| /* |
| * Copyright (C) 2008-2009, Google Inc. |
| * Copyright (C) 2009, Matthias Sohn <matthias.sohn@sap.com> |
| * Copyright (C) 2012, Research In Motion Limited and others |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Distribution License v. 1.0 which is available at |
| * https://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| package org.eclipse.jgit.merge; |
| |
| import java.text.MessageFormat; |
| import java.util.HashMap; |
| |
| import org.eclipse.jgit.internal.JGitText; |
| import org.eclipse.jgit.lib.Config; |
| import org.eclipse.jgit.lib.ObjectInserter; |
| import org.eclipse.jgit.lib.Repository; |
| |
| /** |
| * A method of combining two or more trees together to form an output tree. |
| * <p> |
| * Different strategies may employ different techniques for deciding which paths |
| * (and ObjectIds) to carry from the input trees into the final output tree. |
| */ |
| public abstract class MergeStrategy { |
| /** Simple strategy that sets the output tree to the first input tree. */ |
| public static final MergeStrategy OURS = new StrategyOneSided("ours", 0); //$NON-NLS-1$ |
| |
| /** Simple strategy that sets the output tree to the second input tree. */ |
| public static final MergeStrategy THEIRS = new StrategyOneSided("theirs", 1); //$NON-NLS-1$ |
| |
| /** Simple strategy to merge paths, without simultaneous edits. */ |
| public static final ThreeWayMergeStrategy SIMPLE_TWO_WAY_IN_CORE = new StrategySimpleTwoWayInCore(); |
| |
| /** |
| * Simple strategy to merge paths. It tries to merge also contents. Multiple |
| * merge bases are not supported |
| */ |
| public static final ThreeWayMergeStrategy RESOLVE = new StrategyResolve(); |
| |
| /** |
| * Recursive strategy to merge paths. It tries to merge also contents. |
| * Multiple merge bases are supported |
| * @since 3.0 |
| */ |
| public static final ThreeWayMergeStrategy RECURSIVE = new StrategyRecursive(); |
| |
| private static final HashMap<String, MergeStrategy> STRATEGIES = new HashMap<>(); |
| |
| static { |
| register(OURS); |
| register(THEIRS); |
| register(SIMPLE_TWO_WAY_IN_CORE); |
| register(RESOLVE); |
| register(RECURSIVE); |
| } |
| |
| /** |
| * Register a merge strategy so it can later be obtained by name. |
| * |
| * @param imp |
| * the strategy to register. |
| * @throws java.lang.IllegalArgumentException |
| * a strategy by the same name has already been registered. |
| */ |
| public static void register(MergeStrategy imp) { |
| register(imp.getName(), imp); |
| } |
| |
| /** |
| * Register a merge strategy so it can later be obtained by name. |
| * |
| * @param name |
| * name the strategy can be looked up under. |
| * @param imp |
| * the strategy to register. |
| * @throws java.lang.IllegalArgumentException |
| * a strategy by the same name has already been registered. |
| */ |
| public static synchronized void register(final String name, |
| final MergeStrategy imp) { |
| if (STRATEGIES.containsKey(name)) |
| throw new IllegalArgumentException(MessageFormat.format( |
| JGitText.get().mergeStrategyAlreadyExistsAsDefault, name)); |
| STRATEGIES.put(name, imp); |
| } |
| |
| /** |
| * Locate a strategy by name. |
| * |
| * @param name |
| * name of the strategy to locate. |
| * @return the strategy instance; null if no strategy matches the name. |
| */ |
| public static synchronized MergeStrategy get(String name) { |
| return STRATEGIES.get(name); |
| } |
| |
| /** |
| * Get all registered strategies. |
| * |
| * @return the registered strategy instances. No inherit order is returned; |
| * the caller may modify (and/or sort) the returned array if |
| * necessary to obtain a reasonable ordering. |
| */ |
| public static synchronized MergeStrategy[] get() { |
| final MergeStrategy[] r = new MergeStrategy[STRATEGIES.size()]; |
| STRATEGIES.values().toArray(r); |
| return r; |
| } |
| |
| /** |
| * Get default name of this strategy implementation. |
| * |
| * @return default name of this strategy implementation. |
| */ |
| public abstract String getName(); |
| |
| /** |
| * Create a new merge instance. |
| * |
| * @param db |
| * repository database the merger will read from, and eventually |
| * write results back to. |
| * @return the new merge instance which implements this strategy. |
| */ |
| public abstract Merger newMerger(Repository db); |
| |
| /** |
| * Create a new merge instance. |
| * |
| * @param db |
| * repository database the merger will read from, and eventually |
| * write results back to. |
| * @param inCore |
| * the merge will happen in memory, working folder will not be |
| * modified, in case of a non-trivial merge that requires manual |
| * resolution, the merger will fail. |
| * @return the new merge instance which implements this strategy. |
| */ |
| public abstract Merger newMerger(Repository db, boolean inCore); |
| |
| /** |
| * Create a new merge instance. |
| * <p> |
| * The merge will happen in memory, working folder will not be modified, in |
| * case of a non-trivial merge that requires manual resolution, the merger |
| * will fail. |
| * |
| * @param inserter |
| * inserter to write results back to. |
| * @param config |
| * repo config for reading diff algorithm settings. |
| * @return the new merge instance which implements this strategy. |
| * @since 4.8 |
| */ |
| public abstract Merger newMerger(ObjectInserter inserter, Config config); |
| } |