Scripting: Groundwork for caching script results (elastic#49895)

In order to cache script results in the query shard cache, we need to
check if scripts are deterministic.  This change adds a default method
to the script factories, `isResultDeterministic() -> false` which is
used by the `QueryShardContext`.

Script results were never cached and that does not change here.  Future
changes will implement this method based on whether the results of the
scripts are deterministic or not and therefore cacheable.

Refs: elastic#49466

modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/AnalysisPredicateScript.java

@@ -27,6 +27,7 @@
 import org.apache.lucene.analysis.tokenattributes.TypeAttribute;
 import org.apache.lucene.util.AttributeSource;
 import org.elasticsearch.script.ScriptContext;
+import org.elasticsearch.script.ScriptFactory;
 
 /**
  * A predicate based on the current token in a TokenStream
@@ -107,7 +108,7 @@ public boolean isKeyword() {
      */
     public abstract boolean execute(Token token);
 
-    public interface Factory {
+    public interface Factory extends ScriptFactory {
         AnalysisPredicateScript newInstance();
     }
 

modules/analysis-common/src/test/java/org/elasticsearch/analysis/common/PredicateTokenScriptFilterTests.java

@@ -30,6 +30,7 @@
 import org.elasticsearch.indices.analysis.AnalysisModule;
 import org.elasticsearch.script.Script;
 import org.elasticsearch.script.ScriptContext;
+import org.elasticsearch.script.ScriptFactory;
 import org.elasticsearch.script.ScriptService;
 import org.elasticsearch.test.ESTokenStreamTestCase;
 import org.elasticsearch.test.IndexSettingsModule;
@@ -63,7 +64,7 @@ public boolean execute(Token token) {
         @SuppressWarnings("unchecked")
         ScriptService scriptService = new ScriptService(indexSettings, Collections.emptyMap(), Collections.emptyMap()){
             @Override
-            public <FactoryType> FactoryType compile(Script script, ScriptContext<FactoryType> context) {
+            public <FactoryType extends ScriptFactory> FactoryType compile(Script script, ScriptContext<FactoryType> context) {
                 assertEquals(context, AnalysisPredicateScript.CONTEXT);
                 assertEquals(new Script("my_script"), script);
                 return (FactoryType) factory;

modules/analysis-common/src/test/java/org/elasticsearch/analysis/common/ScriptedConditionTokenFilterTests.java

@@ -30,6 +30,7 @@
 import org.elasticsearch.indices.analysis.AnalysisModule;
 import org.elasticsearch.script.Script;
 import org.elasticsearch.script.ScriptContext;
+import org.elasticsearch.script.ScriptFactory;
 import org.elasticsearch.script.ScriptService;
 import org.elasticsearch.test.ESTokenStreamTestCase;
 import org.elasticsearch.test.IndexSettingsModule;
@@ -63,7 +64,7 @@ public boolean execute(Token token) {
         @SuppressWarnings("unchecked")
         ScriptService scriptService = new ScriptService(indexSettings, Collections.emptyMap(), Collections.emptyMap()){
             @Override
-            public <FactoryType> FactoryType compile(Script script, ScriptContext<FactoryType> context) {
+            public <FactoryType extends ScriptFactory> FactoryType compile(Script script, ScriptContext<FactoryType> context) {
                 assertEquals(context, AnalysisPredicateScript.CONTEXT);
                 assertEquals(new Script("token.getPosition() > 1"), script);
                 return (FactoryType) factory;

modules/lang-expression/src/main/java/org/elasticsearch/script/expression/ExpressionScriptEngine.java

@@ -44,6 +44,7 @@
 import org.elasticsearch.script.ScriptContext;
 import org.elasticsearch.script.ScriptEngine;
 import org.elasticsearch.script.ScriptException;
+import org.elasticsearch.script.ScriptFactory;
 import org.elasticsearch.script.TermsSetQueryScript;
 import org.elasticsearch.search.lookup.SearchLookup;
 
@@ -108,7 +109,12 @@ public String getType() {
     }
 
     @Override
-    public <T> T compile(String scriptName, String scriptSource, ScriptContext<T> context, Map<String, String> params) {
+    public <T extends ScriptFactory> T compile(
+        String scriptName,
+        String scriptSource,
+        ScriptContext<T> context,
+        Map<String, String> params
+    ) {
         // classloader created here
         final SecurityManager sm = System.getSecurityManager();
         SpecialPermission.check();

modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/MustacheScriptEngine.java

