Painless: Add PainlessConstructor

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

@@ -368,7 +368,7 @@ private static MethodHandle lookupReferenceInternal(PainlessLookup painlessLooku
              ref = new FunctionRef(clazz, interfaceMethod, call, handle.type(), captures.length);
          } else {
              // whitelist lookup
-             ref = new FunctionRef(painlessLookup, clazz, type, call, captures.length);
+             ref = FunctionRef.getFunctionRef(painlessLookup, clazz, type, call, captures.length);
          }
          final CallSite callSite = LambdaBootstrap.lambdaBootstrap(
              methodHandlesLookup,

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

@@ -20,13 +20,16 @@
 package org.elasticsearch.painless;
 
 import org.elasticsearch.painless.lookup.PainlessClass;
+import org.elasticsearch.painless.lookup.PainlessConstructor;
 import org.elasticsearch.painless.lookup.PainlessLookup;
 import org.elasticsearch.painless.lookup.PainlessLookupUtility;
 import org.elasticsearch.painless.lookup.PainlessMethod;
 import org.objectweb.asm.Type;
 
 import java.lang.invoke.MethodType;
+import java.lang.reflect.Constructor;
 import java.lang.reflect.Modifier;
+import java.util.List;
 
 import static org.elasticsearch.painless.WriterConstants.CLASS_NAME;
 import static org.objectweb.asm.Opcodes.H_INVOKEINTERFACE;
@@ -59,8 +62,10 @@ public class FunctionRef {
 
     /** interface method */
     public final PainlessMethod interfaceMethod;
-    /** delegate method */
-    public final PainlessMethod delegateMethod;
+    /** delegate method type parameters */
+    public final List<Class<?>> delegateTypeParameters;
+    /** delegate method return type */
+    public final Class<?> delegateReturnType;
 
     /** factory method type descriptor */
     public final String factoryDescriptor;
@@ -80,9 +85,45 @@ public class FunctionRef {
      * @param call the right hand side of a method reference expression
      * @param numCaptures number of captured arguments
      */
-    public FunctionRef(PainlessLookup painlessLookup, Class<?> expected, String type, String call, int numCaptures) {
-        this(expected, painlessLookup.getPainlessStructFromJavaClass(expected).functionalMethod,
-                lookup(painlessLookup, expected, type, call, numCaptures > 0), numCaptures);
+    public static FunctionRef getFunctionRef(PainlessLookup painlessLookup, Class<?> expected, String type, String call, int numCaptures) {
+        if ("new".equals(call)) {
+            return new FunctionRef(expected, painlessLookup.getPainlessStructFromJavaClass(expected).functionalMethod,
+                    lookup(painlessLookup, expected, type), numCaptures);
+        } else {
+            return new FunctionRef(expected, painlessLookup.getPainlessStructFromJavaClass(expected).functionalMethod,
+                    lookup(painlessLookup, expected, type, call, numCaptures > 0), numCaptures);
+        }
+    }
+
+    /**
+     * Creates a new FunctionRef (already resolved)
+     * @param expected functional interface type to implement
+     * @param interfaceMethod functional interface method
+     * @param delegateConstructor implementation constructor
+     * @param numCaptures number of captured arguments
+     */
+    public FunctionRef(Class<?> expected, PainlessMethod interfaceMethod, PainlessConstructor delegateConstructor, int numCaptures) {
+        Constructor<?> javaConstructor = delegateConstructor.javaConstructor;
+        MethodType delegateMethodType = delegateConstructor.methodType;
+
+        interfaceMethodName = interfaceMethod.name;
+        factoryMethodType = MethodType.methodType(expected,
+                delegateMethodType.dropParameterTypes(numCaptures, delegateMethodType.parameterCount()));
+        interfaceMethodType = interfaceMethod.methodType.dropParameterTypes(0, 1);
+
+        delegateClassName = javaConstructor.getDeclaringClass().getName();
+        isDelegateInterface = false;
+        delegateInvokeType = H_NEWINVOKESPECIAL;
+        delegateMethodName = PainlessLookupUtility.CONSTRUCTOR_NAME;
+        this.delegateMethodType = delegateMethodType.dropParameterTypes(0, numCaptures);
+
+        this.interfaceMethod = interfaceMethod;
+        delegateTypeParameters = delegateConstructor.typeParameters;
+        delegateReturnType = void.class;
+
+        factoryDescriptor = factoryMethodType.toMethodDescriptorString();
+        interfaceType = Type.getMethodType(interfaceMethodType.toMethodDescriptorString());
+        delegateType = Type.getMethodType(this.delegateMethodType.toMethodDescriptorString());
     }
 
