MergeResult.java

/*
 * Copyright (C) 2010, Stefan Lay <stefan.lay@sap.com>
 * Copyright (C) 2010-2012, 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
 * 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;
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package org.eclipse.jgit.api;

import java.text.MessageFormat;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.merge.MergeChunk;
import org.eclipse.jgit.merge.MergeChunk.ConflictState;
import org.eclipse.jgit.merge.MergeStrategy;
import org.eclipse.jgit.merge.ResolveMerger.MergeFailureReason;

/**
 * Encapsulates the result of a {@link org.eclipse.jgit.api.MergeCommand}.
 */
public class MergeResult {

    /**
     * The status the merge resulted in.
     */
    public enum MergeStatus {
        /** */
        FAST_FORWARD {
            @Override
            public String toString() {
                return "Fast-forward"; //$NON-NLS-1$
            }

            @Override
            public boolean isSuccessful() {
                return true;
            }
        },
        /**
         * @since 2.0
         */
        FAST_FORWARD_SQUASHED {
            @Override
            public String toString() {
                return "Fast-forward-squashed"; //$NON-NLS-1$
            }

            @Override
            public boolean isSuccessful() {
                return true;
            }
        },
        /** */
        ALREADY_UP_TO_DATE {
            @Override
            public String toString() {
                return "Already-up-to-date"; //$NON-NLS-1$
            }

            @Override
            public boolean isSuccessful() {
                return true;
            }
        },
        /** */
        FAILED {
            @Override
            public String toString() {
                return "Failed"; //$NON-NLS-1$
            }

            @Override
            public boolean isSuccessful() {
                return false;
            }
        },
        /** */
        MERGED {
            @Override
            public String toString() {
                return "Merged"; //$NON-NLS-1$
            }

            @Override
            public boolean isSuccessful() {
                return true;
            }
        },
        /**
         * @since 2.0
         */
        MERGED_SQUASHED {
            @Override
            public String toString() {
                return "Merged-squashed"; //$NON-NLS-1$
            }

            @Override
            public boolean isSuccessful() {
                return true;
            }
        },
        /**
         * @since 3.0
         */
        MERGED_SQUASHED_NOT_COMMITTED {
            @Override
            public String toString() {
                return "Merged-squashed-not-committed"; //$NON-NLS-1$
            }

            @Override
            public boolean isSuccessful() {
                return true;
            }
        },
        /** */
        CONFLICTING {
            @Override
            public String toString() {
                return "Conflicting"; //$NON-NLS-1$
            }

            @Override
            public boolean isSuccessful() {
                return false;
            }
        },
        /**
         * @since 2.2
         */
        ABORTED {
            @Override
            public String toString() {
                return "Aborted"; //$NON-NLS-1$
            }

            @Override
            public boolean isSuccessful() {
                return false;
            }
        },
        /**
         * @since 3.0
         **/
        MERGED_NOT_COMMITTED {
            @Override
            public String toString() {
                return "Merged-not-committed"; //$NON-NLS-1$
            }

            @Override
            public boolean isSuccessful() {
                return true;
            }
        },
        /** */
        NOT_SUPPORTED {
            @Override
            public String toString() {
                return "Not-yet-supported"; //$NON-NLS-1$
            }

            @Override
            public boolean isSuccessful() {
                return false;
            }
        },
        /**
         * Status representing a checkout conflict, meaning that nothing could
         * be merged, as the pre-scan for the trees already failed for certain
         * files (i.e. local modifications prevent checkout of files).
         */
        CHECKOUT_CONFLICT {
            @Override
            public String toString() {
                return "Checkout Conflict"; //$NON-NLS-1$
            }

            @Override
            public boolean isSuccessful() {
                return false;
            }
        };

        /**
         * @return whether the status indicates a successful result
         */
        public abstract boolean isSuccessful();
    }

    private ObjectId[] mergedCommits;

    private ObjectId base;

    private ObjectId newHead;

    private Map<String, int[][]> conflicts;

    private MergeStatus mergeStatus;

    private String description;

    private MergeStrategy mergeStrategy;

    private Map<String, MergeFailureReason> failingPaths;

    private List<String> checkoutConflicts;

    /**
     * Constructor for MergeResult.
     *
     * @param newHead
     *            the object the head points at after the merge
     * @param base
     *            the common base which was used to produce a content-merge. May
     *            be <code>null</code> if the merge-result was produced without
     *            computing a common base
     * @param mergedCommits
     *            all the commits which have been merged together
     * @param mergeStatus
     *            the status the merge resulted in
     * @param mergeStrategy
     *            the used {@link org.eclipse.jgit.merge.MergeStrategy}
     * @param lowLevelResults
     *            merge results as returned by
     *            {@link org.eclipse.jgit.merge.ResolveMerger#getMergeResults()}
     * @since 2.0
     */
    public MergeResult(ObjectId newHead, ObjectId base,
            ObjectId[] mergedCommits, MergeStatus mergeStatus,
            MergeStrategy mergeStrategy,
            Map<String, org.eclipse.jgit.merge.MergeResult<?>> lowLevelResults) {
        this(newHead, base, mergedCommits, mergeStatus, mergeStrategy,
                lowLevelResults, null);
    }