@@ -32,6 +32,7 @@
 import org.elasticsearch.script.ScriptContext;
 import org.elasticsearch.script.ScriptEngine;
 import org.elasticsearch.script.ScriptException;
+import org.elasticsearch.script.ScriptFactory;
 import org.elasticsearch.script.TemplateScript;
 
 import java.io.Reader;
@@ -64,7 +65,12 @@ public final class MustacheScriptEngine implements ScriptEngine {
      * @return a compiled template object for later execution.
      * */
     @Override
-    public <T> T compile(String templateName, String templateSource, ScriptContext<T> context, Map<String, String> options) {
+    public <T extends ScriptFactory> T compile(
+        String templateName,
+        String templateSource,
+        ScriptContext<T> context,
+        Map<String, String> options
+    ) {
         if (context.instanceClazz.equals(TemplateScript.class) == false) {
             throw new IllegalArgumentException("mustache engine does not know how to handle context [" + context.name + "]");
         }

modules/lang-painless/src/main/java/org/elasticsearch/painless/PainlessScriptEngine.java

@@ -28,6 +28,7 @@
 import org.elasticsearch.script.ScriptContext;
 import org.elasticsearch.script.ScriptEngine;
 import org.elasticsearch.script.ScriptException;
+import org.elasticsearch.script.ScriptFactory;
 import org.objectweb.asm.ClassWriter;
 import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.Type;
@@ -66,7 +67,7 @@ public final class PainlessScriptEngine implements ScriptEngine {
      */
     private static final AccessControlContext COMPILATION_CONTEXT;
 
-    /**
+    /*
      * Setup the allowed permissions.
      */
     static {
@@ -122,7 +123,12 @@ public String getType() {
     }
 
     @Override
-    public <T> T compile(String scriptName, String scriptSource, ScriptContext<T> context, Map<String, String> params) {
+    public <T extends ScriptFactory> T compile(
+        String scriptName,
+        String scriptSource,
+        ScriptContext<T> context,
+        Map<String, String> params
+    ) {
         Compiler compiler = contextsToCompilers.get(context);
 
         // Check we ourselves are not being called by unprivileged code.
@@ -162,12 +168,16 @@ public Set<ScriptContext<?>> getSupportedContexts() {
      * @param <T> The factory class.
      * @return A factory class that will return script instances.
      */
-    private <T> Type generateStatefulFactory(Loader loader, ScriptContext<T> context, Set<String> extractedVariables) {
+    private <T extends ScriptFactory> Type generateStatefulFactory(
+        Loader loader,
+        ScriptContext<T> context,
+        Set<String> extractedVariables
+    ) {
         int classFrames = ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS;
         int classAccess = Opcodes.ACC_PUBLIC | Opcodes.ACC_SUPER | Opcodes.ACC_FINAL;
         String interfaceBase = Type.getType(context.statefulFactoryClazz).getInternalName();
         String className = interfaceBase + "$StatefulFactory";
-        String classInterfaces[] = new String[] { interfaceBase };
+        String[] classInterfaces = new String[] { interfaceBase };
 
         ClassWriter writer = new ClassWriter(classFrames);
         writer.visit(WriterConstants.CLASS_VERSION, classAccess, className, null, OBJECT_TYPE.getInternalName(), classInterfaces);
@@ -263,12 +273,17 @@ private <T> Type generateStatefulFactory(Loader loader, ScriptContext<T> context
      * @param <T> The factory class.
      * @return A factory class that will return script instances.
      */
-    private <T> T generateFactory(Loader loader, ScriptContext<T> context, Set<String> extractedVariables, Type classType) {
+    private <T extends ScriptFactory> T generateFactory(
+        Loader loader,
+        ScriptContext<T> context,
+        Set<String> extractedVariables,
+        Type classType
+    ) {
         int classFrames = ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS;
         int classAccess = Opcodes.ACC_PUBLIC | Opcodes.ACC_SUPER| Opcodes.ACC_FINAL;
         String interfaceBase = Type.getType(context.factoryClazz).getInternalName();
         String className = interfaceBase + "$Factory";
-        String classInterfaces[] = new String[] { interfaceBase };
+        String[] classInterfaces = new String[] { interfaceBase };
 
         ClassWriter writer = new ClassWriter(classFrames);
         writer.visit(WriterConstants.CLASS_VERSION, classAccess, className, null, OBJECT_TYPE.getInternalName(), classInterfaces);

modules/lang-painless/src/main/java/org/elasticsearch/painless/action/PainlessExecuteAction.java

@@ -75,6 +75,7 @@
 import org.elasticsearch.script.ScoreScript;
 import org.elasticsearch.script.Script;
 import org.elasticsearch.script.ScriptContext;
+import org.elasticsearch.script.ScriptFactory;
 import org.elasticsearch.script.ScriptService;
 import org.elasticsearch.script.ScriptType;
 import org.elasticsearch.threadpool.ThreadPool;
@@ -415,7 +416,7 @@ public Map<String, Object> getParams() {
 
         public abstract Object execute();
 
-        public interface Factory {
+        public interface Factory extends ScriptFactory {
 
             PainlessTestScript newInstance(Map<String, Object> params);