Changeset 656 for branches

Timestamp:

04/05/13 11:11:26 (3 years ago)

Author:

juhas

Message:

The memo table is created only if it does not yet exist in the database file.
The database file could not be reused otherwise.

Optimized the has_key and get methods to work without calling asdict.

File:

• branches/decorate/memoize.py (modified) (4 diffs)

branches/decorate/memoize.py

@@ -296 +296 @@
         self._conn = db.connect(database)
         self._curs = self._conn.cursor()
-        sql = "create table %s(argstr, fval)" % table
+        sql = "create table if not exists %s(argstr, fval)" % table
         self._curs.execute(sql)
         return
@@ -305 +305 @@
         return
     def __getitem__(self, key):
-        sql = "select * from %s where argstr = ?" % self._table
-        res = tuple(self._curs.execute(sql, (key,)))
+        res = self._select_key_items(key)
         if res: return res[-1][-1] # always get the last one
         raise KeyError, key
@@ -316 +315 @@
         return d
     def has_key(self, key):
-        return key in self.keys()
+        return bool(self._select_key_items(key))
     def get(self, key, value):
-        return self.__asdict__().get(key, value)
+        res = self._select_key_items(key)
+        rv = value
+        if res:  rv = res[-1][-1]
+        return rv
     def items(self):
         return self.__asdict__().items()
@@ -327 +329 @@
     def __repr__(self):
         return "memo(%s)" % self.__asdict__()
+    def _select_key_items(self, key):
+        '''Return a tuple of (key, value) pairs that match the specified key.
+        '''
+        sql = "select * from %s where argstr = ?" % self._table
+        res = tuple(self._curs.execute(sql, (key,)))
+        return res
     pass