Add patch tag infrastructure

This change add patch 'tags', eg 'Acked-by' / 'Reviewed-by', etc., to
patchwork.

Tag parsing is implemented in the patch parser's extract_tags function,
which returns a Counter object of the tags in a comment. These are
stored in the PatchTag (keyed to Tag) objects associated with each
patch.

We need to ensure that the main patch lists do not cause per-patch
queries on the Patch.tags ManyToManyField (this would result in ~500
queries per page), so we introduce a new QuerySet (and Manager) for
Patch, adding a with_tag_counts() method to populate the tag counts in a
single query.

As users may be migrating from previous patchwork versions (ie, with no
tag counts in the database), we add a 'retag' management command.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

3 files changed, 36 insertions, 4 deletions

diff --git a/lib/sql/grant-all.mysql.sql b/lib/sql/grant-all.mysql.sql
index a307675..6a3d547 100644
--- a/lib/sql/grant-all.mysql.sql
+++ b/lib/sql/grant-all.mysql.sql
@@ -23,13 +23,17 @@ GRANT SELECT, UPDATE, INSERT, DELETE ON patchwork_bundlepatch TO 'www-data'@loca
 GRANT SELECT, UPDATE, INSERT, DELETE ON patchwork_patch TO 'www-data'@localhost;
 GRANT SELECT, UPDATE, INSERT, DELETE ON patchwork_emailoptout TO 'www-data'@localhost;
 GRANT SELECT, UPDATE, INSERT, DELETE ON patchwork_patchchangenotification TO 'www-data'@localhost;
+GRANT SELECT, UPDATE, INSERT, DELETE ON patchwork_tag TO 'www-data'@localhost;
+GRANT SELECT, UPDATE, INSERT, DELETE ON patchwork_patchtag TO 'www-data'@localhost;
 
 -- allow the mail user (in this case, 'nobody') to add patches
 GRANT INSERT, SELECT ON patchwork_patch TO 'nobody'@localhost;
 GRANT INSERT, SELECT ON patchwork_comment TO 'nobody'@localhost;
 GRANT INSERT, SELECT ON patchwork_person TO 'nobody'@localhost;
+GRANT INSERT, SELECT, UPDATE, DELETE ON patchwork_patchtag TO 'nobody'@localhost;
 GRANT SELECT ON	patchwork_project TO 'nobody'@localhost;
 GRANT SELECT ON patchwork_state TO 'nobody'@localhost;
+GRANT SELECT ON patchwork_tag TO 'nobody'@localhost;
 
 COMMIT;
 
diff --git a/lib/sql/grant-all.postgres.sql b/lib/sql/grant-all.postgres.sql
index 4498408..477e10a 100644
--- a/lib/sql/grant-all.postgres.sql
+++ b/lib/sql/grant-all.postgres.sql
@@ -23,7 +23,9 @@ GRANT SELECT, UPDATE, INSERT, DELETE ON
 	patchwork_bundlepatch,
 	patchwork_patch,
 	patchwork_emailoptout,
-	patchwork_patchchangenotification
+	patchwork_patchchangenotification,
+	patchwork_tag,
+	patchwork_patchtag
 TO "www-data";
 GRANT SELECT, UPDATE ON
 	auth_group_id_seq,
@@ -44,7 +46,9 @@ GRANT SELECT, UPDATE ON
 	patchwork_state_id_seq,
 	patchwork_emailconfirmation_id_seq,
 	patchwork_userprofile_id_seq,
-	patchwork_userprofile_maintainer_projects_id_seq
+	patchwork_userprofile_maintainer_projects_id_seq,
+	patchwork_tag_id_seq,
+	patchwork_patchtag_id_seq
 TO "www-data";
 
 -- allow the mail user (in this case, 'nobody') to add patches
@@ -53,14 +57,19 @@ GRANT INSERT, SELECT ON
 	patchwork_comment,
 	patchwork_person
 TO "nobody";
+GRANT INSERT, SELECT, UPDATE, DELETE ON
+	patchwork_patchtag
+TO "nobody";
 GRANT SELECT ON
 	patchwork_project,
-	patchwork_state
+	patchwork_state,
+	patchwork_tag
 TO "nobody";
 GRANT UPDATE, SELECT ON
 	patchwork_patch_id_seq,
 	patchwork_person_id_seq,
-	patchwork_comment_id_seq
+	patchwork_comment_id_seq,
+	patchwork_patchtag_id_seq
 TO "nobody";
 
 COMMIT;
diff --git a/lib/sql/migration/015-add-patch-tags.sql b/lib/sql/migration/015-add-patch-tags.sql
new file mode 100644
index 0000000..bdf7330
--- /dev/null
+++ b/lib/sql/migration/015-add-patch-tags.sql
@@ -0,0 +1,19 @@
+BEGIN;
+ALTER TABLE patchwork_project ADD COLUMN use_tags boolean default true;
+
+CREATE TABLE "patchwork_tag" (
+    "id" serial NOT NULL PRIMARY KEY,
+    "name" varchar(20) NOT NULL,
+    "pattern" varchar(50) NOT NULL,
+    "abbrev" varchar(2) NOT NULL UNIQUE
+);
+
+CREATE TABLE "patchwork_patchtag" (
+    "id" serial NOT NULL PRIMARY KEY,
+    "patch_id" integer NOT NULL,
+    "tag_id" integer NOT NULL REFERENCES "patchwork_tag" ("id"),
+    "count" integer NOT NULL,
+    UNIQUE ("patch_id", "tag_id")
+);
+
+COMMIT;