/*

 * Copyright (c) 2003, 2020, 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 sun.reflect.generics.repository;

import java.lang.reflect.Type;

import sun.reflect.generics.factory.GenericsFactory;

import sun.reflect.generics.tree.TypeSignature;

import sun.reflect.generics.parser.SignatureParser;

import sun.reflect.generics.visitor.Reifier;

/**

 * This class represents the generic type information for a constructor.

 * The code is not dependent on a particular reflective implementation.

 * It is designed to be used unchanged by at least core reflection and JDI.

 */

public class FieldRepository extends AbstractRepository<TypeSignature> {

    /** The generic type info.  Lazily initialized. */

    private volatile Type genericType;

    // protected, to enforce use of static factory yet allow subclassing

    protected FieldRepository(String rawSig, GenericsFactory f) {

      super(rawSig, f);

    }

    protected TypeSignature parse(String s) {

        return SignatureParser.make().parseTypeSig(s);

    }

    /**

     * Static factory method.

     * @param rawSig - the generic signature of the reflective object

     * that this repository is servicing

     * @param f - a factory that will provide instances of reflective

     * objects when this repository converts its AST

     * @return a {@code FieldRepository} that manages the generic type

     * information represented in the signature {@code rawSig}

     */

    public static FieldRepository make(String rawSig, GenericsFactory f) {

        return new FieldRepository(rawSig, f);

    }

    /*

     * When queried for a particular piece of type information, the

     * general pattern is to consult the corresponding cached value.

     * If the corresponding field is non-null, it is returned.

     * If not, it is created lazily. This is done by selecting the appropriate

     * part of the tree and transforming it into a reflective object

     * using a visitor, which is created by feeding it the factory

     * with which the repository was created.

     */

    public Type getGenericType() {

        Type value = genericType;

        if (value == null) {

            value = computeGenericType();

            genericType = value;

        }

        return value;

    }

    private Type computeGenericType() {

        Reifier r = getReifier();       // obtain visitor

        getTree().accept(r);            // reify subtree

        return r.getResult();           // extract result from visitor

    }

}