org.eclipse.jgit.ignore;version="4.2.0",
org.eclipse.jgit.ignore.internal;version="4.2.0";x-friends:="org.eclipse.jgit.test",
org.eclipse.jgit.internal;version="4.2.0";x-friends:="org.eclipse.jgit.test,org.eclipse.jgit.http.test",
+ org.eclipse.jgit.internal.ketch;version="4.2.0";x-friends:="org.eclipse.jgit.junit,org.eclipse.jgit.test,org.eclipse.jgit.pgm",
org.eclipse.jgit.internal.storage.dfs;version="4.2.0";x-friends:="org.eclipse.jgit.test,org.eclipse.jgit.http.server",
org.eclipse.jgit.internal.storage.file;version="4.2.0";
x-friends:="org.eclipse.jgit.test,
--- /dev/null
+cannotFetchFromLocalReplica=cannot fetch from LocalReplica
+leaderFailedToStore=leader failed to store
+localReplicaRequired=LocalReplica instance is required
+mismatchedTxnNamespace=mismatched txnNamespace; expected {0} found {1}
+outsideTxnNamespace=ref {0} is outside of txnNamespace {1}
+queuedProposalFailedToApply=queued proposal failed to apply
+unsupportedVoterCount=unsupported voter count {0}, expected one of {1}
--- /dev/null
+/*
+ * 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.KetchConstants.TERM;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.eclipse.jgit.lib.CommitBuilder;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.ObjectInserter;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.lib.TreeFormatter;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * The initial {@link Round} for a leaderless repository, used to establish a
+ * leader.
+ */
+class ElectionRound extends Round {
+ private static final Logger log = LoggerFactory.getLogger(ElectionRound.class);
+
+ private long term;
+
+ ElectionRound(KetchLeader leader, LogIndex head) {
+ super(leader, head);
+ }
+
+ @Override
+ void start() throws IOException {
+ ObjectId id;
+ try (Repository git = leader.openRepository();
+ ObjectInserter inserter = git.newObjectInserter()) {
+ id = bumpTerm(git, inserter);
+ inserter.flush();
+ }
+ runAsync(id);
+ }
+
+ @Override
+ void success() {
+ // Do nothing upon election, KetchLeader will copy the term.
+ }
+
+ long getTerm() {
+ return term;
+ }
+
+ private ObjectId bumpTerm(Repository git, ObjectInserter inserter)
+ throws IOException {
+ CommitBuilder b = new CommitBuilder();
+ if (!ObjectId.zeroId().equals(acceptedOldIndex)) {
+ try (RevWalk rw = new RevWalk(git)) {
+ RevCommit c = rw.parseCommit(acceptedOldIndex);
+ b.setTreeId(c.getTree());
+ b.setParentId(acceptedOldIndex);
+ term = parseTerm(c.getFooterLines(TERM)) + 1;
+ }
+ } else {
+ term = 1;
+ b.setTreeId(inserter.insert(new TreeFormatter()));
+ }
+
+ StringBuilder msg = new StringBuilder();
+ msg.append(KetchConstants.TERM.getName())
+ .append(": ") //$NON-NLS-1$
+ .append(term);
+
+ String tag = leader.getSystem().newLeaderTag();
+ if (tag != null && !tag.isEmpty()) {
+ msg.append(' ').append(tag);
+ }
+
+ b.setAuthor(leader.getSystem().newCommitter());
+ b.setCommitter(b.getAuthor());
+ b.setMessage(msg.toString());
+
+ if (log.isDebugEnabled()) {
+ log.debug("Trying to elect myself " + b.getMessage()); //$NON-NLS-1$
+ }
+ return inserter.insert(b);
+ }
+
+ private static long parseTerm(List<String> footer) {
+ if (footer.isEmpty()) {
+ return 0;
+ }
+
+ String s = footer.get(0);
+ int p = s.indexOf(' ');
+ if (p > 0) {
+ s = s.substring(0, p);
+ }
+ return Long.parseLong(s, 10);
+ }
+}
--- /dev/null
+/*
+ * 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 org.eclipse.jgit.revwalk.FooterKey;
+
+/** Frequently used constants in a Ketch system. */
+public class KetchConstants {
+ /**
+ * Default reference namespace holding {@link #ACCEPTED} and
+ * {@link #COMMITTED} references and the {@link #STAGE} sub-namespace.
+ */
+ public static final String DEFAULT_TXN_NAMESPACE = "refs/txn/"; //$NON-NLS-1$
+
+ /** Reference name holding the RefTree accepted by a follower. */
+ public static final String ACCEPTED = "accepted"; //$NON-NLS-1$
+
+ /** Reference name holding the RefTree known to be committed. */
+ public static final String COMMITTED = "committed"; //$NON-NLS-1$
+
+ /** Reference subdirectory holding proposed heads. */
+ public static final String STAGE = "stage/"; //$NON-NLS-1$
+
+ /** Footer containing the current term. */
+ public static final FooterKey TERM = new FooterKey("Term"); //$NON-NLS-1$
+
+ /** Section for Ketch configuration ({@code ketch}). */
+ public static final String CONFIG_SECTION_KETCH = "ketch"; //$NON-NLS-1$
+
+ /** Behavior for a replica ({@code remote.$name.ketch-type}) */
+ public static final String CONFIG_KEY_TYPE = "ketch-type"; //$NON-NLS-1$
+
+ /** Behavior for a replica ({@code remote.$name.ketch-commit}) */
+ public static final String CONFIG_KEY_COMMIT = "ketch-commit"; //$NON-NLS-1$
+
+ /** Behavior for a replica ({@code remote.$name.ketch-speed}) */
+ public static final String CONFIG_KEY_SPEED = "ketch-speed"; //$NON-NLS-1$
+
+ private KetchConstants() {
+ }
+}
--- /dev/null
+/*
+ * 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.KetchLeader.State.CANDIDATE;
+import static org.eclipse.jgit.internal.ketch.KetchLeader.State.LEADER;
+import static org.eclipse.jgit.internal.ketch.KetchLeader.State.SHUTDOWN;
+import static org.eclipse.jgit.internal.ketch.KetchReplica.Participation.FOLLOWER_ONLY;
+import static org.eclipse.jgit.internal.ketch.Proposal.State.QUEUED;
+
+import java.io.IOException;
+import java.text.MessageFormat;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+
+import org.eclipse.jgit.internal.storage.reftree.RefTree;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * A leader managing consensus across remote followers.
+ * <p>
+ * A leader instance starts up in {@link State#CANDIDATE} and tries to begin a
+ * new term by sending an {@link ElectionRound} to all replicas. Its term starts
+ * if a majority of replicas have accepted this leader instance for the term.
+ * <p>
+ * Once elected by a majority the instance enters {@link State#LEADER} and runs
+ * proposals offered to {@link #queueProposal(Proposal)}. This continues until
+ * the leader is timed out for inactivity, or is deposed by a competing leader
+ * gaining its own majority.
+ * <p>
+ * Once timed out or deposed this {@code KetchLeader} instance should be
+ * discarded, and a new instance takes over.
+ * <p>
+ * Each leader instance coordinates a group of {@link KetchReplica}s. Replica
+ * instances are owned by the leader instance and must be discarded when the
+ * leader is discarded.
+ * <p>
+ * In Ketch all push requests are issued through the leader. The steps are as
+ * follows:
+ * <ul>
+ * <li>Create a {@link Proposal} with the
+ * {@link org.eclipse.jgit.transport.ReceiveCommand}s that represent the push.
+ * <li>Invoke {@link #queueProposal(Proposal)} on the leader instance.
+ * <li>Wait for consensus with {@link Proposal#await()}.
+ * <li>To examine the status of the push, check {@link Proposal#getCommands()},
+ * looking at
+ * {@link org.eclipse.jgit.internal.storage.reftree.Command#getResult()}.
+ * </ul>
+ * <p>
+ * The leader gains consensus by first pushing the needed objects and a
+ * {@link RefTree} representing the desired target repository state to the
+ * {@code refs/txn/accepted} branch on each of the replicas. Once a majority has
+ * succeeded, the leader commits the state by either pushing the
+ * {@code refs/txn/accepted} value to {@code refs/txn/committed} (for
+ * Ketch-aware replicas) or by pushing updates to {@code refs/heads/master},
+ * etc. for stock Git replicas.
+ * <p>
+ * Internally, the actual transport to replicas is performed on background
+ * threads via the {@link KetchSystem}'s executor service. For performance, the
+ * {@link KetchLeader}, {@link KetchReplica} and {@link Proposal} objects share
+ * some state, and may invoke each other's methods on different threads. This
+ * access is protected by the leader's {@link #lock} object. Care must be taken
+ * to prevent concurrent access by correctly obtaining the leader's lock.
+ */
+public abstract class KetchLeader {
+ private static final Logger log = LoggerFactory.getLogger(KetchLeader.class);
+
+ /** Current state of the leader instance. */
+ public static enum State {
+ /** Newly created instance trying to elect itself leader. */
+ CANDIDATE,
+
+ /** Leader instance elected by a majority. */
+ LEADER,
+
+ /** Instance has been deposed by another with a more recent term. */
+ DEPOSED,
+
+ /** Leader has been gracefully shutdown, e.g. due to inactivity. */
+ SHUTDOWN;
+ }
+
+ private final KetchSystem system;
+
+ /** Leader's knowledge of replicas for this repository. */
+ private KetchReplica[] voters;
+ private KetchReplica[] followers;
+ private LocalReplica self;
+
+ /**
+ * Lock protecting all data within this leader instance.
+ * <p>
+ * This lock extends into the {@link KetchReplica} instances used by the
+ * leader. They share the same lock instance to simplify concurrency.
+ */
+ final Lock lock;
+
+ private State state = CANDIDATE;
+
+ /** Term of this leader, once elected. */
+ private long term;
+
+ /**
+ * Pending proposals accepted into the queue in FIFO order.
+ * <p>
+ * These proposals were preflighted and do not contain any conflicts with
+ * each other and their expectations matched the leader's local view of the
+ * agreed upon {@code refs/txn/accepted} tree.
+ */
+ private final List<Proposal> queued;
+
+ /**
+ * State of the repository's RefTree after applying all entries in
+ * {@link #queued}. New proposals must be consistent with this tree to be
+ * appended to the end of {@link #queued}.
+ * <p>
+ * Must be deep-copied with {@link RefTree#copy()} if
+ * {@link #roundHoldsReferenceToRefTree} is {@code true}.
+ */
+ private RefTree refTree;
+
+ /**
+ * If {@code true} {@link #refTree} must be duplicated before queuing the
+ * next proposal. The {@link #refTree} was passed into the constructor of a
+ * {@link ProposalRound}, and that external reference to the {@link RefTree}
+ * object is held by the proposal until it materializes the tree object in
+ * the object store. This field is set {@code true} when the proposal begins
+ * execution and set {@code false} once tree objects are persisted in the
+ * local repository's object store or {@link #refTree} is replaced with a
+ * copy to isolate it from any running rounds.
+ * <p>
+ * If proposals arrive less frequently than the {@code RefTree} is written
+ * out to the repository the {@link #roundHoldsReferenceToRefTree} behavior
+ * avoids duplicating {@link #refTree}, reducing both time and memory used.
+ * However if proposals arrive more frequently {@link #refTree} must be
+ * duplicated to prevent newly queued proposals from corrupting the
+ * {@link #runningRound}.
+ */
+ volatile boolean roundHoldsReferenceToRefTree;
+
+ /** End of the leader's log. */
+ private LogIndex headIndex;
+
+ /** Leader knows this (and all prior) states are committed. */
+ private LogIndex committedIndex;
+
+ /**
+ * Is the leader idle with no work pending? If {@code true} there is no work
+ * for the leader (normal state). This field is {@code false} when the
+ * leader thread is scheduled for execution, or while {@link #runningRound}
+ * defines a round in progress.
+ */
+ private boolean idle;
+
+ /** Current round the leader is preparing and waiting for a vote on. */
+ private Round runningRound;
+
+ /**
+ * Construct a leader for a Ketch instance.
+ *
+ * @param system
+ * Ketch system configuration the leader must adhere to.
+ */
+ protected KetchLeader(KetchSystem system) {
+ this.system = system;
+ this.lock = new ReentrantLock(true /* fair */);
+ this.queued = new ArrayList<>(4);
+ this.idle = true;
+ }
+
+ /** @return system configuration. */
+ KetchSystem getSystem() {
+ return system;
+ }
+
+ /**
+ * Configure the replicas used by this Ketch instance.
+ * <p>
+ * Replicas should be configured once at creation before any proposals are
+ * executed. Once elections happen, <b>reconfiguration is a complicated
+ * concept that is not currently supported</b>.
+ *
+ * @param replicas
+ * members participating with the same repository.
+ */
+ public void setReplicas(Collection<KetchReplica> replicas) {
+ List<KetchReplica> v = new ArrayList<>(5);
+ List<KetchReplica> f = new ArrayList<>(5);
+ for (KetchReplica r : replicas) {
+ switch (r.getParticipation()) {
+ case FULL:
+ v.add(r);
+ break;
+
+ case FOLLOWER_ONLY:
+ f.add(r);
+ break;
+ }
+ }
+
+ Collection<Integer> validVoters = validVoterCounts();
+ if (!validVoters.contains(Integer.valueOf(v.size()))) {
+ throw new IllegalArgumentException(MessageFormat.format(
+ KetchText.get().unsupportedVoterCount,
+ Integer.valueOf(v.size()),
+ validVoters));
+ }
+
+ LocalReplica me = findLocal(v);
+ if (me == null) {
+ throw new IllegalArgumentException(
+ KetchText.get().localReplicaRequired);
+ }
+
+ lock.lock();
+ try {
+ voters = v.toArray(new KetchReplica[v.size()]);
+ followers = f.toArray(new KetchReplica[f.size()]);
+ self = me;
+ } finally {
+ lock.unlock();
+ }
+ }
+
+ private static Collection<Integer> validVoterCounts() {
+ @SuppressWarnings("boxing")
+ Integer[] valid = {
+ // An odd number of voting replicas is required.
+ 1, 3, 5, 7, 9 };
+ return Arrays.asList(valid);
+ }
+
+ private static LocalReplica findLocal(Collection<KetchReplica> voters) {
+ for (KetchReplica r : voters) {
+ if (r instanceof LocalReplica) {
+ return (LocalReplica) r;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Get an instance of the repository for use by a leader thread.
+ * <p>
+ * The caller will close the repository.
+ *
+ * @return opened repository for use by the leader thread.
+ * @throws IOException
+ * cannot reopen the repository for the leader.
+ */
+ protected abstract Repository openRepository() throws IOException;
+
+ /**
+ * Queue a reference update proposal for consensus.
+ * <p>
+ * This method does not wait for consensus to be reached. The proposal is
+ * checked to look for risks of conflicts, and then submitted into the queue
+ * for distribution as soon as possible.
