Change the pkey method so that the caller can optionally set the dictionary

used for the primary key lookup.  This will prevent a database lookup
for each connection object that gets created.  This could be a significant
optimization on a busy system.

Similarly, the get_attnames method allows for the attributes dictionary
to be installed directly.

diff --git a/src/interfaces/python/pg.py b/src/interfaces/python/pg.py
index a5997341bcf6e923583d0de4fbfedae980c049f8..df502397fa6c9b4eaaaeff9d4f8edc03b54c373b 100644 (file)
--- a/src/interfaces/python/pg.py
+++ b/src/interfaces/python/pg.py
@@ -63,17 +63,6 @@ class DB:
                            # that takes a single string arg.  For example
                            # in a CGI set to "%s"
 
-       # Get all the primary keys at once
-       for rel, att in self.db.query("""SELECT
-                           pg_class.relname, pg_attribute.attname
-                       FROM pg_class, pg_attribute, pg_index
-                       WHERE pg_class.oid = pg_attribute.attrelid AND
-                           pg_class.oid = pg_index.indrelid AND
-                           pg_index.indkey[0] = pg_attribute.attnum AND 
-                           pg_index.indisprimary = 't' AND
-                           pg_attribute.attisdropped = 'f'""").getresult():
-           self.__pkeys__[rel] = att
-
    def _do_debug(self, s):
        if not self.debug: return
        if type(self.debug) == StringType: print self.debug % s
@@ -85,10 +74,30 @@ class DB:
        self._do_debug(qstr)
        return self.db.query(qstr)
 
-   # If third arg supplied set primary key to it
    def pkey(self, cl, newpkey = None):
+       """This method returns the primary key of a class.  If newpkey
+           is set and is set and is not a dictionary then set that
+           value as the primary key of the class.  If it is a dictionary
+           then replace the __pkeys__ dictionary with it."""
+       # Get all the primary keys at once
+       if type(newpkey) == DictType:
+           self.__pkeys__ = newpkey
+           return
+
        if newpkey:
            self.__pkeys__[cl] = newpkey
+           return newpkey
+
+       if self.__pkeys__ == {}:
+           for rel, att in self.db.query("""SELECT
+                           pg_class.relname, pg_attribute.attname
+                       FROM pg_class, pg_attribute, pg_index
+                       WHERE pg_class.oid = pg_attribute.attrelid AND
+                           pg_class.oid = pg_index.indrelid AND
+                           pg_index.indkey[0] = pg_attribute.attnum AND 
+                           pg_index.indisprimary = 't' AND
+                           pg_attribute.attisdropped = 'f'""").getresult():
+               self.__pkeys__[rel] = att
 
        # will raise an exception if primary key doesn't exist
        return self.__pkeys__[cl]
@@ -108,7 +117,17 @@ class DB:
            l.append(n[0])
        return l
 
-   def get_attnames(self, cl):
+   def get_attnames(self, cl, newattnames = None):
+       """This method gets a list of attribute names for a class.  If
+           the optional newattnames exists it must be a dictionary and
+           will become the new attribute names dictionary."""
+
+       if type(newattnames) == DictType:
+           self.__attnames__ = newattnames
+           return
+       elif newattnames:
+           raise error, "If supplied, newattnames must be a dictionary"
+
        # May as well cache them
        if self.__attnames__.has_key(cl):
            return self.__attnames__[cl]
@@ -160,7 +179,7 @@ class DB:
            xcl = cl
 
        if keyname == None:         # use the primary key by default
-           keyname = self.__pkeys__[xcl]
+           keyname = self.pkey(xcl)
 
        fnames = self.get_attnames(xcl)
 
@@ -225,6 +244,8 @@ class DB:
    # Update always works on the oid which get returns if available
    # otherwise use the primary key.  Fail if neither.
    def update(self, cl, a):
+       self.pkey(cl)       # make sure we have a self.__pkeys__ dictionary
+
        foid = 'oid_%s' % cl
        if a.has_key(foid):
            where = "oid = %s" % a[foid]