Add get_current_signoffs utility method

This is another SQL-based utility method that dramatically cuts back on
how many queries we run and gets around the shortcoming of arbitrary
joins in Django. It will be used by the new signoff page logic.

Signed-off-by: Dan McGee <dan@archlinux.org>

packages/utils.py

@@ -1,11 +1,12 @@
+from collections import defaultdict
+from operator import itemgetter
+
 from django.db import connection
 from django.db.models import Count, Max
 
-from operator import itemgetter
-
 from main.models import Package
 from main.utils import cache_function
-from .models import PackageGroup, PackageRelation
+from .models import PackageGroup, PackageRelation, Signoff
 
 @cache_function(300)
 def get_group_info(include_arches=None):
@@ -147,4 +148,28 @@ def get_wrong_permissions():
             id__in=to_fetch)
     return relations
 
+def get_current_signoffs():
+    '''Returns a mapping of pkgbase -> signoff objects.'''
+    sql = """
+SELECT DISTINCT s.id
+    FROM packages_signoff s
+    JOIN packages p ON (
+        s.pkgbase = p.pkgbase
+        AND s.pkgver = p.pkgver
+        AND s.pkgrel = p.pkgrel
+        AND s.epoch = p.epoch
+        AND s.arch_id = p.arch_id
+        AND s.repo_id = p.repo_id
+    )
+    JOIN repos r ON p.repo_id = r.id
+    WHERE r.testing = %s
+"""
+    cursor = connection.cursor()
+    cursor.execute(sql, [True])
+    results = cursor.fetchall()
+    # fetch all of the returned signoffs by ID
+    to_fetch = [row[0] for row in results]
+    signoffs = Signoff.objects.select_related('user').in_bulk(to_fetch)
+    return signoffs.values()
+
 # vim: set ts=4 sw=4 et: