[Split database-range-view into normal and cached subclass
clinton@unknownlamer.org**20080115222533
 Caching is useful in many cases but here it does not save too much
 consing and causes errors when instances are deleted from the
 database. A better solution would be to catch unbound persistent slot
 accesses and refresh the cache then.
] {
hunk ./src/web-common.lisp 65
+;; Should be renamed to query-range-view with a query-view parent and
+;; cached-query-view child class. The methods should maybe be renamed
+;; as well.
+;; Min/max support could perhaps be put into a mixin? It is probably
+;; not worth the effort
hunk ./src/web-common.lisp 75
-   (current-window :initform nil :accessor range-view.current-window)
hunk ./src/web-common.lisp 77
+   ;; should total-items be cached?
hunk ./src/web-common.lisp 83
+(defcomponent cached-database-range-view (database-range-view)
+  ((current-window :initform nil :accessor range-view.current-window)))
+
hunk ./src/web-common.lisp 88
+(defgeneric range-view.current-window (range))
+
hunk ./src/web-common.lisp 106
+(defmethod range-view.current-window ((range database-range-view))
+  (let ((limit (range-view.window-size range))
+	(skip (* (range-view.window-size range)
+		 (range-view.offset range))))
+    (mapcar
+     (lambda (i) (cons (incf skip) i))
+     (with-slots (minimum maximum) range
+       (if (reversep range)
+	   (range-view-get-instances range minimum maximum
+				     :from-end t :limit limit :skip skip)
+	   (range-view-get-instances range minimum maximum
+				     :from-end nil :limit limit :skip skip))))))
+
hunk ./src/web-common.lisp 131
-(defun range-view-get-forward (range old-offset new-offset)
-  (let ((base-item (car (last (range-view.current-window-items range))))
-	(limit (range-view.window-size range))
-	(skip (if (= new-offset old-offset)
-		  0
-		  (* (range-view.window-size range)
-		     (1- (- new-offset old-offset))))))
-    (with-slots (minimum maximum) range
-      (if (reversep range)
-	  (range-view-get-instances range minimum (or base-item maximum)
-				    :from-end t :limit limit :skip skip)
-	  (range-view-get-instances range (or base-item minimum) maximum
-				    :from-end nil :limit limit :skip skip)))))
-
-(defun range-view-get-backward (range old-offset new-offset)
-  (let ((base-item (car (range-view.current-window-items range)))
-	(limit (range-view.window-size range))
-	(skip (* (range-view.window-size range)
-		 (1- (- old-offset new-offset)))))
-    (with-slots (minimum maximum) range
-      (if (reversep range)
-	  (range-view-get-instances range (or base-item minimum) maximum
-				    :from-end nil :limit limit :skip skip)
-	  (range-view-get-instances range minimum (or base-item maximum)
-				    :from-end t :limit limit :skip skip)))))
-
-(defmethod (setf range-view.offset) :around (new-offset
-					     (range database-range-view))
-  (assert (>= new-offset 0) (new-offset))
-  (let ((old-offset (range-view.offset range)))
-    (call-next-method)
-    (setf
-     (range-view.current-window range)
-     (let ((start (* (range-view.window-size range)
-		     (range-view.offset range))))
-       (cond ;; Need to loop for the following cases when difference > 1
-	 ((>= new-offset old-offset)
-	  (mapcar
-	   (lambda (i) (cons (incf start) i))
-	   (range-view-get-forward range old-offset new-offset)))
-	 ((< new-offset old-offset)
-	  (nreverse
-	   (mapcar (lambda (i) (cons (incf start) i))
-		   (range-view-get-backward range old-offset new-offset))))))))
-  
-  new-offset)
-
hunk ./src/web-common.lisp 168
+;; cached database range view
+(defun range-view-get-forward (range old-offset new-offset)
+  (let ((base-item (car (last (range-view.current-window-items range))))
+	(limit (range-view.window-size range))
+	(skip (if (= new-offset old-offset)
+		  0
+		  (* (range-view.window-size range)
+		     (1- (- new-offset old-offset))))))
+    (with-slots (minimum maximum) range
+      (if (reversep range)
+	  (range-view-get-instances range minimum (or base-item maximum)
+				    :from-end t :limit limit :skip skip)
+	  (range-view-get-instances range (or base-item minimum) maximum
+				    :from-end nil :limit limit :skip skip)))))
+
+(defun range-view-get-backward (range old-offset new-offset)
+  (let ((base-item (car (range-view.current-window-items range)))
+	(limit (range-view.window-size range))
+	(skip (* (range-view.window-size range)
+		 (1- (- old-offset new-offset)))))
+    (with-slots (minimum maximum) range
+      (if (reversep range)
+	  (range-view-get-instances range (or base-item minimum) maximum
+				    :from-end nil :limit limit :skip skip)
+	  (range-view-get-instances range minimum (or base-item maximum)
+				    :from-end t :limit limit :skip skip)))))
+
+(defun range-view-reload-instances (range old-offset new-offset)
+  
+  (let ((start (* (range-view.window-size range)
+		  (range-view.offset range))))
+    (setf
+     (range-view.current-window range)
+     (mapcar
+      (lambda (i) (cons (incf start) i))
+      (cond 
+	((>= new-offset old-offset)
+	 (range-view-get-forward range old-offset new-offset))
+	((< new-offset old-offset)
+	 (nreverse
+	  (range-view-get-backward range old-offset new-offset))))))))
+
+(defmethod (setf range-view.offset) :around (new-offset
+					     (range cached-database-range-view))
+  (assert (>= new-offset 0) (new-offset))
+  (let ((old-offset (range-view.offset range)))
+    (call-next-method)
+    (range-view-reload-instances range old-offset new-offset)
+    new-offset))
+
hunk ./src/web-common.lisp 334
-(defmethod shows ((self ranged-show-list))
-  (range-view.current-window-items self))
+(defmethod shows ((range ranged-show-list))
+  (range-view.current-window-items range))
hunk ./src/web-common.lisp 351
-	 (<ucw:a :action-body (scroll-forward self)
-		 (<:as-html "Next"))
-	 (<:as-html "Next"))
+	   (<ucw:a :action-body (scroll-forward self)
+		   (<:as-html "Next"))
+	   (<:as-html "Next"))
}