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// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. 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.
// 3. Neither the name of the copyright holders nor the names of its
//    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 THE COPYRIGHT OWNER OR CONTRIBUTORS 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
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// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.

package org.mvel2.asm;

/**
 * A reference to a field or a method.
 *
 * @author Remi Forax
 * @author Eric Bruneton
 */
public final class Handle {

    /**
     * The kind of field or method designated by this Handle. Should be {@link Opcodes#H_GETFIELD},
     * {@link Opcodes#H_GETSTATIC}, {@link Opcodes#H_PUTFIELD}, {@link Opcodes#H_PUTSTATIC}, {@link
     * Opcodes#H_INVOKEVIRTUAL}, {@link Opcodes#H_INVOKESTATIC}, {@link Opcodes#H_INVOKESPECIAL},
     * {@link Opcodes#H_NEWINVOKESPECIAL} or {@link Opcodes#H_INVOKEINTERFACE}.
     */
    private final int tag;

    /** The internal name of the class that owns the field or method designated by this handle. */
    private final String owner;

    /** The name of the field or method designated by this handle. */
    private final String name;

    /** The descriptor of the field or method designated by this handle. */
    private final String descriptor;

    /** Whether the owner is an interface or not. */
    private final boolean isInterface;

    /**
     * Constructs a new field or method handle.
     *
     * @param tag the kind of field or method designated by this Handle. Must be {@link
     *     Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC}, {@link Opcodes#H_PUTFIELD}, {@link
     *     Opcodes#H_PUTSTATIC}, {@link Opcodes#H_INVOKEVIRTUAL}, {@link Opcodes#H_INVOKESTATIC},
     *     {@link Opcodes#H_INVOKESPECIAL}, {@link Opcodes#H_NEWINVOKESPECIAL} or {@link
     *     Opcodes#H_INVOKEINTERFACE}.
     * @param owner the internal name of the class that owns the field or method designated by this
     *     handle.
     * @param name the name of the field or method designated by this handle.
     * @param descriptor the descriptor of the field or method designated by this handle.
     * @deprecated this constructor has been superseded by {@link #Handle(int, String, String, String,
     *     boolean)}.
     */
    @Deprecated
    public Handle(final int tag, final String owner, final String name, final String descriptor) {
        this(tag, owner, name, descriptor, tag == Opcodes.H_INVOKEINTERFACE);
    }

    /**
     * Constructs a new field or method handle.
     *
     * @param tag the kind of field or method designated by this Handle. Must be {@link
     *     Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC}, {@link Opcodes#H_PUTFIELD}, {@link
     *     Opcodes#H_PUTSTATIC}, {@link Opcodes#H_INVOKEVIRTUAL}, {@link Opcodes#H_INVOKESTATIC},
     *     {@link Opcodes#H_INVOKESPECIAL}, {@link Opcodes#H_NEWINVOKESPECIAL} or {@link
     *     Opcodes#H_INVOKEINTERFACE}.
     * @param owner the internal name of the class that owns the field or method designated by this
     *     handle.
     * @param name the name of the field or method designated by this handle.
     * @param descriptor the descriptor of the field or method designated by this handle.
     * @param isInterface whether the owner is an interface or not.
     */
    public Handle(final int tag, final String owner, final String name, final String descriptor, final boolean isInterface) {
        this.tag = tag;
        this.owner = owner;
        this.name = name;
        this.descriptor = descriptor;
        this.isInterface = isInterface;
    }

    /**
     * Returns the kind of field or method designated by this handle.
     *
     * @return {@link Opcodes#H_GETFIELD}, {@link Opcodes#H_GETSTATIC}, {@link Opcodes#H_PUTFIELD},
     *     {@link Opcodes#H_PUTSTATIC}, {@link Opcodes#H_INVOKEVIRTUAL}, {@link
     *     Opcodes#H_INVOKESTATIC}, {@link Opcodes#H_INVOKESPECIAL}, {@link
     *     Opcodes#H_NEWINVOKESPECIAL} or {@link Opcodes#H_INVOKEINTERFACE}.
     */
    public int getTag() {
        return tag;
    }

    /**
     * Returns the internal name of the class that owns the field or method designated by this handle.
     *
     * @return the internal name of the class that owns the field or method designated by this handle.
     */
    public String getOwner() {
        return owner;
    }

    /**
     * Returns the name of the field or method designated by this handle.
     *
     * @return the name of the field or method designated by this handle.
     */
    public String getName() {
        return name;
    }

    /**
     * Returns the descriptor of the field or method designated by this handle.
     *
     * @return the descriptor of the field or method designated by this handle.
     */
    public String getDesc() {
        return descriptor;
    }

    /**
     * Returns true if the owner of the field or method designated by this handle is an interface.
     *
     * @return true if the owner of the field or method designated by this handle is an interface.
     */
    public boolean isInterface() {
        return isInterface;
    }

    @Override
    public boolean equals(final Object object) {
        if (object == this) {
            return true;
        }
        if (!(object instanceof Handle)) {
            return false;
        }
        Handle handle = (Handle) object;
        return tag == handle.tag && isInterface == handle.isInterface && owner.equals(handle.owner) && name.equals(handle.name)
                && descriptor.equals(handle.descriptor);
    }

    @Override
    public int hashCode() {
        return tag + (isInterface ? 64 : 0) + owner.hashCode() * name.hashCode() * descriptor.hashCode();
    }

    /**
     * Returns the textual representation of this handle. The textual representation is:
     *
     * 
     *   for a reference to a class: owner "." name descriptor " (" tag ")",
     *   
for a reference to an interface: owner "." name descriptor " (" tag " itf)".
     * 
     */
    @Override
    public String toString() {
        return owner + '.' + name + descriptor + " (" + tag + (isInterface ? " itf" : "") + ')';
    }
}