org.apache.pig.scripting.jruby

Class JrubyScriptEngine

java.lang.Object

org.apache.pig.scripting.ScriptEngine

org.apache.pig.scripting.jruby.JrubyScriptEngine

public class JrubyScriptEngine
extends ScriptEngine

Implementation of the script engine for Jruby, which facilitates the registration of scripts as UDFs, and also provides information (via the nested class RubyFunctions) on the registered functions.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.pig.scripting.ScriptEngine

ScriptEngine.SupportedScriptLang

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.jruby.embed.ScriptingContainer	rubyEngine

Fields inherited from class org.apache.pig.scripting.ScriptEngine

NAMESPACE_SEPARATOR

Constructor Summary

Constructors

Constructor and Description
JrubyScriptEngine()

Method Summary

Modifier and Type	Method and Description
protected Map<String,Object>	getParamsFromVariables() Returns a map from local variable names to their values
protected String	getScriptingLang() Gets ScriptEngine classname or keyword for the scripting language
protected Map<String,List<PigStats>>	main(PigContext pigContext, String scriptFile) Actually runs the script file.
void	registerFunctions(String path, String namespace, PigContext pigContext) Evaluates the script containing ruby udfs to determine what udfs are defined as well as what libaries and other external resources are necessary.

Methods inherited from class org.apache.pig.scripting.ScriptEngine

getInstance, getJarPath, getPigStatsMap, getScriptAsStream, getSupportedScriptLang, run

Methods inherited from class java.lang.Object

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

Field Detail

rubyEngine

protected static final org.jruby.embed.ScriptingContainer rubyEngine

Constructor Detail

JrubyScriptEngine

public JrubyScriptEngine()

Method Detail

registerFunctions

public void registerFunctions(String path,
                              String namespace,
                              PigContext pigContext)
                       throws IOException

Evaluates the script containing ruby udfs to determine what udfs are defined as well as what libaries and other external resources are necessary. These libraries and resources are then packaged with the job jar itself.

Specified by:

registerFunctions in class ScriptEngine

Parameters:

path - path of the script

namespace - namespace for the functions

pigContext - pigcontext to register functions to pig in the given namespace

Throws:

IOException

main

protected Map<String,List<PigStats>> main(PigContext pigContext,
                                          String scriptFile)
                                   throws IOException

Description copied from class: ScriptEngine

Actually runs the script file. This method will be implemented by individual script engines.

Specified by:

main in class ScriptEngine

Parameters:

pigContext - ScriptPigContext to run the script file

scriptFile - the file

Throws:

IOException

getScriptingLang

protected String getScriptingLang()

Description copied from class: ScriptEngine

Gets ScriptEngine classname or keyword for the scripting language

Specified by:

getScriptingLang in class ScriptEngine

getParamsFromVariables

protected Map<String,Object> getParamsFromVariables()
                                             throws IOException

Description copied from class: ScriptEngine

Returns a map from local variable names to their values

Specified by:

getParamsFromVariables in class ScriptEngine

Throws:

IOException