add CACHE-PLUGINS? option

scheme/httpd/surflets/packages.scm

@@ -93,6 +93,7 @@
 	httpd-logging			;HTTP-SYSLOG
 	shift-reset			;SHIFT and RESET
 	conditions			;exception
+	defrec-package			;define-record
 	scsh				;regexp et al.
 	scheme
 	)
@@ -106,6 +107,7 @@
 	  send-html/finish
 	  send-html
 	  form-query
+	  get-bindings
 	  extract-bindings
 	  extract-single-binding
 	  generate-input-field-name
@@ -125,9 +127,11 @@
 (define-structure servlets servlets-interface
   (open servlet-handler/plugin
 	httpd-responses
+	httpd-request			; HTTP-URL:SEARCH
+	url				; REQUEST:URL
 	parse-html-forms
-	sxml-to-html			;SXML->HTML
-	srfi-1				;FILTER
+	sxml-to-html			; SXML->HTML
+	srfi-1				; FILTER
 	sxml-tree-trans
 	url
 	httpd-request

scheme/httpd/surflets/surflet-handler.scm

@@ -20,8 +20,15 @@
   (return-continuation really-session-return-continuation 
 		       set-session-return-continuation!))
 
+(define-record options
+  (cache-plugins? #t))
+
+(define *options* (make-options))
+;(define *options-lock* (make-lock))   ; currently unused
+
 (define *instance-table* (make-integer-table)) ; instance-id is index
 (define *instance-table-lock* (make-lock))
+
 (define random
   (let* ((source  (make-random-source))
 	 (random-integer (begin
@@ -190,10 +197,10 @@ You can try starting at the <A HREF=~a>beginning</a>."
 (define (get-plugin-rt-structure plugin-name directory)
   (let* ((full-plugin-name (absolute-file-name plugin-name directory))
 	 (load-plugin 
-	  (lambda ()
+	  (lambda (cached?)
 	    (with-fatal-error-handler*
 	     (lambda (condition decline)
-	       (release-lock *plugin-table-lock*)
+	       (if cached? (release-lock *plugin-table-lock*))
 	       (decline))
 	     (lambda ()
 	       ;; load-config-file does not care about cwd(?)
@@ -202,23 +209,32 @@ You can try starting at the <A HREF=~a>beginning</a>."
 	       ;; plugin-structure to load must be named "plugin"
 	       (let ((plugin-structure (reify-structure 'plugin)))
 		 (load-structure plugin-structure)
-		 (table-set! *plugin-table* full-plugin-name 
-			     (cons plugin-structure
-				   (file-last-mod full-plugin-name)))
-		 ;; only now the lock may be released
-		 (release-lock *plugin-table-lock*)
+		 (if cached?
+		     (begin
+		       (table-set! *plugin-table* full-plugin-name 
+				   (cons plugin-structure
+					 (file-last-mod full-plugin-name)))
+		       ;; only now the lock may be released
+		       (release-lock *plugin-table-lock*)))
 		 plugin-structure))))))
 
-  (obtain-lock *plugin-table-lock*)
-  (let ((plugin (table-ref *plugin-table* full-plugin-name)))
-    (if plugin
-	(if (equal? (file-last-mod full-plugin-name) 
-		    (cdr plugin))
-	    (begin
-	      (release-lock *plugin-table-lock*)
-	      (car plugin))
-	    (load-plugin))
-	(load-plugin)))))
+    (if (options:cache-plugins? *options*)
+	(begin
+	  ;; The lock is only obtained and released, if plugins are
+	  ;; cached. LOAD-PLUGIN gets the CACHED? parameter, so
+	  ;; nothing may happen, if in the meanwhile caching is turned
+	  ;; off.
+	  (obtain-lock *plugin-table-lock*)
+	  (let ((plugin (table-ref *plugin-table* full-plugin-name)))
+	    (if plugin
+		(if (equal? (file-last-mod full-plugin-name) 
+			    (cdr plugin))
+		    (begin
+		      (release-lock *plugin-table-lock*)
+		      (car plugin))
+		    (load-plugin #t))
+		(load-plugin #t))))
+	(load-plugin #f))))
 
 (define (reset-plugin-cache!)
   (with-fatal-error-handler*