dbcache.py

   1 import db
   2 from sqlalchemy.orm import eagerload
   3
   4 class Cache(object):
   5
   6     def __init__(self, cls, attr, prefetch=None):
   7         self.cls = cls
   8         self.attr = attr
   9         self._cache = {}
  10         q = db.session.query(self.attr, self.cls)
  11         if prefetch:
  12             q.options(eagerload(prefetch))
  13         for k,v in q:
  14             self._cache[k] = v
  15         self._new = set()
  16
  17     def __getitem__(self, key):
  18         return self._cache[key]
  19
  20     def __contains__(self, key):
  21         return key in self._cache
  22
  23     def __setitem__(self, key, value):
  24         self._cache[key] = value
  25         self._new.add(value)
  26
  27     def get(self, key):
  28         try:
  29             v = self[key]
  30         except KeyError:
  31             v = self.cls(key)
  32             self[key] = v
  33         return v
  34
  35     def flush(self):
  36         db.session.add_all(self._new)
  37         self._new = set()
  38         db.session.flush()
  39
  40 print "generating blob cache ...",
  41 blob_cache = Cache(db.Blob, db.Blob.sha1, db.Blob.newest_commit)
  42 print len(blob_cache._cache)
  43
  44 print "generating file cache ...",
  45 file_cache = Cache(db.Filename, db.Filename.name)
  46 print len(file_cache._cache)
  47
  48 print "generating mail cache ...",
  49 mail_cache = Cache(db.Mail, db.Mail.message_id)
  50 print len(mail_cache._cache)
  51