+ * <p>
+ * Callers must use {@link Proposal#await()} to see if the proposal is done.
+ *
+ * @param proposal
+ * the proposed reference updates to queue for consideration.
+ * Once execution is complete the individual reference result
+ * fields will be populated with the outcome.
+ * @throws InterruptedException
+ * current thread was interrupted. The proposal may have been
+ * aborted if it was not yet queued for execution.
+ * @throws IOException
+ * unrecoverable error preventing proposals from being attempted
+ * by this leader.
+ */
+ public void queueProposal(Proposal proposal)
+ throws InterruptedException, IOException {
+ try {
+ lock.lockInterruptibly();
+ } catch (InterruptedException e) {
+ proposal.abort();
+ throw e;
+ }
+ try {
+ if (refTree == null) {
+ initialize();
+ for (Proposal p : queued) {
+ refTree.apply(p.getCommands());
+ }
+ } else if (roundHoldsReferenceToRefTree) {
+ refTree = refTree.copy();
+ roundHoldsReferenceToRefTree = false;
+ }
+
+ if (!refTree.apply(proposal.getCommands())) {
+ // A conflict exists so abort the proposal.
+ proposal.abort();
+ return;
+ }
+
+ queued.add(proposal);
+ proposal.notifyState(QUEUED);
+
+ if (idle) {
+ scheduleLeader();
+ }
+ } finally {
+ lock.unlock();
+ }
+ }
+
+ private void initialize() throws IOException {
+ try (Repository git = openRepository(); RevWalk rw = new RevWalk(git)) {
+ self.initialize(git);
+
+ ObjectId accepted = self.getTxnAccepted();
+ if (!ObjectId.zeroId().equals(accepted)) {
+ RevCommit c = rw.parseCommit(accepted);
+ headIndex = LogIndex.unknown(accepted);
+ refTree = RefTree.read(rw.getObjectReader(), c.getTree());
+ } else {
+ headIndex = LogIndex.unknown(ObjectId.zeroId());
+ refTree = RefTree.newEmptyTree();
+ }
+ }
+ }
+
+ private void scheduleLeader() {
+ idle = false;
+ system.getExecutor().execute(new Runnable() {
+ @Override
+ public void run() {
+ runLeader();
+ }
+ });
+ }
+
+ private void runLeader() {
+ Round round;
+ lock.lock();
+ try {
+ switch (state) {
+ case CANDIDATE:
+ round = new ElectionRound(this, headIndex);
+ break;
+
+ case LEADER:
+ round = newProposalRound();
+ break;
+
+ case DEPOSED:
+ case SHUTDOWN:
+ default:
+ log.warn("Leader cannot run {}", state); //$NON-NLS-1$
+ // TODO(sop): Redirect proposals.
+ return;
+ }
+ } finally {
+ lock.unlock();
+ }
+
+ try {
+ round.start();
+ } catch (IOException e) {
+ // TODO(sop) Depose leader if it cannot use its repository.
+ log.error(KetchText.get().leaderFailedToStore, e);
+ lock.lock();
+ try {
+ nextRound();
+ } finally {
+ lock.unlock();
+ }
+ }
+ }
+
+ private ProposalRound newProposalRound() {
+ List<Proposal> todo = new ArrayList<>(queued);
+ queued.clear();
+ roundHoldsReferenceToRefTree = true;
+ return new ProposalRound(this, headIndex, todo, refTree);
+ }
+
+ /** @return term of this leader's reign. */
+ long getTerm() {
+ return term;
+ }
+
+ /** @return end of the leader's log. */
+ LogIndex getHead() {
+ return headIndex;
+ }
+
+ /**
+ * @return state leader knows it has committed across a quorum of replicas.
+ */
+ LogIndex getCommitted() {
+ return committedIndex;
+ }
+
+ boolean isIdle() {
+ return idle;
+ }
+
+ void runAsync(Round round) {
+ lock.lock();
+ try {
+ // End of the log is this round. Once transport begins it is
+ // reasonable to assume at least one replica will eventually get
+ // this, and there is reasonable probability it commits.
+ headIndex = round.acceptedNewIndex;
+ runningRound = round;
+
+ for (KetchReplica replica : voters) {
+ replica.pushTxnAcceptedAsync(round);
+ }
+ for (KetchReplica replica : followers) {
+ replica.pushTxnAcceptedAsync(round);
+ }
+ } finally {
+ lock.unlock();
+ }
+ }
+
+ /**
+ * Asynchronous signal from a replica after completion.
+ * <p>
+ * Must be called while {@link #lock} is held by the replica.
+ *
+ * @param replica
+ * replica posting a completion event.
+ */
+ void onReplicaUpdate(KetchReplica replica) {
+ if (log.isDebugEnabled()) {
+ log.debug("Replica {} finished:\n{}", //$NON-NLS-1$
+ replica.describeForLog(), snapshot());
+ }
+
+ if (replica.getParticipation() == FOLLOWER_ONLY) {
+ // Followers cannot vote, so votes haven't changed.
+ return;
+ } else if (runningRound == null) {
+ // No round running, no need to tally votes.
+ return;
+ }
+
+ assert headIndex.equals(runningRound.acceptedNewIndex);
+ int matching = 0;
+ for (KetchReplica r : voters) {
+ if (r.hasAccepted(headIndex)) {
+ matching++;
+ }
+ }
+
+ int quorum = voters.length / 2 + 1;
+ boolean success = matching >= quorum;
+ if (!success) {
+ return;
+ }
+
+ switch (state) {
+ case CANDIDATE:
+ term = ((ElectionRound) runningRound).getTerm();
+ state = LEADER;
+ if (log.isDebugEnabled()) {
+ log.debug("Won election, running term " + term); //$NON-NLS-1$
+ }
+
+ //$FALL-THROUGH$
+ case LEADER:
+ committedIndex = headIndex;
+ if (log.isDebugEnabled()) {
+ log.debug("Committed {} in term {}", //$NON-NLS-1$
+ committedIndex.describeForLog(),
+ Long.valueOf(term));
+ }
+ nextRound();
+ commitAsync(replica);
+ notifySuccess(runningRound);
+ if (log.isDebugEnabled()) {
+ log.debug("Leader state:\n{}", snapshot()); //$NON-NLS-1$
+ }
+ break;
+
+ default:
+ log.debug("Leader ignoring replica while in {}", state); //$NON-NLS-1$
+ break;
+ }
+ }
+
+ private void notifySuccess(Round round) {
+ // Drop the leader lock while notifying Proposal listeners.
+ lock.unlock();
+ try {
+ round.success();
+ } finally {
+ lock.lock();
+ }
+ }
+
+ private void commitAsync(KetchReplica caller) {
+ for (KetchReplica r : voters) {
+ if (r == caller) {
+ continue;
+ }
+ if (r.shouldPushUnbatchedCommit(committedIndex, isIdle())) {
+ r.pushCommitAsync(committedIndex);
+ }
+ }
+ for (KetchReplica r : followers) {
+ if (r == caller) {
+ continue;
+ }
+ if (r.shouldPushUnbatchedCommit(committedIndex, isIdle())) {
+ r.pushCommitAsync(committedIndex);
+ }
+ }
+ }
+
+ /** Schedule the next round; invoked while {@link #lock} is held. */
+ void nextRound() {
+ runningRound = null;
+
+ if (queued.isEmpty()) {
+ idle = true;
+ } else {
+ // Caller holds lock. Reschedule leader on a new thread so
+ // the call stack can unwind and lock is not held unexpectedly
+ // during prepare for the next round.
+ scheduleLeader();
+ }
+ }
+
+ /** @return snapshot this leader. */
+ public LeaderSnapshot snapshot() {
+ lock.lock();
+ try {
+ LeaderSnapshot s = new LeaderSnapshot();
+ s.state = state;
+ s.term = term;
+ s.headIndex = headIndex;
+ s.committedIndex = committedIndex;
+ s.idle = isIdle();
+ for (KetchReplica r : voters) {
+ s.replicas.add(r.snapshot());
+ }
+ for (KetchReplica r : followers) {
+ s.replicas.add(r.snapshot());
+ }
+ return s;
+ } finally {
+ lock.unlock();
+ }
+ }
+
+ /** Gracefully shutdown this leader and cancel outstanding operations. */
+ public void shutdown() {
+ lock.lock();
+ try {
+ if (state != SHUTDOWN) {
+ state = SHUTDOWN;
+ for (KetchReplica r : voters) {
+ r.shutdown();
+ }
+ for (KetchReplica r : followers) {
+ r.shutdown();
+ }
+ }
+ } finally {
+ lock.unlock();
+ }
+ }
+
+ @Override
+ public String toString() {
+ return snapshot().toString();
+ }
+}
--- /dev/null
+/*
+ * 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 java.util.concurrent.TimeUnit.MILLISECONDS;
+import static org.eclipse.jgit.internal.ketch.KetchReplica.CommitSpeed.BATCHED;
+import static org.eclipse.jgit.internal.ketch.KetchReplica.CommitSpeed.FAST;
+import static org.eclipse.jgit.internal.ketch.KetchReplica.State.CURRENT;
+import static org.eclipse.jgit.internal.ketch.KetchReplica.State.LAGGING;
+import static org.eclipse.jgit.internal.ketch.KetchReplica.State.OFFLINE;
+import static org.eclipse.jgit.internal.ketch.KetchReplica.State.UNKNOWN;
+import static org.eclipse.jgit.lib.Constants.HEAD;
+import static org.eclipse.jgit.lib.FileMode.TYPE_GITLINK;
+import static org.eclipse.jgit.transport.ReceiveCommand.Result.NOT_ATTEMPTED;
+import static org.eclipse.jgit.transport.ReceiveCommand.Result.OK;
+import static org.eclipse.jgit.transport.ReceiveCommand.Type.CREATE;
+
+import java.io.IOException;
+import java.lang.ref.WeakReference;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.Callable;
+import java.util.concurrent.Future;
+
+import org.eclipse.jgit.annotations.NonNull;
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.internal.storage.reftree.RefTree;
+import org.eclipse.jgit.lib.AnyObjectId;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.transport.ReceiveCommand;
+import org.eclipse.jgit.treewalk.TreeWalk;
+import org.eclipse.jgit.util.SystemReader;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * A Ketch replica, either {@link LocalReplica} or {@link RemoteGitReplica}.
+ * <p>
+ * Replicas can be either a stock Git replica, or a Ketch-aware replica.
+ * <p>
+ * A stock Git replica has no special knowledge of Ketch and simply stores
+ * objects and references. Ketch communicates with the stock Git replica using
+ * the Git push wire protocol. The {@link KetchLeader} commits an agreed upon
+ * state by pushing all references to the Git replica, for example
+ * {@code "refs/heads/master"} is pushed during commit. Stock Git replicas use
+ * {@link CommitMethod#ALL_REFS} to record the final state.
+ * <p>
+ * Ketch-aware replicas understand the {@code RefTree} sent during the proposal
+ * and during commit are able to update their own reference space to match the
+ * state represented by the {@code RefTree}. Ketch-aware replicas typically use
+ * a {@link org.eclipse.jgit.internal.storage.reftree.RefTreeDatabase} and
+ * {@link CommitMethod#TXN_COMMITTED} to record the final state.
+ * <p>
+ * KetchReplica instances are tightly coupled with a single {@link KetchLeader}.
+ * Some state may be accessed by the leader thread and uses the leader's own
+ * {@link KetchLeader#lock} to protect shared data.
+ */
+public abstract class KetchReplica {
+ static final Logger log = LoggerFactory.getLogger(KetchReplica.class);
+ private static final byte[] PEEL = { ' ', '^' };
+
+ /** Participation of a replica in establishing consensus. */
+ public enum Participation {
+ /** Replica can vote. */
+ FULL,
+
+ /** Replica does not vote, but tracks leader. */
+ FOLLOWER_ONLY;
+ }
+
+ /** How this replica wants to receive Ketch commit operations. */
+ public enum CommitMethod {
+ /** All references are pushed to the peer as standard Git. */
+ ALL_REFS,
+
+ /** Only {@code refs/txn/committed} is written/updated. */
+ TXN_COMMITTED;
+ }
+
+ /** Delay before committing to a replica. */
+ public enum CommitSpeed {
+ /**
+ * Send the commit immediately, even if it could be batched with the
+ * next proposal.
+ */
+ FAST,
+
+ /**
+ * If the next proposal is available, batch the commit with it,
+ * otherwise just send the commit. This generates less network use, but
+ * may provide slower consistency on the replica.
+ */
+ BATCHED;
+ }
+
+ /** Current state of a replica. */
+ public enum State {
+ /** Leader has not yet contacted the replica. */
+ UNKNOWN,
+
+ /** Replica is behind the consensus. */
+ LAGGING,
+
+ /** Replica matches the consensus. */
+ CURRENT,
+
+ /** Replica has a different (or unknown) history. */
+ DIVERGENT,
+
+ /** Replica's history contains the leader's history. */
+ AHEAD,
+
+ /** Replica can not be contacted. */
+ OFFLINE;
+ }
+
+ private final KetchLeader leader;
+ private final String replicaName;
+ private final Participation participation;
+ private final CommitMethod commitMethod;
+ private final CommitSpeed commitSpeed;
+ private final long minRetryMillis;
+ private final long maxRetryMillis;
+ private final Map<ObjectId, List<ReceiveCommand>> staged;
+ private final Map<String, ReceiveCommand> running;
+ private final Map<String, ReceiveCommand> waiting;
+ private final List<ReplicaPushRequest> queued;
+
+ /**
+ * Value known for {@code "refs/txn/accepted"}.
+ * <p>
+ * Raft literature refers to this as {@code matchIndex}.
+ */
+ private ObjectId txnAccepted;
+
+ /**
+ * Value known for {@code "refs/txn/committed"}.
+ * <p>
+ * Raft literature refers to this as {@code commitIndex}. In traditional
+ * Raft this is a state variable inside the follower implementation, but
+ * Ketch keeps it in the leader.
+ */
+ private ObjectId txnCommitted;
+
+ /** What is happening with this replica. */
+ private State state = UNKNOWN;
+ private String error;
+
+ /** Scheduled retry due to communication failure. */
+ private Future<?> retryFuture;
+ private long lastRetryMillis;
+ private long retryAtMillis;
+
+ /**
+ * Configure a replica representation.
+ *
+ * @param leader
+ * instance this replica follows.
+ * @param name
+ * unique-ish name identifying this replica for debugging.
+ * @param cfg
+ * how Ketch should treat the replica.
