Handle missing commits

If gertty is interrupted when fetching commits, or, well, any number
of weird things happen to the git repo, we could end up not having
the needed commits locally.  Do a sanity check before opening a
change and fetch them if needed.

Change-Id: I9bbecd09d1820e405b51a8471c5fd9e4fe8a7841

gertty/app.py

@@ -28,6 +28,7 @@ from gertty import mywid
 from gertty import sync
 from gertty.view import project_list as view_project_list
 from gertty.view import change as view_change
+import gertty.view
 
 WELCOME_TEXT = """\
 Welcome to Gertty!
@@ -226,7 +227,11 @@ class App(object):
                 change_key = change and change.key or None
         if change_key is None:
             return self.error('Change is not in local database.')
-        self.changeScreen(view_change.ChangeView(self, change_key))
+        try:
+            view = view_change.ChangeView(self, change_key)
+            self.changeScreen(view)
+        except gertty.view.DisplayError as e:
+            self.app.error(e.message)
 
     def error(self, message):
         dialog = mywid.MessageDialog('Error', message)

gertty/gitrepo.py

@@ -18,6 +18,7 @@ import os
 import re
 
 import git
+import gitdb
 
 OLD = 0
 NEW = 1
@@ -150,6 +151,14 @@ class Repo(object):
         if not os.path.exists(path):
             git.Repo.clone_from(self.url, self.path)
 
+    def hasCommit(self, sha):
+        repo = git.Repo(self.path)
+        try:
+            repo.commit(sha)
+        except gitdb.exc.BadObject:
+            return False
+        return True
+
     def fetch(self, url, refspec):
         repo = git.Repo(self.path)
         try:

gertty/sync.py

@@ -148,7 +148,7 @@ class SyncProjectTask(Task):
                 # in the db optionally we could sync all changes ever
                 change = session.getChangeByID(c['id'])
                 if change or (c['status'] not in self._closed_statuses):
-                    sync.submitTask(SyncChangeTask(c['id'], self.priority))
+                    sync.submitTask(SyncChangeTask(c['id'], priority=self.priority))
                     self.log.debug("Change %s update %s" % (c['id'], c['updated']))
 
 class SyncChangeByCommitTask(Task):
@@ -167,7 +167,7 @@ class SyncChangeByCommitTask(Task):
         self.log.debug('Query: %s ' % (query,))
         with app.db.getSession() as session:
             for c in changes:
-                sync.submitTask(SyncChangeTask(c['id'], self.priority))
+                sync.submitTask(SyncChangeTask(c['id'], priority=self.priority))
                 self.log.debug("Sync change %s for its commit %s" % (c['id'], self.commit))
 
 class SyncChangeByNumberTask(Task):
@@ -187,15 +187,16 @@ class SyncChangeByNumberTask(Task):
         self.log.debug('Query: %s ' % (query,))
         with app.db.getSession() as session:
             for c in changes:
-                task = SyncChangeTask(c['id'], self.priority)
+                task = SyncChangeTask(c['id'], priority=self.priority)
                 self.tasks.append(task)
                 sync.submitTask(task)
                 self.log.debug("Sync change %s because it is number %s" % (c['id'], self.number))
 
 class SyncChangeTask(Task):
-    def __init__(self, change_id, priority=NORMAL_PRIORITY):
+    def __init__(self, change_id, force_fetch=False, priority=NORMAL_PRIORITY):
         super(SyncChangeTask, self).__init__(priority)
         self.change_id = change_id
+        self.force_fetch = force_fetch
 
