NameRevCommand.java
- /*
- * Copyright (C) 2013, Google Inc. 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.api;
- import java.io.IOException;
- import java.util.ArrayList;
- import java.util.HashMap;
- import java.util.LinkedHashMap;
- import java.util.List;
- import java.util.Map;
- import org.eclipse.jgit.api.errors.GitAPIException;
- import org.eclipse.jgit.api.errors.JGitInternalException;
- import org.eclipse.jgit.errors.MissingObjectException;
- import org.eclipse.jgit.lib.AnyObjectId;
- import org.eclipse.jgit.lib.Constants;
- import org.eclipse.jgit.lib.ObjectId;
- import org.eclipse.jgit.lib.Ref;
- import org.eclipse.jgit.lib.Repository;
- import org.eclipse.jgit.revwalk.FIFORevQueue;
- import org.eclipse.jgit.revwalk.RevCommit;
- import org.eclipse.jgit.revwalk.RevObject;
- import org.eclipse.jgit.revwalk.RevTag;
- import org.eclipse.jgit.revwalk.RevWalk;
- /**
- * Command to find human-readable names of revisions.
- *
- * @see <a
- * href="http://www.kernel.org/pub/software/scm/git/docs/git-name-rev.html"
- * >Git documentation about name-rev</a>
- * @since 3.0
- */
- public class NameRevCommand extends GitCommand<Map<ObjectId, String>> {
- /** Amount of slop to allow walking past the earliest requested commit. */
- private static final int COMMIT_TIME_SLOP = 60 * 60 * 24;
- /** Cost of traversing a merge commit compared to a linear history. */
- private static final int MERGE_COST = 65535;
- private static class NameRevCommit extends RevCommit {
- private String tip;
- private int distance;
- private long cost;
- private NameRevCommit(AnyObjectId id) {
- super(id);
- }
- private StringBuilder format() {
- StringBuilder sb = new StringBuilder(tip);
- if (distance > 0)
- sb.append('~').append(distance);
- return sb;
- }
- @Override
- public String toString() {
- StringBuilder sb = new StringBuilder(getClass().getSimpleName())
- .append('[');
- if (tip != null) {
- sb.append(format());
- } else {
- sb.append((Object) null);
- }
- sb.append(',').append(cost).append(']').append(' ')
- .append(super.toString());
- return sb.toString();
- }
- }
- private final RevWalk walk;
- private final List<String> prefixes;
- private final List<ObjectId> revs;
- private List<Ref> refs;
- private int mergeCost;
- /**
- * Create a new name-rev command.
- *
- * @param repo
- * the {@link org.eclipse.jgit.lib.Repository}
- */
- protected NameRevCommand(Repository repo) {
- super(repo);
- mergeCost = MERGE_COST;
- prefixes = new ArrayList<>(2);
- revs = new ArrayList<>(2);
- walk = new RevWalk(repo) {
- @Override
- public NameRevCommit createCommit(AnyObjectId id) {
- return new NameRevCommit(id);
- }
- };
- }
- /** {@inheritDoc} */
- @Override
- public Map<ObjectId, String> call() throws GitAPIException {
- try {
- Map<ObjectId, String> nonCommits = new HashMap<>();
- FIFORevQueue pending = new FIFORevQueue();
- if (refs != null) {
- for (Ref ref : refs)
- addRef(ref, nonCommits, pending);
- }
- addPrefixes(nonCommits, pending);
- int cutoff = minCommitTime() - COMMIT_TIME_SLOP;
- while (true) {
- NameRevCommit c = (NameRevCommit) pending.next();
- if (c == null)
- break;
- if (c.getCommitTime() < cutoff)
- continue;
- for (int i = 0; i < c.getParentCount(); i++) {
- NameRevCommit p = (NameRevCommit) walk.parseCommit(c.getParent(i));
- long cost = c.cost + (i > 0 ? mergeCost : 1);
- if (p.tip == null || compare(c.tip, cost, p.tip, p.cost) < 0) {
- if (i > 0) {
- p.tip = c.format().append('^').append(i + 1).toString();
- p.distance = 0;
- } else {
- p.tip = c.tip;
- p.distance = c.distance + 1;
- }
- p.cost = cost;
- pending.add(p);
- }
- }
- }
- Map<ObjectId, String> result =
- new LinkedHashMap<>(revs.size());
- for (ObjectId id : revs) {
- RevObject o = walk.parseAny(id);
- if (o instanceof NameRevCommit) {
- NameRevCommit c = (NameRevCommit) o;
- if (c.tip != null)
- result.put(id, simplify(c.format().toString()));
- } else {
- String name = nonCommits.get(id);
- if (name != null)
- result.put(id, simplify(name));
- }
- }
- setCallable(false);
- return result;
- } catch (IOException e) {
- throw new JGitInternalException(e.getMessage(), e);
- } finally {
- walk.close();
- }
- }
- /**
- * Add an object to search for.
- *
- * @param id
- * object ID to add.
- * @return {@code this}
- * @throws org.eclipse.jgit.errors.MissingObjectException
- * the object supplied is not available from the object
- * database.
- * @throws org.eclipse.jgit.api.errors.JGitInternalException
- * a low-level exception of JGit has occurred. The original
- * exception can be retrieved by calling
- * {@link java.lang.Exception#getCause()}.
- */
- public NameRevCommand add(ObjectId id) throws MissingObjectException,
- JGitInternalException {
- checkCallable();
- try {
- walk.parseAny(id);
- } catch (MissingObjectException e) {
- throw e;
- } catch (IOException e) {
- throw new JGitInternalException(e.getMessage(), e);
- }
- revs.add(id.copy());
- return this;
- }
- /**
- * Add multiple objects to search for.
