com.netflix.nicobar.core.module

Class ScriptModuleLoader

java.lang.Object

com.netflix.nicobar.core.module.ScriptModuleLoader

public class ScriptModuleLoader
extends java.lang.Object

Top level API for loading and accessing scripts. Builds and maintains interdependent script modules. Performs coordination between components neccessary for finding, compiling and loading scripts and notifying event listeners. Listeners can be added at any time during the repositories lifecycle, but if they are added at construction time, they are guaranteed to receive the events associate with the loading of archives, while those that are added later will only get events generated after the listener was added. Support pluggable compilers via the ScriptCompilerPluginSpec.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ScriptModuleLoader.Builder Builder used to constract a ScriptModuleLoader

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.ClassLoader	appClassLoader
protected java.util.Set<java.lang.String>	appPackagePaths
protected java.nio.file.Path	compilationRootDir
protected java.util.Map<java.lang.String,java.lang.ClassLoader>	compilerClassLoaders
protected java.util.List<ScriptArchiveCompiler>	compilers
protected JBossModuleLoader	jbossModuleLoader
protected java.util.Set<ScriptModuleListener>	listeners
protected java.util.Map<ModuleId,ScriptModule>	loadedScriptModules Map of script ModuleId to the loaded ScriptModules
protected java.util.Set<ScriptCompilerPluginSpec>	pluginSpecs

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ScriptModuleLoader(java.util.Set<ScriptCompilerPluginSpec> pluginSpecs, java.lang.ClassLoader appClassLoader, java.util.Set<java.lang.String> appPackagePaths, java.util.Set<ScriptModuleListener> listeners, java.nio.file.Path compilationRootDir)

Method Summary

Methods

Modifier and Type	Method and Description
void	addCompilerPlugin(ScriptCompilerPluginSpec pluginSpec) Add a language plugin to this module
void	addListeners(java.util.Set<ScriptModuleListener> listeners) Add listeners to this module loader.
protected void	compileModule(org.jboss.modules.Module module, java.nio.file.Path moduleCompilationRoot) Compiles and links the scripts within the module by locating the correct compiler and delegating the compilation.
protected org.jboss.modules.ModuleSpec	createModuleSpec(ScriptArchive archive, org.jboss.modules.ModuleIdentifier moduleId, java.util.Map<ModuleId,org.jboss.modules.ModuleIdentifier> moduleIdMap, java.nio.file.Path moduleCompilationRoot) Create a JBoss module spec for an about to be created script module.
protected java.util.List<ScriptArchiveCompiler>	findCompilers(ScriptArchive archive) Select a set of compilers to compile this archive.
java.util.Map<ModuleId,ScriptModule>	getAllScriptModules() Get a view of the loaded script modules
java.lang.ClassLoader	getCompilerPluginClassLoader(java.lang.String pluginModuleId)
ScriptModule	getScriptModule(ModuleId scriptModuleId)
ScriptModule	getScriptModule(java.lang.String scriptModuleId)
protected void	notifyArchiveRejected(ScriptArchive scriptArchive, ArchiveRejectedReason reason, java.lang.Throwable cause) Notify listeners that a script archive was rejected by this loader
protected void	notifyModuleUpdate(ScriptModule newModule, ScriptModule oldModule) Convenience method to notify the listeners that there was an update to the script module
void	removeScriptModule(ModuleId scriptModuleId) Remove a module from being served by this instance.
void	updateScriptArchives(java.util.Set<? extends ScriptArchive> candidateArchives) Add or update the existing ScriptModules with the given script archives.

Methods inherited from class java.lang.Object

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

Field Detail

loadedScriptModules

protected final java.util.Map<ModuleId,ScriptModule> loadedScriptModules

Map of script ModuleId to the loaded ScriptModules

compilerClassLoaders

protected final java.util.Map<java.lang.String,java.lang.ClassLoader> compilerClassLoaders

pluginSpecs

protected final java.util.Set<ScriptCompilerPluginSpec> pluginSpecs

appClassLoader

protected final java.lang.ClassLoader appClassLoader

appPackagePaths

protected final java.util.Set<java.lang.String> appPackagePaths

compilers

protected final java.util.List<ScriptArchiveCompiler> compilers

compilationRootDir

protected final java.nio.file.Path compilationRootDir

listeners

protected final java.util.Set<ScriptModuleListener> listeners

jbossModuleLoader

protected final JBossModuleLoader jbossModuleLoader

Constructor Detail

ScriptModuleLoader

protected ScriptModuleLoader(java.util.Set<ScriptCompilerPluginSpec> pluginSpecs,
                  java.lang.ClassLoader appClassLoader,
                  java.util.Set<java.lang.String> appPackagePaths,
                  java.util.Set<ScriptModuleListener> listeners,
                  java.nio.file.Path compilationRootDir)
                      throws org.jboss.modules.ModuleLoadException

