factor out FILE:UPDATE-UNIX-TABLE

Signed-off-by: Sean Whitton <spwhitton@spwhitton.name>

3 files changed, 35 insertions, 29 deletions

diff --git a/src/package.lisp b/src/package.lisp
index de9eb85..edd90ca 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -260,7 +260,8 @@
            #:regex-replaced-lines
            #:directory-exists
            #:symlinked
-           #:is-copy-of))
+           #:is-copy-of
+           #:update-unix-table))
 
 (defpackage :consfigurator.property.os
   (:use #:cl #:consfigurator)
diff --git a/src/property/file.lisp b/src/property/file.lisp
index 71372d8..dd4ae89 100644
--- a/src/property/file.lisp
+++ b/src/property/file.lisp
@@ -409,3 +409,35 @@ removed, and semicolon comment chars will be replaced with '#'."
                  finally (return
                            (nconc new-lines
                                   (sort accum #'string< :key #'cadr)))))))))))
+
+(defun update-unix-table (file source target entries &key (no-source "none"))
+  "Ensure that the UNIX table at FILE (e.g. /etc/fstab) contains each of
+ENTRIES, using a simple merge procedure: existing lines of the file with the
+same value for the TARGETth field are updated to match the corresponding
+members of ENTRIES, except that if the SOURCEth field of the existing entry is
+not NO-SOURCE and the corresponding member of ENTRIES is STRING= to either
+NO-SOURCE or \"PLACEHOLDER\", use the existing field value."
+  (let ((unknown (list no-source "PLACEHOLDER"))
+        (pending (make-hash-table :test #'equal)))
+    (flet ((fields (entry)
+             (remove "" (split-string entry) :test #'string=)))
+      (dolist (entry entries)
+        (setf (gethash (nth target (fields entry)) pending) entry))
+      (map-file-lines
+       file
+       (lambda (lines)
+         (loop for line in lines
+               for line-fields = (fields line)
+               for line-source = (nth source line-fields)
+               and line-target = (nth target line-fields)
+               for entry = (when-let* ((entry (gethash line-target pending))
+                                       (fields (fields entry)))
+                             (and (member (nth source fields)
+                                          unknown :test #'string=)
+                                  (not (string= line-source no-source))
+                                  (setf (nth source fields) line-source)
+                                  (format nil "~{~A~^ ~}" fields)))
+               if entry
+                 collect it into accum and do (remhash line-target pending)
+               else collect line into accum
+               finally (return (nconc accum (hash-table-values pending)))))))))
diff --git a/src/property/fstab.lisp b/src/property/fstab.lisp
index f89365d..7be61a4 100644
--- a/src/property/fstab.lisp
+++ b/src/property/fstab.lisp
@@ -64,12 +64,6 @@ Other properties might fill it in."
 
 ;;;; Properties
 
-(defun entry->source (entry)
-  (car (split-string entry)))
-
-(defun entry->mountpoint (entry)
-  (cadr (remove "" (split-string entry) :test #'string=)))
-
 (defprop entries :posix (&rest entries)
   "Ensure that /etc/fstab contains each of ENTRIES, using a simple merge
 procedure: existing lines of the fstab with the same mount point as any of
@@ -81,28 +75,7 @@ This makes it easy to update mount options without having to specify the
 partition or filesystem UUID in your consfig."
   (:desc (format nil "fstab entries for ~{~A~^, ~}"
                  (mapcar #'entry->mountpoint entries)))
-  (:apply
-   (file:map-file-lines
-    #P"/etc/fstab"
-    (lambda (lines)
-      (let ((pending (make-hash-table :test #'equal)))
-        (dolist (entry entries)
-          (setf (gethash (entry->mountpoint entry) pending) entry))
-        (loop for line in lines
-              for line-source = (entry->source line)
-              and line-mountpoint = (entry->mountpoint line)
-              for entry = (let ((entry (gethash line-mountpoint pending)))
-                            (if (and (member (entry->source entry)
-                                             '("none" "PLACEHOLDER")
-                                             :test #'string=)
-                                     (not (string= line-source "none")))
-                                (format nil "~A ~{~A~^ ~}"
-                                        line-source (cdr (split-string entry)))
-                                entry))
-              if entry
-                collect it into accum and do (remhash line-mountpoint pending)
-              else collect line into accum
-              finally (return (nconc accum (hash-table-values pending)))))))))
+  (:apply (file:update-unix-table #P"/etc/fstab" 0 1 entries)))
 
 (defprop entries-for-volumes :posix ()
   "Add or update entries in /etc/fstab for the host's volumes, as specified with