Support reviewers stats for stable branches

Adds a "-s" option that lets you specify the name of a stable branch
(for example "-s havana") instead of specifying a project (-p) or all
projects (-a).

reviewers.py will then use a specific stable.json file that defines the
set of projects stable-maint-core has authority on, as well as the
contents of that core team.

Note: -s disables result caching since the search is made on
specific branches, which would pollute the general purpose cache.

Change-Id: Idd03f51c98e006972bc93e3ce11e052cd1cc26aa

projects/stable.json

@@ -0,0 +1,42 @@
+{
+    "name": "stable",
+    "unofficial": true,
+    "subprojects": [
+        "openstack/nova",
+        "openstack/swift",
+        "openstack/glance",
+        "openstack/heat",
+        "openstack/ceilometer",
+        "openstack/keystone",
+        "openstack/cinder",
+        "openstack/neutron",
+        "openstack/horizon"
+    ],
+    "core-team": [
+        "arosen",
+        "gandelman-a",
+        "apevec",
+        "zulcss",
+        "danms",
+        "davewalker",
+        "david-lyle",
+        "dolph",
+        "doug-hellmann",
+        "eglynn",
+        "flaper87",
+        "gabriel-hurley",
+        "john-griffith",
+        "jdanjou",
+        "markmc",
+        "markwash",
+        "treinish",
+        "mrunge",
+        "russellb",
+        "stevebaker",
+        "shardy",
+        "vishvananda",
+        "garyk",
+        "markmcclain",
+        "p-draigbrady"
+    ]
+}

reviewstats/cmd/reviewers.py

@@ -229,6 +229,10 @@ def main(argv=None):
     optparser.add_option(
         '-a', '--all', action='store_true',
         help='Generate stats across all known projects (*.json)')
+    optparser.add_option(
+        '-s', '--stable', default='', metavar='BRANCH',
+        help='Generate stats for the specified stable BRANCH ("havana") '
+             'across all integrated projects')
     optparser.add_option(
         '-o', '--output', default='-',
         help='Where to write output. If - stdout is used and only one output'
@@ -250,7 +254,10 @@ def main(argv=None):
 
     options, args = optparser.parse_args()
 
-    projects = utils.get_projects_info(options.project, options.all)
+    if options.stable:
+        projects = utils.get_projects_info('projects/stable.json', False)
+    else:
+        projects = utils.get_projects_info(options.project, options.all)
 
     if not projects:
         print "Please specify a project."
@@ -273,7 +280,8 @@ def main(argv=None):
     }
 
     for project in projects:
-        changes = utils.get_changes([project], options.user, options.key)
+        changes = utils.get_changes([project], options.user, options.key,
+                                    stable=options.stable)
         for change in changes:
             patch_for_change = False
             first_patchset = True

reviewstats/utils.py

@@ -57,7 +57,7 @@ def projects_q(project):
             ')')
 
 
-def get_changes(projects, ssh_user, ssh_key, only_open=False,
+def get_changes(projects, ssh_user, ssh_key, only_open=False, stable='',
                 server='review.openstack.org'):
     all_changes = []
 
@@ -69,10 +69,12 @@ def get_changes(projects, ssh_user, ssh_key, only_open=False,
         changes = []
         logging.debug('Getting changes for project %s' % project['name'])
 
-        if not only_open:
+        if not only_open and not stable:
             # Only use the cache for *all* changes (the entire history).
             # Requesting only the open changes isn't nearly as big of a deal,
             # so just get the current data.
+            # Also do not use cache for stable stats as they cover different
+            # results.
             pickle_fn = '.%s-changes.pickle' % project['name']
 
             if os.path.isfile(pickle_fn):
@@ -89,6 +91,8 @@ def get_changes(projects, ssh_user, ssh_key, only_open=False,
                        '--format JSON' % projects_q(project))
                 if only_open:
                     cmd += ' status:open'
+                if stable:
+                    cmd += ' branch:stable/%s' % stable
                 if changes:
                     cmd += ' resume_sortkey:%s' % changes[-2]['sortKey']
                 stdin, stdout, stderr = client.exec_command(cmd)
@@ -97,7 +101,7 @@ def get_changes(projects, ssh_user, ssh_key, only_open=False,
                 if changes[-1]['rowCount'] == 0:
                     break
 
-            if not only_open:
+            if not only_open and not stable:
                 with open(pickle_fn, 'w') as f:
                     pickle.dump(changes, f)