+ */
+ protected KetchReplica(KetchLeader leader, String name, ReplicaConfig cfg) {
+ this.leader = leader;
+ this.replicaName = name;
+ this.participation = cfg.getParticipation();
+ this.commitMethod = cfg.getCommitMethod();
+ this.commitSpeed = cfg.getCommitSpeed();
+ this.minRetryMillis = cfg.getMinRetry(MILLISECONDS);
+ this.maxRetryMillis = cfg.getMaxRetry(MILLISECONDS);
+ this.staged = new HashMap<>();
+ this.running = new HashMap<>();
+ this.waiting = new HashMap<>();
+ this.queued = new ArrayList<>(4);
+ }
+
+ /** @return system configuration. */
+ public KetchSystem getSystem() {
+ return getLeader().getSystem();
+ }
+
+ /** @return leader instance this replica follows. */
+ public KetchLeader getLeader() {
+ return leader;
+ }
+
+ /** @return unique-ish name for debugging. */
+ public String getName() {
+ return replicaName;
+ }
+
+ /** @return description of this replica for error/debug logging purposes. */
+ protected String describeForLog() {
+ return getName();
+ }
+
+ /** @return how the replica participates in this Ketch system. */
+ public Participation getParticipation() {
+ return participation;
+ }
+
+ /** @return how Ketch will commit to the repository. */
+ public CommitMethod getCommitMethod() {
+ return commitMethod;
+ }
+
+ /** @return when Ketch will commit to the repository. */
+ public CommitSpeed getCommitSpeed() {
+ return commitSpeed;
+ }
+
+ /**
+ * Called by leader to perform graceful shutdown.
+ * <p>
+ * Default implementation cancels any scheduled retry. Subclasses may add
+ * additional logic before or after calling {@code super.shutdown()}.
+ * <p>
+ * Called with {@link KetchLeader#lock} held by caller.
+ */
+ protected void shutdown() {
+ Future<?> f = retryFuture;
+ if (f != null) {
+ retryFuture = null;
+ f.cancel(true);
+ }
+ }
+
+ ReplicaSnapshot snapshot() {
+ ReplicaSnapshot s = new ReplicaSnapshot(this);
+ s.accepted = txnAccepted;
+ s.committed = txnCommitted;
+ s.state = state;
+ s.error = error;
+ s.retryAtMillis = waitingForRetry() ? retryAtMillis : 0;
+ return s;
+ }
+
+ /**
+ * Update the leader's view of the replica after a poll.
+ * <p>
+ * Called with {@link KetchLeader#lock} held by caller.
+ *
+ * @param refs
+ * map of refs from the replica.
+ */
+ void initialize(Map<String, Ref> refs) {
+ if (txnAccepted == null) {
+ txnAccepted = getId(refs.get(getSystem().getTxnAccepted()));
+ }
+ if (txnCommitted == null) {
+ txnCommitted = getId(refs.get(getSystem().getTxnCommitted()));
+ }
+ }
+
+ ObjectId getTxnAccepted() {
+ return txnAccepted;
+ }
+
+ boolean hasAccepted(LogIndex id) {
+ return equals(txnAccepted, id);
+ }
+
+ private static boolean equals(@Nullable ObjectId a, LogIndex b) {
+ return a != null && b != null && AnyObjectId.equals(a, b);
+ }
+
+ /**
+ * Schedule a proposal round with the replica.
+ * <p>
+ * Called with {@link KetchLeader#lock} held by caller.
+ *
+ * @param round
+ * current round being run by the leader.
+ */
+ void pushTxnAcceptedAsync(Round round) {
+ List<ReceiveCommand> cmds = new ArrayList<>();
+ if (commitSpeed == BATCHED) {
+ LogIndex committedIndex = leader.getCommitted();
+ if (equals(txnAccepted, committedIndex)
+ && !equals(txnCommitted, committedIndex)) {
+ prepareTxnCommitted(cmds, committedIndex);
+ }
+ }
+
+ // TODO(sop) Lagging replicas should build accept on the fly.
+ if (round.stageCommands != null) {
+ for (ReceiveCommand cmd : round.stageCommands) {
+ // TODO(sop): Do not send certain object graphs to replica.
+ cmds.add(copy(cmd));
+ }
+ }
+ cmds.add(new ReceiveCommand(
+ round.acceptedOldIndex, round.acceptedNewIndex,
+ getSystem().getTxnAccepted()));
+ pushAsync(new ReplicaPushRequest(this, cmds));
+ }
+
+ private static ReceiveCommand copy(ReceiveCommand c) {
+ return new ReceiveCommand(c.getOldId(), c.getNewId(), c.getRefName());
+ }
+
+ boolean shouldPushUnbatchedCommit(LogIndex committed, boolean leaderIdle) {
+ return (leaderIdle || commitSpeed == FAST) && hasAccepted(committed);
+ }
+
+ void pushCommitAsync(LogIndex committed) {
+ List<ReceiveCommand> cmds = new ArrayList<>();
+ prepareTxnCommitted(cmds, committed);
+ pushAsync(new ReplicaPushRequest(this, cmds));
+ }
+
+ private void prepareTxnCommitted(List<ReceiveCommand> cmds,
+ ObjectId committed) {
+ removeStaged(cmds, committed);
+ cmds.add(new ReceiveCommand(
+ txnCommitted, committed,
+ getSystem().getTxnCommitted()));
+ }
+
+ private void removeStaged(List<ReceiveCommand> cmds, ObjectId committed) {
+ List<ReceiveCommand> a = staged.remove(committed);
+ if (a != null) {
+ delete(cmds, a);
+ }
+ if (staged.isEmpty() || !(committed instanceof LogIndex)) {
+ return;
+ }
+
+ LogIndex committedIndex = (LogIndex) committed;
+ Iterator<Map.Entry<ObjectId, List<ReceiveCommand>>> itr = staged
+ .entrySet().iterator();
+ while (itr.hasNext()) {
+ Map.Entry<ObjectId, List<ReceiveCommand>> e = itr.next();
+ if (e.getKey() instanceof LogIndex) {
+ LogIndex stagedIndex = (LogIndex) e.getKey();
+ if (stagedIndex.isBefore(committedIndex)) {
+ delete(cmds, e.getValue());
+ itr.remove();
+ }
+ }
+ }
+ }
+
+ private static void delete(List<ReceiveCommand> cmds,
+ List<ReceiveCommand> createCmds) {
+ for (ReceiveCommand cmd : createCmds) {
+ ObjectId id = cmd.getNewId();
+ String name = cmd.getRefName();
+ cmds.add(new ReceiveCommand(id, ObjectId.zeroId(), name));
+ }
+ }
+
+ /**
+ * Determine the next push for this replica (if any) and start it.
+ * <p>
+ * If the replica has successfully accepted the committed state of the
+ * leader, this method will push all references to the replica using the
+ * configured {@link CommitMethod}.
+ * <p>
+ * If the replica is {@link State#LAGGING} this method will begin catch up
+ * by sending a more recent {@code refs/txn/accepted}.
+ * <p>
+ * Must be invoked with {@link KetchLeader#lock} held by caller.
+ */
+ private void runNextPushRequest() {
+ LogIndex committed = leader.getCommitted();
+ if (!equals(txnCommitted, committed)
+ && shouldPushUnbatchedCommit(committed, leader.isIdle())) {
+ pushCommitAsync(committed);
+ }
+
+ if (queued.isEmpty() || !running.isEmpty() || waitingForRetry()) {
+ return;
+ }
+
+ // Collapse all queued requests into a single request.
+ Map<String, ReceiveCommand> cmdMap = new HashMap<>();
+ for (ReplicaPushRequest req : queued) {
+ for (ReceiveCommand cmd : req.getCommands()) {
+ String name = cmd.getRefName();
+ ReceiveCommand old = cmdMap.remove(name);
+ if (old != null) {
+ cmd = new ReceiveCommand(
+ old.getOldId(), cmd.getNewId(),
+ name);
+ }
+ cmdMap.put(name, cmd);
+ }
+ }
+ queued.clear();
+ waiting.clear();
+
+ List<ReceiveCommand> next = new ArrayList<>(cmdMap.values());
+ for (ReceiveCommand cmd : next) {
+ running.put(cmd.getRefName(), cmd);
+ }
+ startPush(new ReplicaPushRequest(this, next));
+ }
+
+ private void pushAsync(ReplicaPushRequest req) {
+ if (defer(req)) {
+ // TODO(sop) Collapse during long retry outage.
+ for (ReceiveCommand cmd : req.getCommands()) {
+ waiting.put(cmd.getRefName(), cmd);
+ }
+ queued.add(req);
+ } else {
+ for (ReceiveCommand cmd : req.getCommands()) {
+ running.put(cmd.getRefName(), cmd);
+ }
+ startPush(req);
+ }
+ }
+
+ private boolean defer(ReplicaPushRequest req) {
+ if (waitingForRetry()) {
+ // Prior communication failure; everything is deferred.
+ return true;
+ }
+
+ for (ReceiveCommand nextCmd : req.getCommands()) {
+ ReceiveCommand priorCmd = waiting.get(nextCmd.getRefName());
+ if (priorCmd == null) {
+ priorCmd = running.get(nextCmd.getRefName());
+ }
+ if (priorCmd != null) {
+ // Another request pending on same ref; that must go first.
+ // Verify priorCmd.newId == nextCmd.oldId?
+ return true;
+ }
+ }
+ return false;
+ }
+
+ private boolean waitingForRetry() {
+ Future<?> f = retryFuture;
+ return f != null && !f.isDone();
+ }
+
+ private void retryLater(ReplicaPushRequest req) {
+ Collection<ReceiveCommand> cmds = req.getCommands();
+ for (ReceiveCommand cmd : cmds) {
+ cmd.setResult(NOT_ATTEMPTED, null);
+ if (!waiting.containsKey(cmd.getRefName())) {
+ waiting.put(cmd.getRefName(), cmd);
+ }
+ }
+ queued.add(0, new ReplicaPushRequest(this, cmds));
+
+ if (!waitingForRetry()) {
+ long delay = KetchSystem.delay(
+ lastRetryMillis,
+ minRetryMillis, maxRetryMillis);
+ if (log.isDebugEnabled()) {
+ log.debug("Retrying {} after {} ms", //$NON-NLS-1$
+ describeForLog(), Long.valueOf(delay));
+ }
+ lastRetryMillis = delay;
+ retryAtMillis = SystemReader.getInstance().getCurrentTime() + delay;
+ retryFuture = getSystem().getExecutor()
+ .schedule(new WeakRetryPush(this), delay, MILLISECONDS);
+ }
+ }
+
+ /** Weakly holds a retrying replica, allowing it to garbage collect. */
+ static class WeakRetryPush extends WeakReference<KetchReplica>
+ implements Callable<Void> {
+ WeakRetryPush(KetchReplica r) {
+ super(r);
+ }
+
+ @Override
+ public Void call() throws Exception {
+ KetchReplica r = get();
+ if (r != null) {
+ r.doRetryPush();
+ }
+ return null;
+ }
+ }
+
+ private void doRetryPush() {
+ leader.lock.lock();
+ try {
+ retryFuture = null;
+ runNextPushRequest();
+ } finally {
+ leader.lock.unlock();
+ }
+ }
+
+ /**
+ * Begin executing a single push.
+ * <p>
+ * This method must move processing onto another thread.
+ * Called with {@link KetchLeader#lock} held by caller.
+ *
+ * @param req
+ * the request to send to the replica.
+ */
+ protected abstract void startPush(ReplicaPushRequest req);
+
+ /**
+ * Callback from {@link ReplicaPushRequest} upon success or failure.
+ * <p>
+ * Acquires the {@link KetchLeader#lock} and updates the leader's internal
+ * knowledge about this replica to reflect what has been learned during a
+ * push to the replica. In some cases of divergence this method may take
+ * some time to determine how the replica has diverged; to reduce contention
+ * this is evaluated before acquiring the leader lock.
+ *
+ * @param repo
+ * local repository instance used by the push thread.
+ * @param req
+ * push request just attempted.
+ */
+ void afterPush(@Nullable Repository repo, ReplicaPushRequest req) {
+ ReceiveCommand acceptCmd = null;
+ ReceiveCommand commitCmd = null;
+ List<ReceiveCommand> stages = null;
+
+ for (ReceiveCommand cmd : req.getCommands()) {
+ String name = cmd.getRefName();
+ if (name.equals(getSystem().getTxnAccepted())) {
+ acceptCmd = cmd;
+ } else if (name.equals(getSystem().getTxnCommitted())) {
+ commitCmd = cmd;
+ } else if (cmd.getResult() == OK && cmd.getType() == CREATE
+ && name.startsWith(getSystem().getTxnStage())) {
+ if (stages == null) {
+ stages = new ArrayList<>();
+ }
+ stages.add(cmd);
+ }
+ }
+
+ State newState = null;
+ ObjectId acceptId = readId(req, acceptCmd);
+ if (repo != null && acceptCmd != null && acceptCmd.getResult() != OK
+ && req.getException() == null) {
+ try (LagCheck lag = new LagCheck(this, repo)) {
+ newState = lag.check(acceptId, acceptCmd);
+ acceptId = lag.getRemoteId();
+ }
+ }
+
+ leader.lock.lock();
+ try {
+ for (ReceiveCommand cmd : req.getCommands()) {
+ running.remove(cmd.getRefName());
+ }
+
+ Throwable err = req.getException();
+ if (err != null) {
+ state = OFFLINE;
+ error = err.toString();
+ retryLater(req);
+ leader.onReplicaUpdate(this);
+ return;
+ }
+
+ lastRetryMillis = 0;
+ error = null;
+ updateView(req, acceptId, commitCmd);
+
+ if (acceptCmd != null && acceptCmd.getResult() == OK) {
+ state = hasAccepted(leader.getHead()) ? CURRENT : LAGGING;
+ if (stages != null) {
+ staged.put(acceptCmd.getNewId(), stages);
+ }
+ } else if (newState != null) {
+ state = newState;
+ }
+
+ leader.onReplicaUpdate(this);
+ runNextPushRequest();
+ } finally {
+ leader.lock.unlock();
+ }
+ }
+
+ private void updateView(ReplicaPushRequest req, @Nullable ObjectId acceptId,
+ ReceiveCommand commitCmd) {
+ if (acceptId != null) {
+ txnAccepted = acceptId;
+ }
+
+ ObjectId committed = readId(req, commitCmd);
+ if (committed != null) {
+ txnCommitted = committed;
+ } else if (acceptId != null && txnCommitted == null) {
+ // Initialize during first conversation.
+ Map<String, Ref> adv = req.getRefs();
+ if (adv != null) {
+ Ref refs = adv.get(getSystem().getTxnCommitted());
+ txnCommitted = getId(refs);
+ }
+ }
+ }
+
+ @Nullable
+ private static ObjectId readId(ReplicaPushRequest req,
+ @Nullable ReceiveCommand cmd) {
+ if (cmd == null) {
+ // Ref was not in the command list, do not trust advertisement.
