Allow to cancel waiting tasks for non-existing repos without scheduling themv3.3.11upstream/stable-3.3

A waiting task for a non-existing repository can come into existence
when the repository gets deleted before a waiting task gets scheduled,
and thus becomes a running task.

A waiting task for a non-existing repository cannot be (re)scheduled
because there is a check for repository existence in that code-path.
However, such a task would remain in the waiting queue and rescheduling
would be tried again and again without a chance to get finished as the
only way for a task to get finished was to run it.

This change allows to finish a waiting task when its repository doesn't
exist. The ReplicationTasksStorage now tries to delete task file(s)
from both running and waiting directories.

Change-Id: Ibbdd5023e2a008484215da02403c9935d21fbf13

3 files changed, 43 insertions, 4 deletions

diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationQueue.java b/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationQueue.java
index 990e387..cf83df8 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationQueue.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationQueue.java
@@ -27,6 +27,7 @@ import com.google.gerrit.extensions.events.ProjectDeletedListener;
 import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.server.events.EventDispatcher;
 import com.google.gerrit.server.git.WorkQueue;
+import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.util.logging.NamedFluentLogger;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
@@ -59,6 +60,7 @@ public class ReplicationQueue
   private final DynamicItem<EventDispatcher> dispatcher;
   private final Provider<ReplicationDestinations> destinations; // For Guice circular dependency
   private final ReplicationTasksStorage replicationTasksStorage;
+  private final ProjectCache projectCache;
   private volatile boolean running;
   private volatile boolean replaying;
   private final Queue<ReferenceUpdatedEvent> beforeStartupEventsQueue;
@@ -71,13 +73,15 @@ public class ReplicationQueue
       Provider<ReplicationDestinations> rd,
       DynamicItem<EventDispatcher> dis,
       ReplicationStateListeners sl,
-      ReplicationTasksStorage rts) {
+      ReplicationTasksStorage rts,
+      ProjectCache pc) {
     replConfig = rc;
     workQueue = wq;
     dispatcher = dis;
     destinations = rd;
     stateLog = sl;
     replicationTasksStorage = rts;
+    projectCache = pc;
     beforeStartupEventsQueue = Queues.newConcurrentLinkedQueue();
   }
 
@@ -194,7 +198,12 @@ public class ReplicationQueue
       replaying = true;
       for (ReplicationTasksStorage.ReplicateRefUpdate t : replicationTasksStorage.listWaiting()) {
         try {
-          fire(new URIish(t.uri), Project.nameKey(t.project), t.ref);
+          Project.NameKey projectName = Project.nameKey(t.project);
+          if (!projectCache.get(projectName).isPresent()) {
+            repLog.atSevere().log("Cannot replicate %s; Local repository does not exist");
+            replicationTasksStorage.cancelWaiting(t);
+          }
+          fire(new URIish(t.uri), projectName, t.ref);
         } catch (URISyntaxException e) {
           repLog.atSevere().withCause(e).log("Encountered malformed URI for persisted event %s", t);
         }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java b/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java
index 3947ebc..a0e9094 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java
@@ -148,6 +148,10 @@ public class ReplicationTasksStorage {
     }
   }
 
+  public void cancelWaiting(ReplicateRefUpdate update) {
+    new Task(update).cancelWaiting();
+  }
+
   public List<ReplicateRefUpdate> listWaiting() {
     return list(createDir(waitingUpdates));
   }
@@ -237,9 +241,22 @@ public class ReplicationTasksStorage {
     }
 
     public void finish() {
+      logger.atFine().log("DELETE %s %s", running, updateLog());
+      deleteTask(running);
+    }
+
+    /**
+     * Should only be used when it's impossible for the waiting task to become running, such as when
+     * the project no longer exists
+     */
+    public void cancelWaiting() {
+      logger.atFine().log("DELETE %s %s", waiting, updateLog());
+      deleteTask(waiting);
+    }
+
+    private void deleteTask(Path p) {
       try {
-        logger.atFine().log("DELETE %s %s", running, updateLog());
-        Files.delete(running);
+        Files.delete(p);
       } catch (IOException e) {
         logger.atSevere().withCause(e).log("Error while deleting task %s", taskKey);
       }
diff --git a/src/test/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorageTaskTest.java b/src/test/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorageTaskTest.java
index d9fbbe5..46ce31f 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorageTaskTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorageTaskTest.java
@@ -281,6 +281,19 @@ public class ReplicationTasksStorageTaskTest {
   }
 
   @Test
+  public void canCancelWaitingTask() throws Exception {
+    Task task = tasksStorage.new Task(REF_UPDATE);
+
+    task.create();
+    assertIsWaiting(task);
+
+    task.cancelWaiting();
+
+    assertNotWaiting(task);
+    assertNotRunning(task);
+  }
+
+  @Test
   public void illegalFinishNonRunningTaskIsGraceful() throws Exception {
     Task task = tasksStorage.new Task(REF_UPDATE);
     task.finish();