01/08: Support setting a statement timeout

[Christopher Baines]

cbaines pushed a commit to branch master
in repository data-service.

commit 0cc78b90aec0ccdd8740092a465753cc71bca704
Author: Christopher Baines <address@hidden>
AuthorDate: Fri Apr 24 08:59:32 2020 +0100

    Support setting a statement timeout
    
    To stop queries related to the web server that run for a long time.
---
 guix-data-service/database.scm | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/guix-data-service/database.scm b/guix-data-service/database.scm
index 455ce82..df4daac 100644
--- a/guix-data-service/database.scm
+++ b/guix-data-service/database.scm
@@ -34,7 +34,7 @@
 (define pg-conn-finish
   (@@ (squee) pg-conn-finish))
 
-(define* (with-postgresql-connection name f)
+(define* (with-postgresql-connection name f #:key (statement-timeout #f))
   (define paramstring
     (string-append
      (or (getenv "GUIX_DATA_SERVICE_DATABASE_PARAMSTRING")
@@ -47,6 +47,11 @@
   (let* ((conn (connect-to-postgres-paramstring
                 (or (getenv "GUIX_DATA_SERVICE_DATABASE_URI")
                     paramstring))))
+    (when statement-timeout
+      (exec-query
+       conn
+       (simple-format #f "SET statement_timeout = ~A"
+                      statement-timeout)))
     (with-throw-handler
       #t
       (lambda ()