Source Code for Module buildbot.db.base

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 2  # redistribute it and/or modify it under the terms of the GNU General Public 
 3  # License as published by the Free Software Foundation, version 2. 
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 5  # This program is distributed in the hope that it will be useful, but WITHOUT 
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 7  # FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more 
 8  # details. 
 9  # 
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12  # Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 
13  # 
14  # Copyright Buildbot Team Members 
15   
16 -class DBConnectorComponent(object): 
17      # A fixed component of the DBConnector, handling one particular aspect of 
18      # the database.  Instances of subclasses are assigned to attributes of the 
19      # DBConnector object, so that they are available at e.g., 
20      # C{master.db.model} or C{master.db.changes}.  This parent class takes care 
21      # of the necessary backlinks and other housekeeping. 
22   
23      connector = None 
24   
25 -    def __init__(self, connector): 
26          self.db = connector 
27   
28          # set up caches 
29          for method in dir(self.__class__): 
30              o = getattr(self, method) 
31              if isinstance(o, CachedMethod): 
32                  setattr(self, method, o.get_cached_method(self)) 
33   
34      _is_check_length_necessary = None 
35 -    def check_length(self, col, value): 
36          # for use by subclasses to check that 'value' will fit in 'col', where 
37          # 'col' is a table column from the model. 
38   
39          # ignore this check for database engines that either provide this error 
40          # themselves (postgres) or that do not enforce maximum-length 
41          # restrictions (sqlite) 
42          if not self._is_check_length_necessary: 
43              if self.db.pool.engine.dialect.name == 'mysql': 
44                  self._is_check_length_necessary = True 
45              else: 
46                  # not necessary, so just stub out the method 
47                  self.check_length = lambda col, value : None 
48                  return 
49   
50          assert col.type.length, "column %s does not have a length" % (col,) 
51          if value and len(value) > col.type.length: 
52              raise RuntimeError( 
53                  "value for column %s is greater than max of %d characters: %s" 
54                      % (col, col.type.length, value)) 
55   
56   
57 -class CachedMethod(object): 
58 -    def __init__(self, cache_name, method): 
59          self.cache_name = cache_name 
60          self.method = method 
61   
62 -    def get_cached_method(self, component): 
63          meth = self.method 
64   
65          meth_name = meth.__name__ 
66          cache = component.db.master.caches.get_cache(self.cache_name, 
67                  lambda key : meth(component, key)) 
68          def wrap(key, no_cache=0): 
69              if no_cache: 
70                  return meth(component, key) 
71              return cache.get(key) 
72          wrap.__name__ = meth_name + " (wrapped)" 
73          wrap.__module__ = meth.__module__ 
74          wrap.__doc__ = meth.__doc__ 
75          wrap.cache = cache 
76          return wrap 
77   
78 -def cached(cache_name): 
79      return lambda method : CachedMethod(cache_name, method) 
80