03/06: Stop opening a PostgreSQL connection per request

[Christopher Baines]

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

commit 18b6dd9e6d4463e47ce457187d956c1c3dd8dd08
Author: Christopher Baines <mail@cbaines.net>
AuthorDate: Sat Oct 3 09:22:29 2020 +0100

    Stop opening a PostgreSQL connection per request
    
    This was good in that it avoided having to deal with long running 
connections,
    but it probably takes some time to open the connection, and these changes 
are
    a step towards offloading the PostgreSQL queries to other threads, so they
    don't block the threads for fibers.
---
 guix-data-service/web/controller.scm |  9 +++------
 guix-data-service/web/server.scm     | 13 ++++---------
 scripts/guix-data-service.in         | 14 +++++++++-----
 3 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/guix-data-service/web/controller.scm 
b/guix-data-service/web/controller.scm
index 4cf1f82..a8a8696 100644
--- a/guix-data-service/web/controller.scm
+++ b/guix-data-service/web/controller.scm
@@ -391,8 +391,7 @@
 
 (define* (controller request method-and-path-components
                      mime-types body
-                     secret-key-base
-                     #:key postgresql-statement-timeout)
+                     secret-key-base)
   (define (controller-thunk)
     (match method-and-path-components
       (('GET "assets" rest ...)
@@ -430,16 +429,14 @@
                       "The README.html file does not exist")
               #:code 404))))
       (_
-       (with-postgresql-connection
-        "web"
+       (with-thread-postgresql-connection
         (lambda (conn)
           (controller-with-database-connection request
                                                method-and-path-components
                                                mime-types
                                                body
                                                conn
-                                               secret-key-base))
-        #:statement-timeout postgresql-statement-timeout))))
+                                               secret-key-base))))))
   (call-with-error-handling
    controller-thunk
    #:on-error 'backtrace
diff --git a/guix-data-service/web/server.scm b/guix-data-service/web/server.scm
index 8f0ce56..05c0a58 100644
--- a/guix-data-service/web/server.scm
+++ b/guix-data-service/web/server.scm
@@ -29,8 +29,7 @@
   #:use-module (guix-data-service web util)
   #:export (start-guix-data-service-web-server))
 
-(define (handler request body controller secret-key-base
-                 postgresql-statement-timeout)
+(define (handler request body controller secret-key-base)
   (display
    (format #f "~a ~a\n"
            (request-method request)
@@ -43,18 +42,14 @@
                              request-components)
                        mime-types
                        body
-                       secret-key-base
-                       #:postgresql-statement-timeout
-                       postgresql-statement-timeout))))
+                       secret-key-base))))
 
-(define* (start-guix-data-service-web-server port host secret-key-base
-                                             #:key 
postgresql-statement-timeout)
+(define* (start-guix-data-service-web-server port host secret-key-base)
   (call-with-error-handling
    (lambda ()
      (run-server (lambda (request body)
                    (handler request body controller
-                            secret-key-base
-                            postgresql-statement-timeout))
+                            secret-key-base))
                  #:host host
                  #:port port))
    #:on-error 'backtrace
diff --git a/scripts/guix-data-service.in b/scripts/guix-data-service.in
index 70274d0..d3ed0d8 100644
--- a/scripts/guix-data-service.in
+++ b/scripts/guix-data-service.in
@@ -31,6 +31,7 @@
              (gcrypt pk-crypto)
              (guix pki)
              (guix-data-service config)
+             (guix-data-service database)
              (guix-data-service web server)
              (guix-data-service web controller)
              (guix-data-service web nar controller))
@@ -194,9 +195,12 @@
                    (assq-ref opts 'host)
                    (assq-ref opts 'port))
 
-    (start-guix-data-service-web-server
-     (assq-ref opts 'port)
-     (assq-ref opts 'host)
-     (assq-ref opts 'secret-key-base)
-     #:postgresql-statement-timeout
+    (with-postgresql-connection-per-thread
+     "web"
+     (lambda ()
+       (start-guix-data-service-web-server
+        (assq-ref opts 'port)
+        (assq-ref opts 'host)
+        (assq-ref opts 'secret-key-base)))
+     #:statement-timeout
      (assq-ref opts 'postgresql-statement-timeout))))