jaroslav@1646: /*
jaroslav@1646:  * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
jaroslav@1646:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jaroslav@1646:  *
jaroslav@1646:  * This code is free software; you can redistribute it and/or modify it
jaroslav@1646:  * under the terms of the GNU General Public License version 2 only, as
jaroslav@1646:  * published by the Free Software Foundation.  Oracle designates this
jaroslav@1646:  * particular file as subject to the "Classpath" exception as provided
jaroslav@1646:  * by Oracle in the LICENSE file that accompanied this code.
jaroslav@1646:  *
jaroslav@1646:  * This code is distributed in the hope that it will be useful, but WITHOUT
jaroslav@1646:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jaroslav@1646:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jaroslav@1646:  * version 2 for more details (a copy is included in the LICENSE file that
jaroslav@1646:  * accompanied this code).
jaroslav@1646:  *
jaroslav@1646:  * You should have received a copy of the GNU General Public License version
jaroslav@1646:  * 2 along with this work; if not, write to the Free Software Foundation,
jaroslav@1646:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jaroslav@1646:  *
jaroslav@1646:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
jaroslav@1646:  * or visit www.oracle.com if you need additional information or have any
jaroslav@1646:  * questions.
jaroslav@1646:  */
jaroslav@1646: package java.lang.invoke;
jaroslav@1646: 
jaroslav@1646: import java.io.Serializable;
jaroslav@1646: import java.lang.reflect.Method;
jaroslav@1646: import java.security.AccessController;
jaroslav@1646: import java.security.PrivilegedActionException;
jaroslav@1646: import java.security.PrivilegedExceptionAction;
jaroslav@1646: import java.util.Objects;
jaroslav@1646: 
jaroslav@1646: /**
jaroslav@1646:  * Serialized form of a lambda expression.  The properties of this class
jaroslav@1646:  * represent the information that is present at the lambda factory site, including
jaroslav@1646:  * static metafactory arguments such as the identity of the primary functional
jaroslav@1646:  * interface method and the identity of the implementation method, as well as
jaroslav@1646:  * dynamic metafactory arguments such as values captured from the lexical scope
jaroslav@1646:  * at the time of lambda capture.
jaroslav@1646:  *
jaroslav@1646:  * <p>Implementors of serializable lambdas, such as compilers or language
jaroslav@1646:  * runtime libraries, are expected to ensure that instances deserialize properly.
jaroslav@1646:  * One means to do so is to ensure that the {@code writeReplace} method returns
jaroslav@1646:  * an instance of {@code SerializedLambda}, rather than allowing default
jaroslav@1646:  * serialization to proceed.
jaroslav@1646:  *
jaroslav@1646:  * <p>{@code SerializedLambda} has a {@code readResolve} method that looks for
jaroslav@1646:  * a (possibly private) static method called
jaroslav@1646:  * {@code $deserializeLambda$(SerializedLambda)} in the capturing class, invokes
jaroslav@1646:  * that with itself as the first argument, and returns the result.  Lambda classes
jaroslav@1646:  * implementing {@code $deserializeLambda$} are responsible for validating
jaroslav@1646:  * that the properties of the {@code SerializedLambda} are consistent with a
jaroslav@1646:  * lambda actually captured by that class.
jaroslav@1646:  *
jaroslav@1646:  * @see LambdaMetafactory
jaroslav@1646:  */
jaroslav@1646: public final class SerializedLambda implements Serializable {
jaroslav@1646:     private static final long serialVersionUID = 8025925345765570181L;
jaroslav@1646:     private final Class<?> capturingClass;
jaroslav@1646:     private final String functionalInterfaceClass;
jaroslav@1646:     private final String functionalInterfaceMethodName;
jaroslav@1646:     private final String functionalInterfaceMethodSignature;
jaroslav@1646:     private final String implClass;
jaroslav@1646:     private final String implMethodName;
jaroslav@1646:     private final String implMethodSignature;
jaroslav@1646:     private final int implMethodKind;
jaroslav@1646:     private final String instantiatedMethodType;
jaroslav@1646:     private final Object[] capturedArgs;
jaroslav@1646: 
jaroslav@1646:     /**
jaroslav@1646:      * Create a {@code SerializedLambda} from the low-level information present
jaroslav@1646:      * at the lambda factory site.
