| /* |
| * Copyright (c) 2015, 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 |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * 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 2015 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.dynalink; |
| |
| import java.util.Objects; |
| |
| /** |
| * Operation that associates a name with another operation. Typically used with |
| * operations that normally take a name or an index to bind them to a fixed |
| * name. E.g. |
| * <pre> |
| * new NamedOperation( |
| * new NamespaceOperation( |
| * StandardOperation.GET, |
| * StandardNamespace.PROPERTY), |
| * "color") |
| * </pre> |
| * will be a named operation for getting the property named "color" on the |
| * object it is applied to, and |
| * <pre> |
| * new NamedOperation( |
| * new NamespaceOperation( |
| * StandardOperation.GET, |
| * StandardNamespace.ELEMENT), |
| * 3) |
| * </pre> |
| * will be a named operation for getting the element at index 3 from the collection |
| * it is applied to ("name" in this context is akin to "address" and encompasses both |
| * textual names, numeric indices, or any other kinds of addressing that linkers can |
| * understand). In these cases, the expected signature of the call site for the |
| * operation will change to no longer include the name parameter. Specifically, |
| * the documentation for all {@link StandardOperation} members describes how |
| * they are affected by being incorporated into a named operation. |
| * <p>While {@code NamedOperation} can be constructed directly, it is often convenient |
| * to use the {@link Operation#named(Object)} factory method instead, e.g.: |
| * <pre> |
| * StandardOperation.GET |
| * .withNamespace(StandardNamespace.ELEMENT), |
| * .named(3) |
| * ) |
| * </pre> |
| * <p> |
| * Even though {@code NamedOperation} is most often used with {@link NamespaceOperation} as |
| * its base, it can have other operations as its base too (except another named operation). |
| * Specifically, {@link StandardOperation#CALL} as well as {@link StandardOperation#NEW} can |
| * both be used with {@code NamedOperation} directly. The contract for these operations is such |
| * that when they are used as named operations, their name is only used for diagnostic messages, |
| * usually containing the textual representation of the source expression that retrieved the |
| * callee, e.g. {@code StandardOperation.CALL.named("window.open")}. |
| * </p> |
| */ |
| public final class NamedOperation implements Operation { |
| private final Operation baseOperation; |
| private final Object name; |
| |
| /** |
| * Creates a new named operation. |
| * @param baseOperation the base operation that is associated with a name. |
| * @param name the name associated with the base operation. Note that the |
| * name is not necessarily a string, but can be an arbitrary object. As the |
| * name is used for addressing, it can be an {@link Integer} when meant |
| * to be used as an index into an array or list etc. |
| * @throws NullPointerException if either {@code baseOperation} or |
| * {@code name} is null. |
| * @throws IllegalArgumentException if {@code baseOperation} is itself a |
| * {@code NamedOperation}. |
| */ |
| public NamedOperation(final Operation baseOperation, final Object name) { |
| if (baseOperation instanceof NamedOperation) { |
| throw new IllegalArgumentException("baseOperation is a NamedOperation"); |
| } |
| this.baseOperation = Objects.requireNonNull(baseOperation, "baseOperation is null"); |
| this.name = Objects.requireNonNull(name, "name is null"); |
| } |
| |
| /** |
| * Returns the base operation of this named operation. |
| * @return the base operation of this named operation. |
| */ |
| public Operation getBaseOperation() { |
| return baseOperation; |
| } |
| |
| /** |
| * Returns the name of this named operation. |
| * @return the name of this named operation. |
| */ |
| public Object getName() { |
| return name; |
| } |
| |
| /** |
| * Finds or creates a named operation that differs from this one only in the name. |
| * @param newName the new name to replace the old name with. |
| * @return a named operation with the changed name. |
| * @throws NullPointerException if the name is null. |
| */ |
| public final NamedOperation changeName(final String newName) { |
| return new NamedOperation(baseOperation, newName); |
| } |
| |
| /** |
| * Compares this named operation to another object. Returns true if the |
| * other object is also a named operation, and both their base operations |
| * and name are equal. |
| */ |
| @Override |
| public boolean equals(final Object obj) { |
| if (obj instanceof NamedOperation) { |
| final NamedOperation other = (NamedOperation)obj; |
| return baseOperation.equals(other.baseOperation) && name.equals(other.name); |
| } |
| return false; |
| } |
| |
| /** |
| * Returns the hash code of this named operation. It is defined to be equal |
| * to {@code baseOperation.hashCode() + 31 * name.hashCode()}. |
| */ |
| @Override |
| public int hashCode() { |
| return baseOperation.hashCode() + 31 * name.hashCode(); |
| } |
| |
| /** |
| * Returns the string representation of this named operation. It is defined |
| * to be equal to {@code baseOperation.toString() + ":" + name.toString()}. |
| */ |
| @Override |
| public String toString() { |
| return baseOperation.toString() + ":" + name.toString(); |
| } |
| |
| /** |
| * If the passed operation is a named operation, returns its |
| * {@link #getBaseOperation()}, otherwise returns the operation as is. |
| * @param op the operation |
| * @return the base operation of the passed operation. |
| */ |
| public static Operation getBaseOperation(final Operation op) { |
| return op instanceof NamedOperation ? ((NamedOperation)op).baseOperation : op; |
| } |
| |
| /** |
| * If the passed operation is a named operation, returns its |
| * {@link #getName()}, otherwise returns null. Note that a named operation |
| * object can never have a null name, therefore returning null is indicative |
| * that the passed operation is not, in fact, a named operation. |
| * @param op the operation |
| * @return the name in the passed operation, or null if it is not a named |
| * operation. |
| */ |
| public static Object getName(final Operation op) { |
| return op instanceof NamedOperation ? ((NamedOperation)op).name : null; |
| } |
| } |