/*

 * Copyright (c) 2014, 2019, Oracle and/or its affiliates. All rights reserved.

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

 *

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

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

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

 * by Oracle in the LICENSE file that accompanied this code.

 *

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

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * 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,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

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

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package java.lang.invoke;

import jdk.internal.vm.annotation.DontInline;

import jdk.internal.vm.annotation.ForceInline;

import jdk.internal.vm.annotation.Stable;

import java.lang.invoke.VarHandle.AccessMode;

import java.lang.reflect.Method;

import java.lang.reflect.Modifier;

import java.util.ArrayList;

import java.util.List;

import static java.lang.invoke.MethodHandleNatives.Constants.REF_invokeStatic;

/**

 * A var handle form containing a set of member name, one for each operation.

 * Each member characterizes a static method.

 */

final class VarForm {

    final Class<?> implClass;

    final @Stable MethodType[] methodType_table;

    final @Stable MemberName[] memberName_table;

    VarForm(Class<?> implClass, Class<?> receiver, Class<?> value, Class<?>... intermediate) {

        this.methodType_table = new MethodType[VarHandle.AccessType.COUNT];

        this.memberName_table = new MemberName[VarHandle.AccessMode.COUNT];

        this.implClass = implClass;

        if (receiver == null) {

            initMethodTypes(value, intermediate);

        } else {

            Class<?>[] coordinates = new Class<?>[intermediate.length + 1];

            coordinates[0] = receiver;

            System.arraycopy(intermediate, 0, coordinates, 1, intermediate.length);

            initMethodTypes(value, coordinates);

        }

    }

    // Used by IndirectVarHandle

    VarForm(Class<?> value, Class<?>[] coordinates) {

        this.methodType_table = new MethodType[VarHandle.AccessType.COUNT];

        this.memberName_table = null;

        this.implClass = null;

        initMethodTypes(value, coordinates);

    }

    void initMethodTypes(Class<?> value, Class<?>... coordinates) {

        Class<?> erasedValue = MethodTypeForm.canonicalize(value, MethodTypeForm.ERASE);

        Class<?>[] erasedCoordinates = MethodTypeForm.canonicalizeAll(coordinates, MethodTypeForm.ERASE);

        if (erasedValue != null) {

            value = erasedValue;

        }

        if (erasedCoordinates != null) {

            coordinates = erasedCoordinates;

        }

        MethodType type = MethodType.methodType(value, coordinates);

        // (Receiver, <Intermediates>)Value

        methodType_table[VarHandle.AccessType.GET.ordinal()] = type;

        // (Receiver, <Intermediates>, Value)Value

        type = methodType_table[VarHandle.AccessType.GET_AND_UPDATE.ordinal()] =

                type.appendParameterTypes(value);

        // (Receiver, <Intermediates>, Value)void

        methodType_table[VarHandle.AccessType.SET.ordinal()] = type.changeReturnType(void.class);

        // (Receiver, <Intermediates>, Value, Value)Value

        type = methodType_table[VarHandle.AccessType.COMPARE_AND_EXCHANGE.ordinal()] =

                type.appendParameterTypes(value);

        // (Receiver, <Intermediates>, Value, Value)boolean

        methodType_table[VarHandle.AccessType.COMPARE_AND_SET.ordinal()] =

                type.changeReturnType(boolean.class);

    }

    @ForceInline

    final MethodType getMethodType(int type) {

        return methodType_table[type];

    }

    @ForceInline

    final MemberName getMemberName(int mode) {

        MemberName mn = getMemberNameOrNull(mode);

        if (mn == null) {

            throw new UnsupportedOperationException();

        }

        return mn;

    }

    @ForceInline

    final MemberName getMemberNameOrNull(int mode) {

        MemberName mn = memberName_table[mode];

        if (mn == null) {

            mn = resolveMemberName(mode);

        }

        return mn;

    }

    @DontInline

    MemberName resolveMemberName(int mode) {

        AccessMode value = AccessMode.values()[mode];

        String methodName = value.methodName();

        MethodType type = methodType_table[value.at.ordinal()].insertParameterTypes(0, VarHandle.class);

        return memberName_table[mode] = MethodHandles.Lookup.IMPL_LOOKUP

            .resolveOrNull(REF_invokeStatic, implClass, methodName, type);

    }

    @Stable

    MethodType[] methodType_V_table;

    @ForceInline

    final MethodType[] getMethodType_V_init() {

        MethodType[] table = new MethodType[VarHandle.AccessType.values().length];

        for (int i = 0; i < methodType_table.length; i++) {

            MethodType mt = methodType_table[i];

            // TODO only adjust for sig-poly methods returning Object

            table[i] = mt.changeReturnType(void.class);

        }

        methodType_V_table = table;

        return table;

    }

    @ForceInline

    final MethodType getMethodType_V(int type) {

        MethodType[] table = methodType_V_table;

        if (table == null) {

            table = getMethodType_V_init();

        }

        return table[type];

    }

}