jaroslav@1646:      *
jaroslav@1646:      * @param capturingClass The class in which the lambda expression appears
jaroslav@1646:      * @param functionalInterfaceClass Name, in slash-delimited form, of static
jaroslav@1646:      *                                 type of the returned lambda object
jaroslav@1646:      * @param functionalInterfaceMethodName Name of the functional interface
jaroslav@1646:      *                                      method for the present at the
jaroslav@1646:      *                                      lambda factory site
jaroslav@1646:      * @param functionalInterfaceMethodSignature Signature of the functional
jaroslav@1646:      *                                           interface method present at
jaroslav@1646:      *                                           the lambda factory site
jaroslav@1646:      * @param implMethodKind Method handle kind for the implementation method
jaroslav@1646:      * @param implClass Name, in slash-delimited form, for the class holding
jaroslav@1646:      *                  the implementation method
jaroslav@1646:      * @param implMethodName Name of the implementation method
jaroslav@1646:      * @param implMethodSignature Signature of the implementation method
jaroslav@1646:      * @param instantiatedMethodType The signature of the primary functional
jaroslav@1646:      *                               interface method after type variables
jaroslav@1646:      *                               are substituted with their instantiation
jaroslav@1646:      *                               from the capture site
jaroslav@1646:      * @param capturedArgs The dynamic arguments to the lambda factory site,
jaroslav@1646:      *                     which represent variables captured by
jaroslav@1646:      *                     the lambda
jaroslav@1646:      */
jaroslav@1646:     public SerializedLambda(Class<?> capturingClass,
jaroslav@1646:                             String functionalInterfaceClass,
jaroslav@1646:                             String functionalInterfaceMethodName,
jaroslav@1646:                             String functionalInterfaceMethodSignature,
jaroslav@1646:                             int implMethodKind,
jaroslav@1646:                             String implClass,
jaroslav@1646:                             String implMethodName,
jaroslav@1646:                             String implMethodSignature,
jaroslav@1646:                             String instantiatedMethodType,
jaroslav@1646:                             Object[] capturedArgs) {
jaroslav@1646:         this.capturingClass = capturingClass;
jaroslav@1646:         this.functionalInterfaceClass = functionalInterfaceClass;
jaroslav@1646:         this.functionalInterfaceMethodName = functionalInterfaceMethodName;
jaroslav@1646:         this.functionalInterfaceMethodSignature = functionalInterfaceMethodSignature;
jaroslav@1646:         this.implMethodKind = implMethodKind;
jaroslav@1646:         this.implClass = implClass;
jaroslav@1646:         this.implMethodName = implMethodName;
jaroslav@1646:         this.implMethodSignature = implMethodSignature;
jaroslav@1646:         this.instantiatedMethodType = instantiatedMethodType;
jaroslav@1646:         this.capturedArgs = Objects.requireNonNull(capturedArgs).clone();
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     /**
jaroslav@1646:      * Get the name of the class that captured this lambda.
jaroslav@1646:      * @return the name of the class that captured this lambda
jaroslav@1646:      */
jaroslav@1646:     public String getCapturingClass() {
jaroslav@1646:         return capturingClass.getName().replace('.', '/');
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     /**
jaroslav@1646:      * Get the name of the invoked type to which this
jaroslav@1646:      * lambda has been converted
jaroslav@1646:      * @return the name of the functional interface class to which
jaroslav@1646:      * this lambda has been converted
jaroslav@1646:      */
jaroslav@1646:     public String getFunctionalInterfaceClass() {
jaroslav@1646:         return functionalInterfaceClass;
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     /**
jaroslav@1646:      * Get the name of the primary method for the functional interface
jaroslav@1646:      * to which this lambda has been converted.
jaroslav@1646:      * @return the name of the primary methods of the functional interface
jaroslav@1646:      */
jaroslav@1646:     public String getFunctionalInterfaceMethodName() {
jaroslav@1646:         return functionalInterfaceMethodName;
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     /**
jaroslav@1646:      * Get the signature of the primary method for the functional
jaroslav@1646:      * interface to which this lambda has been converted.
jaroslav@1646:      * @return the signature of the primary method of the functional
jaroslav@1646:      * interface
jaroslav@1646:      */
jaroslav@1646:     public String getFunctionalInterfaceMethodSignature() {
jaroslav@1646:         return functionalInterfaceMethodSignature;
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     /**
jaroslav@1646:      * Get the name of the class containing the implementation
jaroslav@1646:      * method.
jaroslav@1646:      * @return the name of the class containing the implementation
jaroslav@1646:      * method
jaroslav@1646:      */
jaroslav@1646:     public String getImplClass() {
jaroslav@1646:         return implClass;
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     /**
jaroslav@1646:      * Get the name of the implementation method.