+ return null;
+
+ } else if (cmd.getResult() == OK) {
+ // Currently at newId.
+ return cmd.getNewId();
+ }
+
+ Map<String, Ref> refs = req.getRefs();
+ return refs != null ? getId(refs.get(cmd.getRefName())) : null;
+ }
+
+ /**
+ * Fetch objects from the remote using the calling thread.
+ * <p>
+ * Called without {@link KetchLeader#lock}.
+ *
+ * @param repo
+ * local repository to fetch objects into.
+ * @param req
+ * the request to fetch from a replica.
+ * @throws IOException
+ * communication with the replica was not possible.
+ */
+ protected abstract void blockingFetch(Repository repo,
+ ReplicaFetchRequest req) throws IOException;
+
+ /**
+ * Build a list of commands to commit {@link CommitMethod#ALL_REFS}.
+ *
+ * @param git
+ * local leader repository to read committed state from.
+ * @param current
+ * all known references in the replica's repository. Typically
+ * this comes from a push advertisement.
+ * @param committed
+ * state being pushed to {@code refs/txn/committed}.
+ * @return commands to update during commit.
+ * @throws IOException
+ * cannot read the committed state.
+ */
+ protected Collection<ReceiveCommand> prepareCommit(Repository git,
+ Map<String, Ref> current, ObjectId committed) throws IOException {
+ List<ReceiveCommand> delta = new ArrayList<>();
+ Map<String, Ref> remote = new HashMap<>(current);
+ try (RevWalk rw = new RevWalk(git);
+ TreeWalk tw = new TreeWalk(rw.getObjectReader())) {
+ tw.setRecursive(true);
+ tw.addTree(rw.parseCommit(committed).getTree());
+ while (tw.next()) {
+ if (tw.getRawMode(0) != TYPE_GITLINK
+ || tw.isPathSuffix(PEEL, 2)) {
+ // Symbolic references cannot be pushed.
+ // Caching peeled values is handled remotely.
+ continue;
+ }
+
+ // TODO(sop) Do not send certain ref names to replica.
+ String name = RefTree.refName(tw.getPathString());
+ Ref oldRef = remote.remove(name);
+ ObjectId oldId = getId(oldRef);
+ ObjectId newId = tw.getObjectId(0);
+ if (!AnyObjectId.equals(oldId, newId)) {
+ delta.add(new ReceiveCommand(oldId, newId, name));
+ }
+ }
+ }
+
+ // Delete any extra references not in the committed state.
+ for (Ref ref : remote.values()) {
+ if (canDelete(ref)) {
+ delta.add(new ReceiveCommand(
+ ref.getObjectId(), ObjectId.zeroId(),
+ ref.getName()));
+ }
+ }
+ return delta;
+ }
+
+ boolean canDelete(Ref ref) {
+ String name = ref.getName();
+ if (HEAD.equals(name)) {
+ return false;
+ }
+ if (name.startsWith(getSystem().getTxnNamespace())) {
+ return false;
+ }
+ // TODO(sop) Do not delete precious names from replica.
+ return true;
+ }
+
+ @NonNull
+ static ObjectId getId(@Nullable Ref ref) {
+ if (ref != null) {
+ ObjectId id = ref.getObjectId();
+ if (id != null) {
+ return id;
+ }
+ }
+ return ObjectId.zeroId();
+ }
+}
--- /dev/null
+/*
+ * 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.KetchConstants.ACCEPTED;
+import static org.eclipse.jgit.internal.ketch.KetchConstants.COMMITTED;
+import static org.eclipse.jgit.internal.ketch.KetchConstants.CONFIG_KEY_TYPE;
+import static org.eclipse.jgit.internal.ketch.KetchConstants.CONFIG_SECTION_KETCH;
+import static org.eclipse.jgit.internal.ketch.KetchConstants.DEFAULT_TXN_NAMESPACE;
+import static org.eclipse.jgit.internal.ketch.KetchConstants.STAGE;
+import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_KEY_NAME;
+import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_KEY_REMOTE;
+
+import java.net.URISyntaxException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.lib.PersonIdent;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.transport.RemoteConfig;
+import org.eclipse.jgit.transport.URIish;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Ketch system-wide configuration.
+ * <p>
+ * This class provides useful defaults for testing and small proof of concepts.
+ * Full scale installations are expected to subclass and override methods to
+ * provide consistent configuration across all managed repositories.
+ * <p>
+ * Servers should configure their own {@link ScheduledExecutorService}.
+ */
+public class KetchSystem {
+ private static final Random RNG = new Random();
+
+ /** @return default executor, one thread per available processor. */
+ public static ScheduledExecutorService defaultExecutor() {
+ return DefaultExecutorHolder.I;
+ }
+
+ private final ScheduledExecutorService executor;
+ private final String txnNamespace;
+ private final String txnAccepted;
+ private final String txnCommitted;
+ private final String txnStage;
+
+ /** Create a default system with a thread pool of 1 thread per CPU. */
+ public KetchSystem() {
+ this(defaultExecutor(), DEFAULT_TXN_NAMESPACE);
+ }
+
+ /**
+ * Create a Ketch system with the provided executor service.
+ *
+ * @param executor
+ * thread pool to run background operations.
+ * @param txnNamespace
+ * reference namespace for the RefTree graph and associated
+ * transaction state. Must begin with {@code "refs/"} and end
+ * with {@code '/'}, for example {@code "refs/txn/"}.
+ */
+ public KetchSystem(ScheduledExecutorService executor, String txnNamespace) {
+ this.executor = executor;
+ this.txnNamespace = txnNamespace;
+ this.txnAccepted = txnNamespace + ACCEPTED;
+ this.txnCommitted = txnNamespace + COMMITTED;
+ this.txnStage = txnNamespace + STAGE;
+ }
+
+ /** @return executor to perform background operations. */
+ public ScheduledExecutorService getExecutor() {
+ return executor;
+ }
+
+ /**
+ * Get the namespace used for the RefTree graph and transaction management.
+ *
+ * @return reference namespace such as {@code "refs/txn/"}.
+ */
+ public String getTxnNamespace() {
+ return txnNamespace;
+ }
+
+ /** @return name of the accepted RefTree graph. */
+ public String getTxnAccepted() {
+ return txnAccepted;
+ }
+
+ /** @return name of the committed RefTree graph. */
+ public String getTxnCommitted() {
+ return txnCommitted;
+ }
+
+ /** @return prefix for staged objects, e.g. {@code "refs/txn/stage/"}. */
+ public String getTxnStage() {
+ return txnStage;
+ }
+
+ /** @return identity line for the committer header of a RefTreeGraph. */
+ public PersonIdent newCommitter() {
+ String name = "ketch"; //$NON-NLS-1$
+ String email = "ketch@system"; //$NON-NLS-1$
+ return new PersonIdent(name, email);
+ }
+
+ /**
+ * Construct a random tag to identify a candidate during leader election.
+ * <p>
+ * Multiple processes trying to elect themselves leaders at exactly the same
+ * time (rounded to seconds) using the same {@link #newCommitter()} identity
+ * strings, for the same term, may generate the same ObjectId for the
+ * election commit and falsely assume they have both won.
+ * <p>
+ * Candidates add this tag to their election ballot commit to disambiguate
+ * the election. The tag only needs to be unique for a given triplet of
+ * {@link #newCommitter()}, system time (rounded to seconds), and term. If
+ * every replica in the system uses a unique {@code newCommitter} (such as
+ * including the host name after the {@code "@"} in the email address) the
+ * tag could be the empty string.
+ * <p>
+ * The default implementation generates a few bytes of random data.
+ *
+ * @return unique tag; null or empty string if {@code newCommitter()} is
+ * sufficiently unique to identify the leader.
+ */
+ @Nullable
+ public String newLeaderTag() {
+ int n = RNG.nextInt(1 << (6 * 4));
+ return String.format("%06x", Integer.valueOf(n)); //$NON-NLS-1$
+ }
+
+ /**
+ * Construct the KetchLeader instance of a repository.
+ *
+ * @param repo
+ * local repository stored by the leader.
+ * @return leader instance.
+ * @throws URISyntaxException
+ * a follower configuration contains an unsupported URI.
+ */
+ public KetchLeader createLeader(final Repository repo)
+ throws URISyntaxException {
+ KetchLeader leader = new KetchLeader(this) {
+ @Override
+ protected Repository openRepository() {
+ repo.incrementOpen();
+ return repo;
+ }
+ };
+ leader.setReplicas(createReplicas(leader, repo));
+ return leader;
+ }
+
+ /**
+ * Get the collection of replicas for a repository.
+ * <p>
+ * The collection of replicas must include the local repository.
+ *
+ * @param leader
+ * the leader driving these replicas.
+ * @param repo
+ * repository to get the replicas of.
+ * @return collection of replicas for the specified repository.
+ * @throws URISyntaxException
+ * a configured URI is invalid.
+ */
+ protected List<KetchReplica> createReplicas(KetchLeader leader,
+ Repository repo) throws URISyntaxException {
+ List<KetchReplica> replicas = new ArrayList<>();
+ Config cfg = repo.getConfig();
+ String localName = getLocalName(cfg);
+ for (String name : cfg.getSubsections(CONFIG_KEY_REMOTE)) {
+ if (!hasParticipation(cfg, name)) {
+ continue;
+ }
+
+ ReplicaConfig kc = ReplicaConfig.newFromConfig(cfg, name);
+ if (name.equals(localName)) {
+ replicas.add(new LocalReplica(leader, name, kc));
+ continue;
+ }
+
+ RemoteConfig rc = new RemoteConfig(cfg, name);
+ List<URIish> uris = rc.getPushURIs();
+ if (uris.isEmpty()) {
+ uris = rc.getURIs();
+ }
+ for (URIish uri : uris) {
+ String n = uris.size() == 1 ? name : uri.getHost();
+ replicas.add(new RemoteGitReplica(leader, n, uri, kc, rc));
+ }
+ }
+ return replicas;
+ }
+
+ private static boolean hasParticipation(Config cfg, String name) {
+ return cfg.getString(CONFIG_KEY_REMOTE, name, CONFIG_KEY_TYPE) != null;
+ }
+
+ private static String getLocalName(Config cfg) {
+ return cfg.getString(CONFIG_SECTION_KETCH, null, CONFIG_KEY_NAME);
+ }
+
+ static class DefaultExecutorHolder {
+ private static final Logger log = LoggerFactory.getLogger(KetchSystem.class);
+ static final ScheduledExecutorService I = create();
+
+ private static ScheduledExecutorService create() {
+ int cores = Runtime.getRuntime().availableProcessors();
+ int threads = Math.max(5, cores);
+ log.info("Using {} threads", Integer.valueOf(threads)); //$NON-NLS-1$
+ return Executors.newScheduledThreadPool(
+ threads,
+ new ThreadFactory() {
+ private final AtomicInteger threadCnt = new AtomicInteger();
+
+ @Override
+ public Thread newThread(Runnable r) {
+ int id = threadCnt.incrementAndGet();
+ Thread thr = new Thread(r);
+ thr.setName("KetchExecutor-" + id); //$NON-NLS-1$
+ return thr;
+ }
+ });
+ }
+
+ private DefaultExecutorHolder() {
+ }
+ }
+
+ /**
+ * Compute a delay in a {@code min..max} interval with random jitter.
+ *
+ * @param last
+ * amount of delay waited before the last attempt. This is used
+ * to seed the next delay interval. Should be 0 if there was no
+ * prior delay.
+ * @param min
+ * shortest amount of allowable delay between attempts.
+ * @param max
+ * longest amount of allowable delay between attempts.
+ * @return new amount of delay to wait before the next attempt.
+ */
+ static long delay(long last, long min, long max) {
+ long r = Math.max(0, last * 3 - min);
+ if (r > 0) {
+ int c = (int) Math.min(r + 1, Integer.MAX_VALUE);
+ r = RNG.nextInt(c);
+ }
+ return Math.max(Math.min(min + r, max), min);
+ }
+}
--- /dev/null
+/*
+ * 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 org.eclipse.jgit.nls.NLS;
+import org.eclipse.jgit.nls.TranslationBundle;
+
+/** Translation bundle for the Ketch implementation. */
+public class KetchText extends TranslationBundle {
+ /** @return instance of this translation bundle. */
+ public static KetchText get() {
+ return NLS.getBundleFor(KetchText.class);
+ }
+
+ // @formatter:off
+ /***/ public String cannotFetchFromLocalReplica;
+ /***/ public String leaderFailedToStore;
+ /***/ public String localReplicaRequired;
+ /***/ public String mismatchedTxnNamespace;
+ /***/ public String outsideTxnNamespace;
+ /***/ public String queuedProposalFailedToApply;
+ /***/ public String unsupportedVoterCount;
+}
--- /dev/null
+/*
+ * 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.KetchReplica.State.AHEAD;
+import static org.eclipse.jgit.internal.ketch.KetchReplica.State.DIVERGENT;
+import static org.eclipse.jgit.internal.ketch.KetchReplica.State.LAGGING;
+import static org.eclipse.jgit.internal.ketch.KetchReplica.State.UNKNOWN;
+import static org.eclipse.jgit.lib.Constants.OBJ_COMMIT;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.Map;
+
+import org.eclipse.jgit.errors.MissingObjectException;
+import org.eclipse.jgit.lib.AnyObjectId;
+import org.eclipse.jgit.lib.ObjectId;
+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;
+
+/**
+ * A helper to check if a {@link KetchReplica} is ahead or behind the leader.
+ */
+class LagCheck implements AutoCloseable {
+ private final KetchReplica replica;
+ private final Repository repo;
+ private RevWalk rw;
+ private ObjectId remoteId;
+
+ LagCheck(KetchReplica replica, Repository repo) {
+ this.replica = replica;
+ this.repo = repo;
+ initRevWalk();
+ }
+
+ private void initRevWalk() {
+ if (rw != null) {
+ rw.close();
+ }
+
+ rw = new RevWalk(repo);
+ rw.setRetainBody(false);
+ }
+
+ public void close() {
+ if (rw != null) {
+ rw.close();
+ rw = null;
+ }
+ }
+
+ ObjectId getRemoteId() {
+ return remoteId;
+ }
+
+ KetchReplica.State check(ObjectId acceptId, ReceiveCommand acceptCmd) {
+ remoteId = acceptId;
+ if (remoteId == null) {
+ // Nothing advertised by the replica, value is unknown.
+ return UNKNOWN;
+ }
+
+ if (AnyObjectId.equals(remoteId, ObjectId.zeroId())) {
+ // Replica does not have the txnAccepted reference.
+ return LAGGING;
+ }
+
+ try {
+ RevCommit remote;
+ try {
+ remote = parseRemoteCommit(acceptCmd.getRefName());
+ } catch (RefGoneException gone) {
+ // Replica does not have the txnAccepted reference.
