canvas-lms/db/migrate/20181217155351_speed_up_max...

113 lines
4.7 KiB
Ruby

# frozen_string_literal: true
#
# Copyright (C) 2018 - present Instructure, Inc.
#
# This file is part of Canvas.
#
# Canvas is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, version 3 of the License.
#
# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.
class SpeedUpMaxConcurrentTriggers < ActiveRecord::Migration[5.1]
tag :predeploy
def up
if connection.adapter_name == "PostgreSQL"
search_path = Shard.current.name
execute(<<~SQL) # rubocop:disable Rails/SquishedSQLHeredocs
CREATE OR REPLACE FUNCTION #{connection.quote_table_name("delayed_jobs_after_delete_row_tr_fn")} () RETURNS trigger AS $$
DECLARE
running_count integer;
BEGIN
IF OLD.strand IS NOT NULL THEN
PERFORM pg_advisory_xact_lock(half_md5_as_bigint(OLD.strand));
IF OLD.id % 20 = 0 THEN
running_count := (SELECT COUNT(*) FROM (
SELECT 1 as one FROM delayed_jobs WHERE strand = OLD.strand AND next_in_strand = 't' LIMIT OLD.max_concurrent
) subquery_for_count);
IF running_count < OLD.max_concurrent THEN
UPDATE delayed_jobs SET next_in_strand = 't' WHERE id IN (
SELECT id FROM delayed_jobs j2 WHERE next_in_strand = 'f' AND
j2.strand = OLD.strand ORDER BY j2.id ASC LIMIT (OLD.max_concurrent - running_count) FOR UPDATE
);
END IF;
ELSE
UPDATE delayed_jobs SET next_in_strand = 't' WHERE id =
(SELECT id FROM delayed_jobs j2 WHERE next_in_strand = 'f' AND
j2.strand = OLD.strand ORDER BY j2.id ASC LIMIT 1 FOR UPDATE);
END IF;
END IF;
RETURN OLD;
END;
$$ LANGUAGE plpgsql SET search_path TO #{search_path};
SQL
# don't need the full count on insert
execute(<<~SQL) # rubocop:disable Rails/SquishedSQLHeredocs
CREATE OR REPLACE FUNCTION #{connection.quote_table_name("delayed_jobs_before_insert_row_tr_fn")} () RETURNS trigger AS $$
BEGIN
IF NEW.strand IS NOT NULL THEN
PERFORM pg_advisory_xact_lock(half_md5_as_bigint(NEW.strand));
IF (SELECT COUNT(*) FROM (
SELECT 1 AS one FROM delayed_jobs WHERE strand = NEW.strand LIMIT NEW.max_concurrent
) subquery_for_count) = NEW.max_concurrent THEN
NEW.next_in_strand := 'f';
END IF;
END IF;
RETURN NEW;
END;
$$ LANGUAGE plpgsql SET search_path TO #{search_path};;
SQL
end
end
def down
if connection.adapter_name == "PostgreSQL"
search_path = Shard.current.name
execute(<<~SQL) # rubocop:disable Rails/SquishedSQLHeredocs
CREATE OR REPLACE FUNCTION #{connection.quote_table_name("delayed_jobs_after_delete_row_tr_fn")} () RETURNS trigger AS $$
DECLARE
running_count integer;
BEGIN
IF OLD.strand IS NOT NULL THEN
PERFORM pg_advisory_xact_lock(half_md5_as_bigint(OLD.strand));
running_count := (SELECT COUNT(*) FROM delayed_jobs WHERE strand = OLD.strand AND next_in_strand = 't');
IF running_count < OLD.max_concurrent THEN
UPDATE delayed_jobs SET next_in_strand = 't' WHERE id IN (
SELECT id FROM delayed_jobs j2 WHERE next_in_strand = 'f' AND
j2.strand = OLD.strand ORDER BY j2.id ASC LIMIT (OLD.max_concurrent - running_count) FOR UPDATE
);
END IF;
END IF;
RETURN OLD;
END;
$$ LANGUAGE plpgsql SET search_path TO #{search_path};
SQL
# don't need the full count on insert
execute(<<~SQL) # rubocop:disable Rails/SquishedSQLHeredocs
CREATE OR REPLACE FUNCTION #{connection.quote_table_name("delayed_jobs_before_insert_row_tr_fn")} () RETURNS trigger AS $$
BEGIN
IF NEW.strand IS NOT NULL THEN
PERFORM pg_advisory_xact_lock(half_md5_as_bigint(NEW.strand));
IF (SELECT COUNT(*) FROM delayed_jobs WHERE strand = NEW.strand) >= NEW.max_concurrent THEN
NEW.next_in_strand := 'f';
END IF;
END IF;
RETURN NEW;
END;
$$ LANGUAGE plpgsql SET search_path TO #{search_path};;
SQL
end
end
end