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- /*
- * Copyright (C) 2016, Google Inc.
- * 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;
- * 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.
- */
-
- package org.eclipse.jgit.internal.ketch;
-
- import static org.eclipse.jgit.internal.ketch.Proposal.State.RUNNING;
-
- import java.io.IOException;
- import java.time.Duration;
- import java.util.ArrayList;
- import java.util.Collections;
- import java.util.HashMap;
- import java.util.HashSet;
- import java.util.List;
- import java.util.Map;
- import java.util.Set;
- import java.util.concurrent.TimeoutException;
- import java.util.stream.Collectors;
-
- import org.eclipse.jgit.annotations.Nullable;
- import org.eclipse.jgit.internal.storage.reftree.Command;
- import org.eclipse.jgit.internal.storage.reftree.RefTree;
- import org.eclipse.jgit.lib.CommitBuilder;
- import org.eclipse.jgit.lib.ObjectId;
- import org.eclipse.jgit.lib.ObjectInserter;
- import org.eclipse.jgit.lib.PersonIdent;
- import org.eclipse.jgit.lib.Ref;
- import org.eclipse.jgit.lib.Repository;
- import org.eclipse.jgit.revwalk.RevCommit;
- import org.eclipse.jgit.revwalk.RevWalk;
- import org.eclipse.jgit.transport.ReceiveCommand;
- import org.eclipse.jgit.util.time.ProposedTimestamp;
-
- /** A {@link Round} that aggregates and sends user {@link Proposal}s. */
- class ProposalRound extends Round {
- private final List<Proposal> todo;
- private RefTree queuedTree;
-
- ProposalRound(KetchLeader leader, LogIndex head, List<Proposal> todo,
- @Nullable RefTree tree) {
- super(leader, head);
- this.todo = todo;
-
- if (tree != null && canCombine(todo)) {
- this.queuedTree = tree;
- } else {
- leader.roundHoldsReferenceToRefTree = false;
- }
- }
-
- private static boolean canCombine(List<Proposal> todo) {
- Proposal first = todo.get(0);
- for (int i = 1; i < todo.size(); i++) {
- if (!canCombine(first, todo.get(i))) {
- return false;
- }
- }
- return true;
- }
-
- private static boolean canCombine(Proposal a, Proposal b) {
- String aMsg = nullToEmpty(a.getMessage());
- String bMsg = nullToEmpty(b.getMessage());
- return aMsg.equals(bMsg) && canCombine(a.getAuthor(), b.getAuthor());
- }
-
- private static String nullToEmpty(@Nullable String str) {
- return str != null ? str : ""; //$NON-NLS-1$
- }
-
- private static boolean canCombine(@Nullable PersonIdent a,
- @Nullable PersonIdent b) {
- if (a != null && b != null) {
- // Same name and email address. Combine timestamp as the two
- // proposals are running concurrently and appear together or
- // not at all from the point of view of an outside reader.
- return a.getName().equals(b.getName())
- && a.getEmailAddress().equals(b.getEmailAddress());
- }
-
- // If a and b are null, both will be the system identity.
- return a == null && b == null;
- }
-
- void start() throws IOException {
- for (Proposal p : todo) {
- p.notifyState(RUNNING);
- }
- try {
- ObjectId id;
- try (Repository git = leader.openRepository();
- ProposedTimestamp ts = getSystem().getClock().propose()) {
- id = insertProposals(git, ts);
- blockUntil(ts);
- }
- runAsync(id);
- } catch (NoOp e) {
- for (Proposal p : todo) {
- p.success();
- }
- leader.lock.lock();
- try {
- leader.nextRound();
- } finally {
- leader.lock.unlock();
- }
- } catch (IOException e) {
- abort();
- throw e;
- }
- }
-
- private ObjectId insertProposals(Repository git, ProposedTimestamp ts)
- throws IOException, NoOp {
- ObjectId id;
- try (ObjectInserter inserter = git.newObjectInserter()) {
- // TODO(sop) Process signed push certificates.
-
- if (queuedTree != null) {
- id = insertSingleProposal(git, ts, inserter);
- } else {
- id = insertMultiProposal(git, ts, inserter);
- }
-
- stageCommands = makeStageList(git, inserter);
- inserter.flush();
- }
- return id;
- }
-
- private ObjectId insertSingleProposal(Repository git, ProposedTimestamp ts,
- ObjectInserter inserter) throws IOException, NoOp {
- // Fast path: tree is passed in with all proposals applied.
