Add (cuirass logging) module.

* src/cuirass/logging.scm: New file.
* Makefile.am (dist_pkgmodule_DATA): Add it.
* src/cuirass/base.scm (handle-build-event): Use 'log-message' instead
of 'log'.

2 files changed, 55 insertions, 16 deletions

diff --git a/src/cuirass/base.scm b/src/cuirass/base.scm
index 1daa428..d57612e 100644
--- a/src/cuirass/base.scm
+++ b/src/cuirass/base.scm
@@ -20,6 +20,7 @@
 ;;; along with Cuirass.  If not, see <http://www.gnu.org/licenses/>.
 
 (define-module (cuirass base)
+  #:use-module (cuirass logging)
   #:use-module (cuirass database)
   #:use-module (gnu packages)
   #:use-module (guix build utils)
@@ -247,30 +248,20 @@ and so on. "
 (define* (handle-build-event db event
                              #:key (log-port (current-error-port)))
   "Handle EVENT, a build event sexp as produced by 'build-event-output-port'."
-  (define now
-    (current-time time-utc))
-
-  (define date
-    (date->string (time-utc->date now) "~5"))
-
-  (define (log fmt . args)
-    (apply format log-port (string-append date " " fmt "\n")
-           args))
-
   ;; TODO: Update DB according to EVENT.
   (match event
     (('build-started drv _ ...)
-     (log "build started: '~a'" drv))
+     (log-message "build started: '~a'" drv))
     (('build-remote drv host _ ...)
-     (log "build of '~a' offloaded to '~a'" drv host))
+     (log-message "build of '~a' offloaded to '~a'" drv host))
     (('build-succeeded drv _ ...)
-     (log "build succeeded: '~a'" drv))
+     (log-message "build succeeded: '~a'" drv))
     (('substituter-started item _ ...)
-     (log "substituter started: '~a'" item))
+     (log-message "substituter started: '~a'" item))
     (('substituter-succeeded item _ ...)
-     (log "substituter succeeded: '~a'" item))
+     (log-message "substituter succeeded: '~a'" item))
     (_
-     (log "build event: ~s" event))))
+     (log-message "build event: ~s" event))))
 
 (define (build-packages store db jobs)
   "Build JOBS and return a list of Build results."
diff --git a/src/cuirass/logging.scm b/src/cuirass/logging.scm
new file mode 100644
index 0000000..bd1eed3
--- /dev/null
+++ b/src/cuirass/logging.scm
@@ -0,0 +1,48 @@
+;;; logging.scm -- Event logging.
+;;; Copyright © 2018 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; This file is part of Cuirass.
+;;;
+;;; Cuirass is free software: you can redistribute it and/or modify
+;;; it under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation, either version 3 of the License, or
+;;; (at your option) any later version.
+;;;
+;;; Cuirass is distributed in the hope that it will be useful,
+;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with Cuirass.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (cuirass logging)
+  #:use-module (srfi srfi-19)
+  #:use-module (ice-9 format)
+  #:export (current-logging-port
+            current-logging-procedure
+            log-message))
+
+(define current-logging-port
+  (make-parameter (current-error-port)))
+
+(define (log-to-port port str)
+  (define now
+    (current-time time-utc))
+
+  (define date
+    (date->string (time-utc->date now) "~5"))
+
+  (display (string-append date " " str "\n")
+           port))
+
+(define current-logging-procedure
+  ;; The logging procedure.  This could be 'syslog', for instance.
+  (make-parameter (lambda (str)
+                    (log-to-port (current-logging-port) str))))
+
+(define-syntax-rule (log-message fmt args ...)
+  "Log the given message as one line."
+  ;; Note: Use '@' to make sure -Wformat detects this use of 'format'.
+  ((current-logging-procedure)
+   ((@ (ice-9 format) format) #f fmt args ...)))