     def __repr__(self):
         return '<SyncChangeTask %s>' % (self.change_id,)
@@ -228,18 +229,19 @@ class SyncChangeTask(Task):
             new_revision = False
             for remote_commit, remote_revision in remote_change.get('revisions', {}).items():
                 revision = session.getRevisionByCommit(remote_commit)
-                if not revision:
-                    # TODO: handle multiple parents
-                    url = sync.app.config.url + change.project.name
-                    if 'anonymous http' in remote_revision['fetch']:
-                        ref = remote_revision['fetch']['anonymous http']['ref']
-                    else:
-                        ref = remote_revision['fetch']['http']['ref']
-                        url = list(urlparse.urlsplit(url))
-                        url[1] = '%s:%s@%s' % (sync.app.config.username,
-                                               sync.app.config.password, url[1])
-                        url = urlparse.urlunsplit(url)
+                # TODO: handle multiple parents
+                url = sync.app.config.url + change.project.name
+                if 'anonymous http' in remote_revision['fetch']:
+                    ref = remote_revision['fetch']['anonymous http']['ref']
+                else:
+                    ref = remote_revision['fetch']['http']['ref']
+                    url = list(urlparse.urlsplit(url))
+                    url[1] = '%s:%s@%s' % (sync.app.config.username,
+                                           sync.app.config.password, url[1])
+                    url = urlparse.urlunsplit(url)
+                if (not revision) or self.force_fetch:
                     fetches.append((url, ref))
+                if not revision:
                     revision = change.createRevision(remote_revision['_number'],
                                                      remote_revision['commit']['message'], remote_commit,
                                                      remote_revision['commit']['parents'][0]['commit'])
@@ -419,7 +421,7 @@ class UploadReviewTask(Task):
             # Inside db session for rollback
             sync.post('changes/%s/revisions/%s/review' % (change.id, revision.commit),
                       data)
-            sync.submitTask(SyncChangeTask(change.id, self.priority))
+            sync.submitTask(SyncChangeTask(change.id, priority=self.priority))
 
 class Sync(object):
     def __init__(self, app):

gertty/view/__init__.py

@@ -0,0 +1,16 @@
+# Copyright 2014 OpenStack Foundation
+#
+# 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.
+
+class DisplayError(Exception):
+    pass

gertty/view/change.py

@@ -20,6 +20,7 @@ from gertty import gitrepo
 from gertty import mywid
 from gertty import sync
 from gertty.view import diff as view_diff
+import gertty.view
 
 class ReviewDialog(urwid.WidgetWrap):
     signals = ['save', 'cancel']
@@ -330,8 +331,32 @@ This Screen
         self.listbox.body.append(urwid.Divider())
         self.listbox_patchset_start = len(self.listbox.body)
 
+        self.checkGitRepo()
         self.refresh()
 
+    def checkGitRepo(self):
+        missing_revisions = False
+        change_number = None
+        change_id = None
+        with self.app.db.getSession() as session:
+            change = session.getChange(self.change_key)
+            change_number = change.number
+            change_id = change.id
+            repo = self.app.getRepo(change.project.name)
+            for revision in change.revisions:
+                if not (repo.hasCommit(revision.parent) and
+                        repo.hasCommit(revision.commit)):
+                    missing_revisions = True
+                    break
+        if missing_revisions:
+            self.app.log.warning("Missing some commits for change %s" % change_number)
+            task = sync.SyncChangeTask(change_id, force_fetch=True,
+                                       priority=sync.HIGH_PRIORITY)
+            self.app.sync.submitTask(task)
+            succeeded = task.wait(300)
+            if not succeeded:
+                raise gertty.view.DisplayError("Git commits not present in local repository")
+
     def refresh(self):
         change_info = []
         with self.app.db.getSession() as session:

gertty/view/change_list.py

@@ -16,6 +16,7 @@ import urwid
 
 from gertty import mywid
 from gertty.view import change as view_change
+import gertty.view
 
 class ChangeRow(urwid.Button):
     change_focus_map = {None: 'focused',
@@ -154,4 +155,8 @@ This Screen
         return super(ChangeListView, self).keypress(size, key)
 
     def onSelect(self, button, change_key):
-        self.app.changeScreen(view_change.ChangeView(self.app, change_key))
+        try:
+            view = view_change.ChangeView(self.app, change_key)
+            self.app.changeScreen(view)
+        except gertty.view.DisplayError as e:
+            self.app.error(e.message)