From ed114265cdde01c71193f38d00e6fef8a6b1bebb Mon Sep 17 00:00:00 2001
From: Christopher Baines <mail@cbaines.net>
Date: Sat, 12 Nov 2022 11:36:19 +0000
Subject: [PATCH] Handle deleting from blocked_builds when builds are scheduled

As scheduling a build might unblock others.
---
 guix-data-service/model/blocked-builds.scm    | 31 +++++++++++++++++--
 .../web/build-server/controller.scm           |  2 +-
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/guix-data-service/model/blocked-builds.scm b/guix-data-service/model/blocked-builds.scm
index 708aaba..480b554 100644
--- a/guix-data-service/model/blocked-builds.scm
+++ b/guix-data-service/model/blocked-builds.scm
@@ -27,7 +27,7 @@
   #:use-module (guix-data-service model system)
   #:use-module (guix-data-service model guix-revision)
   #:use-module (guix-data-service model build)
-  #:export (handle-populating-blocked-builds-for-scheduled-builds
+  #:export (handle-blocked-builds-entries-for-scheduled-builds
             handle-populating-blocked-builds-for-build-failures
             handle-removing-blocking-build-entries-for-successful-builds
 
@@ -178,7 +178,7 @@ ON CONFLICT DO NOTHING")
 
   #t)
 
-(define (handle-populating-blocked-builds-for-scheduled-builds conn build-ids)
+(define (handle-blocked-builds-entries-for-scheduled-builds conn build-ids)
   (define (get-build-details build-id)
     (define query
       "
@@ -188,6 +188,29 @@ WHERE id = $1")
 
     (exec-query conn query (list (number->string build-id))))
 
+  (define delete-query
+    (string-append
+     "
+DELETE FROM blocked_builds
+WHERE EXISTS (
+  SELECT 1
+  FROM builds
+  WHERE builds.id IN (" (string-join
+                         (map number->string build-ids)
+                         ", ")
+  ")
+    AND EXISTS (
+          SELECT 1
+          FROM latest_build_status
+          WHERE latest_build_status.build_id = builds.id
+            AND latest_build_status.status = 'scheduled'
+        )
+    AND blocked_builds.build_server_id = builds.build_server_id
+    AND blocked_builds.blocking_derivation_output_details_set_id
+         = builds.derivation_output_details_set_id
+)"))
+
+  ;; Insert entries for each build if it's blocked
   (for-each
    (lambda (build-id)
      (match (get-build-details build-id)
@@ -207,6 +230,10 @@ WHERE id = $1")
               blocking-derivation-output-details-set-ids)))))))
    build-ids)
 
+  ;; This build being scheduled might unblock other builds, so delete the
+  ;; associated entries
+  (exec-query conn delete-query '())
+
   #t)
 
 (define (handle-populating-blocked-builds-for-build-failures conn build-ids)
diff --git a/guix-data-service/web/build-server/controller.scm b/guix-data-service/web/build-server/controller.scm
index 750fb67..a35a62f 100644
--- a/guix-data-service/web/build-server/controller.scm
+++ b/guix-data-service/web/build-server/controller.scm
@@ -217,7 +217,7 @@
        build-ids)
 
       (spawn-fiber-for-build-handler
-       handle-populating-blocked-builds-for-scheduled-builds
+       handle-blocked-builds-entries-for-scheduled-builds
        '("scheduled")
        items
        build-ids)