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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

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 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

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 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

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 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file, and Oracle licenses the original version of this file under the BSD

 * license:

 */

/*

   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 jdk.internal.dynalink.linker;

import java.lang.invoke.MethodHandle;

import java.lang.invoke.MethodHandles;

import java.lang.invoke.MethodType;

import java.lang.invoke.SwitchPoint;

import java.util.List;

import java.util.Objects;

import jdk.internal.dynalink.CallSiteDescriptor;

import jdk.internal.dynalink.support.Guards;

/**

 */

public class GuardedInvocation {

    private final MethodHandle invocation;

    private final MethodHandle guard;

    private final Class<? extends Throwable> exception;

    private final SwitchPoint[] switchPoints;

    /**

     *

     * @throws NullPointerException if invocation is null.

     */

    public GuardedInvocation(final MethodHandle invocation) {

        this(invocation, null, (SwitchPoint)null, null);

    }

    /**

     *

     * @throws NullPointerException if invocation is null.

     */

    public GuardedInvocation(final MethodHandle invocation, final MethodHandle guard) {

        this(invocation, guard, (SwitchPoint)null, null);

    }

    /**

     *

     * @throws NullPointerException if invocation is null.

     */

    public GuardedInvocation(final MethodHandle invocation, final SwitchPoint switchPoint) {

        this(invocation, null, switchPoint, null);

    }

    /**

     *

     * @throws NullPointerException if invocation is null.

     */

    public GuardedInvocation(final MethodHandle invocation, final MethodHandle guard, final SwitchPoint switchPoint) {

        this(invocation, guard, switchPoint, null);

    }

    /**

     *

     * @throws NullPointerException if invocation is null.

     */

    public GuardedInvocation(final MethodHandle invocation, final MethodHandle guard, final SwitchPoint switchPoint, final Class<? extends Throwable> exception) {

        this.invocation = Objects.requireNonNull(invocation);

        this.guard = guard;

        this.switchPoints = switchPoint == null ? null : new SwitchPoint[] { switchPoint };

        this.exception = exception;

    }

    /**

     *

     * @throws NullPointerException if invocation is null.

     */

    public GuardedInvocation(final MethodHandle invocation, final MethodHandle guard, final SwitchPoint[] switchPoints, final Class<? extends Throwable> exception) {

        this.invocation = Objects.requireNonNull(invocation);

        this.guard = guard;

        this.switchPoints = switchPoints == null ? null : switchPoints.clone();

        this.exception = exception;

    }

    /**

     * Returns the invocation method handle.

     *

     * @return the invocation method handle. It will never be null.

     */

    public MethodHandle getInvocation() {

        return invocation;

    }

    /**

     * Returns the guard method handle.

     *

     * @return the guard method handle. Can be null.

     */

    public MethodHandle getGuard() {

        return guard;

    }

    /**

     *

     */

    public SwitchPoint[] getSwitchPoints() {

        return switchPoints == null ? null : switchPoints.clone();

    }

    /**

     *

     */

    public Class<? extends Throwable> getException() {

        return exception;

    }

    /**

     */

    public boolean hasBeenInvalidated() {

        if (switchPoints == null) {

            return false;

        }

        for (final SwitchPoint sp : switchPoints) {

            if (sp.hasBeenInvalidated()) {

                return true;

            }

        }

        return false;

    }

    /**

     * Creates a new guarded invocation with different methods, preserving the switch point.

     *

     * @param newInvocation the new invocation

     * @param newGuard the new guard

     * @return a new guarded invocation with the replaced methods and the same switch point as this invocation.

     */

    public GuardedInvocation replaceMethods(final MethodHandle newInvocation, final MethodHandle newGuard) {

        return new GuardedInvocation(newInvocation, newGuard, switchPoints, exception);

    }

    /**

     */

    public GuardedInvocation addSwitchPoint(final SwitchPoint newSwitchPoint) {

        if (newSwitchPoint == null) {

            return this;

        }

        final SwitchPoint[] newSwitchPoints;

        if (switchPoints != null) {

            newSwitchPoints = new SwitchPoint[switchPoints.length + 1];

            System.arraycopy(switchPoints, 0, newSwitchPoints, 0, switchPoints.length);

            newSwitchPoints[switchPoints.length] = newSwitchPoint;

        } else {

            newSwitchPoints = new SwitchPoint[] { newSwitchPoint };

        }

        return new GuardedInvocation(invocation, guard, newSwitchPoints, exception);

    }

    private GuardedInvocation replaceMethodsOrThis(final MethodHandle newInvocation, final MethodHandle newGuard) {

        if (newInvocation == invocation && newGuard == guard) {

            return this;

        }

        return replaceMethods(newInvocation, newGuard);

    }

    /**

     * @param newType the new type of the invocation.