jaroslav@1646:      * @return the name of the implementation method
jaroslav@1646:      */
jaroslav@1646:     public String getImplMethodName() {
jaroslav@1646:         return implMethodName;
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     /**
jaroslav@1646:      * Get the signature of the implementation method.
jaroslav@1646:      * @return the signature of the implementation method
jaroslav@1646:      */
jaroslav@1646:     public String getImplMethodSignature() {
jaroslav@1646:         return implMethodSignature;
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     /**
jaroslav@1646:      * Get the method handle kind (see {@link MethodHandleInfo}) of
jaroslav@1646:      * the implementation method.
jaroslav@1646:      * @return the method handle kind of the implementation method
jaroslav@1646:      */
jaroslav@1646:     public int getImplMethodKind() {
jaroslav@1646:         return implMethodKind;
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     /**
jaroslav@1646:      * Get the signature of the primary functional interface method
jaroslav@1646:      * after type variables are substituted with their instantiation
jaroslav@1646:      * from the capture site.
jaroslav@1646:      * @return the signature of the primary functional interface method
jaroslav@1646:      * after type variable processing
jaroslav@1646:      */
jaroslav@1646:     public final String getInstantiatedMethodType() {
jaroslav@1646:         return instantiatedMethodType;
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     /**
jaroslav@1646:      * Get the count of dynamic arguments to the lambda capture site.
jaroslav@1646:      * @return the count of dynamic arguments to the lambda capture site
jaroslav@1646:      */
jaroslav@1646:     public int getCapturedArgCount() {
jaroslav@1646:         return capturedArgs.length;
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     /**
jaroslav@1646:      * Get a dynamic argument to the lambda capture site.
jaroslav@1646:      * @param i the argument to capture
jaroslav@1646:      * @return a dynamic argument to the lambda capture site
jaroslav@1646:      */
jaroslav@1646:     public Object getCapturedArg(int i) {
jaroslav@1646:         return capturedArgs[i];
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     private Object readResolve() throws ReflectiveOperationException {
jaroslav@1646:         try {
jaroslav@1646:             Method deserialize = AccessController.doPrivileged(new PrivilegedExceptionAction<Method>() {
jaroslav@1646:                 @Override
jaroslav@1646:                 public Method run() throws Exception {
jaroslav@1646:                     Method m = capturingClass.getDeclaredMethod("$deserializeLambda$", SerializedLambda.class);
jaroslav@1646:                     m.setAccessible(true);
jaroslav@1646:                     return m;
jaroslav@1646:                 }
jaroslav@1646:             });
jaroslav@1646: 
jaroslav@1646:             return deserialize.invoke(null, this);
jaroslav@1646:         }
jaroslav@1646:         catch (PrivilegedActionException e) {
jaroslav@1646:             Exception cause = e.getException();
jaroslav@1646:             if (cause instanceof ReflectiveOperationException)
jaroslav@1646:                 throw (ReflectiveOperationException) cause;
jaroslav@1646:             else if (cause instanceof RuntimeException)
jaroslav@1646:                 throw (RuntimeException) cause;
jaroslav@1646:             else
jaroslav@1646:                 throw new RuntimeException("Exception in SerializedLambda.readResolve", e);
jaroslav@1646:         }
jaroslav@1646:     }
jaroslav@1646: 
jaroslav@1646:     @Override
jaroslav@1646:     public String toString() {
jaroslav@1646:         String implKind=MethodHandleInfo.referenceKindToString(implMethodKind);
jaroslav@1646:         return String.format("SerializedLambda[%s=%s, %s=%s.%s:%s, " +
jaroslav@1646:                              "%s=%s %s.%s:%s, %s=%s, %s=%d]",
jaroslav@1646:                              "capturingClass", capturingClass,
jaroslav@1646:                              "functionalInterfaceMethod", functionalInterfaceClass,
jaroslav@1646:                                functionalInterfaceMethodName,
jaroslav@1646:                                functionalInterfaceMethodSignature,
jaroslav@1646:                              "implementation",
jaroslav@1646:                                implKind,
jaroslav@1646:                                implClass, implMethodName, implMethodSignature,
jaroslav@1646:                              "instantiatedMethodType", instantiatedMethodType,
jaroslav@1646:                              "numCaptured", capturedArgs.length);
jaroslav@1646:     }
jaroslav@1646: }