r9336: 12 May 2004 Kevin Rosenberg (kevin@rosenberg.net)

[clsql.git] / sql / initialize.lisp

diff --git a/sql/initialize.lisp b/sql/initialize.lisp
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+;;;; -*- Mode: LISP; Syntax: ANSI-Common-Lisp; Base: 10 -*-
+;;;; *************************************************************************
+;;;; FILE IDENTIFICATION
+;;;;
+;;;; Name:          initialize.lisp
+;;;; Purpose:       Initializion routines for backend
+;;;; Programmers:   Kevin M. Rosenberg 
+;;;; Date Started:  May 2002
+;;;;
+;;;; $Id$
+;;;;
+;;;; This file, part of CLSQL, is Copyright (c) 2002-2004 by Kevin M. Rosenberg
+;;;; and Copyright (c) 1999-2001 by Pierre R. Mai
+;;;;
+;;;; CLSQL users are granted the rights to distribute and use this software
+;;;; as governed by the terms of the Lisp Lesser GNU Public License
+;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
+;;;; *************************************************************************
+
+(in-package #:clsql-sys)
+
+(defvar *loaded-database-types* nil
+  "Contains a list of database types which have been defined/loaded.")
+
+(defmethod database-type-load-foreign (x)
+  (error "No generic function defined for database-type-load-foreign with parameters of ~S" x))
+
+(defmethod database-type-load-foreign :after (database-type)
+  (when (database-type-library-loaded database-type)
+     (pushnew database-type *loaded-database-types*)))
+
+(defun reload-database-types ()
+  "Reloads any foreign code for the loaded database types after a dump."
+  (mapc #'database-type-load-foreign *loaded-database-types*))
+
+(defvar *default-database-type* nil
+  "Specifies the default type of database.")
+
+(defvar *initialized-database-types* nil
+  "Contains a list of database types which have been initialized by calls
+to initialize-database-type.")
+
+(defun initialize-database-type (&key (database-type *default-database-type*))
+  "Initialize the given database-type, if it is not already
+initialized, as indicated by `*initialized-database-types*'."
+  (when (member database-type *initialized-database-types*)
+    (return-from initialize-database-type database-type))
+  
+  (let ((system (intern (concatenate 'string 
+                         (symbol-name '#:clsql-)
+                         (symbol-name database-type)))))
+    (when (not (find-package system))
+      (asdf:operate 'asdf:load-op system)))
+  
+  (when (database-initialize-database-type database-type)
+    (push database-type *initialized-database-types*)
+    database-type))
+