Optimize performance of bzr-controlled buffers. It turns out that

"bzr log" is very slow (several seconds on a Core Duo), even with
"--limit=1".  So disable display of the revision in the mode line, and
reduce the number of places that need to know the revision.  Also,
cache the output of "bzr ls", which is also slow-ish.

diff --git a/v7/src/edwin/vc.scm b/v7/src/edwin/vc.scm
index fa8287a013f9b841a8c139c268732ebc5f4a8d8e..b578f1f216582713edf886083814c11bfd0e22a9 100644 (file)
--- a/v7/src/edwin/vc.scm
+++ b/v7/src/edwin/vc.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: vc.scm,v 1.108 2007/12/18 03:59:33 cph Exp $
+$Id: vc.scm,v 1.109 2007/12/20 01:24:29 cph Exp $
 
 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
     1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
@@ -175,9 +175,12 @@ Otherwise, VC will compare the file to the copy in the repository."
 (define (define-vc-type-operation name type procedure)
   (1d-table/put! (vc-type-operations type) name procedure))
 
-(define (vc-type-operation type name)
+(define (vc-type-operation type name #!optional error?)
   (or (1d-table/get (vc-type-operations type) name #f)
-      (error:bad-range-argument name 'VC-TYPE-OPERATION)))
+      (begin
+       (if error?
+           (error:bad-range-argument name 'VC-TYPE-OPERATION))
+       #f)))
 
 (define (vc-call name master . arguments)
   (apply (vc-type-operation (vc-master-type master) name) master arguments))
@@ -330,45 +333,28 @@ Otherwise, VC will compare the file to the copy in the repository."
 
 (define (vc-mode-line master buffer)
   (let ((workfile-buffer (vc-workfile-buffer master #f)))
-    (let ((buffer (or buffer workfile-buffer))
-         (revision
-          (or (vc-backend-workfile-revision master)
-              (vc-backend-default-revision master))))
-      (let ((locker (vc-backend-locking-user master revision))
-           (user-name (current-user-name)))
-       (set-variable!
-        vc-mode-line-status
-        (string-append
-         " "
-         (vc-type-display-name (vc-master-type master))
-         (if (ref-variable vc-display-status buffer)
-             (if revision
-                 (string-append
-                  (cond ((not locker) "-")
-                        ((string=? locker user-name) ":")
-                        (else (string-append ":" locker ":")))
-                  revision)
-                 " @@")
-             ""))
-        buffer)
-       (buffer-modeline-event! buffer 'VC-MODE-LINE-STATUS)
-       (if (and (buffer-writeable? buffer)
-                (eq? buffer workfile-buffer)
-                ;; If the file is locked by some other user, make the
-                ;; buffer read-only.  Like this, even root cannot modify a
-                ;; file that someone else has locked.
-                (or (and locker (not (string=? locker user-name)))
-                    ;; If the user is root, and the file is not
-                    ;; owner-writeable, then pretend that we can't write it
-                    ;; even though we can (because root can write
-                    ;; anything).  This way, even root cannot modify a file
-                    ;; that isn't locked.
-                    (and (user-is-root?)
-                         (fix:= 0
-                                (fix:and #o200
-                                         (file-modes
-                                          (vc-master-workfile master)))))))
-           (set-buffer-read-only! buffer))))))
+    (let ((buffer (or buffer workfile-buffer)))
+      (set-variable!
+       vc-mode-line-status
+       (string-append
+       " "
+       (vc-type-display-name (vc-master-type master))
+       (if (vc-backend-display-status? master buffer)
+           (let ((revision
+                  (or (vc-backend-workfile-revision master)
+                      (vc-backend-default-revision master))))
+             (let ((locker (vc-backend-locking-user master revision))
+                   (user-name (current-user-name)))
+               (if revision
+                   (string-append
+                    (cond ((not locker) "-")
+                          ((string=? locker user-name) ":")
+                          (else (string-append ":" locker ":")))
+                    revision)
+                   " @@")))
+           ""))
+       buffer)
+      (buffer-modeline-event! buffer 'VC-MODE-LINE-STATUS))))
 \f
 ;;;; VC-MASTER association
 
@@ -1222,6 +1208,13 @@ the value of vc-log-mode-hook."
   ;; The return value is a boolean indicating that MASTER is valid.
   (vc-call 'VALID? master))
 
+(define (vc-backend-display-status? master buffer)
+  (let ((operation
+        (vc-type-operation (vc-master-type master) 'DISPLAY-STATUS? #f)))
+    (if operation
+       (operation buffer)
+       (ref-variable vc-display-status buffer))))
+
 (define (vc-backend-default-revision master)
   ;; MASTER is a valid VC-MASTER object.
   ;; The default revision (usually the head of the trunk) is returned.
@@ -2357,16 +2350,24 @@ the value of vc-log-mode-hook."
 
 (define-vc-type-operation 'FIND-MASTER vc-type:bzr
   (lambda (workfile control-dir)
-    (and (%bzr-workfile-versioned? workfile)
-        (make-vc-master vc-type:bzr
-                        (merge-pathnames "README" control-dir)
-                        workfile))))
+    (let ((master
+          (make-vc-master vc-type:bzr
+                          (merge-pathnames "README" control-dir)
+                          workfile)))
+      (and (%bzr-master-valid? master)
+          master))))
 
 (define-vc-type-operation 'VALID? vc-type:bzr
   (lambda (master)
-    (%bzr-workfile-cache master
-                        'WORKFILE-VERSIONED?
-                        %bzr-workfile-versioned?)))
+    (%bzr-master-valid? master)))
+
+(define (%bzr-master-valid? master)
+  (%bzr-workfile-cache master 'WORKFILE-VERSIONED? %bzr-workfile-versioned?))
+
+(define-vc-type-operation 'DISPLAY-STATUS? vc-type:bzr
+  (lambda (buffer)
+    buffer
+    #f))
 
 (define-vc-type-operation 'DEFAULT-REVISION vc-type:bzr
   (lambda (master)
@@ -2379,12 +2380,11 @@ the value of vc-log-mode-hook."
 
 (define-vc-type-operation 'LOCKING-USER vc-type:bzr
   (lambda (master revision)
+    revision                           ;ignore
     ;; The workfile is "locked" if it is modified.
     ;; We consider the workfile's owner to be the locker.
     (let ((status (get-bzr-status master)))
       (and status
-          (or (not revision)
-              (equal? revision (bzr-workfile-revision master)))
           (bzr-status-modified? status)
           (unix/uid->string
            (file-attributes/uid
@@ -2591,10 +2591,8 @@ the value of vc-log-mode-hook."
       (or (parse-bzr-status
           (%bzr-run-command workfile "status" "--short"
                             (file-namestring workfile)))
-         (cond ((%bzr-workfile-versioned? workfile)
+         (cond ((%bzr-master-valid? master)
                 (make-bzr-status 'VERSIONED 'UNMODIFIED #f))
-               ((%bzr-workfile-ignored? workfile)
-                (make-bzr-status 'UNVERSIONED 'UNMODIFIED #f))
                (else
                 (if (if (default-object? required?) #f required?)
                     (error "Unable to determine Bazaar status of file:"