1 files changed, 0 insertions, 345 deletions
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/RepoSequence.java b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/RepoSequence.java
deleted file mode 100644
index 11266f9318..0000000000
--- a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/RepoSequence.java
+++ /dev/null
@@ -1,345 +0,0 @@
-// Copyright (C) 2016 The Android Open Source Project
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package com.google.gerrit.server.notedb;
-
-import static com.google.common.base.Preconditions.checkArgument;
-import static com.google.common.base.Preconditions.checkNotNull;
-import static com.google.gerrit.reviewdb.client.RefNames.REFS;
-import static com.google.gerrit.reviewdb.client.RefNames.REFS_SEQUENCES;
-import static java.nio.charset.StandardCharsets.UTF_8;
-import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
-
-import com.github.rholder.retry.RetryException;
-import com.github.rholder.retry.Retryer;
-import com.github.rholder.retry.RetryerBuilder;
-import com.github.rholder.retry.StopStrategies;
-import com.github.rholder.retry.WaitStrategies;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.CharMatcher;
-import com.google.common.base.Predicates;
-import com.google.common.base.Throwables;
-import com.google.common.collect.ImmutableList;
-import com.google.common.primitives.Ints;
-import com.google.common.util.concurrent.Runnables;
-import com.google.gerrit.common.Nullable;
-import com.google.gerrit.reviewdb.client.Project;
-import com.google.gerrit.reviewdb.client.RefNames;
-import com.google.gerrit.server.extensions.events.GitReferenceUpdated;
-import com.google.gerrit.server.git.GitRepositoryManager;
-import com.google.gwtorm.server.OrmException;
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReentrantLock;
-import org.eclipse.jgit.errors.IncorrectObjectTypeException;
-import org.eclipse.jgit.lib.ObjectId;
-import org.eclipse.jgit.lib.ObjectInserter;
-import org.eclipse.jgit.lib.ObjectLoader;
-import org.eclipse.jgit.lib.Ref;
-import org.eclipse.jgit.lib.RefUpdate;
-import org.eclipse.jgit.lib.Repository;
-import org.eclipse.jgit.revwalk.RevWalk;
-import org.eclipse.jgit.transport.ReceiveCommand;
-
-/**
- * Class for managing an incrementing sequence backed by a git repository.
- *
- * <p>The current sequence number is stored as UTF-8 text in a blob pointed to by a ref in the
- * {@code refs/sequences/*} namespace. Multiple processes can share the same sequence by
- * incrementing the counter using normal git ref updates. To amortize the cost of these ref updates,
- * processes can increment the counter by a larger number and hand out numbers from that range in
- * memory until they run out. This means concurrent processes will hand out somewhat non-monotonic
- * numbers.
- */
-public class RepoSequence {
-  @FunctionalInterface
-  public interface Seed {
-    int get() throws OrmException;
-  }
-
-  @VisibleForTesting
-  static RetryerBuilder<RefUpdate.Result> retryerBuilder() {
-    return RetryerBuilder.<RefUpdate.Result>newBuilder()
-        .retryIfResult(Predicates.equalTo(RefUpdate.Result.LOCK_FAILURE))
-        .withWaitStrategy(
-            WaitStrategies.join(
-                WaitStrategies.exponentialWait(5, TimeUnit.SECONDS),
-                WaitStrategies.randomWait(50, TimeUnit.MILLISECONDS)))
-        .withStopStrategy(StopStrategies.stopAfterDelay(30, TimeUnit.SECONDS));
-  }
-
-  private static final Retryer<RefUpdate.Result> RETRYER = retryerBuilder().build();
-
-  private final GitRepositoryManager repoManager;
-  private final GitReferenceUpdated gitRefUpdated;
-  private final Project.NameKey projectName;
-  private final String refName;
-  private final Seed seed;
-  private final int floor;
-  private final int batchSize;
-  private final Runnable afterReadRef;
-  private final Retryer<RefUpdate.Result> retryer;
-
-  // Protects all non-final fields.