+ return LAGGING;
+ } catch (MissingObjectException notFound) {
+ // Local repository does not know this commit so it cannot
+ // be including the replica's log.
+ return DIVERGENT;
+ }
+
+ RevCommit head = rw.parseCommit(acceptCmd.getNewId());
+ if (rw.isMergedInto(remote, head)) {
+ return LAGGING;
+ }
+
+ // TODO(sop) Check term to see if my leader was deposed.
+ if (rw.isMergedInto(head, remote)) {
+ return AHEAD;
+ } else {
+ return DIVERGENT;
+ }
+ } catch (IOException err) {
+ KetchReplica.log.error(String.format(
+ "Cannot compare %s", //$NON-NLS-1$
+ acceptCmd.getRefName()), err);
+ return UNKNOWN;
+ }
+ }
+
+ private RevCommit parseRemoteCommit(String refName)
+ throws IOException, MissingObjectException, RefGoneException {
+ try {
+ return rw.parseCommit(remoteId);
+ } catch (MissingObjectException notLocal) {
+ // Fall through and try to acquire the object by fetching it.
+ }
+
+ ReplicaFetchRequest fetch = new ReplicaFetchRequest(
+ Collections.singleton(refName),
+ Collections.<ObjectId> emptySet());
+ try {
+ replica.blockingFetch(repo, fetch);
+ } catch (IOException fetchErr) {
+ KetchReplica.log.error(String.format(
+ "Cannot fetch %s (%s) from %s", //$NON-NLS-1$
+ remoteId.abbreviate(8).name(), refName,
+ replica.describeForLog()), fetchErr);
+ throw new MissingObjectException(remoteId, OBJ_COMMIT);
+ }
+
+ Map<String, Ref> adv = fetch.getRefs();
+ if (adv == null) {
+ throw new MissingObjectException(remoteId, OBJ_COMMIT);
+ }
+
+ Ref ref = adv.get(refName);
+ if (ref == null || ref.getObjectId() == null) {
+ throw new RefGoneException();
+ }
+
+ initRevWalk();
+ remoteId = ref.getObjectId();
+ return rw.parseCommit(remoteId);
+ }
+
+ private static class RefGoneException extends Exception {
+ private static final long serialVersionUID = 1L;
+ }
+}
--- /dev/null
+/*
+ * 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.KetchReplica.State.OFFLINE;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.lib.ObjectId;
+
+/** A snapshot of a leader and its view of the world. */
+public class LeaderSnapshot {
+ final List<ReplicaSnapshot> replicas = new ArrayList<>();
+ KetchLeader.State state;
+ long term;
+ LogIndex headIndex;
+ LogIndex committedIndex;
+ boolean idle;
+
+ LeaderSnapshot() {
+ }
+
+ /** @return unmodifiable view of configured replicas. */
+ public Collection<ReplicaSnapshot> getReplicas() {
+ return Collections.unmodifiableList(replicas);
+ }
+
+ /** @return current state of the leader. */
+ public KetchLeader.State getState() {
+ return state;
+ }
+
+ /**
+ * @return {@code true} if the leader is not running a round to reach
+ * consensus, and has no rounds queued.
+ */
+ public boolean isIdle() {
+ return idle;
+ }
+
+ /**
+ * @return term of this leader. Valid only if {@link #getState()} is
+ * currently {@link KetchLeader.State#LEADER}.
+ */
+ public long getTerm() {
+ return term;
+ }
+
+ /**
+ * @return end of the leader's log; null if leader hasn't started up enough
+ * to begin its own election.
+ */
+ @Nullable
+ public LogIndex getHead() {
+ return headIndex;
+ }
+
+ /**
+ * @return state the leader knows is committed on a majority of participant
+ * replicas. Null until the leader instance has committed a log
+ * index within its own term.
+ */
+ @Nullable
+ public LogIndex getCommitted() {
+ return committedIndex;
+ }
+
+ @Override
+ public String toString() {
+ StringBuilder s = new StringBuilder();
+ s.append(isIdle() ? "IDLE" : "RUNNING"); //$NON-NLS-1$ //$NON-NLS-2$
+ s.append(" state ").append(getState()); //$NON-NLS-1$
+ if (getTerm() > 0) {
+ s.append(" term ").append(getTerm()); //$NON-NLS-1$
+ }
+ s.append('\n');
+ s.append(String.format(
+ "%-10s %12s %12s\n", //$NON-NLS-1$
+ "Replica", "Accepted", "Committed")); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+ s.append("------------------------------------\n"); //$NON-NLS-1$
+ debug(s, "(leader)", getHead(), getCommitted()); //$NON-NLS-1$
+ s.append('\n');
+ for (ReplicaSnapshot r : getReplicas()) {
+ debug(s, r);
+ s.append('\n');
+ }
+ s.append('\n');
+ return s.toString();
+ }
+
+ private static void debug(StringBuilder b, ReplicaSnapshot s) {
+ KetchReplica replica = s.getReplica();
+ debug(b, replica.getName(), s.getAccepted(), s.getCommitted());
+ b.append(String.format(" %-8s %s", //$NON-NLS-1$
+ replica.getParticipation(), s.getState()));
+ if (s.getState() == OFFLINE) {
+ String err = s.getErrorMessage();
+ if (err != null) {
+ b.append(" (").append(err).append(')'); //$NON-NLS-1$
+ }
+ }
+ }
+
+ private static void debug(StringBuilder s, String name,
+ ObjectId accepted, ObjectId committed) {
+ s.append(String.format(
+ "%-10s %-12s %-12s", //$NON-NLS-1$
+ name, str(accepted), str(committed)));
+ }
+
+ static String str(ObjectId c) {
+ if (c instanceof LogIndex) {
+ return ((LogIndex) c).describeForLog();
+ } else if (c != null) {
+ return c.abbreviate(8).name();
+ }
+ return "-"; //$NON-NLS-1$
+ }
+}
--- /dev/null
+/*
+ * 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.KetchReplica.CommitMethod.ALL_REFS;
+import static org.eclipse.jgit.internal.ketch.KetchReplica.CommitMethod.TXN_COMMITTED;
+import static org.eclipse.jgit.lib.RefDatabase.ALL;
+import static org.eclipse.jgit.transport.ReceiveCommand.Result.OK;
+import static org.eclipse.jgit.transport.ReceiveCommand.Result.REJECTED_OTHER_REASON;
+
+import java.io.IOException;
+import java.text.MessageFormat;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+
+import org.eclipse.jgit.internal.storage.reftree.RefTreeDatabase;
+import org.eclipse.jgit.lib.BatchRefUpdate;
+import org.eclipse.jgit.lib.NullProgressMonitor;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.RefDatabase;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.transport.ReceiveCommand;
+
+/** Ketch replica running on the same system as the {@link KetchLeader}. */
+public class LocalReplica extends KetchReplica {
+ /**
+ * Configure a local replica.
+ *
+ * @param leader
+ * instance this replica follows.
+ * @param name
+ * unique-ish name identifying this replica for debugging.
+ * @param cfg
+ * how Ketch should treat the local system.
+ */
+ public LocalReplica(KetchLeader leader, String name, ReplicaConfig cfg) {
+ super(leader, name, cfg);
+ }
+
+ @Override
+ protected String describeForLog() {
+ return String.format("%s (leader)", getName()); //$NON-NLS-1$
+ }
+
+ /**
+ * Initializes local replica by reading accepted and committed references.
+ * <p>
+ * Loads accepted and committed references from the reference database of
+ * the local replica and stores their current ObjectIds in memory.
+ *
+ * @param repo
+ * repository to initialize state from.
+ * @throws IOException
+ * cannot read repository state.
+ */
+ void initialize(Repository repo) throws IOException {
+ RefDatabase refdb = repo.getRefDatabase();
+ if (refdb instanceof RefTreeDatabase) {
+ RefTreeDatabase treeDb = (RefTreeDatabase) refdb;
+ String txnNamespace = getSystem().getTxnNamespace();
+ if (!txnNamespace.equals(treeDb.getTxnNamespace())) {
+ throw new IOException(MessageFormat.format(
+ KetchText.get().mismatchedTxnNamespace,
+ txnNamespace, treeDb.getTxnNamespace()));
+ }
+ refdb = treeDb.getBootstrap();
+ }
+ initialize(refdb.exactRef(
+ getSystem().getTxnAccepted(),
+ getSystem().getTxnCommitted()));
+ }
+
+ @Override
+ protected void startPush(final ReplicaPushRequest req) {
+ getSystem().getExecutor().execute(new Runnable() {
+ @Override
+ public void run() {
+ try (Repository git = getLeader().openRepository()) {
+ try {
+ update(git, req);
+ req.done(git);
+ } catch (Throwable err) {
+ req.setException(git, err);
+ }
+ } catch (IOException err) {
+ req.setException(null, err);
+ }
+ }
+ });
+ }
+
+ @Override
+ protected void blockingFetch(Repository repo, ReplicaFetchRequest req)
+ throws IOException {
+ throw new IOException(KetchText.get().cannotFetchFromLocalReplica);
+ }
+
+ private void update(Repository git, ReplicaPushRequest req)
+ throws IOException {
+ RefDatabase refdb = git.getRefDatabase();
+ CommitMethod method = getCommitMethod();
+
+ // Local replica probably uses RefTreeDatabase, the request should
+ // be only for the txnNamespace, so drop to the bootstrap layer.
+ if (refdb instanceof RefTreeDatabase) {
+ if (!isOnlyTxnNamespace(req.getCommands())) {
+ return;
+ }
+
+ refdb = ((RefTreeDatabase) refdb).getBootstrap();
+ method = TXN_COMMITTED;
+ }
+
+ BatchRefUpdate batch = refdb.newBatchUpdate();
+ batch.setRefLogIdent(getSystem().newCommitter());
+ batch.setRefLogMessage("ketch", false); //$NON-NLS-1$
+ batch.setAllowNonFastForwards(true);
+
+ // RefDirectory updates multiple references sequentially.
+ // Run everything else first, then accepted (if present),
+ // then committed (if present). This ensures an earlier
+ // failure will not update these critical references.
+ ReceiveCommand accepted = null;
+ ReceiveCommand committed = null;
+ for (ReceiveCommand cmd : req.getCommands()) {
+ String name = cmd.getRefName();
+ if (name.equals(getSystem().getTxnAccepted())) {
+ accepted = cmd;
+ } else if (name.equals(getSystem().getTxnCommitted())) {
+ committed = cmd;
+ } else {
+ batch.addCommand(cmd);
+ }
+ }
+ if (committed != null && method == ALL_REFS) {
+ Map<String, Ref> refs = refdb.getRefs(ALL);
+ batch.addCommand(prepareCommit(git, refs, committed.getNewId()));
+ }
+ if (accepted != null) {
+ batch.addCommand(accepted);
+ }
+ if (committed != null) {
+ batch.addCommand(committed);
+ }
+
+ try (RevWalk rw = new RevWalk(git)) {
+ batch.execute(rw, NullProgressMonitor.INSTANCE);
+ }
+
+ // KetchReplica only cares about accepted and committed in
+ // advertisement. If they failed, store the current values
+ // back in the ReplicaPushRequest.
+ List<String> failed = new ArrayList<>(2);
+ checkFailed(failed, accepted);
+ checkFailed(failed, committed);
+ if (!failed.isEmpty()) {
+ String[] arr = failed.toArray(new String[failed.size()]);
+ req.setRefs(refdb.exactRef(arr));
+ }
+ }
+
+ private static void checkFailed(List<String> failed, ReceiveCommand cmd) {
+ if (cmd != null && cmd.getResult() != OK) {
+ failed.add(cmd.getRefName());
+ }
+ }
+
+ private boolean isOnlyTxnNamespace(Collection<ReceiveCommand> cmdList) {
+ // Be paranoid and reject non txnNamespace names, this
+ // is a programming error in Ketch that should not occur.
+
+ String txnNamespace = getSystem().getTxnNamespace();
+ for (ReceiveCommand cmd : cmdList) {
+ if (!cmd.getRefName().startsWith(txnNamespace)) {
+ cmd.setResult(REJECTED_OTHER_REASON,
+ MessageFormat.format(
+ KetchText.get().outsideTxnNamespace,
+ cmd.getRefName(), txnNamespace));
+ ReceiveCommand.abort(cmdList);
+ return false;
+ }
+ }
+ return true;
+ }
+}
--- /dev/null
+/*
+ * 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 org.eclipse.jgit.lib.AnyObjectId;
+import org.eclipse.jgit.lib.ObjectId;
+
+/**
+ * An ObjectId for a commit extended with incrementing log index.
+ * <p>
+ * For any two LogIndex instances, {@code A} is an ancestor of {@code C}
+ * reachable through parent edges in the graph if {@code A.index < C.index}.
+ * LogIndex provides a performance optimization for Ketch, the same information
+ * can be obtained from {@link org.eclipse.jgit.revwalk.RevWalk}.
+ * <p>
+ * Index values are only valid within a single {@link KetchLeader} instance
+ * after it has won an election. By restricting scope to a single leader new
+ * leaders do not need to traverse the entire history to determine the next
+ * {@code index} for new proposals. This differs from Raft, where leader
+ * election uses the log index and the term number to determine which replica
+ * holds a sufficiently up-to-date log. Since Ketch uses Git objects for storage
+ * of its replicated log, it keeps the term number as Raft does but uses
+ * standard Git operations to imply the log index.
+ * <p>
+ * {@link Round#runAsync(AnyObjectId)} bumps the index as each new round is
+ * constructed.
+ */
+public class LogIndex extends ObjectId {
+ static LogIndex unknown(AnyObjectId id) {
+ return new LogIndex(id, 0);
+ }
+
+ private final long index;
+
+ private LogIndex(AnyObjectId id, long index) {
+ super(id);
+ this.index = index;
+ }
+
+ LogIndex nextIndex(AnyObjectId id) {
+ return new LogIndex(id, index + 1);
+ }
+
+ /** @return index provided by the current leader instance. */
+ public long getIndex() {
+ return index;
+ }
+
+ /**
+ * Check if this log position committed before another log position.
+ * <p>
+ * Only valid for log positions in memory for the current leader.
+ *
+ * @param c
+ * other (more recent) log position.
+ * @return true if this log position was before {@code c} or equal to c and
+ * therefore any agreement of {@code c} implies agreement on this
+ * log position.
+ */
+ boolean isBefore(LogIndex c) {
+ return index <= c.index;
+ }
+
+ /**
+ * @return string suitable for debug logging containing the log index and
+ * abbreviated ObjectId.
