Move package utility functions

We now have a few of them, so move them to their own file like we do in the
other applications.

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

1 files changed, 103 insertions, 0 deletions

diff --git a/packages/utils.py b/packages/utils.py
new file mode 100644
index 00000000..204e5bf2
--- /dev/null
+++ b/packages/utils.py
@@ -0,0 +1,103 @@
+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
+
+@cache_function(300)
+def get_group_info():
+    raw_groups = PackageGroup.objects.values_list(
+            'name', 'pkg__arch__name').order_by('name').annotate(
+             cnt=Count('pkg'), last_update=Max('pkg__last_update'))
+    # now for post_processing. we need to seperate things out and add
+    # the count in for 'any' to all of the other architectures.
+    group_mapping = {}
+    for grp in raw_groups:
+        arch_groups = group_mapping.setdefault(grp[1], {})
+        arch_groups[grp[0]] = {'name': grp[0], 'arch': grp[1],
+                'count': grp[2], 'last_update': grp[3]}
+
+    # we want to promote the count of 'any' packages in groups to the
+    # other architectures, and also add any 'any'-only groups
+    if 'any' in group_mapping:
+        any_groups = group_mapping['any']
+        del group_mapping['any']
+        for arch, arch_groups in group_mapping.iteritems():
+            for grp in any_groups.itervalues():
+                if grp['name'] in arch_groups:
+                    found = arch_groups[grp['name']]
+                    found['count'] += grp['count']
+                    if grp['last_update'] > found['last_update']:
+                        found['last_update'] = grp['last_update']
+                else:
+                    new_g = grp.copy()
+                    # override the arch to not be 'any'
+                    new_g['arch'] = arch
+                    arch_groups[grp['name']] = new_g
+
+    # now transform it back into a sorted list
+    groups = []
+    for val in group_mapping.itervalues():
+        groups.extend(val.itervalues())
+    return sorted(groups, key=itemgetter('name', 'arch'))
+
+@cache_function(300)
+def get_differences_info(arch_a, arch_b):
+    # This is a monster. Join packages against itself, looking for packages in
+    # our non-'any' architectures only, and not having a corresponding package
+    # entry in the other table (or having one with a different pkgver). We will
+    # then go and fetch all of these packages from the database and display
+    # them later using normal ORM models.
+    sql = """
+SELECT p.id, q.id
+    FROM packages p
+    LEFT JOIN packages q
+    ON (
+        p.pkgname = q.pkgname
+        AND p.repo_id = q.repo_id
+        AND p.arch_id != q.arch_id
+        AND p.id != q.id
+    )
+    WHERE p.arch_id IN (%s, %s)
+    AND (
+        q.id IS NULL
+        OR
+        p.pkgver != q.pkgver
+        OR
+        p.pkgrel != q.pkgrel
+    )
+"""
+    cursor = connection.cursor()
+    cursor.execute(sql, [arch_a.id, arch_b.id])
+    results = cursor.fetchall()
+    to_fetch = []
+    for row in results:
+        # column A will always have a value, column B might be NULL
+        to_fetch.append(row[0])
+    # fetch all of the necessary packages
+    pkgs = Package.objects.in_bulk(to_fetch)
+    # now build a list of tuples containing differences
+    differences = []
+    for row in results:
+        pkg_a = pkgs.get(row[0])
+        pkg_b = pkgs.get(row[1])
+        # We want arch_a to always appear first
+        # pkg_a should never be None
+        if pkg_a.arch == arch_a:
+            item = (pkg_a.pkgname, pkg_a.repo, pkg_a, pkg_b)
+        else:
+            # pkg_b can be None in this case, so be careful
+            name = pkg_a.pkgname if pkg_a else pkg_b.pkgname
+            repo = pkg_a.repo if pkg_a else pkg_b.repo
+            item = (name, repo, pkg_b, pkg_a)
+        if item not in differences:
+            differences.append(item)
+
+    # now sort our list by repository, package name
+    differences.sort(key=lambda a: (a[1].name, a[0]))
+    return differences
+
+# vim: set ts=4 sw=4 et: