Checkpoint

svn path=/scripts/rpki/sql.py; revision=927

1 files changed, 59 insertions, 0 deletions

diff --git a/scripts/rpki/sql.py b/scripts/rpki/sql.py
new file mode 100644
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+++ b/scripts/rpki/sql.py
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+# $Id$
+
+import MySQLdb
+
+def connect(cfg, section="sql"):
+  """Connect to a MySQL database using connection parameters from an
+     rpki.config.parser object.
+  """
+
+  return MySQLdb.connect(user   = cfg.get(section, "sql-username"),
+                         db     = cfg.get(section, "sql-database"),
+                         passwd = cfg.get(section, "sql-password"))
+
+class sql_persistant(object):
+  """Mixin for persistant class that needs to be stored in SQL.
+  """
+
+  ## @var sql_children
+  # Dictionary listing this class's children in the tree of SQL
+  # tables.  Key is the class object of a child, value is the name of
+  # the attribute in this class at which a list of the resulting child
+  # objects are stored.
+  sql_children = {}
+
+  @classmethod
+  def sql_fetch(cls, db, **kwargs):
+    """Fetch rows from SQL based on a canned query and a set of
+    keyword arguments, and instantiate them as objects, returning a
+    list of the instantiated objects.
+
+    This is a class method because in general we don't even know how
+    many matches the SQL lookup will return until after we've
+    performed it.
+    """
+
+    cur = db.cursor()
+    cur.execute(self.sql_fetch_cmd % kwargs)
+    rows = cur.fetchall()
+    cur.close()
+    objs = []
+    for row in rows:
+      obj = cls()
+      obj.sql_objectify(row)
+      objs.append(obj)
+      if isinstance(obj, sql_persistant):
+        for kid in obj.sql_children:
+          setattr(obj, obj.sql_children[kid], kid.sql_fetch(db))
+    return objs
+      
+  def sql_objectify(self, row):
+    """Initialize self with values returned by self.sql_fetch().
+
+    This method is also responsible for performing the
+    fetch/objectify() cycle on any of its children in the tree of
+    classes representing SQL tables in this database.  But I'm trying
+    to move that responsibility to self.sql_fetch()....    
+    """
+
+    raise NotImplementedError