     /**
@@ -112,9 +153,7 @@ public FunctionRef(Class<?> expected, PainlessMethod interfaceMethod, PainlessMe
             isDelegateInterface = delegateMethod.target.isInterface();
         }
 
-        if ("<init>".equals(delegateMethod.name)) {
-            delegateInvokeType = H_NEWINVOKESPECIAL;
-        } else if (Modifier.isStatic(delegateMethod.modifiers)) {
+        if (Modifier.isStatic(delegateMethod.modifiers)) {
             delegateInvokeType = H_INVOKESTATIC;
         } else if (delegateMethod.target.isInterface()) {
             delegateInvokeType = H_INVOKEINTERFACE;
@@ -126,7 +165,8 @@ public FunctionRef(Class<?> expected, PainlessMethod interfaceMethod, PainlessMe
         this.delegateMethodType = delegateMethodType.dropParameterTypes(0, numCaptures);
 
         this.interfaceMethod = interfaceMethod;
-        this.delegateMethod = delegateMethod;
+        delegateTypeParameters = delegateMethod.arguments;
+        delegateReturnType = delegateMethod.rtn;
 
         factoryDescriptor = factoryMethodType.toMethodDescriptorString();
         interfaceType = Type.getMethodType(interfaceMethodType.toMethodDescriptorString());
@@ -151,13 +191,37 @@ public FunctionRef(Class<?> expected,
         isDelegateInterface = false;
 
         this.interfaceMethod = null;
-        delegateMethod = null;
+        delegateTypeParameters = null;
+        delegateReturnType = null;
 
         factoryDescriptor = null;
         interfaceType = null;
         delegateType = null;
     }
 
+    /**
+     * Looks up {@code type} from the whitelist, and returns a matching constructor.
+     */
+    private static PainlessConstructor lookup(PainlessLookup painlessLookup, Class<?> expected, String type) {
+        // check its really a functional interface
+        // for e.g. Comparable
+        PainlessMethod method = painlessLookup.getPainlessStructFromJavaClass(expected).functionalMethod;
+        if (method == null) {
+            throw new IllegalArgumentException("Cannot convert function reference [" + type + "::new] " +
+                    "to [" + PainlessLookupUtility.typeToCanonicalTypeName(expected) + "], not a functional interface");
+        }
+
+        // lookup requested constructor
+        PainlessClass struct = painlessLookup.getPainlessStructFromJavaClass(painlessLookup.getJavaClassFromPainlessType(type));
+        PainlessConstructor impl = struct.constructors.get(PainlessLookupUtility.buildPainlessConstructorKey(method.arguments.size()));
+
+        if (impl == null) {
+            throw new IllegalArgumentException("Unknown reference [" + type + "::new] matching [" + expected + "]");
+        }
+
+        return impl;
+    }
+
     /**
      * Looks up {@code type::call} from the whitelist, and returns a matching method.
      */
@@ -174,27 +238,22 @@ private static PainlessMethod lookup(PainlessLookup painlessLookup, Class<?> exp
         // lookup requested method
         PainlessClass struct = painlessLookup.getPainlessStructFromJavaClass(painlessLookup.getJavaClassFromPainlessType(type));
         final PainlessMethod impl;
-        // ctor ref
-        if ("new".equals(call)) {
-            impl = struct.constructors.get(PainlessLookupUtility.buildPainlessMethodKey("<init>", method.arguments.size()));
-        } else {
-            // look for a static impl first
-            PainlessMethod staticImpl =
-                    struct.staticMethods.get(PainlessLookupUtility.buildPainlessMethodKey(call, method.arguments.size()));
-            if (staticImpl == null) {
-                // otherwise a virtual impl
-                final int arity;
-                if (receiverCaptured) {
-                    // receiver captured
-                    arity = method.arguments.size();
-                } else {
-                    // receiver passed
-                    arity = method.arguments.size() - 1;
-                }
-                impl = struct.methods.get(PainlessLookupUtility.buildPainlessMethodKey(call, arity));
+        // look for a static impl first
+        PainlessMethod staticImpl =
+                struct.staticMethods.get(PainlessLookupUtility.buildPainlessMethodKey(call, method.arguments.size()));
+        if (staticImpl == null) {
+            // otherwise a virtual impl
+            final int arity;
+            if (receiverCaptured) {
+                // receiver captured
+                arity = method.arguments.size();
             } else {
-                impl = staticImpl;
+                // receiver passed
+                arity = method.arguments.size() - 1;
             }
+            impl = struct.methods.get(PainlessLookupUtility.buildPainlessMethodKey(call, arity));
+        } else {
+            impl = staticImpl;
         }
         if (impl == null) {
             throw new IllegalArgumentException("Unknown reference [" + type + "::" + call + "] matching " +

modules/lang-painless/src/main/java/org/elasticsearch/painless/lookup/PainlessClass.java

