/*
Copyright 2009-2013 Attila Szegedi
Licensed under both the Apache License, Version 2.0 (the "Apache License")
and the BSD License (the "BSD License"), with licensee being free to
choose either of the two at their discretion.
You may not use this file except in compliance with either the Apache
License or the BSD License.
If you choose to use this file in compliance with the Apache License, the
following notice applies to you:
You may obtain a copy of the Apache 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.
If you choose to use this file in compliance with the BSD License, the
following notice applies to you:
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
* Neither the name of the copyright holder nor the names of
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.dynalang.dynalink.beans;
import java.lang.invoke.MethodHandle;
import org.dynalang.dynalink.linker.GuardedInvocation;
/**
* Represents one component for a GuardedInvocation of a potentially composite operation of an
* {@link AbstractJavaLinker}. In addition to holding a guarded invocation, it holds semantic information about its
* guard. All guards produced in the AbstractJavaLinker are either "Class.isInstance()" or "getClass() == clazz"
* expressions. This allows choosing the most restrictive guard as the guard for the composition of two components.
* @author Attila Szegedi
* @version $Id: $
*/
class GuardedInvocationComponent {
enum ValidationType {
NONE, // No guard; the operation can be linked unconditionally (quite rare); least strict.
INSTANCE_OF, // "validatorClass.isInstance(obj)" guard
EXACT_CLASS, // "obj.getClass() == validatorClass" guard; most strict.
IS_ARRAY, // "obj.getClass().isArray()"
}
private final GuardedInvocation guardedInvocation;
private final Validator validator;
GuardedInvocationComponent(MethodHandle invocation) {
this(invocation, null, ValidationType.NONE);
}
GuardedInvocationComponent(MethodHandle invocation, MethodHandle guard, ValidationType validationType) {
this(invocation, guard, null, validationType);
}
GuardedInvocationComponent(MethodHandle invocation, MethodHandle guard, Class<?> validatorClass,
ValidationType validationType) {
this(invocation, guard, new Validator(validatorClass, validationType));
}
GuardedInvocationComponent(GuardedInvocation guardedInvocation, Class<?> validatorClass,
ValidationType validationType) {
this(guardedInvocation, new Validator(validatorClass, validationType));
}
GuardedInvocationComponent replaceInvocation(MethodHandle newInvocation) {
return replaceInvocation(newInvocation, guardedInvocation.getGuard());
}
GuardedInvocationComponent replaceInvocation(MethodHandle newInvocation, MethodHandle newGuard) {
return new GuardedInvocationComponent(guardedInvocation.replaceMethods(newInvocation,
newGuard), validator);
}
private GuardedInvocationComponent(MethodHandle invocation, MethodHandle guard, Validator validator) {
this(new GuardedInvocation(invocation, guard), validator);
}
private GuardedInvocationComponent(GuardedInvocation guardedInvocation, Validator validator) {
this.guardedInvocation = guardedInvocation;
this.validator = validator;
}
GuardedInvocation getGuardedInvocation() {
return guardedInvocation;
}
Class<?> getValidatorClass() {
return validator.validatorClass;
}
ValidationType getValidationType() {
return validator.validationType;
}
GuardedInvocationComponent compose(MethodHandle compositeInvocation, MethodHandle otherGuard,
Class<?> otherValidatorClass, ValidationType otherValidationType) {
final Validator compositeValidator = validator.compose(new Validator(otherValidatorClass, otherValidationType));
final MethodHandle compositeGuard = compositeValidator == validator ? guardedInvocation.getGuard() : otherGuard;
return new GuardedInvocationComponent(compositeInvocation, compositeGuard, compositeValidator);
}
private static class Validator {
/*private*/ final Class<?> validatorClass;
/*private*/ final ValidationType validationType;
Validator(Class<?> validatorClass, ValidationType validationType) {
this.validatorClass = validatorClass;
this.validationType = validationType;
}
Validator compose(Validator other) {
if(other.validationType == ValidationType.NONE) {
return this;
}
switch(validationType) {
case NONE:
return other;
case INSTANCE_OF:
switch(other.validationType) {
case INSTANCE_OF:
if(isAssignableFrom(other)) {
return other;
} else if(other.isAssignableFrom(this)) {
return this;
}
break;
case EXACT_CLASS:
if(isAssignableFrom(other)) {
return other;
}
break;
case IS_ARRAY:
if(validatorClass.isArray()) {
return this;
}
break;
default:
throw new AssertionError();
}
break;
case EXACT_CLASS:
switch(other.validationType) {
case INSTANCE_OF:
if(other.isAssignableFrom(this)) {
return this;
}
break;
case EXACT_CLASS:
if(validatorClass == other.validatorClass) {
return this;
}
break;
case IS_ARRAY:
if(validatorClass.isArray()) {
return this;
}
break;
default:
throw new AssertionError();
}
break;
case IS_ARRAY:
switch(other.validationType) {
case INSTANCE_OF:
case EXACT_CLASS:
if(other.validatorClass.isArray()) {
return other;
}
break;
case IS_ARRAY:
return this;
default:
throw new AssertionError();
}
break;
default:
throw new AssertionError();
}
throw new AssertionError("Incompatible composition " + this + " vs " + other);
}
private boolean isAssignableFrom(Validator other) {
return validatorClass.isAssignableFrom(other.validatorClass);
}
@Override
public String toString() {
return "Validator[" + validationType + (validatorClass == null ? "" : (" " + validatorClass.getName())) + "]";
}
}
}