- *
- * @param ids
- * object IDs to add.
- * @return {@code this}
- * @throws org.eclipse.jgit.errors.MissingObjectException
- * the object supplied is not available from the object
- * database.
- * @throws org.eclipse.jgit.api.errors.JGitInternalException
- * a low-level exception of JGit has occurred. The original
- * exception can be retrieved by calling
- * {@link java.lang.Exception#getCause()}.
- */
- public NameRevCommand add(Iterable<ObjectId> ids)
- throws MissingObjectException, JGitInternalException {
- for (ObjectId id : ids)
- add(id);
- return this;
- }
- /**
- * Add a ref prefix to the set that results must match.
- * <p>
- * If an object matches multiple refs equally well, the first matching ref
- * added with {@link #addRef(Ref)} is preferred, or else the first matching
- * prefix added by {@link #addPrefix(String)}.
- *
- * @param prefix
- * prefix to add; the prefix must end with a slash
- * @return {@code this}
- */
- public NameRevCommand addPrefix(String prefix) {
- checkCallable();
- prefixes.add(prefix);
- return this;
- }
- /**
- * Add all annotated tags under {@code refs/tags/} to the set that all
- * results must match.
- * <p>
- * Calls {@link #addRef(Ref)}; see that method for a note on matching
- * priority.
- *
- * @return {@code this}
- * @throws JGitInternalException
- * a low-level exception of JGit has occurred. The original
- * exception can be retrieved by calling
- * {@link java.lang.Exception#getCause()}.
- */
- public NameRevCommand addAnnotatedTags() {
- checkCallable();
- if (refs == null)
- refs = new ArrayList<>();
- try {
- for (Ref ref : repo.getRefDatabase()
- .getRefsByPrefix(Constants.R_TAGS)) {
- ObjectId id = ref.getObjectId();
- if (id != null && (walk.parseAny(id) instanceof RevTag))
- addRef(ref);
- }
- } catch (IOException e) {
- throw new JGitInternalException(e.getMessage(), e);
- }
- return this;
- }
- /**
- * Add a ref to the set that all results must match.
- * <p>
- * If an object matches multiple refs equally well, the first matching ref
- * added with {@link #addRef(Ref)} is preferred, or else the first matching
- * prefix added by {@link #addPrefix(String)}.
- *
- * @param ref
- * ref to add.
- * @return {@code this}
- */
- public NameRevCommand addRef(Ref ref) {
- checkCallable();
- if (refs == null)
- refs = new ArrayList<>();
- refs.add(ref);
- return this;
- }
- NameRevCommand setMergeCost(int cost) {
- mergeCost = cost;
- return this;
- }
- private void addPrefixes(Map<ObjectId, String> nonCommits,
- FIFORevQueue pending) throws IOException {
- if (!prefixes.isEmpty()) {
- for (String prefix : prefixes)
- addPrefix(prefix, nonCommits, pending);
- } else if (refs == null)
- addPrefix(Constants.R_REFS, nonCommits, pending);
- }
- private void addPrefix(String prefix, Map<ObjectId, String> nonCommits,
- FIFORevQueue pending) throws IOException {
- for (Ref ref : repo.getRefDatabase().getRefsByPrefix(prefix))
- addRef(ref, nonCommits, pending);
- }
- private void addRef(Ref ref, Map<ObjectId, String> nonCommits,
- FIFORevQueue pending) throws IOException {
- if (ref.getObjectId() == null)
- return;
- RevObject o = walk.parseAny(ref.getObjectId());
- while (o instanceof RevTag) {
- RevTag t = (RevTag) o;
- nonCommits.put(o, ref.getName());
- o = t.getObject();
- walk.parseHeaders(o);
- }
- if (o instanceof NameRevCommit) {
- NameRevCommit c = (NameRevCommit) o;
- if (c.tip == null)
- c.tip = ref.getName();
- pending.add(c);
- } else if (!nonCommits.containsKey(o))
- nonCommits.put(o, ref.getName());
- }
- private int minCommitTime() throws IOException {
- int min = Integer.MAX_VALUE;
- for (ObjectId id : revs) {
- RevObject o = walk.parseAny(id);
- while (o instanceof RevTag) {
- o = ((RevTag) o).getObject();
- walk.parseHeaders(o);
- }
- if (o instanceof RevCommit) {
- RevCommit c = (RevCommit) o;
- if (c.getCommitTime() < min)
- min = c.getCommitTime();
- }
- }
- return min;
- }
- private long compare(String leftTip, long leftCost, String rightTip, long rightCost) {
- long c = leftCost - rightCost;
- if (c != 0 || prefixes.isEmpty())
- return c;
- int li = -1;
- int ri = -1;
- for (int i = 0; i < prefixes.size(); i++) {
- String prefix = prefixes.get(i);
- if (li < 0 && leftTip.startsWith(prefix))
- li = i;
- if (ri < 0 && rightTip.startsWith(prefix))
- ri = i;
- }
- // Don't tiebreak if prefixes are the same, in order to prefer first-parent
- // paths.
- return li - ri;
- }
- private static String simplify(String refName) {
- if (refName.startsWith(Constants.R_HEADS))
- return refName.substring(Constants.R_HEADS.length());
- if (refName.startsWith(Constants.R_TAGS))
- return refName.substring(Constants.R_TAGS.length());
- if (refName.startsWith(Constants.R_REFS))
- return refName.substring(Constants.R_REFS.length());
- return refName;
- }
- }