@@ -24,7 +24,8 @@
 import java.util.Map;
 
 public final class PainlessClass {
-    public final Map<String, PainlessMethod> constructors;
+    public final Map<Integer, PainlessConstructor> constructors;
+
     public final Map<String, PainlessMethod> staticMethods;
     public final Map<String, PainlessMethod> methods;
 
@@ -36,13 +37,14 @@ public final class PainlessClass {
 
     public final PainlessMethod functionalMethod;
 
-    PainlessClass(Map<String, PainlessMethod> constructors,
+    PainlessClass(Map<Integer, PainlessConstructor> constructors,
             Map<String, PainlessMethod> staticMethods, Map<String, PainlessMethod> methods,
             Map<String, PainlessField> staticFields, Map<String, PainlessField> fields,
             Map<String, MethodHandle> getterMethodHandles, Map<String, MethodHandle> setterMethodHandles,
             PainlessMethod functionalMethod) {
 
         this.constructors = Collections.unmodifiableMap(constructors);
+
         this.staticMethods = Collections.unmodifiableMap(staticMethods);
         this.methods = Collections.unmodifiableMap(methods);
 

modules/lang-painless/src/main/java/org/elasticsearch/painless/lookup/PainlessClassBuilder.java

@@ -24,7 +24,8 @@
 import java.util.Map;
 
 final class PainlessClassBuilder {
-    final Map<String, PainlessMethod> constructors;
+    final Map<Integer, PainlessConstructor> constructors;
+
     final Map<String, PainlessMethod> staticMethods;
     final Map<String, PainlessMethod> methods;
 
@@ -38,6 +39,7 @@ final class PainlessClassBuilder {
 
     PainlessClassBuilder() {
         constructors = new HashMap<>();
+
         staticMethods = new HashMap<>();
         methods = new HashMap<>();
 

modules/lang-painless/src/main/java/org/elasticsearch/painless/lookup/PainlessConstructor.java

@@ -0,0 +1,39 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.painless.lookup;
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodType;
+import java.lang.reflect.Constructor;
+import java.util.List;
+
+public class PainlessConstructor {
+    public final Constructor<?> javaConstructor;
+    public final List<Class<?>> typeParameters;
+    public final MethodHandle methodHandle;
+    public final MethodType methodType;
+
+    PainlessConstructor(Constructor<?> javaConstructor, List<Class<?>> typeParameters, MethodHandle methodHandle, MethodType methodType) {
+        this.javaConstructor = javaConstructor;
+        this.typeParameters = typeParameters;
+        this.methodHandle = methodHandle;
+        this.methodType = methodType;
+    }
+}

modules/lang-painless/src/main/java/org/elasticsearch/painless/lookup/PainlessLookupBuilder.java

@@ -40,15 +40,47 @@
 import java.util.Objects;
 import java.util.regex.Pattern;
 
-import static org.elasticsearch.painless.lookup.PainlessLookupUtility.CONSTRUCTOR_NAME;
 import static org.elasticsearch.painless.lookup.PainlessLookupUtility.DEF_CLASS_NAME;
+import static org.elasticsearch.painless.lookup.PainlessLookupUtility.buildPainlessConstructorKey;
 import static org.elasticsearch.painless.lookup.PainlessLookupUtility.buildPainlessFieldKey;
 import static org.elasticsearch.painless.lookup.PainlessLookupUtility.buildPainlessMethodKey;
 import static org.elasticsearch.painless.lookup.PainlessLookupUtility.typeToCanonicalTypeName;
 import static org.elasticsearch.painless.lookup.PainlessLookupUtility.typeToJavaType;
 import static org.elasticsearch.painless.lookup.PainlessLookupUtility.typesToCanonicalTypeNames;
 