+ */
+ @SuppressWarnings("boxing")
+ public String describeForLog() {
+ return String.format("%5d/%s", index, abbreviate(6).name()); //$NON-NLS-1$
+ }
+
+ @SuppressWarnings("boxing")
+ @Override
+ public String toString() {
+ return String.format("LogId[%5d/%s]", index, name()); //$NON-NLS-1$
+ }
+}
--- /dev/null
+/*
+ * 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.ABORTED;
+import static org.eclipse.jgit.internal.ketch.Proposal.State.EXECUTED;
+import static org.eclipse.jgit.internal.ketch.Proposal.State.NEW;
+import static org.eclipse.jgit.transport.ReceiveCommand.Result.NOT_ATTEMPTED;
+import static org.eclipse.jgit.transport.ReceiveCommand.Result.OK;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.errors.MissingObjectException;
+import org.eclipse.jgit.internal.storage.reftree.Command;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.PersonIdent;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.transport.PushCertificate;
+import org.eclipse.jgit.transport.ReceiveCommand;
+
+/**
+ * A proposal to be applied in a Ketch system.
+ * <p>
+ * Pushing to a Ketch leader results in the leader making a proposal. The
+ * proposal includes the list of reference updates. The leader attempts to send
+ * the proposal to a quorum of replicas by pushing the proposal to a "staging"
+ * area under the {@code refs/txn/stage/} namespace. If the proposal succeeds
+ * then the changes are durable and the leader can commit the proposal.
+ * <p>
+ * Proposals are executed by {@link KetchLeader#queueProposal(Proposal)}, which
+ * runs them asynchronously in the background. Proposals are thread-safe futures
+ * allowing callers to {@link #await()} for results or be notified by callback
+ * using {@link #addListener(Runnable)}.
+ */
+public class Proposal {
+ /** Current state of the proposal. */
+ public enum State {
+ /** Proposal has not yet been given to a {@link KetchLeader}. */
+ NEW(false),
+
+ /**
+ * Proposal was validated and has entered the queue, but a round
+ * containing this proposal has not started yet.
+ */
+ QUEUED(false),
+
+ /** Round containing the proposal has begun and is in progress. */
+ RUNNING(false),
+
+ /**
+ * Proposal was executed through a round. Individual results from
+ * {@link Proposal#getCommands()}, {@link Command#getResult()} explain
+ * the success or failure outcome.
+ */
+ EXECUTED(true),
+
+ /** Proposal was aborted and did not reach consensus. */
+ ABORTED(true);
+
+ private final boolean done;
+
+ private State(boolean done) {
+ this.done = done;
+ }
+
+ /** @return true if this is a terminal state. */
+ public boolean isDone() {
+ return done;
+ }
+ }
+
+ private final List<Command> commands;
+ private PersonIdent author;
+ private String message;
+ private PushCertificate pushCert;
+ private final List<Runnable> listeners = new CopyOnWriteArrayList<>();
+ private final AtomicReference<State> state = new AtomicReference<>(NEW);
+
+ /**
+ * Create a proposal from a list of Ketch commands.
+ *
+ * @param cmds
+ * prepared list of commands.
+ */
+ public Proposal(List<Command> cmds) {
+ commands = Collections.unmodifiableList(new ArrayList<>(cmds));
+ }
+
+ /**
+ * Create a proposal from a collection of received commands.
+ *
+ * @param rw
+ * walker to assist in preparing commands.
+ * @param cmds
+ * list of pending commands.
+ * @throws MissingObjectException
+ * newId of a command is not found locally.
+ * @throws IOException
+ * local objects cannot be accessed.
+ */
+ public Proposal(RevWalk rw, Collection<ReceiveCommand> cmds)
+ throws MissingObjectException, IOException {
+ commands = asCommandList(rw, cmds);
+ }
+
+ private static List<Command> asCommandList(RevWalk rw,
+ Collection<ReceiveCommand> cmds)
+ throws MissingObjectException, IOException {
+ List<Command> commands = new ArrayList<>(cmds.size());
+ for (ReceiveCommand cmd : cmds) {
+ commands.add(new Command(rw, cmd));
+ }
+ return Collections.unmodifiableList(commands);
+ }
+
+ /** @return commands from this proposal. */
+ public Collection<Command> getCommands() {
+ return commands;
+ }
+
+ /** @return optional author of the proposal. */
+ @Nullable
+ public PersonIdent getAuthor() {
+ return author;
+ }
+
+ /**
+ * Set the author for the proposal.
+ *
+ * @param who
+ * optional identity of the author of the proposal.
+ * @return {@code this}
+ */
+ public Proposal setAuthor(@Nullable PersonIdent who) {
+ author = who;
+ return this;
+ }
+
+ /** @return optional message for the commit log of the RefTree. */
+ @Nullable
+ public String getMessage() {
+ return message;
+ }
+
+ /**
+ * Set the message to appear in the commit log of the RefTree.
+ *
+ * @param msg
+ * message text for the commit.
+ * @return {@code this}
+ */
+ public Proposal setMessage(@Nullable String msg) {
+ message = msg != null && !msg.isEmpty() ? msg : null;
+ return this;
+ }
+
+ /** @return optional certificate signing the references. */
+ @Nullable
+ public PushCertificate getPushCertificate() {
+ return pushCert;
+ }
+
+ /**
+ * Set the push certificate signing the references.
+ *
+ * @param cert
+ * certificate, may be null.
+ * @return {@code this}
+ */
+ public Proposal setPushCertificate(@Nullable PushCertificate cert) {
+ pushCert = cert;
+ return this;
+ }
+
+ /**
+ * Add a callback to be invoked when the proposal is done.
+ * <p>
+ * A proposal is done when it has entered either {@link State#EXECUTED} or
+ * {@link State#ABORTED} state. If the proposal is already done
+ * {@code callback.run()} is immediately invoked on the caller's thread.
+ *
+ * @param callback
+ * method to run after the proposal is done. The callback may be
+ * run on a Ketch system thread and should be completed quickly.
+ */
+ public void addListener(Runnable callback) {
+ boolean runNow = false;
+ synchronized (state) {
+ if (state.get().isDone()) {
+ runNow = true;
+ } else {
+ listeners.add(callback);
+ }
+ }
+ if (runNow) {
+ callback.run();
+ }
+ }
+
+ /** Set command result as OK. */
+ void success() {
+ for (Command c : commands) {
+ if (c.getResult() == NOT_ATTEMPTED) {
+ c.setResult(OK);
+ }
+ }
+ notifyState(EXECUTED);
+ }
+
+ /** Mark commands as "transaction aborted". */
+ void abort() {
+ Command.abort(commands, null);
+ notifyState(ABORTED);
+ }
+
+ /** @return read the current state of the proposal. */
+ public State getState() {
+ return state.get();
+ }
+
+ /**
+ * @return {@code true} if the proposal was attempted. A true value does not
+ * mean consensus was reached, only that the proposal was considered
+ * and will not be making any more progress beyond its current
+ * state.
+ */
+ public boolean isDone() {
+ return state.get().isDone();
+ }
+
+ /**
+ * Wait for the proposal to be attempted and {@link #isDone()} to be true.
+ *
+ * @throws InterruptedException
+ * caller was interrupted before proposal executed.
+ */
+ public void await() throws InterruptedException {
+ synchronized (state) {
+ while (!state.get().isDone()) {
+ state.wait();
+ }
+ }
+ }
+
+ /**
+ * Wait for the proposal to be attempted and {@link #isDone()} to be true.
+ *
+ * @param wait
+ * how long to wait.
+ * @param unit
+ * unit describing the wait time.
+ * @return true if the proposal is done; false if the method timed out.
+ * @throws InterruptedException
+ * caller was interrupted before proposal executed.
+ */
+ public boolean await(long wait, TimeUnit unit) throws InterruptedException {
+ synchronized (state) {
+ if (state.get().isDone()) {
+ return true;
+ }
+ state.wait(unit.toMillis(wait));
+ return state.get().isDone();
+ }
+ }
+
+ /**
+ * Wait for the proposal to exit a state.
+ *
+ * @param notIn
+ * state the proposal should not be in to return.
+ * @param wait
+ * how long to wait.
+ * @param unit
+ * unit describing the wait time.
+ * @return true if the proposal exited the state; false on time out.
+ * @throws InterruptedException
+ * caller was interrupted before proposal executed.
+ */
+ public boolean awaitStateChange(State notIn, long wait, TimeUnit unit)
+ throws InterruptedException {
+ synchronized (state) {
+ if (state.get() != notIn) {
+ return true;
+ }
+ state.wait(unit.toMillis(wait));
+ return state.get() != notIn;
+ }
+ }
+
+ void notifyState(State s) {
+ synchronized (state) {
+ state.set(s);
+ state.notifyAll();
+ }
+ if (s.isDone()) {
+ for (Runnable callback : listeners) {
+ callback.run();
+ }
+ listeners.clear();
+ }
+ }
+
+ @Override
+ public String toString() {
+ StringBuilder s = new StringBuilder();
+ s.append("Ketch Proposal {\n"); //$NON-NLS-1$
+ s.append(" ").append(state.get()).append('\n'); //$NON-NLS-1$
+ if (author != null) {
+ s.append(" author ").append(author).append('\n'); //$NON-NLS-1$
+ }
+ if (message != null) {
+ s.append(" message ").append(message).append('\n'); //$NON-NLS-1$
+ }
+ for (Command c : commands) {
+ s.append(" "); //$NON-NLS-1$
+ format(s, c.getOldRef(), "CREATE"); //$NON-NLS-1$
+ s.append(' ');
+ format(s, c.getNewRef(), "DELETE"); //$NON-NLS-1$
+ s.append(' ').append(c.getRefName());
+ if (c.getResult() != ReceiveCommand.Result.NOT_ATTEMPTED) {
+ s.append(' ').append(c.getResult()); // $NON-NLS-1$
+ }
+ s.append('\n');
+ }
+ s.append('}');
+ return s.toString();
+ }
+
+ private static void format(StringBuilder s, @Nullable Ref r, String n) {
+ if (r == null) {
+ s.append(n);
+ } else if (r.isSymbolic()) {
+ s.append(r.getTarget().getName());
+ } else {
+ ObjectId id = r.getObjectId();
+ if (id != null) {
+ s.append(id.abbreviate(8).name());
+ }
+ }
+ }
+}
--- /dev/null
+/*
+ * 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.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+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;
+
+/** 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()) {
+ id = insertProposals(git);
+ }
+ 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)
+ throws IOException, NoOp {
+ ObjectId id;
+ try (ObjectInserter inserter = git.newObjectInserter()) {
+ // TODO(sop) Process signed push certificates.
+
+ if (queuedTree != null) {
+ id = insertSingleProposal(git, inserter);
+ } else {
+ id = insertMultiProposal(git, inserter);
+ }
+
+ stageCommands = makeStageList(git, inserter);
+ inserter.flush();
+ }
+ return id;
+ }
+
+ private ObjectId insertSingleProposal(Repository git,
+ 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());
+ b.setAuthor(p.getAuthor() != null ? p.getAuthor() : b.getCommitter());
+ b.setMessage(message(p));
+ return inserter.insert(b);
+ }
+
+ private ObjectId insertMultiProposal(Repository git,
+ 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();
+ 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 static class NoOp extends Exception {
+ private static final long serialVersionUID = 1L;
+ }
+}
--- /dev/null
+/*
+ * 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.KetchReplica.CommitMethod.ALL_REFS;
+import static org.eclipse.jgit.transport.ReceiveCommand.Result.LOCK_FAILURE;
+import static org.eclipse.jgit.transport.ReceiveCommand.Result.NOT_ATTEMPTED;
+import static org.eclipse.jgit.transport.ReceiveCommand.Result.OK;
+import static org.eclipse.jgit.transport.ReceiveCommand.Result.REJECTED_NODELETE;
+import static org.eclipse.jgit.transport.ReceiveCommand.Result.REJECTED_NONFASTFORWARD;
+import static org.eclipse.jgit.transport.ReceiveCommand.Result.REJECTED_OTHER_REASON;
+import static org.eclipse.jgit.lib.Ref.Storage.NETWORK;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.errors.NotSupportedException;
+import org.eclipse.jgit.errors.TransportException;
+import org.eclipse.jgit.lib.AnyObjectId;
+import org.eclipse.jgit.lib.NullProgressMonitor;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.ObjectIdRef;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.transport.FetchConnection;
+import org.eclipse.jgit.transport.PushConnection;
+import org.eclipse.jgit.transport.ReceiveCommand;
+import org.eclipse.jgit.transport.RemoteConfig;
+import org.eclipse.jgit.transport.RemoteRefUpdate;
+import org.eclipse.jgit.transport.Transport;
+import org.eclipse.jgit.transport.URIish;
+
+/**
+ * Representation of a Git repository on a remote replica system.
+ * <p>
+ * {@link KetchLeader} will contact the replica using the Git wire protocol.
+ * <p>
+ * The remote replica may be fully Ketch-aware, or a standard Git server.
+ */
+public class RemoteGitReplica extends KetchReplica {
+ private final URIish uri;
+ private final RemoteConfig remoteConfig;
+
+ /**
+ * Configure a new remote.
+ *
+ * @param leader
+ * instance this replica follows.
+ * @param name
+ * unique-ish name identifying this remote for debugging.
+ * @param uri
+ * URI to connect to the follower's repository.
+ * @param cfg
+ * how Ketch should treat the remote system.
+ * @param rc
+ * optional remote configuration describing how to contact the
+ * peer repository.
