Introduce build "last_status" field.

* src/sql/upgrade-3.sql: New file.
* Makefile.am (dist_sql_DATA): Add it.
* src/schema.sql (Builds)[last_status]: New field.
* src/cuirass/database.scm (db-update-build-status!): Honor it.
(db-get-builds): Return it.
* tests/database.scm ("db-update-build-status!"): New test.

Makefile.am

@@ -80,7 +80,8 @@ dist_pkgdata_DATA = src/schema.sql
 
 dist_sql_DATA = 				\
   src/sql/upgrade-1.sql				\
-  src/sql/upgrade-2.sql
+  src/sql/upgrade-2.sql				\
+  src/sql/upgrade-3.sql
 
 dist_css_DATA =					\
   src/static/css/cuirass.css			\

src/cuirass/database.scm

@@ -788,13 +788,25 @@ log file for DRV."
         ;; Update only if we're switching to a different status; otherwise
         ;; leave things unchanged.  This ensures that 'stoptime' remains valid
         ;; and doesn't change every time we mark DRV as 'succeeded' several
-        ;; times in a row, for instance.
+        ;; times in a row, for instance.  The 'last_status' field is updated
+        ;; with the status of the last completed build with the same
+        ;; 'job_name' and 'specification'.
         (begin
           (let ((rows
-                 (exec-query/bind db "UPDATE Builds SET stoptime=" now
-                                  ", status=" status
-                                  "WHERE derivation=" drv
-                                  " AND status != " status ";")))
+                 (exec-query/bind db "
+UPDATE Builds SET stoptime =" now
+", status =" status
+", last_status =
+(SELECT Builds.status FROM (SELECT job_name, specification FROM Builds
+INNER JOIN Evaluations ON Builds.evaluation = Evaluations.id WHERE
+derivation = " drv ") AS cur, Builds INNER JOIN
+Evaluations ON Builds.evaluation = Evaluations.id
+WHERE cur.job_name = Builds.job_name AND
+cur.specification = Evaluations.specification AND
+Builds.status >= 0
+ORDER BY evaluation DESC LIMIT 1)
+WHERE derivation =" drv
+" AND status != " status ";")))
             (when (positive? rows)
               (db-add-event 'build
                             now
@@ -1014,8 +1026,9 @@ OR :borderhightime IS NULL OR :borderhighid IS NULL)")))
                                     (string-join rest " AND ")))))
            (query
             (format #f " SELECT Builds.derivation, Builds.id, Builds.timestamp,
-Builds.starttime, Builds.stoptime, Builds.log, Builds.status, Builds.priority,
-Builds.max_silent, Builds.timeout, Builds.job_name, Builds.system,
+Builds.starttime, Builds.stoptime, Builds.log, Builds.status,
+Builds.last_status, Builds.priority, Builds.max_silent,
+Builds.timeout, Builds.job_name, Builds.system,
 Builds.worker, Builds.nix_name, Builds.evaluation, agg.name, agg.outputs_name,
 agg.outputs_path,agg.bp_build, agg.bp_type, agg.bp_file_size,
 agg.bp_checksum, agg.bp_path
@@ -1063,7 +1076,7 @@ ORDER BY ~a;"
         (match builds
           (() (reverse result))
           (((derivation id timestamp starttime stoptime log status
-                        priority max-silent timeout job-name
+                        last-status priority max-silent timeout job-name
                         system worker nix-name eval-id specification
                         outputs-name outputs-path
                         products-id products-type products-file-size
@@ -1077,6 +1090,8 @@ ORDER BY ~a;"
                          (#:stoptime . ,(string->number stoptime))
                          (#:log . ,log)
                          (#:status . ,(string->number status))
+                         (#:last-status . ,(and last-status
+                                                (string->number last-status)))
                          (#:priority . ,(string->number priority))
                          (#:max-silent . ,(string->number max-silent))
                          (#:timeout . ,(string->number timeout))

src/schema.sql

@@ -63,6 +63,7 @@ CREATE TABLE Builds (
   nix_name      TEXT NOT NULL,
   log           TEXT NOT NULL,
   status        INTEGER NOT NULL,
+  last_status   INTEGER,
   priority      INTEGER NOT NULL DEFAULT 0,
   max_silent    INTEGER NOT NULL DEFAULT 0,
   timeout       INTEGER NOT NULL DEFAULT 0,

src/sql/upgrade-3.sql

+BEGIN TRANSACTION;
+
+ALTER TABLE Builds ADD COLUMN last_status INTEGER,
+
+COMMIT;

tests/database.scm

@@ -64,11 +64,13 @@
 
 (define* (make-dummy-build drv
                            #:optional (eval-id 2)
-                           #:key (outputs
-                                  `(("foo" . ,(format #f "~a.output" drv)))))
+                           #:key
+                           (job-name "job")
+                           (outputs
+                            `(("foo" . ,(format #f "~a.output" drv)))))
   `((#:derivation . ,drv)
     (#:eval-id . ,eval-id)
-    (#:job-name . "job")
+    (#:job-name . ,job-name)
     (#:timestamp . ,(time-second (current-time time-utc)))
     (#:system . "x86_64-linux")
     (#:nix-name . "foo")
@@ -445,6 +447,23 @@ timestamp, checkouttime, evaltime) VALUES ('guix', 0, 0, 0, 0);")
                  ((id) (string->number id)))))
           (>= (db-get-build-percentage last-id) 50)))))
 
+  (test-equal "db-update-build-status!"
+    (list #f 1)
+    (begin
+      (db-add-evaluation "guix"
+                         (make-dummy-checkouts "fakesha5" "fakesha6"))
+      (db-add-build (make-dummy-build "/old-build.drv" 3
+                                      #:job-name "job-1"
+                                      #:outputs `(("out" . "/old"))))
+      (db-add-build (make-dummy-build "/new-build.drv" 4
+                                      #:job-name "job-1"
+                                      #:outputs `(("out" . "/new"))))
+      (db-update-build-status! "/old-build.drv" 1)
+      (db-update-build-status! "/new-build.drv" 0)
+      (map (cut assq-ref <> #:last-status)
+           (list (db-get-build "/old-build.drv")
+                 (db-get-build "/new-build.drv")))))
+
   (test-assert "db-close"
     (begin
       (exec-query (%db) (format #f "DROP OWNED BY CURRENT_USER;"))