-public class PainlessLookupBuilder {
+public final class PainlessLookupBuilder {
+
+    private static class PainlessConstructorCacheKey {
+
+        private final Class<?> targetType;
+        private final List<Class<?>> typeParameters;
+
+        private PainlessConstructorCacheKey(Class<?> targetType, List<Class<?>> typeParameters) {
+            this.targetType = targetType;
+            this.typeParameters = Collections.unmodifiableList(typeParameters);
+        }
+
+        @Override
+        public boolean equals(Object object) {
+            if (this == object) {
+                return true;
+            }
+
+            if (object == null || getClass() != object.getClass()) {
+                return false;
+            }
+
+            PainlessConstructorCacheKey that = (PainlessConstructorCacheKey)object;
+
+            return Objects.equals(targetType, that.targetType) &&
+                   Objects.equals(typeParameters, that.typeParameters);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(targetType, typeParameters);
+        }
+    }
 
     private static class PainlessMethodCacheKey {
 
@@ -120,8 +152,9 @@ public int hashCode() {
         }
     }
 
-    private static final Map<PainlessMethodCacheKey, PainlessMethod> painlessMethodCache = new HashMap<>();
-    private static final Map<PainlessFieldCacheKey,  PainlessField>  painlessFieldCache  = new HashMap<>();
+    private static final Map<PainlessConstructorCacheKey, PainlessConstructor> painlessConstuctorCache = new HashMap<>();
+    private static final Map<PainlessMethodCacheKey,      PainlessMethod>      painlessMethodCache     = new HashMap<>();
+    private static final Map<PainlessFieldCacheKey,       PainlessField>       painlessFieldCache      = new HashMap<>();
 
     private static final Pattern CLASS_NAME_PATTERN  = Pattern.compile("^[_a-zA-Z][._a-zA-Z0-9]*$");
     private static final Pattern METHOD_NAME_PATTERN = Pattern.compile("^[_a-zA-Z][_a-zA-Z0-9]*$");
@@ -343,11 +376,10 @@ public void addPainlessConstructor(Class<?> targetClass, List<Class<?>> typePara
                     "[[" + targetCanonicalClassName + "], " + typesToCanonicalTypeNames(typeParameters) + "] not found", nsme);
         }
 
-        String painlessMethodKey = buildPainlessMethodKey(CONSTRUCTOR_NAME, typeParametersSize);
-        PainlessMethod painlessConstructor = painlessClassBuilder.constructors.get(painlessMethodKey);
+        int painlessConstructorKey = buildPainlessConstructorKey(typeParametersSize);
+        PainlessConstructor painlessConstructor = painlessClassBuilder.constructors.get(painlessConstructorKey);
 
         if (painlessConstructor == null) {
-            org.objectweb.asm.commons.Method asmConstructor = org.objectweb.asm.commons.Method.getMethod(javaConstructor);
             MethodHandle methodHandle;
 
             try {
@@ -359,17 +391,16 @@ public void addPainlessConstructor(Class<?> targetClass, List<Class<?>> typePara
 
             MethodType methodType = methodHandle.type();
 
-            painlessConstructor = painlessMethodCache.computeIfAbsent(
-                    new PainlessMethodCacheKey(targetClass, CONSTRUCTOR_NAME, typeParameters),
-                    key -> new PainlessMethod(CONSTRUCTOR_NAME, targetClass, null, void.class, typeParameters,
-                                              asmConstructor, javaConstructor.getModifiers(), methodHandle, methodType)
+            painlessConstructor = painlessConstuctorCache.computeIfAbsent(
+                    new PainlessConstructorCacheKey(targetClass, typeParameters),
+                    key -> new PainlessConstructor(javaConstructor, typeParameters, methodHandle, methodType)
             );
 
-            painlessClassBuilder.constructors.put(painlessMethodKey, painlessConstructor);
-        } else if (painlessConstructor.arguments.equals(typeParameters) == false){
+            painlessClassBuilder.constructors.put(painlessConstructorKey, painlessConstructor);
+        } else if (painlessConstructor.typeParameters.equals(typeParameters) == false){
             throw new IllegalArgumentException("cannot have constructors " +
                     "[[" + targetCanonicalClassName + "], " + typesToCanonicalTypeNames(typeParameters) + "] and " +
-                    "[[" + targetCanonicalClassName + "], " + typesToCanonicalTypeNames(painlessConstructor.arguments) + "] " +
+                    "[[" + targetCanonicalClassName + "], " + typesToCanonicalTypeNames(painlessConstructor.typeParameters) + "] " +
                     "with the same arity and different type parameters");
         }
     }

modules/lang-painless/src/main/java/org/elasticsearch/painless/lookup/PainlessLookupUtility.java

@@ -336,6 +336,13 @@ public static boolean isConstantType(Class<?> type) {
                type == String.class;
     }
 
+    /**
+     * Constructs a painless constructor key used to lookup painless constructors from a painless class.
+     */
+    public static int buildPainlessConstructorKey(int constructorArity) {
+        return constructorArity;
+    }
+
     /**
      * Constructs a painless method key used to lookup painless methods from a painless class.
      */