+ */
+ public RemoteGitReplica(KetchLeader leader, String name, URIish uri,
+ ReplicaConfig cfg, @Nullable RemoteConfig rc) {
+ super(leader, name, cfg);
+ this.uri = uri;
+ this.remoteConfig = rc;
+ }
+
+ /** @return URI to contact the remote peer repository. */
+ public URIish getURI() {
+ return uri;
+ }
+
+ /** @return optional configuration describing how to contact the peer. */
+ @Nullable
+ protected RemoteConfig getRemoteConfig() {
+ return remoteConfig;
+ }
+
+ @Override
+ protected String describeForLog() {
+ return String.format("%s @ %s", getName(), getURI()); //$NON-NLS-1$
+ }
+
+ @Override
+ protected void startPush(final ReplicaPushRequest req) {
+ getSystem().getExecutor().execute(new Runnable() {
+ @Override
+ public void run() {
+ try (Repository git = getLeader().openRepository()) {
+ try {
+ push(git, req);
+ req.done(git);
+ } catch (Throwable err) {
+ req.setException(git, err);
+ }
+ } catch (IOException err) {
+ req.setException(null, err);
+ }
+ }
+ });
+ }
+
+ private void push(Repository repo, ReplicaPushRequest req)
+ throws NotSupportedException, TransportException, IOException {
+ Map<String, Ref> adv;
+ List<RemoteCommand> cmds = asUpdateList(req.getCommands());
+ try (Transport transport = Transport.open(repo, uri)) {
+ RemoteConfig rc = getRemoteConfig();
+ if (rc != null) {
+ transport.applyConfig(rc);
+ }
+ transport.setPushAtomic(true);
+ adv = push(repo, transport, cmds);
+ }
+ for (RemoteCommand c : cmds) {
+ c.copyStatusToResult();
+ }
+ req.setRefs(adv);
+ }
+
+ private Map<String, Ref> push(Repository git, Transport transport,
+ List<RemoteCommand> cmds) throws IOException {
+ Map<String, RemoteRefUpdate> updates = asUpdateMap(cmds);
+ try (PushConnection connection = transport.openPush()) {
+ Map<String, Ref> adv = connection.getRefsMap();
+ RemoteRefUpdate accepted = updates.get(getSystem().getTxnAccepted());
+ if (accepted != null && !isExpectedValue(adv, accepted)) {
+ abort(cmds);
+ return adv;
+ }
+
+ RemoteRefUpdate committed = updates.get(getSystem().getTxnCommitted());
+ if (committed != null && !isExpectedValue(adv, committed)) {
+ abort(cmds);
+ return adv;
+ }
+ if (committed != null && getCommitMethod() == ALL_REFS) {
+ prepareCommit(git, cmds, updates, adv,
+ committed.getNewObjectId());
+ }
+
+ connection.push(NullProgressMonitor.INSTANCE, updates);
+ return adv;
+ }
+ }
+
+ private static boolean isExpectedValue(Map<String, Ref> adv,
+ RemoteRefUpdate u) {
+ Ref r = adv.get(u.getRemoteName());
+ if (!AnyObjectId.equals(getId(r), u.getExpectedOldObjectId())) {
+ ((RemoteCommand) u).cmd.setResult(LOCK_FAILURE);
+ return false;
+ }
+ return true;
+ }
+
+ private void prepareCommit(Repository git, List<RemoteCommand> cmds,
+ Map<String, RemoteRefUpdate> updates, Map<String, Ref> adv,
+ ObjectId committed) throws IOException {
+ for (ReceiveCommand cmd : prepareCommit(git, adv, committed)) {
+ RemoteCommand c = new RemoteCommand(cmd);
+ cmds.add(c);
+ updates.put(c.getRemoteName(), c);
+ }
+ }
+
+ private static List<RemoteCommand> asUpdateList(
+ Collection<ReceiveCommand> cmds) {
+ try {
+ List<RemoteCommand> toPush = new ArrayList<>(cmds.size());
+ for (ReceiveCommand cmd : cmds) {
+ toPush.add(new RemoteCommand(cmd));
+ }
+ return toPush;
+ } catch (IOException e) {
+ // Cannot occur as no IO was required to build the command.
+ throw new IllegalStateException(e);
+ }
+ }
+
+ private static Map<String, RemoteRefUpdate> asUpdateMap(
+ List<RemoteCommand> cmds) {
+ Map<String, RemoteRefUpdate> m = new LinkedHashMap<>();
+ for (RemoteCommand cmd : cmds) {
+ m.put(cmd.getRemoteName(), cmd);
+ }
+ return m;
+ }
+
+ private static void abort(List<RemoteCommand> cmds) {
+ List<ReceiveCommand> tmp = new ArrayList<>(cmds.size());
+ for (RemoteCommand cmd : cmds) {
+ tmp.add(cmd.cmd);
+ }
+ ReceiveCommand.abort(tmp);
+ }
+
+ protected void blockingFetch(Repository repo, ReplicaFetchRequest req)
+ throws NotSupportedException, TransportException {
+ try (Transport transport = Transport.open(repo, uri)) {
+ RemoteConfig rc = getRemoteConfig();
+ if (rc != null) {
+ transport.applyConfig(rc);
+ }
+ fetch(transport, req);
+ }
+ }
+
+ private void fetch(Transport transport, ReplicaFetchRequest req)
+ throws NotSupportedException, TransportException {
+ try (FetchConnection conn = transport.openFetch()) {
+ Map<String, Ref> remoteRefs = conn.getRefsMap();
+ req.setRefs(remoteRefs);
+
+ List<Ref> want = new ArrayList<>();
+ for (String name : req.getWantRefs()) {
+ Ref ref = remoteRefs.get(name);
+ if (ref != null && ref.getObjectId() != null) {
+ want.add(ref);
+ }
+ }
+ for (ObjectId id : req.getWantObjects()) {
+ want.add(new ObjectIdRef.Unpeeled(NETWORK, id.name(), id));
+ }
+
+ conn.fetch(NullProgressMonitor.INSTANCE, want,
+ Collections.<ObjectId> emptySet());
+ }
+ }
+
+ static class RemoteCommand extends RemoteRefUpdate {
+ final ReceiveCommand cmd;
+
+ RemoteCommand(ReceiveCommand cmd) throws IOException {
+ super(null, null,
+ cmd.getNewId(), cmd.getRefName(),
+ true /* force update */,
+ null /* no local tracking ref */,
+ cmd.getOldId());
+ this.cmd = cmd;
+ }
+
+ void copyStatusToResult() {
+ if (cmd.getResult() == NOT_ATTEMPTED) {
+ switch (getStatus()) {
+ case OK:
+ case UP_TO_DATE:
+ case NON_EXISTING:
+ cmd.setResult(OK);
+ break;
+
+ case REJECTED_NODELETE:
+ cmd.setResult(REJECTED_NODELETE);
+ break;
+
+ case REJECTED_NONFASTFORWARD:
+ cmd.setResult(REJECTED_NONFASTFORWARD);
+ break;
+
+ case REJECTED_OTHER_REASON:
+ cmd.setResult(REJECTED_OTHER_REASON, getMessage());
+ break;
+
+ default:
+ cmd.setResult(REJECTED_OTHER_REASON, getStatus().name());
+ break;
+ }
+ }
+ }
+ }
+}
--- /dev/null
+/*
+ * 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 java.util.concurrent.TimeUnit.DAYS;
+import static java.util.concurrent.TimeUnit.HOURS;
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static org.eclipse.jgit.internal.ketch.KetchConstants.CONFIG_KEY_COMMIT;
+import static org.eclipse.jgit.internal.ketch.KetchConstants.CONFIG_KEY_SPEED;
+import static org.eclipse.jgit.internal.ketch.KetchConstants.CONFIG_KEY_TYPE;
+import static org.eclipse.jgit.lib.ConfigConstants.CONFIG_KEY_REMOTE;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.eclipse.jgit.internal.ketch.KetchReplica.CommitMethod;
+import org.eclipse.jgit.internal.ketch.KetchReplica.CommitSpeed;
+import org.eclipse.jgit.internal.ketch.KetchReplica.Participation;
+import org.eclipse.jgit.lib.Config;
+
+/** Configures a {@link KetchReplica}. */
+public class ReplicaConfig {
+ /**
+ * Read a configuration from a config block.
+ *
+ * @param cfg
+ * configuration to read.
+ * @param name
+ * of the replica being configured.
+ * @return replica configuration for {@code name}.
+ */
+ public static ReplicaConfig newFromConfig(Config cfg, String name) {
+ return new ReplicaConfig().fromConfig(cfg, name);
+ }
+
+ private Participation participation = Participation.FULL;
+ private CommitMethod commitMethod = CommitMethod.ALL_REFS;
+ private CommitSpeed commitSpeed = CommitSpeed.BATCHED;
+ private long minRetry = SECONDS.toMillis(5);
+ private long maxRetry = MINUTES.toMillis(1);
+
+ /** @return participation of the replica in the system. */
+ public Participation getParticipation() {
+ return participation;
+ }
+
+ /** @return how Ketch should apply committed changes. */
+ public CommitMethod getCommitMethod() {
+ return commitMethod;
+ }
+
+ /** @return how quickly should Ketch commit. */
+ public CommitSpeed getCommitSpeed() {
+ return commitSpeed;
+ }
+
+ /**
+ * Returns the minimum wait delay before retrying a failure.
+ *
+ * @param unit
+ * to get retry delay in.
+ * @return minimum delay before retrying a failure.
+ */
+ public long getMinRetry(TimeUnit unit) {
+ return unit.convert(minRetry, MILLISECONDS);
+ }
+
+ /**
+ * Returns the maximum wait delay before retrying a failure.
+ *
+ * @param unit
+ * to get retry delay in.
+ * @return maximum delay before retrying a failure.
+ */
+ public long getMaxRetry(TimeUnit unit) {
+ return unit.convert(maxRetry, MILLISECONDS);
+ }
+
+ /**
+ * Update the configuration from a config block.
+ *
+ * @param cfg
+ * configuration to read.
+ * @param name
+ * of the replica being configured.
+ * @return {@code this}
+ */
+ public ReplicaConfig fromConfig(Config cfg, String name) {
+ participation = cfg.getEnum(
+ CONFIG_KEY_REMOTE, name, CONFIG_KEY_TYPE,
+ participation);
+ commitMethod = cfg.getEnum(
+ CONFIG_KEY_REMOTE, name, CONFIG_KEY_COMMIT,
+ commitMethod);
+ commitSpeed = cfg.getEnum(
+ CONFIG_KEY_REMOTE, name, CONFIG_KEY_SPEED,
+ commitSpeed);
+ minRetry = getMillis(cfg, name, "ketch-minRetry", minRetry); //$NON-NLS-1$
+ maxRetry = getMillis(cfg, name, "ketch-maxRetry", maxRetry); //$NON-NLS-1$
+ return this;
+ }
+
+ private static long getMillis(Config cfg, String name, String key,
+ long defaultValue) {
+ String valStr = cfg.getString(CONFIG_KEY_REMOTE, name, key);
+ if (valStr == null) {
+ return defaultValue;
+ }
+
+ valStr = valStr.trim();
+ if (valStr.isEmpty()) {
+ return defaultValue;
+ }
+
+ Matcher m = UnitMap.PATTERN.matcher(valStr);
+ if (!m.matches()) {
+ return defaultValue;
+ }
+
+ String digits = m.group(1);
+ String unitName = m.group(2).trim();
+ TimeUnit unit = UnitMap.UNITS.get(unitName);
+ if (unit == null) {
+ return defaultValue;
+ }
+
+ try {
+ if (digits.indexOf('.') == -1) {
+ return unit.toMillis(Long.parseLong(digits));
+ }
+
+ double val = Double.parseDouble(digits);
+ return (long) (val * unit.toMillis(1));
+ } catch (NumberFormatException nfe) {
+ return defaultValue;
+ }
+ }
+
+ static class UnitMap {
+ static final Pattern PATTERN = Pattern
+ .compile("^([1-9][0-9]*(?:\\.[0-9]*)?)\\s*(.*)$"); //$NON-NLS-1$
+
+ static final Map<String, TimeUnit> UNITS;
+
+ static {
+ Map<String, TimeUnit> m = new HashMap<>();
+ TimeUnit u = MILLISECONDS;
+ m.put("", u); //$NON-NLS-1$
+ m.put("ms", u); //$NON-NLS-1$
+ m.put("millis", u); //$NON-NLS-1$
+ m.put("millisecond", u); //$NON-NLS-1$
+ m.put("milliseconds", u); //$NON-NLS-1$
+
+ u = SECONDS;
+ m.put("s", u); //$NON-NLS-1$
+ m.put("sec", u); //$NON-NLS-1$
+ m.put("secs", u); //$NON-NLS-1$
+ m.put("second", u); //$NON-NLS-1$
+ m.put("seconds", u); //$NON-NLS-1$
+
+ u = MINUTES;
+ m.put("m", u); //$NON-NLS-1$
+ m.put("min", u); //$NON-NLS-1$
+ m.put("mins", u); //$NON-NLS-1$
+ m.put("minute", u); //$NON-NLS-1$
+ m.put("minutes", u); //$NON-NLS-1$
+
+ u = HOURS;
+ m.put("h", u); //$NON-NLS-1$
+ m.put("hr", u); //$NON-NLS-1$
+ m.put("hrs", u); //$NON-NLS-1$
+ m.put("hour", u); //$NON-NLS-1$
+ m.put("hours", u); //$NON-NLS-1$
+
+ u = DAYS;
+ m.put("d", u); //$NON-NLS-1$
+ m.put("day", u); //$NON-NLS-1$
+ m.put("days", u); //$NON-NLS-1$
+
+ UNITS = Collections.unmodifiableMap(m);
+ }
+
+ private UnitMap() {
+ }
+ }
+}
--- /dev/null
+/*
+ * 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 java.util.Map;
+import java.util.Set;
+
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
+
+/** A fetch request to obtain objects from a replica, and its result. */
+public class ReplicaFetchRequest {
+ private final Set<String> wantRefs;
+ private final Set<ObjectId> wantObjects;
+ private Map<String, Ref> refs;
+
+ /**
+ * Construct a new fetch request for a replica.
+ *
+ * @param wantRefs
+ * named references to be fetched.
+ * @param wantObjects
+ * specific objects to be fetched.
+ */
+ public ReplicaFetchRequest(Set<String> wantRefs,
+ Set<ObjectId> wantObjects) {
+ this.wantRefs = wantRefs;
+ this.wantObjects = wantObjects;
+ }
+
+ /** @return references to be fetched. */
+ public Set<String> getWantRefs() {
+ return wantRefs;
+ }
+
+ /** @return objects to be fetched. */
+ public Set<ObjectId> getWantObjects() {
+ return wantObjects;
+ }
+
+ /** @return remote references, usually from the advertisement. */
+ @Nullable
+ public Map<String, Ref> getRefs() {
+ return refs;
+ }
+
+ /**
+ * @param refs
+ * references observed from the replica.
+ */
+ public void setRefs(Map<String, Ref> refs) {
+ this.refs = refs;
+ }
+}
--- /dev/null
+/*
+ * 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 java.util.Collection;
+import java.util.Map;
+
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.transport.ReceiveCommand;
+
+/**
+ * A push request sending objects to a replica, and its result.
+ * <p>
+ * Implementors of {@link KetchReplica} must populate the command result fields,
+ * {@link #setRefs(Map)}, and call one of
+ * {@link #setException(Repository, Throwable)} or {@link #done(Repository)} to
+ * finish processing.
+ */
+public class ReplicaPushRequest {
+ private final KetchReplica replica;
+ private final Collection<ReceiveCommand> commands;
+ private Map<String, Ref> refs;
+ private Throwable exception;
+ private boolean notified;
+
+ /**
+ * Construct a new push request for a replica.
+ *
+ * @param replica
+ * the replica being pushed to.
+ * @param commands
+ * commands to be executed.
+ */
+ public ReplicaPushRequest(KetchReplica replica,
+ Collection<ReceiveCommand> commands) {
+ this.replica = replica;
+ this.commands = commands;
+ }
+
+ /** @return commands to be executed, and their results. */
+ public Collection<ReceiveCommand> getCommands() {
+ return commands;
+ }
+
+ /** @return remote references, usually from the advertisement. */
+ @Nullable
+ public Map<String, Ref> getRefs() {
+ return refs;
+ }
+
+ /**
+ * @param refs
+ * references observed from the replica.
