| /* |
| * Copyright (C) 2016, Google Inc. and others |
| * |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Distribution License v. 1.0 which is available at |
| * https://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: BSD-3-Clause |
| */ |
| |
| package org.eclipse.jgit.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; |
| import org.eclipse.jgit.util.time.MonotonicClock; |
| import org.eclipse.jgit.util.time.ProposedTimestamp; |
| |
| /** |
| * Ketch replica running on the same system as the |
| * {@link org.eclipse.jgit.internal.ketch.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); |
| } |
| |
| /** {@inheritDoc} */ |
| @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())); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected void startPush(ReplicaPushRequest req) { |
| getSystem().getExecutor().execute(() -> { |
| MonotonicClock clk = getSystem().getClock(); |
| try (Repository git = getLeader().openRepository(); |
| ProposedTimestamp ts = clk.propose()) { |
| try { |
| update(git, req, ts); |
| req.done(git); |
| } catch (Throwable err) { |
| req.setException(git, err); |
| } |
| } catch (IOException err) { |
| req.setException(null, err); |
| } |
| }); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| protected void blockingFetch(Repository repo, ReplicaFetchRequest req) |
| throws IOException { |
| throw new IOException(KetchText.get().cannotFetchFromLocalReplica); |
| } |
| |
| private void update(Repository git, ReplicaPushRequest req, |
| ProposedTimestamp ts) 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.addProposedTimestamp(ts); |
| batch.setRefLogIdent(getSystem().newCommitter(ts)); |
| 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[0]); |
| 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; |
| } |
| } |