/*
* Copyright (C) 2009, Christian Halstrick <christian.halstrick@sap.com>
* and other copyright owners as documented in the project's IP log.
*
* This program and the accompanying materials are made available
* under the terms of the Eclipse Distribution License v1.0 which
* accompanies this distribution, is reproduced below, and is
* available at http://www.eclipse.org/org/documents/edl-v10.php
*
* All rights reserved.
*
* 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 Eclipse Foundation, Inc. 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
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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package org.eclipse.jgit.merge;
import java.util.Iterator;
import java.util.List;
import org.eclipse.jgit.diff.Sequence;
import org.eclipse.jgit.merge.MergeChunk.ConflictState;
import org.eclipse.jgit.util.IntList;
/**
* The result of merging a number of {@link Sequence} objects. These sequences
* have one common predecessor sequence. The result of a merge is a list of
* MergeChunks. Each MergeChunk contains either a range (a subsequence) from
* one of the merged sequences, a range from the common predecessor or a
* conflicting range from one of the merged sequences. A conflict will be
* reported as multiple chunks, one for each conflicting range. The first chunk
* for a conflict is marked specially to distinguish the border between two
* consecutive conflicts.
* <p>
* This class does not know anything about how to present the merge result to
* the end-user. MergeFormatters have to be used to construct something human
* readable.
*
* @param <S>
* type of sequence.
*/
public class MergeResult<S extends Sequence> implements Iterable<MergeChunk> {
private final List<S> sequences;
final IntList chunks = new IntList();
private boolean containsConflicts = false;
/**
* Creates a new empty MergeResult
*
* @param sequences
* contains the common predecessor sequence at position 0
* followed by the merged sequences. This list should not be
* modified anymore during the lifetime of this {@link MergeResult}.
*/
public MergeResult(List<S> sequences) {
this.sequences = sequences;
}
/**
* Adds a new range from one of the merged sequences or from the common
* predecessor. This method can add conflicting and non-conflicting ranges
* controlled by the conflictState parameter
*
* @param srcIdx
* determines from which sequence this range comes. An index of
* x specifies the x+1 element in the list of sequences
* specified to the constructor
* @param begin
* the first element from the specified sequence which should be
* included in the merge result. Indexes start with 0.
* @param end
* specifies the end of the range to be added. The element this
* index points to is the first element which not added to the
* merge result. All elements between begin (including begin) and
* this element are added.
* @param conflictState
* when set to NO_CONLICT a non-conflicting range is added.
* This will end implicitly all open conflicts added before.
*/
public void add(int srcIdx, int begin, int end, ConflictState conflictState) {
chunks.add(conflictState.ordinal());
chunks.add(srcIdx);
chunks.add(begin);
chunks.add(end);
if (conflictState != ConflictState.NO_CONFLICT)
containsConflicts = true;
}
/**
* Returns the common predecessor sequence and the merged sequence in one
* list. The common predecessor is is the first element in the list
*
* @return the common predecessor at position 0 followed by the merged
* sequences.
*/
public List<S> getSequences() {
return sequences;
}
static final ConflictState[] states = ConflictState.values();
/**
* @return an iterator over the MergeChunks. The iterator does not support
* the remove operation
*/
public Iterator<MergeChunk> iterator() {
return new Iterator<MergeChunk>() {
int idx;
public boolean hasNext() {
return (idx < chunks.size());
}
public MergeChunk next() {
ConflictState state = states[chunks.get(idx++)];
int srcIdx = chunks.get(idx++);
int begin = chunks.get(idx++);
int end = chunks.get(idx++);
return new MergeChunk(srcIdx, begin, end, state);
}
public void remove() {
throw new UnsupportedOperationException();
}
};
}
/**
* @return true if this merge result contains conflicts
*/
public boolean containsConflicts() {
return containsConflicts;
}
/**
* Sets explicitly whether this merge should be seen as containing a
* conflict or not. Needed because during RecursiveMerger we want to do
* content-merges and take the resulting content (even with conflict
* markers!) as new conflict-free content
*
* @param containsConflicts
* @since 3.5
*/
protected void setContainsConflicts(boolean containsConflicts) {
this.containsConflicts = containsConflicts;
}
}