-  private final Lock counterLock;
-
-  private int limit;
-  private int counter;
-
-  @VisibleForTesting int acquireCount;
-
-  public RepoSequence(
-      GitRepositoryManager repoManager,
-      GitReferenceUpdated gitRefUpdated,
-      Project.NameKey projectName,
-      String name,
-      Seed seed,
-      int batchSize) {
-    this(
-        repoManager,
-        gitRefUpdated,
-        projectName,
-        name,
-        seed,
-        batchSize,
-        Runnables.doNothing(),
-        RETRYER,
-        0);
-  }
-
-  public RepoSequence(
-      GitRepositoryManager repoManager,
-      GitReferenceUpdated gitRefUpdated,
-      Project.NameKey projectName,
-      String name,
-      Seed seed,
-      int batchSize,
-      int floor) {
-    this(
-        repoManager,
-        gitRefUpdated,
-        projectName,
-        name,
-        seed,
-        batchSize,
-        Runnables.doNothing(),
-        RETRYER,
-        floor);
-  }
-
-  @VisibleForTesting
-  RepoSequence(
-      GitRepositoryManager repoManager,
-      GitReferenceUpdated gitRefUpdated,
-      Project.NameKey projectName,
-      String name,
-      Seed seed,
-      int batchSize,
-      Runnable afterReadRef,
-      Retryer<RefUpdate.Result> retryer) {
-    this(repoManager, gitRefUpdated, projectName, name, seed, batchSize, afterReadRef, retryer, 0);
-  }
-
-  RepoSequence(
-      GitRepositoryManager repoManager,
-      GitReferenceUpdated gitRefUpdated,
-      Project.NameKey projectName,
-      String name,
-      Seed seed,
-      int batchSize,
-      Runnable afterReadRef,
-      Retryer<RefUpdate.Result> retryer,
-      int floor) {
-    this.repoManager = checkNotNull(repoManager, "repoManager");
-    this.gitRefUpdated = checkNotNull(gitRefUpdated, "gitRefUpdated");
-    this.projectName = checkNotNull(projectName, "projectName");
-
-    checkArgument(
-        name != null
-            && !name.startsWith(REFS)
-            && !name.startsWith(REFS_SEQUENCES.substring(REFS.length())),
-        "name should be a suffix to follow \"refs/sequences/\", got: %s",
-        name);
-    this.refName = RefNames.REFS_SEQUENCES + name;
-
-    this.seed = checkNotNull(seed, "seed");
-    this.floor = floor;
-
-    checkArgument(batchSize > 0, "expected batchSize > 0, got: %s", batchSize);
-    this.batchSize = batchSize;
-    this.afterReadRef = checkNotNull(afterReadRef, "afterReadRef");
-    this.retryer = checkNotNull(retryer, "retryer");
-
-    counterLock = new ReentrantLock(true);
-  }
-
-  public int next() throws OrmException {
-    counterLock.lock();
-    try {
-      if (counter >= limit) {
-        acquire(batchSize);
-      }
-      return counter++;
-    } finally {
-      counterLock.unlock();
-    }
-  }
-
-  public ImmutableList<Integer> next(int count) throws OrmException {
-    if (count == 0) {
-      return ImmutableList.of();
-    }
-    checkArgument(count > 0, "count is negative: %s", count);
-    counterLock.lock();
-    try {
-      List<Integer> ids = new ArrayList<>(count);
-      while (counter < limit) {
-        ids.add(counter++);
-        if (ids.size() == count) {
-          return ImmutableList.copyOf(ids);
-        }
-      }
-      acquire(Math.max(count - ids.size(), batchSize));
-      while (ids.size() < count) {
-        ids.add(counter++);
-      }
-      return ImmutableList.copyOf(ids);
-    } finally {
-      counterLock.unlock();
-    }
-  }
-
-  @VisibleForTesting
-  public void set(int val) throws OrmException {
-    // Don't bother spinning. This is only for tests, and a test that calls set
-    // concurrently with other writes is doing it wrong.