     * @return a guarded invocation with the new type applied to it.

     */

    public GuardedInvocation asType(final MethodType newType) {

        return replaceMethodsOrThis(invocation.asType(newType), guard == null ? null : Guards.asType(guard, newType));

    }

    /**

     * @param linkerServices the linker services to use for the conversion

     * @param newType the new type of the invocation.

     * @return a guarded invocation with the new type applied to it.

     */

    public GuardedInvocation asType(final LinkerServices linkerServices, final MethodType newType) {

        return replaceMethodsOrThis(linkerServices.asType(invocation, newType), guard == null ? null :

            Guards.asType(linkerServices, guard, newType));

    }

    /**

     * @param linkerServices the linker services to use for the conversion

     * @param newType the new type of the invocation.

     * @return a guarded invocation with the new type applied to it.

     */

    public GuardedInvocation asTypeSafeReturn(final LinkerServices linkerServices, final MethodType newType) {

        return replaceMethodsOrThis(linkerServices.asTypeLosslessReturn(invocation, newType), guard == null ? null :

            Guards.asType(linkerServices, guard, newType));

    }

    /**

     * @param desc a call descriptor whose method type is adapted.

     * @return a guarded invocation with the new type applied to it.

     */

    public GuardedInvocation asType(final CallSiteDescriptor desc) {

        return asType(desc.getMethodType());

    }

    /**

     * @param pos the position of the first argument being filtered

     * @param filters the argument filters

     * @return a filtered invocation

     */

    public GuardedInvocation filterArguments(final int pos, final MethodHandle... filters) {

        return replaceMethods(MethodHandles.filterArguments(invocation, pos, filters), guard == null ? null :

            MethodHandles.filterArguments(guard, pos, filters));

    }

    /**

     * @param pos the position of the first argument being dropped

     * @param valueTypes the types of the values being dropped

     * @return an invocation that drops arguments

     */

    public GuardedInvocation dropArguments(final int pos, final List<Class<?>> valueTypes) {

        return replaceMethods(MethodHandles.dropArguments(invocation, pos, valueTypes), guard == null ? null :

            MethodHandles.dropArguments(guard, pos, valueTypes));

    }

    /**

     * @param pos the position of the first argument being dropped

     * @param valueTypes the types of the values being dropped

     * @return an invocation that drops arguments

     */

    public GuardedInvocation dropArguments(final int pos, final Class<?>... valueTypes) {

        return replaceMethods(MethodHandles.dropArguments(invocation, pos, valueTypes), guard == null ? null :

            MethodHandles.dropArguments(guard, pos, valueTypes));

    }

    /**

     * @return a composite method handle.

     */

    public MethodHandle compose(final MethodHandle fallback) {

        return compose(fallback, fallback, fallback);

    }

    /**

     * @return a composite method handle.

     */

    public MethodHandle compose(final MethodHandle guardFallback, final MethodHandle switchpointFallback, final MethodHandle catchFallback) {

        final MethodHandle guarded =

                guard == null ?

                        invocation :

                        MethodHandles.guardWithTest(

                                guard,

                                invocation,

                                guardFallback);

        final MethodHandle catchGuarded =

                exception == null ?

                        guarded :

                                guarded,

                                exception,

                                MethodHandles.dropArguments(

                                    catchFallback,

                                    0,

                                    exception));

        if (switchPoints == null) {

            return catchGuarded;

        }

        MethodHandle spGuarded = catchGuarded;

        for (final SwitchPoint sp : switchPoints) {

            spGuarded = sp.guardWithTest(spGuarded, switchpointFallback);

        }

        return spGuarded;

    }

}