- ObjectId treeId = queuedTree.writeTree(inserter);
- queuedTree = null;
- leader.roundHoldsReferenceToRefTree = false;
-
- if (!ObjectId.zeroId().equals(acceptedOldIndex)) {
- try (RevWalk rw = new RevWalk(git)) {
- RevCommit c = rw.parseCommit(acceptedOldIndex);
- if (treeId.equals(c.getTree())) {
- throw new NoOp();
- }
- }
- }
-
- Proposal p = todo.get(0);
- CommitBuilder b = new CommitBuilder();
- b.setTreeId(treeId);
- if (!ObjectId.zeroId().equals(acceptedOldIndex)) {
- b.setParentId(acceptedOldIndex);
- }
- b.setCommitter(leader.getSystem().newCommitter(ts));
- b.setAuthor(p.getAuthor() != null ? p.getAuthor() : b.getCommitter());
- b.setMessage(message(p));
- return inserter.insert(b);
- }
-
- private ObjectId insertMultiProposal(Repository git, ProposedTimestamp ts,
- ObjectInserter inserter) throws IOException, NoOp {
- // The tree was not passed in, or there are multiple proposals
- // each needing their own commit. Reset the tree and replay each
- // proposal in order as individual commits.
- ObjectId lastIndex = acceptedOldIndex;
- ObjectId oldTreeId;
- RefTree tree;
- if (ObjectId.zeroId().equals(lastIndex)) {
- oldTreeId = ObjectId.zeroId();
- tree = RefTree.newEmptyTree();
- } else {
- try (RevWalk rw = new RevWalk(git)) {
- RevCommit c = rw.parseCommit(lastIndex);
- oldTreeId = c.getTree();
- tree = RefTree.read(rw.getObjectReader(), c.getTree());
- }
- }
-
- PersonIdent committer = leader.getSystem().newCommitter(ts);
- for (Proposal p : todo) {
- if (!tree.apply(p.getCommands())) {
- // This should not occur, previously during queuing the
- // commands were successfully applied to the pending tree.
- // Abort the entire round.
- throw new IOException(
- KetchText.get().queuedProposalFailedToApply);
- }
-
- ObjectId treeId = tree.writeTree(inserter);
- if (treeId.equals(oldTreeId)) {
- continue;
- }
-
- CommitBuilder b = new CommitBuilder();
- b.setTreeId(treeId);
- if (!ObjectId.zeroId().equals(lastIndex)) {
- b.setParentId(lastIndex);
- }
- b.setAuthor(p.getAuthor() != null ? p.getAuthor() : committer);
- b.setCommitter(committer);
- b.setMessage(message(p));
- lastIndex = inserter.insert(b);
- }
- if (lastIndex.equals(acceptedOldIndex)) {
- throw new NoOp();
- }
- return lastIndex;
- }
-
- private String message(Proposal p) {
- StringBuilder m = new StringBuilder();
- String msg = p.getMessage();
- if (msg != null && !msg.isEmpty()) {
- m.append(msg);
- while (m.length() < 2 || m.charAt(m.length() - 2) != '\n'
- || m.charAt(m.length() - 1) != '\n') {
- m.append('\n');
- }
- }
- m.append(KetchConstants.TERM.getName())
- .append(": ") //$NON-NLS-1$
- .append(leader.getTerm());
- return m.toString();
- }
-
- void abort() {
- for (Proposal p : todo) {
- p.abort();
- }
- }
-
- void success() {
- for (Proposal p : todo) {
- p.success();
- }
- }
-
- private List<ReceiveCommand> makeStageList(Repository git,
- ObjectInserter inserter) throws IOException {
- // For each branch, collapse consecutive updates to only most recent,
- // avoiding sending multiple objects in a rapid fast-forward chain, or
- // rewritten content.
- Map<String, ObjectId> byRef = new HashMap<>();
- for (Proposal p : todo) {
- for (Command c : p.getCommands()) {
- Ref n = c.getNewRef();
- if (n != null && !n.isSymbolic()) {
- byRef.put(n.getName(), n.getObjectId());
- }
- }
- }
- if (byRef.isEmpty()) {
- return Collections.emptyList();
- }
-
- Set<ObjectId> newObjs = new HashSet<>(byRef.values());
- StageBuilder b = new StageBuilder(
- leader.getSystem().getTxnStage(),
- acceptedNewIndex);
- return b.makeStageList(newObjs, git, inserter);
- }
-
- private void blockUntil(ProposedTimestamp ts)
- throws TimeIsUncertainException {
- List<ProposedTimestamp> times = todo.stream()
- .flatMap(p -> p.getProposedTimestamps().stream())
- .collect(Collectors.toCollection(ArrayList::new));
- times.add(ts);
-
- try {
- Duration maxWait = getSystem().getMaxWaitForMonotonicClock();
- ProposedTimestamp.blockUntil(times, maxWait);
- } catch (InterruptedException | TimeoutException e) {
- throw new TimeIsUncertainException(e);
- }
- }
-
- private static class NoOp extends Exception {
- private static final long serialVersionUID = 1L;
- }
- }
|