Also, with caching enabled, references may be held to objects past the lifetime of any real usage.

If caching is enabled and this method is called with a false argument, the caches will be emptied.

Caching is enabled by default.

Parameters:

enabled - if true, caching is enabled

See Also:

clearCaches()

setInvokerOptimizationEnabled

public void setInvokerOptimizationEnabled(boolean enabled)

To optimize invocation of reflected Java methods, the engine generates special glue classes that will call the methods directly. By default the optimization is enabled since it allows to speedup method invocation compared with calling Method.invoke by factor 2-2.5 under JDK 1.4.2 and by factor 10-15 under JDK 1.3.1. If increase memory consumption is too high or the optimization brings no benefits in a particular VM, then the optimization can be disabled.

Parameters:

enabled - if true, invoke optimization is enabled.

newClassSerialNumber

public final int newClassSerialNumber()

Internal engine method to return serial number for generated classes to ensure name uniqueness.