    /**
     * Constructor for MergeResult.
     *
     * @param newHead
     *            the object the head points at after the merge
     * @param base
     *            the common base which was used to produce a content-merge. May
     *            be <code>null</code> if the merge-result was produced without
     *            computing a common base
     * @param mergedCommits
     *            all the commits which have been merged together
     * @param mergeStatus
     *            the status the merge resulted in
     * @param mergeStrategy
     *            the used {@link org.eclipse.jgit.merge.MergeStrategy}
     * @param lowLevelResults
     *            merge results as returned by
     *            {@link org.eclipse.jgit.merge.ResolveMerger#getMergeResults()}
     * @param description
     *            a user friendly description of the merge result
     */
    public MergeResult(ObjectId newHead, ObjectId base,
            ObjectId[] mergedCommits, MergeStatus mergeStatus,
            MergeStrategy mergeStrategy,
            Map<String, org.eclipse.jgit.merge.MergeResult<?>> lowLevelResults,
            String description) {
        this(newHead, base, mergedCommits, mergeStatus, mergeStrategy,
                lowLevelResults, null, description);
    }

    /**
     * Constructor for MergeResult.
     *
     * @param newHead
     *            the object the head points at after the merge
     * @param base
     *            the common base which was used to produce a content-merge. May
     *            be <code>null</code> if the merge-result was produced without
     *            computing a common base
     * @param mergedCommits
     *            all the commits which have been merged together
     * @param mergeStatus
     *            the status the merge resulted in
     * @param mergeStrategy
     *            the used {@link org.eclipse.jgit.merge.MergeStrategy}
     * @param lowLevelResults
     *            merge results as returned by
     *            {@link org.eclipse.jgit.merge.ResolveMerger#getMergeResults()}
     * @param failingPaths
     *            list of paths causing this merge to fail as returned by
     *            {@link org.eclipse.jgit.merge.ResolveMerger#getFailingPaths()}
     * @param description
     *            a user friendly description of the merge result
     */
    public MergeResult(ObjectId newHead, ObjectId base,
            ObjectId[] mergedCommits, MergeStatus mergeStatus,
            MergeStrategy mergeStrategy,
            Map<String, org.eclipse.jgit.merge.MergeResult<?>> lowLevelResults,
            Map<String, MergeFailureReason> failingPaths, String description) {
        this.newHead = newHead;
        this.mergedCommits = mergedCommits;
        this.base = base;
        this.mergeStatus = mergeStatus;
        this.mergeStrategy = mergeStrategy;
        this.description = description;
        this.failingPaths = failingPaths;
        if (lowLevelResults != null)
            for (Map.Entry<String, org.eclipse.jgit.merge.MergeResult<?>> result : lowLevelResults
                    .entrySet())
                addConflict(result.getKey(), result.getValue());
    }

    /**
     * Creates a new result that represents a checkout conflict before the
     * operation even started for real.
     *
     * @param checkoutConflicts
     *            the conflicting files
     */
    public MergeResult(List<String> checkoutConflicts) {
        this.checkoutConflicts = checkoutConflicts;
        this.mergeStatus = MergeStatus.CHECKOUT_CONFLICT;
    }

    /**
     * Get the object the head points at after the merge
     *
     * @return the object the head points at after the merge
     */
    public ObjectId getNewHead() {
        return newHead;
    }

    /**
     * Get the merge status
     *
     * @return the status the merge resulted in
     */
    public MergeStatus getMergeStatus() {
        return mergeStatus;
    }

    /**
     * Get the commits which have been merged
     *
     * @return all the commits which have been merged together
     */
    public ObjectId[] getMergedCommits() {
        return mergedCommits;
    }

    /**
     * Get the common base
     *
     * @return base the common base which was used to produce a content-merge.
     *         May be <code>null</code> if the merge-result was produced without
     *         computing a common base
     */
    public ObjectId getBase() {
        return base;
    }

    /** {@inheritDoc} */
    @SuppressWarnings("nls")
    @Override
    public String toString() {
        boolean first = true;
        StringBuilder commits = new StringBuilder();
        for (ObjectId commit : mergedCommits) {
            if (!first)
                commits.append(", ");
            else
                first = false;
            commits.append(ObjectId.toString(commit));
        }
        return MessageFormat.format(
                JGitText.get().mergeUsingStrategyResultedInDescription,
                commits, ObjectId.toString(base), mergeStrategy.getName(),
                mergeStatus, (description == null ? "" : ", " + description));
    }

