X-Git-Url: http://git.kpe.io/?a=blobdiff_plain;f=sql%2Fpool.cl;h=bf790a46c58b6dae9034ef5204c52f44ea572a6f;hb=1785177d3364ad0ad8917193b5b00310ef88105e;hp=14efa2326ddbc6131e2faeb5a7967f3eeeab0e85;hpb=c86ceae4227949bc6a43469d265fbac3d7355d4e;p=clsql.git

diff --git a/sql/pool.cl b/sql/pool.cl
index 14efa23..bf790a4 100644
--- a/sql/pool.cl
+++ b/sql/pool.cl
@@ -4,10 +4,10 @@
 ;;;;
 ;;;; Name:          pool.cl
 ;;;; Purpose:       Support function for connection pool
-;;;; Programmers:   Kevin M. Rosenberg
+;;;; Programmers:   Kevin M. Rosenberg, Marc Battyani
 ;;;; Date Started:  Apr 2002
 ;;;;
-;;;; $Id: pool.cl,v 1.2 2002/04/28 00:50:17 kevin Exp $
+;;;; $Id: pool.cl,v 1.3 2002/05/01 20:22:16 marc.battyani Exp $
 ;;;;
 ;;;; This file, part of CLSQL, is Copyright (c) 2002 by Kevin M. Rosenberg
 ;;;;
@@ -21,39 +21,70 @@
 
 (defvar *db-pool* (make-hash-table :test #'equal))
 
-(defun make-conn-vector ()
-  "Creates an empty connection vector"
-  (make-array 5 :fill-pointer 0 :adjustable t))
+(defclass conn-pool ()
+  ((connection-spec :accessor connection-spec :initarg :connection-spec)
+   (database-type :accessor database-type :initarg :database-type)
+   (free-connections :accessor free-connections
+		     :initform (make-array 5 :fill-pointer 0 :adjustable t))
+   (all-connections :accessor all-connections
+		    :initform (make-array 5 :fill-pointer 0 :adjustable t))))
 
-(defun find-or-create-conn-vector (connection-spec database-type)
+(defun acquire-from-conn-pool (pool)
+  (if (zerop (length (free-connections pool)))
+    (let ((conn (connect (connection-spec pool)
+			 :database-type (database-type pool) :if-exists :new)))
+      (vector-push-extend conn (all-connections pool))
+      (setf (conn-pool conn) pool)
+      conn)
+    (vector-pop (free-connections pool))))
+
+(defun release-to-conn-pool (conn)
+  (vector-push-extend conn (free-connections (conn-pool conn))))
+
+(defun clear-conn-pool (pool)
+  (loop for conn across (all-connections pool)
+	do (disconnect :database conn))
+  (setf (fill-pointer (free-connections pool)) 0)
+  (setf (fill-pointer (all-connections pool)) 0))
+
+(defun find-or-create-conn-pool (connection-spec database-type)
   "Find connection vector in hash table, creates a new conn-vector if not found"
   (let* ((key (list connection-spec database-type))
-	 (conn-vector (gethash key *db-pool*)))
-    (unless conn-vector
-      (setq conn-vector (make-conn-vector))
-      (setf (gethash key *db-pool*) conn-vector))
-    conn-vector))
-
-(defun acquire-from-pool (connection-spec database-type)
-  (let ((conn-vector (find-or-create-conn-vector connection-spec database-type)))
-    (when (zerop (length conn-vector))
-      (vector-push-extend 
-       (connect connection-spec :database-type database-type :if-exists :new) 
-       conn-vector))
-    (vector-pop conn-vector)))
+	 (conn-pool (gethash key *db-pool*)))
+    (unless conn-pool
+      (setq conn-pool (make-instance 'conn-pool
+				     :connection-spec connection-spec
+				     :database-type database-type))
+      (setf (gethash key *db-pool*) conn-pool))
+    conn-pool))
+
+(defun acquire-from-pool (connection-spec database-type &optional pool)
+  (unless pool (setf pool (find-or-create-conn-pool connection-spec database-type)))
+  (acquire-from-conn-pool pool))
 
 (defun release-to-pool (database)
-  (let ((conn-vector (find-or-create-conn-vector (connection-spec database)
-					   (database-type database))))
-    (vector-push-extend database conn-vector)))
+  (release-to-conn-pool database))
 
-(defun disconnect-pooled ()
+(defun disconnect-pooled (&optional clear)
   "Disconnects all connections in the pool"
   (maphash
-   #'(lambda (key conn-vector)
+   #'(lambda (key conn-pool)
        (declare (ignore key))
-       (dotimes (i (length conn-vector))
-	 (disconnect (aref conn-vector i)))
-       (setf (fill-pointer conn-vector) 0))
+       (clear-conn-pool conn-pool))
    *db-pool*)
+  (when clear (clrhash *db-pool*))
   t)
+
+;;; with-db-from-pool is the macro you should use if you want to use pooled connections.
+;;; You can use it with a connection spec and database type or directly with a conn-pool.
+;;; When you give a conn-pool the connection spec and database type are ignored
+
+(defmacro with-db-from-pool ((db-var connection-spec database-type &optional conn-pool) &body body)
+  "Evaluate the body in an environment, where `db-var' is bound to a
+database connection acquired from the connection pool
+The connection is automatically released to the connection pool on exit from the body.
+If a pool is given then the connection-spec database-type are ignored."
+  `(let ((,db-var (acquire-from-pool ,connection-spec ,database-type ,conn-pool)))
+     (unwind-protect
+	  (let ((,db-var ,db-var)) ,@body)
+       (release-to-pool ,db-var))))