Throws:

org.jboss.modules.ModuleLoadException

Method Detail

updateScriptArchives

public void updateScriptArchives(java.util.Set<? extends ScriptArchive> candidateArchives)

Add or update the existing ScriptModules with the given script archives. This method will convert the archives to modules and then compile + link them in to the dependency graph. It will then recursively re-link any modules depending on the new modules. If this loader already contains an old version of the module, it will be unloaded on successful compile of the new module.

Parameters:

candidateArchives - archives to load or update

createModuleSpec

protected org.jboss.modules.ModuleSpec createModuleSpec(ScriptArchive archive,
                                            org.jboss.modules.ModuleIdentifier moduleId,
                                            java.util.Map<ModuleId,org.jboss.modules.ModuleIdentifier> moduleIdMap,
                                            java.nio.file.Path moduleCompilationRoot)
                                                 throws org.jboss.modules.ModuleLoadException

Create a JBoss module spec for an about to be created script module.

Parameters:

archive - the script archive being converted to a module.

moduleId - the JBoss module identifier.

moduleIdMap - a map of loaded script module IDs to jboss module identifiers

moduleCompilationRoot - a path to a directory that will hold compiled classes for this module.

Throws:

org.jboss.modules.ModuleLoadException

compileModule

protected void compileModule(org.jboss.modules.Module module,
                 java.nio.file.Path moduleCompilationRoot)
                      throws ScriptCompilationException,
                             java.io.IOException

Compiles and links the scripts within the module by locating the correct compiler and delegating the compilation. the classes will be loaded into the module's classloader upon completion.

Parameters:

module - module to be compiled

moduleCompilationRoot - the directory to store compiled classes in.

Throws:

ScriptCompilationException

java.io.IOException

addCompilerPlugin

public void addCompilerPlugin(ScriptCompilerPluginSpec pluginSpec)
                       throws org.jboss.modules.ModuleLoadException

Add a language plugin to this module

Parameters:

pluginSpec -

Throws:

org.jboss.modules.ModuleLoadException

removeScriptModule

public void removeScriptModule(ModuleId scriptModuleId)

Remove a module from being served by this instance. Note that any instances of the module cached outside of this module loader will remain un-effected and will continue to operate.

getScriptModule

@Nullable
public ScriptModule getScriptModule(java.lang.String scriptModuleId)

getCompilerPluginClassLoader

@Nullable
public java.lang.ClassLoader getCompilerPluginClassLoader(java.lang.String pluginModuleId)

getScriptModule

@Nullable
public ScriptModule getScriptModule(ModuleId scriptModuleId)

getAllScriptModules

public java.util.Map<ModuleId,ScriptModule> getAllScriptModules()

Get a view of the loaded script modules

Returns:

immutable view of the Map that retains the script modules. Map ModuleId the loaded ScriptModule

addListeners

public void addListeners(java.util.Set<ScriptModuleListener> listeners)

Add listeners to this module loader. Listeners will only be notified of events that occurred after they were added.

Parameters:

listeners - listeners to add

findCompilers

protected java.util.List<ScriptArchiveCompiler> findCompilers(ScriptArchive archive)

Select a set of compilers to compile this archive.

notifyModuleUpdate

protected void notifyModuleUpdate(@Nullable
                      ScriptModule newModule,
                      @Nullable
                      ScriptModule oldModule)

Convenience method to notify the listeners that there was an update to the script module

Parameters:

newModule - newly loaded module

oldModule - module that was displaced by the new module

notifyArchiveRejected

protected void notifyArchiveRejected(ScriptArchive scriptArchive,
                         ArchiveRejectedReason reason,
                         @Nullable
                         java.lang.Throwable cause)

Notify listeners that a script archive was rejected by this loader

Parameters:

scriptArchive - archive that was rejected

reason - reason it was rejected

cause - underlying exception which triggered the rejection