Speed up loading change screen

If a change has many revisions, loading the change screen may be
slow because we verify the presence of each commit and its parent
individually.

Instead, do that in a batch to speed things up.

Change-Id: Ib4b1c34500b98b8bb7307a5aaca86802a15e635d

gertty/gitrepo.py

@@ -259,15 +259,17 @@ class Repo(object):
                 raise GitCloneError("No URL available for git clone")
             git.Repo.clone_from(self.url, self.path)
 
-    def hasCommit(self, sha):
+    def checkCommits(self, shas):
+        invalid = set()
         repo = git.Repo(self.path)
-        try:
-            repo.commit(sha)
-        except gitdb.exc.BadObject:
-            return False
-        except ValueError:
-            return False
-        return True
+        for sha in shas:
+            try:
+                repo.commit(sha)
+            except gitdb.exc.BadObject:
+                invalid.add(sha)
+            except ValueError:
+                invalid.add(sha)
+        return invalid
 
     def fetch(self, url, refspec):
         repo = git.Repo(self.path)

gertty/sync.py

@@ -989,8 +989,7 @@ class CheckRevisionsTask(Task):
             for change in project.open_changes:
                 if repo:
                     for revision in change.revisions:
-                        if not (repo.hasCommit(revision.parent) and
-                                repo.hasCommit(revision.commit)):
+                        if repo.checkCommits([revision.parent, revision.commit]):
                             to_sync.add(change.id)
                 else:
                     to_sync.add(change.id)

gertty/view/change.py

@@ -415,16 +415,16 @@ class ChangeMessageBox(mywid.HyperText):
         if message.author.username == self.app.config.username:
             name_style = 'change-message-own-name'
             header_style = 'change-message-own-header'
-            reviewer_string = message.author.name
+            reviewer_string = message.author_name
         else:
             name_style = 'change-message-name'
             header_style = 'change-message-header'
             if message.author.email:
                 reviewer_string = "%s <%s>" % (
-                    message.author.name,
+                    message.author_name,
                     message.author.email)
             else:
-                reviewer_string = message.author.name
+                reviewer_string = message.author_name
 
         text = [(name_style, reviewer_string),
                 (header_style, ': '+lines.pop(0)),
@@ -591,18 +591,17 @@ class ChangeView(urwid.WidgetWrap):
         missing_revisions = set()
         change_number = None
         change_id = None
+        shas = set()
         with self.app.db.getSession() as session:
             change = session.getChange(self.change_key)
+            change_project_name = change.project.name
             change_number = change.number
             change_id = change.id
-            repo = gitrepo.get_repo(change.project.name, self.app.config)
             for revision in change.revisions:
-                if not repo.hasCommit(revision.parent):
-                    missing_revisions.add(revision.parent)
-                if not repo.hasCommit(revision.commit):
-                    missing_revisions.add(revision.commit)
-                if missing_revisions:
-                    break
+                shas.add(revision.parent)
+                shas.add(revision.commit)
+        repo = gitrepo.get_repo(change_project_name, self.app.config)
+        missing_revisions = repo.checkCommits(shas)
         if missing_revisions:
             if self.app.sync.offline:
                 raise gertty.view.DisplayError("Git commits not present in local repository")