Refactor infra git libs and testing.

infra/services/gnumbd/support/config_ref.py

-# Copyright 2014 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-import json
-import logging
-
-from infra.services.gnumbd.support.util import cached_property
-from infra.services.gnumbd.support.git import INVALID
-
-LOGGER = logging.getLogger(__name__)
-
-class ConfigRef(object):
-  CONVERT = {
-    'interval': lambda self, val: float(val),
-    'pending_tag_prefix': lambda self, val: str(val),
-    'pending_ref_prefix': lambda self, val: str(val),
-    'enabled_refglobs': lambda self, val: map(str, list(val)),
-  }
-  DEFAULTS = {
-    'interval': 5.0,
-    'pending_tag_prefix': 'refs/pending-tags',
-    'pending_ref_prefix': 'refs/pending',
-    'enabled_refglobs': [],
-  }
-
-  def __init__(self, ref, filename='config.json'):
-    self.ref = ref
-    self.repo = ref.repo
-    self.filename = filename
-
-  def __getitem__(self, key):
-    return self.current[key]
-
-  @cached_property
-  def current(self):
-    cur = self.ref.commit
-
-    while cur is not None and cur is not INVALID:
-      LOGGER.debug('Evaluating config at %s:%s', cur.hsh, self.filename)
-      try:
-        data = self.repo.run('cat-file', 'blob',
-                             '%s:%s' % (cur.hsh, self.filename))
-        data = json.loads(data)
-        if not isinstance(data, dict):
-          LOGGER.error('Non-dict config: %r', data)
-          continue
-
-        ret = {}
-        for k, def_v in self.DEFAULTS.iteritems():
-          ret[k] = self.CONVERT[k](self, data.get(k, def_v))
-
-        LOGGER.debug('Using configuration at %s: %r', cur.hsh, ret)
-        return ret
-      except Exception:
-        LOGGER.exception('Caught exception while processing')
-      finally:
-        cur = cur.parent
-    LOGGER.warn('Using default config: %r', self.DEFAULTS)
-    return dict(self.DEFAULTS)
-
-  def evaluate(self):
-    del self.current
-    return self.current