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A library for computing diffs, applying patches, generation side-by-side view in Java
/*
* SPDX-License-Identifier: Apache-1.1
*
* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2003 The Apache Software Foundation.
* Copyright (c) 1996-2006 Juancarlo Añez
* Copyright (c) 2010 Dmitry Naumenko ([email protected])
* Copyright (c) 2015-2016 Brenden Kromhout and contributors to java-diff-utils
* 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. The end-user documentation included with the redistribution, if
* any, must include the following acknowledgement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgement may appear in the software itself,
* if and wherever such third-party acknowledgements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [email protected].
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 APACHE SOFTWARE FOUNDATION OR
* ITS 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 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* The type of the compared elements in the 'lines'.
*/
public abstract class Delta {
/** The original chunk. */
private Chunk original;
/** The revised chunk. */
private Chunk revised;
/**
* Specifies the type of the delta.
*
*/
public enum TYPE {
/** A change in the original. */
CHANGE,
/** A delete from the original. */
DELETE,
/** An insert into the original. */
INSERT
}
/**
* Construct the delta for original and revised chunks
*
* @param original Chunk describing the original text. Must not be {@code null}.
* @param revised Chunk describing the revised text. Must not be {@code null}.
*/
public Delta(Chunk original, Chunk revised) {
if (original == null) {
throw new IllegalArgumentException("original must not be null");
}
if (revised == null) {
throw new IllegalArgumentException("revised must not be null");
}
this.original = original;
this.revised = revised;
}
/**
* Verifies that this delta can be used to patch the given text.
*
* @param target the text to patch.
* @throws PatchFailedException if the patch cannot be applied.
*/
public abstract void verify(List target) throws PatchFailedException;
/**
* Applies this delta as the patch for a given target
*
* @param target the given target
* @throws PatchFailedException
*/
public abstract void applyTo(List target) throws PatchFailedException;
/**
* Cancel this delta for a given revised text. The action is opposite to
* patch.
*
* @param target the given revised text
*/
public abstract void restore(List target);
/**
* Returns the type of delta
* @return the type enum
*/
public abstract TYPE getType();
/**
* @return The Chunk describing the original text.
*/
public Chunk getOriginal() {
return original;
}
/**
* @param original The Chunk describing the original text to set.
*/
public void setOriginal(Chunk original) {
this.original = original;
}
/**
* @return The Chunk describing the revised text.
*/
public Chunk getRevised() {
return revised;
}
/**
* @param revised The Chunk describing the revised text to set.
*/
public void setRevised(Chunk revised) {
this.revised = revised;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((original == null) ? 0 : original.hashCode());
result = prime * result + ((revised == null) ? 0 : revised.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Delta other = (Delta) obj;
if (original == null) {
if (other.original != null)
return false;
} else if (!original.equals(other.original))
return false;
if (revised == null) {
return other.revised == null;
} else {
return revised.equals(other.revised);
}
}
}