    /**
     * Set conflicts
     *
     * @param conflicts
     *            the conflicts to set
     */
    public void setConflicts(Map<String, int[][]> conflicts) {
        this.conflicts = conflicts;
    }

    /**
     * Add a conflict
     *
     * @param path
     *            path of the file to add a conflict for
     * @param conflictingRanges
     *            the conflicts to set
     */
    public void addConflict(String path, int[][] conflictingRanges) {
        if (conflicts == null)
            conflicts = new HashMap<>();
        conflicts.put(path, conflictingRanges);
    }

    /**
     * Add a conflict
     *
     * @param path
     *            path of the file to add a conflict for
     * @param lowLevelResult
     *            a {@link org.eclipse.jgit.merge.MergeResult}
     */
    public void addConflict(String path, org.eclipse.jgit.merge.MergeResult<?> lowLevelResult) {
        if (!lowLevelResult.containsConflicts())
            return;
        if (conflicts == null)
            conflicts = new HashMap<>();
        int nrOfConflicts = 0;
        // just counting
        for (MergeChunk mergeChunk : lowLevelResult) {
            if (mergeChunk.getConflictState().equals(ConflictState.FIRST_CONFLICTING_RANGE)) {
                nrOfConflicts++;
            }
        }
        int currentConflict = -1;
        int[][] ret=new int[nrOfConflicts][mergedCommits.length+1];
        for (MergeChunk mergeChunk : lowLevelResult) {
            // to store the end of this chunk (end of the last conflicting range)
            int endOfChunk = 0;
            if (mergeChunk.getConflictState().equals(ConflictState.FIRST_CONFLICTING_RANGE)) {
                if (currentConflict > -1) {
                    // there was a previous conflicting range for which the end
                    // is not set yet - set it!
                    ret[currentConflict][mergedCommits.length] = endOfChunk;
                }
                currentConflict++;
                endOfChunk = mergeChunk.getEnd();
                ret[currentConflict][mergeChunk.getSequenceIndex()] = mergeChunk.getBegin();
            }
            if (mergeChunk.getConflictState().equals(ConflictState.NEXT_CONFLICTING_RANGE)) {
                if (mergeChunk.getEnd() > endOfChunk)
                    endOfChunk = mergeChunk.getEnd();
                ret[currentConflict][mergeChunk.getSequenceIndex()] = mergeChunk.getBegin();
            }
        }
        conflicts.put(path, ret);
    }

    /**
     * Returns information about the conflicts which occurred during a
     * {@link org.eclipse.jgit.api.MergeCommand}. The returned value maps the
     * path of a conflicting file to a two-dimensional int-array of line-numbers
     * telling where in the file conflict markers for which merged commit can be
     * found.
     * <p>
     * If the returned value contains a mapping "path"-&gt;[x][y]=z then this
     * means
     * <ul>
     * <li>the file with path "path" contains conflicts</li>
     * <li>if y &lt; "number of merged commits": for conflict number x in this
     * file the chunk which was copied from commit number y starts on line
     * number z. All numberings and line numbers start with 0.</li>
     * <li>if y == "number of merged commits": the first non-conflicting line
     * after conflict number x starts at line number z</li>
     * </ul>
     * <p>
     * Example code how to parse this data:
     *
     * <pre>
     * MergeResult m=...;
     * Map&lt;String, int[][]&gt; allConflicts = m.getConflicts();
     * for (String path : allConflicts.keySet()) {
     *  int[][] c = allConflicts.get(path);
     *  System.out.println("Conflicts in file " + path);
     *  for (int i = 0; i &lt; c.length; ++i) {
     *      System.out.println("  Conflict #" + i);
     *      for (int j = 0; j &lt; (c[i].length) - 1; ++j) {
     *          if (c[i][j] &gt;= 0)
     *              System.out.println("    Chunk for "
     *                      + m.getMergedCommits()[j] + " starts on line #"
     *                      + c[i][j]);
     *      }
     *  }
     * }
     * </pre>
     *
     * @return the conflicts or <code>null</code> if no conflict occurred
     */
    public Map<String, int[][]> getConflicts() {
        return conflicts;
    }

    /**
     * Returns a list of paths causing this merge to fail as returned by
     * {@link org.eclipse.jgit.merge.ResolveMerger#getFailingPaths()}
     *
     * @return the list of paths causing this merge to fail or <code>null</code>
     *         if no failure occurred
     */
    public Map<String, MergeFailureReason> getFailingPaths() {
        return failingPaths;
    }

    /**
     * Returns a list of paths that cause a checkout conflict. These paths
     * prevent the operation from even starting.
     *
     * @return the list of files that caused the checkout conflict.
     */
    public List<String> getCheckoutConflicts() {
        return checkoutConflicts;
    }
}