Merge lp:~cjwatson/launchpad/db-git-recipes into lp:launchpad/db-devel

[Colin Watson]

Add SourcePackageRecipeData.base_git_repository and SourcePackageRecipeDataInstruction.git_repository columns.

Add SourcePackageRecipeData.base_git_repository and SourcePackageRecipeDataInstruction.git_repository columns.

I believe that this is enough to support Git recipes. We don't need reference paths in this case, because recipes already have a "revspec" which in the Git case may name a reference (or a specific commit, or ...). This simplifies things.

I considered adding a constraint to the effect that if SourcePackageRecipeData.base_branch is not null then all the SourcePackageRecipeDataInstruction rows that refer to it must use branch rather than git_repository and vice versa, but I think that ends up being overcomplicated and doesn't buy us very much. Let me know if you disagree.

[William Grant (wgrant)]

You also need indexes on the new columns, and probably some kind of deletion handling.

review: Needs Fixing

[Colin Watson (cjwatson)]

I've sorted out the indexes (and checked that the DROP/CREATE on the index for base_branch is quick on dogfood - sub-100ms to create the modified index). As per IRC, deletion handling isn't needed in the database branch because it'll be handled explicitly in GitRepository._getDeletionRequirements.

[William Grant (wgrant)]

review: Approve (db)

=== added file 'database/schema/patch-2209-73-0.sql'
--- database/schema/patch-2209-73-0.sql	1970-01-01 00:00:00 +0000
+++ database/schema/patch-2209-73-0.sql	2016-01-11 14:38:00 +0000
@@ -0,0 +1,30 @@
+-- Copyright 2016 Canonical Ltd.  This software is licensed under the
+-- GNU Affero General Public License version 3 (see the file LICENSE).
+
+SET client_min_messages=ERROR;
+
+ALTER TABLE SourcePackageRecipeData
+    ADD COLUMN base_git_repository integer REFERENCES GitRepository;
+ALTER TABLE SourcePackageRecipeData
+    ALTER COLUMN base_branch DROP NOT NULL;
+ALTER TABLE SourcePackageRecipeData
+    ADD CONSTRAINT one_base_vcs CHECK ((base_branch IS NOT NULL) != (base_git_repository IS NOT NULL));
+
+DROP INDEX sourcepackagerecipedata__base_branch__idx;
+CREATE INDEX sourcepackagerecipedata__base_branch__idx
+    ON SourcePackageRecipeData(base_branch) WHERE base_branch IS NOT NULL;
+CREATE INDEX sourcepackagerecipedata__base_git_repository__idx
+    ON SourcePackageRecipeData(base_git_repository) WHERE base_git_repository IS NOT NULL;
+
+COMMENT ON COLUMN SourcePackageRecipeData.base_git_repository IS 'The Git repository the recipe is based on.';
+
+ALTER TABLE SourcePackageRecipeDataInstruction
+    ADD COLUMN git_repository integer REFERENCES GitRepository;
+ALTER TABLE SourcePackageRecipeDataInstruction
+    ALTER COLUMN branch DROP NOT NULL;
+ALTER TABLE SourcePackageRecipeDataInstruction
+    ADD CONSTRAINT one_vcs CHECK ((branch IS NOT NULL) != (git_repository IS NOT NULL));
+
+COMMENT ON COLUMN SourcePackageRecipeDataInstruction.git_repository IS 'The Git repository containing the branch being merged or nested.';
+
+INSERT INTO LaunchpadDatabaseRevision VALUES (2209, 73, 0);