[IMP] runbot_merge: avoid unnecessary fetches

* avoid fetching PRs for un-managed branches if we know up-front
* avoid processing comments with no commands (avoids fetching the
  corresponding PR which we know nothing about yet and which may or
  may not be for a managed branch)

runbot_merge/controllers/__init__.py

@@ -205,26 +205,26 @@ def handle_comment(env, event):
     if 'pull_request' not in event['issue']:
         return "issue comment, ignoring"
 
-    _logger.info(
-        'comment: %s %s:%s "%s"',
-        event['sender']['login'],
-        event['repository']['full_name'],
-        event['issue']['number'],
-        event['comment']['body'],
-    )
+    repo = event['repository']['full_name']
+    issue = event['issue']['number']
+    author = event['sender']['login']
+    comment = event['comment']['body']
+    _logger.info('comment: %s %s:%s "%s"', author, repo, issue, comment)
 
-    partner = env['res.partner'].search([('github_login', '=', event['sender']['login']),])
+    partner = env['res.partner'].search([('github_login', '=', author), ])
     if not partner:
-        _logger.info("ignoring comment from %s: not in system", event['sender']['login'])
+        _logger.info("ignoring comment from %s: not in system", author)
         return 'ignored'
 
-    pr = env['runbot_merge.pull_requests']._get_or_schedule(
-        event['repository']['full_name'],
-        event['issue']['number'],
-    )
+    repository = env['runbot_merge.repository'].search([('name', '=', repo)])
+    if not repository.project_id._find_commands(comment):
+        return "No commands, ignoring"
+
+    pr = env['runbot_merge.pull_requests']._get_or_schedule(repo, issue)
     if not pr:
         return "Unknown PR, scheduling fetch"
-    return pr._parse_commands(partner, event['comment']['body'])
+
+    return pr._parse_commands(partner, comment)
 
 def handle_review(env, event):
     partner = env['res.partner'].search([('github_login', '=', event['review']['user']['login'])])
@@ -235,6 +235,7 @@ def handle_review(env, event):
     pr = env['runbot_merge.pull_requests']._get_or_schedule(
         event['repository']['full_name'],
         event['pull_request']['number'],
+        event['pull_request']['base']['ref']
     )
     if not pr:
         return "Unknown PR, scheduling fetch"

runbot_merge/models/pull_requests.py

@@ -243,17 +243,26 @@ class Project(models.Model):
             if not f:
                 return
 
-            repo = self.env['runbot_merge.repository'].search([('name', '=', f.repository)])
-            if repo:
-                repo._load_pr(f.number)
-            else:
-                _logger.warn("Fetch job for unknown repository %s, disabling & skipping", f.repository)
+            f.repository._load_pr(f.number)
 
             # commit after each fetched PR
             f.active = False
             if commit:
                 self.env.cr.commit()
 
+    def _find_commands(self, comment):
+        return re.findall(
+            '^{}:? (.*)$'.format(self.github_prefix),
+            comment, re.MULTILINE)
+
+    def _has_branch(self, name):
+        self.env.cr.execute("""
+        SELECT 1 FROM runbot_merge_branch
+        WHERE project_id = %s AND name = %s
+        LIMIT 1
+        """, (self.id, name))
+        return bool(self.env.cr.rowcount)
+
 class Repository(models.Model):
     _name = 'runbot_merge.repository'
 
@@ -274,6 +283,11 @@ class Repository(models.Model):
 
         # fetch PR object and handle as *opened*
         issue, pr = gh.pr(number)
+
+        if not self.project_id._has_branch(pr['base']['ref']):
+            _logger.info("Tasked with loading PR %d for un-managed branch %s, ignoring", pr['number'], pr['base']['ref'])
+            return
+
         controllers.handle_pr(self.env, {
             'action': 'opened',
             'pull_request': pr,
@@ -382,18 +396,28 @@ class PullRequests(models.Model):
         for r in self:
             r.batch_id = r.batch_ids.filtered(lambda b: b.active)[:1]
 
-    def _get_or_schedule(self, repo_name, number):
+    def _get_or_schedule(self, repo_name, number, target=None):
+        repo = self.env['runbot_merge.repository'].search([('name', '=', repo_name)])
+        if not repo:
+            return
+
+        if target and not repo.project_id._has_branch(target):
+            return
+
         pr = self.search([
-            ('repository.name', '=', repo_name),
+            ('repository', '=', repo.id),
             ('number', '=', number,)
         ])
         if pr:
             return pr
 
         Fetch = self.env['runbot_merge.fetch_job']
-        if Fetch.search([('repository', '=', repo_name), ('number', '=', number)]):
+        if Fetch.search([('repository', '=', repo.id), ('number', '=', number)]):
             return
-        Fetch.create({'repository': repo_name, 'number': number})
+        Fetch.create({
+            'repository': repo.id,
+            'number': number,
+        })
 
     def _parse_command(self, commandstring):
         m = re.match(r'(\w+)(?:([+-])|=(.*))?', commandstring)
@@ -452,7 +476,7 @@ class PullRequests(models.Model):
 
         commands = dict(
             ps
-            for m in re.findall('^{}:? (.*)$'.format(self.repository.project_id.github_prefix), comment, re.MULTILINE)
+            for m in self.repository.project_id._find_commands(comment)
             for c in m.strip().split()
             for ps in [self._parse_command(c)]
             if ps is not None
@@ -901,5 +925,5 @@ class FetchJob(models.Model):
     _name = 'runbot_merge.fetch_job'
 
     active = fields.Boolean(default=True)
-    repository = fields.Char(index=True)
-    number = fields.Integer(index=True)
+    repository = fields.Many2one('runbot_merge.repository', index=True, required=True)
+    number = fields.Integer(index=True, required=True)