Package org.apache.tinkerpop.gremlin.jsr223

Class GremlinLangScriptEngine

java.lang.Object

javax.script.AbstractScriptEngine

org.apache.tinkerpop.gremlin.jsr223.GremlinLangScriptEngine

All Implemented Interfaces:

ScriptEngine, GremlinScriptEngine

public class GremlinLangScriptEngine
extends AbstractScriptEngine
implements GremlinScriptEngine

A GremlinScriptEngine implementation that evaluates Gremlin scripts using gremlin-language. As it uses gremlin-language and thus the ANTLR parser, it is not capable of process arbitrary scripts as the GremlinGroovyScriptEngine can and is therefore a more secure Gremlin evaluator. It is obviously restricted to the capabilities of the ANTLR grammar so therefore syntax that includes things like lambdas are not supported. For bytecode evaluation it simply uses the JavaTranslator.

As an internal note, technically, this is an incomplete implementation of the GremlinScriptEngine in the traditional sense as a drop-in replacement for something like the GremlinGroovyScriptEngine. As a result, this GremlinScriptEngine cannot pass the GremlinScriptEngineSuite tests in full. On the other hand, this limitation is precisely what makes this implementation better from a security perspective. Ultimately, this implementation represents the first step to changes in what it means to have a GremlinScriptEngine. In some sense, there is question why a GremlinScriptEngine approach is necessary at all except for easily plugging into the existing internals of Gremlin Server or more specifically the GremlinExecutor.

Field Summary

Fields inherited from class javax.script.AbstractScriptEngine

context

Fields inherited from interface org.apache.tinkerpop.gremlin.jsr223.GremlinScriptEngine

HIDDEN_G

Fields inherited from interface javax.script.ScriptEngine

ARGV, ENGINE, ENGINE_VERSION, FILENAME, LANGUAGE, LANGUAGE_VERSION, NAME

Constructor Summary

Constructors

Constructor	Description
GremlinLangScriptEngine()	Creates a new instance using no Customizer.
GremlinLangScriptEngine(Customizer... customizers)

Method Summary

Modifier and Type	Method	Description
Bindings	createBindings()
Object	eval(Reader reader, ScriptContext context)
Object	eval(String script, ScriptContext context)	Gremlin scripts evaluated by the grammar must be bound to "g" and should evaluate to a "g" in the ScriptContext that is of type TraversalSource
Traversal.Admin	eval(Bytecode bytecode, Bindings bindings, String traversalSource)	Bytecode is evaluated by the JavaTranslator.
GremlinScriptEngineFactory	getFactory()
protected ScriptContext	getScriptContext(Bindings nn)	Creates the ScriptContext using a GremlinScriptContext which avoids a significant amount of additional object creation on script evaluation.

Methods inherited from class javax.script.AbstractScriptEngine

eval, eval, eval, eval, get, getBindings, getContext, put, setBindings, setContext

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.tinkerpop.gremlin.jsr223.GremlinScriptEngine

eval

Methods inherited from interface javax.script.ScriptEngine

eval, eval, eval, eval, get, getBindings, getContext, put, setBindings, setContext

Constructor Detail

GremlinLangScriptEngine

public GremlinLangScriptEngine()

Creates a new instance using no Customizer.

GremlinLangScriptEngine

public GremlinLangScriptEngine(Customizer... customizers)

Method Detail

getFactory

public GremlinScriptEngineFactory getFactory()

Specified by:

getFactory in interface GremlinScriptEngine

Specified by:

getFactory in interface ScriptEngine

eval

public Traversal.Admin eval(Bytecode bytecode,
                            Bindings bindings,
                            String traversalSource)
                     throws ScriptException

Bytecode is evaluated by the JavaTranslator.

Specified by:

eval in interface GremlinScriptEngine

Throws:

ScriptException

eval

public Object eval(String script,
                   ScriptContext context)
            throws ScriptException

Gremlin scripts evaluated by the grammar must be bound to "g" and should evaluate to a "g" in the ScriptContext that is of type TraversalSource

Specified by:

eval in interface ScriptEngine

Throws:

ScriptException

eval

public Object eval(Reader reader,
                   ScriptContext context)
            throws ScriptException

Specified by:

eval in interface ScriptEngine

Throws:

ScriptException

createBindings

public Bindings createBindings()

Specified by:

createBindings in interface ScriptEngine

getScriptContext

protected ScriptContext getScriptContext(Bindings nn)

Creates the ScriptContext using a GremlinScriptContext which avoids a significant amount of additional object creation on script evaluation.

Overrides:

getScriptContext in class AbstractScriptEngine