move tag/package owners to separate table

Changing owner is triggering repo regeneration in kojira. As it is
something which doesn't have any effect on repodata, let's put it to
separate table and let kojira ignore these changes.

Fixes: https://pagure.io/koji/issue/956

docs/schema-upgrade-1.18-1.19.sql

@@ -4,5 +4,55 @@
 
 BEGIN;
 
+CREATE TABLE tag_package_owners (
+	package_id INTEGER NOT NULL REFERENCES package(id),
+	tag_id INTEGER NOT NULL REFERENCES tag (id),
+	owner INTEGER NOT NULL REFERENCES users(id),
+-- versioned - see earlier description of versioning
+	create_event INTEGER NOT NULL REFERENCES events(id) DEFAULT get_event(),
+	revoke_event INTEGER REFERENCES events(id),
+	creator_id INTEGER NOT NULL REFERENCES users(id),
+	revoker_id INTEGER REFERENCES users(id),
+	active BOOLEAN DEFAULT 'true' CHECK (active),
+	CONSTRAINT active_revoke_sane CHECK (
+		(active IS NULL AND revoke_event IS NOT NULL AND revoker_id IS NOT NULL)
+		OR (active IS NOT NULL AND revoke_event IS NULL AND revoker_id IS NULL)),
+	PRIMARY KEY (create_event, package_id, tag_id),
+	UNIQUE (package_id,tag_id,active)
+) WITHOUT OIDS;
+
+CREATE OR REPLACE FUNCTION convert_owners() RETURNS SETOF tag_packages AS
+$BODY$
+DECLARE
+    r tag_packages%rowtype;
+    r2 tag_packages%rowtype;
+    last_owner int;
+BEGIN
+    FOR r IN SELECT package_id, tag_id FROM tag_packages GROUP BY package_id, tag_id ORDER BY package_id, tag_id
+    LOOP
+        last_owner := 0;
+        FOR r2 IN SELECT * FROM tag_packages WHERE package_id = r.package_id AND tag_id = r.tag_id ORDER BY create_event
+        LOOP
+            -- always use first and last (active) row
+            IF last_owner = 0 OR r2.active IS TRUE THEN
+                last_owner := r2.owner;
+                RETURN NEXT r2; -- return current row of SELECT
+            ELSE
+                -- copy others only if owner changed
+                IF last_owner <> r2.owner THEN
+                    RETURN NEXT r2;
+                    last_owner := r2.owner;
+                END IF;
+            END IF;
+        END LOOP;
+    END LOOP;
+    RETURN;
+END
+$BODY$
+LANGUAGE plpgsql;
+
+INSERT INTO tag_package_owners (SELECT package_id, tag_id, owner create_event revoke_event creator_id revoker_id active FROM convert_owners());
+ALTER TABLE tag_packages DROP COLUMN owner;
+DROP FUNCTION convert_owners();
 
 COMMIT;

docs/schema.sql

@@ -604,6 +604,23 @@ CREATE INDEX tag_packages_create_event ON tag_packages(create_event);
 CREATE INDEX tag_packages_revoke_event ON tag_packages(revoke_event);
 CREATE INDEX tag_packages_owner ON tag_packages(owner);
 
+CREATE TABLE tag_package_owners (
+	package_id INTEGER NOT NULL REFERENCES package(id),
+	tag_id INTEGER NOT NULL REFERENCES tag (id),
+	owner INTEGER NOT NULL REFERENCES users(id),
+-- versioned - see earlier description of versioning
+	create_event INTEGER NOT NULL REFERENCES events(id) DEFAULT get_event(),
+	revoke_event INTEGER REFERENCES events(id),
+	creator_id INTEGER NOT NULL REFERENCES users(id),
+	revoker_id INTEGER REFERENCES users(id),
+	active BOOLEAN DEFAULT 'true' CHECK (active),
+	CONSTRAINT active_revoke_sane CHECK (
+		(active IS NULL AND revoke_event IS NOT NULL AND revoker_id IS NOT NULL)
+		OR (active IS NOT NULL AND revoke_event IS NULL AND revoker_id IS NULL)),
+	PRIMARY KEY (create_event, package_id, tag_id),
+	UNIQUE (package_id,tag_id,active)
+) WITHOUT OIDS;
+
 -- package groups (per tag). used for generating comps for the tag repos
 CREATE TABLE groups (
 	id SERIAL NOT NULL PRIMARY KEY,