Add new models relating to builds and build servers

These will allow tracking what's going on with build servers.

Makefile.am

@@ -31,8 +31,11 @@ assetsdir = $(datadir)/@PACKAGE@
 SOURCES =						\
   guix-data-service/comparison.scm			\
   guix-data-service/config.scm				\
-  guix-data-service/jobs/load-new-guix-revision.scm	\
   guix-data-service/jobs.scm				\
+  guix-data-service/jobs/load-new-guix-revision.scm	\
+  guix-data-service/model/build-server.scm		\
+  guix-data-service/model/build-status.scm		\
+  guix-data-service/model/build.scm			\
   guix-data-service/model/derivation.scm		\
   guix-data-service/model/guix-revision-package.scm	\
   guix-data-service/model/guix-revision.scm		\

guix-data-service/model/build-server.scm

@@ -0,0 +1,9 @@
+(define-module (guix-data-service model build-server)
+  #:use-module (squee)
+  #:export (select-build-servers))
+
+(define (select-build-servers conn)
+  (exec-query conn
+              (string-append
+               "SELECT id, url, lookup_all_derivations "
+               "FROM build_servers")))

guix-data-service/model/build-status.scm

@@ -0,0 +1,36 @@
+(define-module (guix-data-service model build-status)
+  #:use-module (squee)
+  #:export (build-statuses
+            insert-build-status))
+
+(define build-statuses
+  '((-2 . "scheduled")
+    (-1 . "started")
+    (0 . "succeeded")
+    (1 . "failed")
+    (2 . "failed-dependency")
+    (3 . "failed-other")
+    (4 . "canceled")))
+
+(define (insert-build-status conn internal-build-id
+                             starttime stoptime status)
+  (exec-query conn
+              (string-append
+               "INSERT INTO build_status "
+               "(internal_build_id, starttime, stoptime, status) "
+               "VALUES "
+               "(" internal-build-id ", "
+               (if (eq? starttime 0)
+                   "NULL"
+                   (string-append "to_timestamp("
+                                  (number->string starttime)
+                                  ")"))
+               ", "
+               (if (eq? stoptime 0)
+                   "NULL"
+                   (string-append "to_timestamp("
+                                  (number->string stoptime)
+                                  ")"))
+               ", "
+               "'" status "'"
+               ")")))

guix-data-service/model/build.scm

@@ -0,0 +1,84 @@
+(define-module (guix-data-service model build)
+  #:use-module (squee)
+  #:export (select-build-stats
+            select-builds-with-context
+            select-build-by-build-server-and-id
+            insert-build
+            ensure-build-exists))
+
+(define (select-build-stats conn)
+  (define query
+    (string-append
+     "SELECT latest_build_status.status AS build_status, COUNT(*) "
+     "FROM derivations "
+     "FULL OUTER JOIN builds ON builds.derivation_id = derivations.id "
+     "FULL OUTER JOIN "
+     "(SELECT DISTINCT ON (internal_build_id) * FROM build_status "
+     "ORDER BY internal_build_id, status_fetched_at DESC"
+     ") AS latest_build_status "
+     "ON builds.internal_id = latest_build_status.internal_build_id "
+     "GROUP BY (builds.id IS NULL), latest_build_status.status "
+     "ORDER BY build_status"))
+
+  (exec-query conn query))
+
+(define (select-builds-with-context conn)
+  (define query
+    (string-append
+     "SELECT builds.id, build_servers.url, derivations.file_name, "
+     "latest_build_status.status_fetched_at, latest_build_status.starttime, "
+     "latest_build_status.stoptime, latest_build_status.status "
+     "FROM builds "
+     "INNER JOIN build_servers ON build_servers.id = builds.build_server_id "
+     "INNER JOIN derivations ON derivations.id = builds.derivation_id "
+     "INNER JOIN "
+     "(SELECT DISTINCT ON (internal_build_id) * "
+     "FROM build_status "
+     "ORDER BY internal_build_id, status_fetched_at DESC"
+     ") AS latest_build_status "
+     "ON latest_build_status.internal_build_id = builds.internal_id "
+     "ORDER BY latest_build_status.status_fetched_at DESC "
+     "LIMIT 100"))
+
+  (exec-query conn query))
+
+(define (select-build-by-build-server-and-id
+         conn build-server-id id)
+  (exec-query conn
+              (string-append
+               "SELECT internal_id, id, build_server_id, "
+               "derivation_id, timestamp "
+               "FROM builds "
+               "WHERE build_server_id = $1 AND id = $2")
+              (list build-server-id
+                    (number->string id))))
+
+(define (insert-build conn id build-server-id derivation-id timestamp)
+  (caar
+   (exec-query conn
+               (string-append
+                "INSERT INTO builds "
+                "(id, build_server_id, derivation_id, timestamp) "
+                "VALUES "
+                "($1, $2, $3, to_timestamp($4))"
+                "RETURNING "
+                "(internal_id)")
+               (list (number->string id)
+                     build-server-id
+                     derivation-id
+                     (number->string timestamp)))))
+
+(define (ensure-build-exists conn build-server-id id
+                             derivation-id timestamp)
+  (let ((existing-build
+         (select-build-by-build-server-and-id
+          conn build-server-id id)))
+
+    (if (null? existing-build)
+        (insert-build conn
+                      id
+                      build-server-id
+                      derivation-id
+                      timestamp)
+        (caar existing-build))))
+