+ */
+ public void setRefs(Map<String, Ref> refs) {
+ this.refs = refs;
+ }
+
+ /** @return exception thrown, if any. */
+ @Nullable
+ public Throwable getException() {
+ return exception;
+ }
+
+ /**
+ * Mark the request as crashing with a communication error.
+ * <p>
+ * This method may take significant time acquiring the leader lock and
+ * updating the Ketch state machine with the failure.
+ *
+ * @param repo
+ * local repository reference used by the push attempt.
+ * @param err
+ * exception thrown during communication.
+ */
+ public void setException(@Nullable Repository repo, Throwable err) {
+ if (KetchReplica.log.isErrorEnabled()) {
+ KetchReplica.log.error(describe("failed"), err); //$NON-NLS-1$
+ }
+ if (!notified) {
+ notified = true;
+ exception = err;
+ replica.afterPush(repo, this);
+ }
+ }
+
+ /**
+ * Mark the request as completed without exception.
+ * <p>
+ * This method may take significant time acquiring the leader lock and
+ * updating the Ketch state machine with results from this replica.
+ *
+ * @param repo
+ * local repository reference used by the push attempt.
+ */
+ public void done(Repository repo) {
+ if (KetchReplica.log.isDebugEnabled()) {
+ KetchReplica.log.debug(describe("completed")); //$NON-NLS-1$
+ }
+ if (!notified) {
+ notified = true;
+ replica.afterPush(repo, this);
+ }
+ }
+
+ private String describe(String heading) {
+ StringBuilder b = new StringBuilder();
+ b.append("push to "); //$NON-NLS-1$
+ b.append(replica.describeForLog());
+ b.append(' ').append(heading).append(":\n"); //$NON-NLS-1$
+ for (ReceiveCommand cmd : commands) {
+ b.append(String.format(
+ " %-12s %-12s %s %s", //$NON-NLS-1$
+ LeaderSnapshot.str(cmd.getOldId()),
+ LeaderSnapshot.str(cmd.getNewId()),
+ cmd.getRefName(),
+ cmd.getResult()));
+ if (cmd.getMessage() != null) {
+ b.append(' ').append(cmd.getMessage());
+ }
+ b.append('\n');
+ }
+ return b.toString();
+ }
+}
--- /dev/null
+/*
+ * 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 java.util.Date;
+
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.lib.ObjectId;
+
+/**
+ * A snapshot of a replica.
+ *
+ * @see LeaderSnapshot
+ */
+public class ReplicaSnapshot {
+ final KetchReplica replica;
+ ObjectId accepted;
+ ObjectId committed;
+ KetchReplica.State state;
+ String error;
+ long retryAtMillis;
+
+ ReplicaSnapshot(KetchReplica replica) {
+ this.replica = replica;
+ }
+
+ /** @return the replica this snapshot describes the state of. */
+ public KetchReplica getReplica() {
+ return replica;
+ }
+
+ /** @return current state of the replica. */
+ public KetchReplica.State getState() {
+ return state;
+ }
+
+ /** @return last known Git commit at {@code refs/txn/accepted}. */
+ @Nullable
+ public ObjectId getAccepted() {
+ return accepted;
+ }
+
+ /** @return last known Git commit at {@code refs/txn/committed}. */
+ @Nullable
+ public ObjectId getCommitted() {
+ return committed;
+ }
+
+ /**
+ * @return if {@link #getState()} == {@link KetchReplica.State#OFFLINE} an
+ * optional human-readable message from the transport system
+ * explaining the failure.
+ */
+ @Nullable
+ public String getErrorMessage() {
+ return error;
+ }
+
+ /**
+ * @return time (usually in the future) when the leader will retry
+ * communication with the offline or lagging replica; null if no
+ * retry is scheduled or necessary.
+ */
+ @Nullable
+ public Date getRetryAt() {
+ return retryAtMillis > 0 ? new Date(retryAtMillis) : null;
+ }
+}
--- /dev/null
+/*
+ * 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 java.io.IOException;
+import java.util.List;
+
+import org.eclipse.jgit.lib.AnyObjectId;
+import org.eclipse.jgit.transport.ReceiveCommand;
+
+/**
+ * One round-trip to all replicas proposing a log entry.
+ * <p>
+ * In Raft a log entry represents a state transition at a specific index in the
+ * replicated log. The leader can only append log entries to the log.
+ * <p>
+ * In Ketch a log entry is recorded under the {@code refs/txn} namespace. This
+ * occurs when:
+ * <ul>
+ * <li>a replica wants to establish itself as a new leader by proposing a new
+ * term (see {@link ElectionRound})
+ * <li>an established leader wants to gain consensus on new {@link Proposal}s
+ * (see {@link ProposalRound})
+ * </ul>
+ */
+abstract class Round {
+ final KetchLeader leader;
+ final LogIndex acceptedOldIndex;
+ LogIndex acceptedNewIndex;
+ List<ReceiveCommand> stageCommands;
+
+ Round(KetchLeader leader, LogIndex head) {
+ this.leader = leader;
+ this.acceptedOldIndex = head;
+ }
+
+ /**
+ * Creates a commit for {@code refs/txn/accepted} and calls
+ * {@link #runAsync(AnyObjectId)} to begin execution of the round across
+ * the system.
+ * <p>
+ * If references are being updated (such as in a {@link ProposalRound}) the
+ * RefTree may be modified.
+ * <p>
+ * Invoked without {@link KetchLeader#lock} to build objects.
+ *
+ * @throws IOException
+ * the round cannot build new objects within the leader's
+ * repository. The leader may be unable to execute.
+ */
+ abstract void start() throws IOException;
+
+ /**
+ * Asynchronously distribute the round's new value for
+ * {@code refs/txn/accepted} to all replicas.
+ * <p>
+ * Invoked by {@link #start()} after new commits have been created for the
+ * log. The method passes {@code newId} to {@link KetchLeader} to be
+ * distributed to all known replicas.
+ *
+ * @param newId
+ * new value for {@code refs/txn/accepted}.
+ */
+ void runAsync(AnyObjectId newId) {
+ acceptedNewIndex = acceptedOldIndex.nextIndex(newId);
+ leader.runAsync(this);
+ }
+
+ /**
+ * Notify the round it was accepted by a majority of the system.
+ * <p>
+ * Invoked by the leader with {@link KetchLeader#lock} held by the caller.
+ */
+ abstract void success();
+}
--- /dev/null
+/*
+ * 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.lib.FileMode.TYPE_GITLINK;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.eclipse.jgit.annotations.Nullable;
+import org.eclipse.jgit.lib.AnyObjectId;
+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.Repository;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevObject;
+import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.transport.ReceiveCommand;
+import org.eclipse.jgit.treewalk.EmptyTreeIterator;
+import org.eclipse.jgit.treewalk.TreeWalk;
+import org.eclipse.jgit.treewalk.filter.TreeFilter;
+
+/** Constructs a set of commands to stage content during a proposal. */
+public class StageBuilder {
+ /**
+ * Acceptable number of references to send in a single stage transaction.
+ * <p>
+ * If the number of unique objects exceeds this amount the builder will
+ * attempt to decrease the reference count by chaining commits..
+ */
+ private static final int SMALL_BATCH_SIZE = 5;
+
+ /**
+ * Acceptable number of commits to chain together using parent pointers.
+ * <p>
+ * When staging many unique commits the {@link StageBuilder} batches
+ * together unrelated commits as parents of a temporary commit. After the
+ * proposal completes the temporary commit is discarded and can be garbage
+ * collected by all replicas.
+ */
+ private static final int TEMP_PARENT_BATCH_SIZE = 128;
+
+ private static final byte[] PEEL = { ' ', '^' };
+
+ private final String txnStage;
+ private final String txnId;
+
+ /**
+ * Construct a stage builder for a transaction.
+ *
+ * @param txnStageNamespace
+ * namespace for transaction references to build
+ * {@code "txnStageNamespace/txnId.n"} style names.
+ * @param txnId
+ * identifier used to name temporary staging refs.
+ */
+ public StageBuilder(String txnStageNamespace, ObjectId txnId) {
+ this.txnStage = txnStageNamespace;
+ this.txnId = txnId.name();
+ }
+
+ /**
+ * Compare two RefTrees and return commands to stage new objects.
+ * <p>
+ * This method ignores the lineage between the two RefTrees and does a
+ * straight diff on the two trees. New objects will be staged. The diff
+ * strategy is useful to catch-up a lagging replica, without sending every
+ * intermediate step. This may mean the replica does not have the same
+ * object set as other replicas if there are rewinds or branch deletes.
+ *
+ * @param git
+ * source repository to read {@code oldTree} and {@code newTree}
+ * from.
+ * @param oldTree
+ * accepted RefTree on the replica ({@code refs/txn/accepted}).
+ * Use {@link ObjectId#zeroId()} if the remote does not have any
+ * ref tree, e.g. a new replica catching up.
+ * @param newTree
+ * RefTree being sent to the replica. The trees will be compared.
+ * @return list of commands to create {@code "refs/txn/stage/..."}
+ * references on replicas anchoring new objects into the repository
+ * while a transaction gains consensus.
+ * @throws IOException
+ * {@code git} cannot be accessed to compare {@code oldTree} and
+ * {@code newTree} to build the object set.
+ */
+ public List<ReceiveCommand> makeStageList(Repository git, ObjectId oldTree,
+ ObjectId newTree) throws IOException {
+ try (RevWalk rw = new RevWalk(git);
+ TreeWalk tw = new TreeWalk(rw.getObjectReader());
+ ObjectInserter ins = git.newObjectInserter()) {
+ if (AnyObjectId.equals(oldTree, ObjectId.zeroId())) {
+ tw.addTree(new EmptyTreeIterator());
+ } else {
+ tw.addTree(rw.parseTree(oldTree));
+ }
+ tw.addTree(rw.parseTree(newTree));
+ tw.setFilter(TreeFilter.ANY_DIFF);
+ tw.setRecursive(true);
+
+ Set<ObjectId> newObjs = new HashSet<>();
+ while (tw.next()) {
+ if (tw.getRawMode(1) == TYPE_GITLINK
+ && !tw.isPathSuffix(PEEL, 2)) {
+ newObjs.add(tw.getObjectId(1));
+ }
+ }
+
+ List<ReceiveCommand> cmds = makeStageList(newObjs, git, ins);
+ ins.flush();
+ return cmds;
+ }
+ }
+
+ /**
+ * Construct a set of commands to stage objects on a replica.
+ *
+ * @param newObjs
+ * objects to send to a replica.
+ * @param git
+ * local repository to read source objects from. Required to
+ * perform minification of {@code newObjs}.
+ * @param inserter
+ * inserter to write temporary commit objects during minification
+ * if many new branches are created by {@code newObjs}.
+ * @return list of commands to create {@code "refs/txn/stage/..."}
+ * references on replicas anchoring {@code newObjs} into the
+ * repository while a transaction gains consensus.
+ * @throws IOException
+ * {@code git} cannot be accessed to perform minification of
+ * {@code newObjs}.
+ */
+ public List<ReceiveCommand> makeStageList(Set<ObjectId> newObjs,
+ @Nullable Repository git, @Nullable ObjectInserter inserter)
+ throws IOException {
+ if (git == null || newObjs.size() <= SMALL_BATCH_SIZE) {
+ // Without a source repository can only construct unique set.
+ List<ReceiveCommand> cmds = new ArrayList<>(newObjs.size());
+ for (ObjectId id : newObjs) {
+ stage(cmds, id);
+ }
+ return cmds;
+ }
+
+ List<ReceiveCommand> cmds = new ArrayList<>();
+ List<RevCommit> commits = new ArrayList<>();
+ reduceObjects(cmds, commits, git, newObjs);
+
+ if (inserter == null || commits.size() <= 1
+ || (cmds.size() + commits.size()) <= SMALL_BATCH_SIZE) {
+ // Without an inserter to aggregate commits, or for a small set of
+ // commits just send one stage ref per commit.
+ for (RevCommit c : commits) {
+ stage(cmds, c.copy());
+ }
+ return cmds;
+ }
+
+ // 'commits' is sorted most recent to least recent commit.
+ // Group batches of commits and build a chain.
+ // TODO(sop) Cluster by restricted graphs to support filtering.
+ ObjectId tip = null;
+ for (int end = commits.size(); end > 0;) {
+ int start = Math.max(0, end - TEMP_PARENT_BATCH_SIZE);
+ List<RevCommit> batch = commits.subList(start, end);
+ List<ObjectId> parents = new ArrayList<>(1 + batch.size());
+ if (tip != null) {
+ parents.add(tip);
+ }
+ parents.addAll(batch);
+
+ CommitBuilder b = new CommitBuilder();
+ b.setTreeId(batch.get(0).getTree());
+ b.setParentIds(parents);
+ b.setAuthor(tmpAuthor(batch));
+ b.setCommitter(b.getAuthor());
+ tip = inserter.insert(b);
+ end = start;
+ }
+ stage(cmds, tip);
+ return cmds;
+ }
+
+ private static PersonIdent tmpAuthor(List<RevCommit> commits) {
+ // Construct a predictable author using most recent commit time.
+ int t = 0;
+ for (int i = 0; i < commits.size();) {
+ t = Math.max(t, commits.get(i).getCommitTime());
+ }
+ String name = "Ketch Stage"; //$NON-NLS-1$
+ String email = "tmp@tmp"; //$NON-NLS-1$
+ return new PersonIdent(name, email, t * 1000L, 0);
+ }
+
+ private void reduceObjects(List<ReceiveCommand> cmds,
+ List<RevCommit> commits, Repository git,
+ Set<ObjectId> newObjs) throws IOException {
+ try (RevWalk rw = new RevWalk(git)) {
+ rw.setRetainBody(false);
+
+ for (ObjectId id : newObjs) {
+ RevObject obj = rw.parseAny(id);
+ if (obj instanceof RevCommit) {
+ rw.markStart((RevCommit) obj);
+ } else {
+ stage(cmds, id);
+ }
+ }
+
+ for (RevCommit c; (c = rw.next()) != null;) {
+ commits.add(c);
+ rw.markUninteresting(c);
+ }
+ }
+ }
+
+ private void stage(List<ReceiveCommand> cmds, ObjectId id) {
+ int estLen = txnStage.length() + txnId.length() + 5;
+ StringBuilder n = new StringBuilder(estLen);
+ n.append(txnStage).append(txnId).append('.');
+ n.append(Integer.toHexString(cmds.size()));
+ cmds.add(new ReceiveCommand(ObjectId.zeroId(), id, n.toString()));
+ }
+}
--- /dev/null
+/**
+ * Distributed consensus system built on Git.
+ */
+package org.eclipse.jgit.internal.ketch;
projects / jgit.git / commitdiff