ProjectRepairer: Refactor to extract the repository lookup

copyPackTo() validates the destination URI and opens the repository to
locate it on disk before copying anything, neither of which has to do
with packs.

Move both into objectsDir(), which reports the repository's objects
directory, or nothing if the project cannot be repaired at that
destination. What is left is copyPacksTo(), taking the directory to
copy from. The now trivial copyInOrder() folds into it.

Change-Id: I2d1ba0a23671d6db115f18a35420f4c04a24c0ec

src/main/java/com/googlesource/gerrit/plugins/replication/ProjectRepairer.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/ProjectRepairer.java b/src/main/java/com/googlesource/gerrit/plugins/replication/ProjectRepairer.java
index 89ac793..68a2c9d 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/ProjectRepairer.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/ProjectRepairer.java
@@ -17,6 +17,7 @@
 import static com.googlesource.gerrit.plugins.replication.ReplicationQueue.repLog;
 
 import com.google.common.base.Strings;
+import com.google.gerrit.common.Nullable;
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.inject.Inject;
@@ -49,7 +50,16 @@
 
   public boolean repair(Project.NameKey project, URIish uri, OutputStream out, boolean copyPacks)
       throws InterruptedIOException {
-    if (copyPacks && !copyPackTo(project, uri, out)) {
+    if (!copyPacks) {
+      return true;
+    }
+
+    Path objectsDir = objectsDir(project, uri);
+    if (objectsDir == null) {
+      return false;
+    }
+
+    if (!copyPacksTo(objectsDir.resolve("pack"), uri, out)) {
       repLog.atSevere().log("Repair failed for %s on %s", project.get(), uri);
       return false;
     }
@@ -60,35 +70,32 @@
     return AdminApiFactory.isSSH(uri) && !AdminApiFactory.isGerrit(uri);
   }
 
-  private boolean copyPackTo(Project.NameKey project, URIish uri, OutputStream out)
-      throws InterruptedIOException {
+  @Nullable
+  private Path objectsDir(Project.NameKey project, URIish uri) {
     if (Strings.isNullOrEmpty(uri.getHost())) {
       repLog.atSevere().log("Cannot repair %s: URI has no host: %s", project.get(), uri);
-      return false;
+      return null;
     }
     if (Strings.isNullOrEmpty(uri.getPath())) {
       repLog.atSevere().log("Cannot repair %s: URI has no path: %s", project.get(), uri);
-      return false;
+      return null;
     }
 
-    Path packDir;
     try (Repository repo = gitManager.openRepository(project)) {
-      packDir = repo.getDirectory().toPath().resolve("objects").resolve("pack");
+      return repo.getDirectory().toPath().resolve("objects");
     } catch (IOException e) {
       repLog.atSevere().withCause(e).log("Cannot open repository %s for repair", project.get());
-      return false;
+      return null;
     }
-
-    if (!Files.isDirectory(packDir)) {
-      repLog.atSevere().log("No objects/pack directory for project %s", project.get());
-      return false;
-    }
-
-    return copyInOrder(packDir, uri, out);
   }
 
-  private boolean copyInOrder(Path packDir, URIish uri, OutputStream out)
+  private boolean copyPacksTo(Path packDir, URIish uri, OutputStream out)
       throws InterruptedIOException {
+    if (!Files.isDirectory(packDir)) {
+      repLog.atSevere().log("No objects/pack directory %s", packDir);
+      return false;
+    }
+
     return copy(packDir, uri, out, PACK_DIR, "*.pack") == 0
         && copy(packDir, uri, out, PACK_DIR, "*.idx", "*.bitmap", "*.rev") == 0;
   }