-    counterLock.lock();
-    try {
-      try (Repository repo = repoManager.openRepository(projectName);
-          RevWalk rw = new RevWalk(repo)) {
-        checkResult(store(repo, rw, null, val));
-        counter = limit;
-      } catch (IOException e) {
-        throw new OrmException(e);
-      }
-    } finally {
-      counterLock.unlock();
-    }
-  }
-
-  private void acquire(int count) throws OrmException {
-    try (Repository repo = repoManager.openRepository(projectName);
-        RevWalk rw = new RevWalk(repo)) {
-      TryAcquire attempt = new TryAcquire(repo, rw, count);
-      checkResult(retryer.call(attempt));
-      counter = attempt.next;
-      limit = counter + count;
-      acquireCount++;
-    } catch (ExecutionException | RetryException e) {
-      if (e.getCause() != null) {
-        Throwables.throwIfInstanceOf(e.getCause(), OrmException.class);
-      }
-      throw new OrmException(e);
-    } catch (IOException e) {
-      throw new OrmException(e);
-    }
-  }
-
-  private void checkResult(RefUpdate.Result result) throws OrmException {
-    if (!refUpdated(result)) {
-      throw new OrmException("failed to update " + refName + ": " + result);
-    }
-  }
-
-  private boolean refUpdated(RefUpdate.Result result) {
-    return result == RefUpdate.Result.NEW || result == RefUpdate.Result.FORCED;
-  }
-
-  private class TryAcquire implements Callable<RefUpdate.Result> {
-    private final Repository repo;
-    private final RevWalk rw;
-    private final int count;
-
-    private int next;
-
-    private TryAcquire(Repository repo, RevWalk rw, int count) {
-      this.repo = repo;
-      this.rw = rw;
-      this.count = count;
-    }
-
-    @Override
-    public RefUpdate.Result call() throws Exception {
-      Ref ref = repo.exactRef(refName);
-      int nextCandidate;
-      afterReadRef.run();
-      ObjectId oldId;
-      if (ref == null) {
-        oldId = ObjectId.zeroId();
-        nextCandidate = seed.get();
-      } else {
-        oldId = ref.getObjectId();
-        nextCandidate = parse(oldId);
-      }
-      next = Math.max(floor, nextCandidate);
-      return store(repo, rw, oldId, next + count);
-    }
-
-    private int parse(ObjectId id) throws IOException, OrmException {
-      ObjectLoader ol = rw.getObjectReader().open(id, OBJ_BLOB);
-      if (ol.getType() != OBJ_BLOB) {
-        // In theory this should be thrown by open but not all implementations
-        // may do it properly (certainly InMemoryRepository doesn't).
-        throw new IncorrectObjectTypeException(id, OBJ_BLOB);
-      }
-      String str = CharMatcher.whitespace().trimFrom(new String(ol.getCachedBytes(), UTF_8));
-      Integer val = Ints.tryParse(str);
-      if (val == null) {
-        throw new OrmException("invalid value in " + refName + " blob at " + id.name());
-      }
-      return val;
-    }
-  }
-
-  private RefUpdate.Result store(Repository repo, RevWalk rw, @Nullable ObjectId oldId, int val)
-      throws IOException {
-    ObjectId newId;
-    try (ObjectInserter ins = repo.newObjectInserter()) {
-      newId = ins.insert(OBJ_BLOB, Integer.toString(val).getBytes(UTF_8));
-      ins.flush();
-    }
-    RefUpdate ru = repo.updateRef(refName);
-    if (oldId != null) {
-      ru.setExpectedOldObjectId(oldId);
-    }
-    ru.setNewObjectId(newId);
-    ru.setForceUpdate(true); // Required for non-commitish updates.
-    RefUpdate.Result result = ru.update(rw);
-    if (refUpdated(result)) {
-      gitRefUpdated.fire(projectName, ru, null);
-    }
-    return result;
-  }
-
-  public static ReceiveCommand storeNew(ObjectInserter ins, String name, int val)
-      throws IOException {
-    ObjectId newId = ins.insert(OBJ_BLOB, Integer.toString(val).getBytes(UTF_8));
-    return new ReceiveCommand(ObjectId.zeroId(), newId, RefNames.REFS_SEQUENCES + name);
-  }
-}