1 files changed, 68 insertions, 19 deletions

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/Sequences.java b/gerrit-server/src/main/java/com/google/gerrit/server/Sequences.java
index 4ab42f30f7..930f3f3e32 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/Sequences.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/Sequences.java
@@ -18,9 +18,16 @@ import static com.google.common.base.Preconditions.checkArgument;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableList;
+import com.google.gerrit.metrics.Description;
+import com.google.gerrit.metrics.Description.Units;
+import com.google.gerrit.metrics.Field;
+import com.google.gerrit.metrics.MetricMaker;
+import com.google.gerrit.metrics.Timer2;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.config.AllProjectsName;
+import com.google.gerrit.server.config.AllUsersName;
 import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.gerrit.server.extensions.events.GitReferenceUpdated;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.notedb.NotesMigration;
 import com.google.gerrit.server.notedb.RepoSequence;
@@ -32,50 +39,87 @@ import java.util.ArrayList;
 import java.util.List;
 import org.eclipse.jgit.lib.Config;
 
-@SuppressWarnings("deprecation")
 @Singleton
 public class Sequences {
-  public static final String CHANGES = "changes";
+  public static final String NAME_ACCOUNTS = "accounts";
+  public static final String NAME_CHANGES = "changes";
+
+  public static int getChangeSequenceGap(Config cfg) {
+    return cfg.getInt("noteDb", "changes", "initialSequenceGap", 1000);
+  }
+
+  private enum SequenceType {
+    ACCOUNTS,
+    CHANGES;
+  }
 
   private final Provider<ReviewDb> db;
   private final NotesMigration migration;
+  private final RepoSequence accountSeq;
   private final RepoSequence changeSeq;
+  private final Timer2<SequenceType, Boolean> nextIdLatency;
 
   @Inject
   Sequences(
       @GerritServerConfig Config cfg,
-      final Provider<ReviewDb> db,
+      Provider<ReviewDb> db,
       NotesMigration migration,
       GitRepositoryManager repoManager,
-      AllProjectsName allProjects) {
+      GitReferenceUpdated gitRefUpdated,
+      AllProjectsName allProjects,
+      AllUsersName allUsers,
+      MetricMaker metrics) {
     this.db = db;
     this.migration = migration;
 
-    final int gap = cfg.getInt("noteDb", "changes", "initialSequenceGap", 0);
-    changeSeq =
+    int accountBatchSize = cfg.getInt("noteDb", "accounts", "sequenceBatchSize", 1);
+    accountSeq =
         new RepoSequence(
             repoManager,
-            allProjects,
-            CHANGES,
-            new RepoSequence.Seed() {
-              @Override
-              public int get() throws OrmException {
-                return db.get().nextChangeId() + gap;
-              }
-            },
-            cfg.getInt("noteDb", "changes", "sequenceBatchSize", 20));
+            gitRefUpdated,
+            allUsers,
+            NAME_ACCOUNTS,
+            () -> ReviewDb.FIRST_ACCOUNT_ID,
+            accountBatchSize);
+
+    int gap = getChangeSequenceGap(cfg);
+    @SuppressWarnings("deprecation")
+    RepoSequence.Seed changeSeed = () -> db.get().nextChangeId() + gap;
+    int changeBatchSize = cfg.getInt("noteDb", "changes", "sequenceBatchSize", 20);
+    changeSeq =
+        new RepoSequence(
+            repoManager, gitRefUpdated, allProjects, NAME_CHANGES, changeSeed, changeBatchSize);
+
+    nextIdLatency =
+        metrics.newTimer(
+            "sequence/next_id_latency",
+            new Description("Latency of requesting IDs from repo sequences")
+                .setCumulative()
+                .setUnit(Units.MILLISECONDS),
+            Field.ofEnum(SequenceType.class, "sequence"),
+            Field.ofBoolean("multiple"));
+  }
+
+  public int nextAccountId() throws OrmException {
+    try (Timer2.Context timer = nextIdLatency.start(SequenceType.ACCOUNTS, false)) {
+      return accountSeq.next();
+    }
   }
 
   public int nextChangeId() throws OrmException {
     if (!migration.readChangeSequence()) {
-      return db.get().nextChangeId();
+      return nextChangeId(db.get());
+    }
+    try (Timer2.Context timer = nextIdLatency.start(SequenceType.CHANGES, false)) {
+      return changeSeq.next();
     }
-    return changeSeq.next();
   }
 
   public ImmutableList<Integer> nextChangeIds(int count) throws OrmException {
     if (migration.readChangeSequence()) {
-      return changeSeq.next(count);
+      try (Timer2.Context timer = nextIdLatency.start(SequenceType.CHANGES, count > 1)) {
+        return changeSeq.next(count);
+      }
     }
 
     if (count == 0) {
@@ -85,7 +129,7 @@ public class Sequences {
     List<Integer> ids = new ArrayList<>(count);
     ReviewDb db = this.db.get();
     for (int i = 0; i < count; i++) {
-      ids.add(db.nextChangeId());
+      ids.add(nextChangeId(db));
     }
     return ImmutableList.copyOf(ids);
   }
@@ -94,4 +138,9 @@ public class Sequences {
   public RepoSequence getChangeIdRepoSequence() {
     return changeSeq;
   }
+
+  @SuppressWarnings("deprecation")
+  private static int nextChangeId(ReviewDb db) throws OrmException {
+    return db.nextChangeId();
+  }
 }