org.mozilla.javascript.commonjs.module.provider
Class SoftCachingModuleScriptProvider

java.lang.Object
  org.mozilla.javascript.commonjs.module.provider.CachingModuleScriptProviderBase
      org.mozilla.javascript.commonjs.module.provider.SoftCachingModuleScriptProvider

All Implemented Interfaces:

java.io.Serializable, ModuleScriptProvider

public class SoftCachingModuleScriptProvider
extends CachingModuleScriptProviderBase

A module script provider that uses a module source provider to load modules and caches the loaded modules. It softly references the loaded modules' Rhino Script objects, thus a module once loaded can become eligible for garbage collection if it is otherwise unused under memory pressure. Instances of this class are thread safe.

Version:

$Id: SoftCachingModuleScriptProvider.java,v 1.3 2011/04/07 20:26:12 hannes%helma.at Exp $

Author:

Attila Szegedi

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.mozilla.javascript.commonjs.module.provider.CachingModuleScriptProviderBase

CachingModuleScriptProviderBase.CachedModuleScript

Constructor Summary

SoftCachingModuleScriptProvider(ModuleSourceProvider moduleSourceProvider)
Creates a new module provider with the specified module source provider.

Method Summary

protected CachingModuleScriptProviderBase.CachedModuleScript	getLoadedModule(java.lang.String moduleId) Retrieves an already loaded moduleScript stored using CachingModuleScriptProviderBase.putLoadedModule(String, ModuleScript, Object).
ModuleScript	getModuleScript(Context cx, java.lang.String moduleId, java.net.URI uri, java.net.URI base, Scriptable paths) Returns a module script.
protected void	putLoadedModule(java.lang.String moduleId, ModuleScript moduleScript, java.lang.Object validator) Store a loaded module script for later retrieval using CachingModuleScriptProviderBase.getLoadedModule(String).

Methods inherited from class org.mozilla.javascript.commonjs.module.provider.CachingModuleScriptProviderBase

getConcurrencyLevel

Methods inherited from class java.lang.Object

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

Constructor Detail

SoftCachingModuleScriptProvider

public SoftCachingModuleScriptProvider(ModuleSourceProvider moduleSourceProvider)

Creates a new module provider with the specified module source provider.

Parameters:

moduleSourceProvider - provider for modules' source code

Method Detail

getModuleScript

public ModuleScript getModuleScript(Context cx,
                                    java.lang.String moduleId,
                                    java.net.URI uri,
                                    java.net.URI base,
                                    Scriptable paths)
                             throws java.lang.Exception

Description copied from interface: ModuleScriptProvider

Returns a module script. It should attempt to load the module script if it is not already available to it, or return an already loaded module script instance if it is available to it.

Specified by:

getModuleScript in interface ModuleScriptProvider

Overrides:

getModuleScript in class CachingModuleScriptProviderBase

Parameters:

cx - current context. Can be used to compile module scripts.

moduleId - the ID of the module. An implementation must only accept an absolute ID, starting with a term.

uri - the URI of the module. If this is not null, resolution of moduleId is bypassed and the script is directly loaded from moduleUri

base - the module path base URI from which moduleUri was derived.

paths - the value of the require() function's "paths" attribute. If the require() function is sandboxed, it will be null, otherwise it will be a JavaScript Array object. It is up to the provider implementation whether and how it wants to honor the contents of the array.

Returns:

a module script representing the compiled code of the module. Null should be returned if the script could not found.

Throws:

java.lang.Exception - if there was an unrecoverable problem obtaining the script

java.lang.IllegalArgumentException - if the module ID is syntactically not a valid absolute module identifier.

getLoadedModule

protected CachingModuleScriptProviderBase.CachedModuleScript getLoadedModule(java.lang.String moduleId)

Description copied from class: CachingModuleScriptProviderBase

Retrieves an already loaded moduleScript stored using CachingModuleScriptProviderBase.putLoadedModule(String, ModuleScript, Object).

Specified by:

getLoadedModule in class CachingModuleScriptProviderBase

Parameters:

moduleId - the ID of the module

Returns:

a cached module script, or null if the module is not loaded.

putLoadedModule

protected void putLoadedModule(java.lang.String moduleId,
                               ModuleScript moduleScript,
                               java.lang.Object validator)

Description copied from class: CachingModuleScriptProviderBase

Store a loaded module script for later retrieval using CachingModuleScriptProviderBase.getLoadedModule(String).

Specified by:

putLoadedModule in class CachingModuleScriptProviderBase

Parameters:

moduleId - the ID of the module

moduleScript - the module script

validator - the validator for the module's source text entity