Merge branch 'bliss' of https://github.com/dullbananas/lemmy into bliss

This commit is contained in:
Dull Bananas 2023-12-30 16:52:18 +00:00
commit d67bd5f249

View file

@ -36,43 +36,104 @@ BEGIN
END
$$;
-- Selects both old and new rows in a trigger. Column 1 is -1 if old and 1 if new, which can be used with `sum` to get
-- the number to add to a count. Column 2 is the original row as a composite value.
CREATE FUNCTION r.combine_transition_tables (tg_op text)
RETURNS SETOF record
LANGUAGE plpgsql
AS $$
BEGIN
IF (TG_OP IN ('UPDATE', 'DELETE')) THEN
RETURN QUERY
SELECT
-1,
old_table
FROM
old_table;
END IF;
IF (TG_OP IN ('UPDATE', 'INSERT')) THEN
RETURN QUERY
SELECT
1,
new_table
FROM
new_table;
END IF;
RETURN;
END
$$;
-- Creates triggers for all operation types, which can't be 1 trigger when transition tables are used
CREATE PROCEDURE r.create_triggers (table_name text, function_name text)
-- This function creates statement-level triggers for all operation types. It's designed this way
-- because of these limitations:
-- * A trigger that uses transition tables can only handle 1 operation type.
-- * Transition tables must be relevant for the operation type (for example, `NEW TABLE` is
-- not allowed for a `DELETE` trigger)
-- * Transition tables are only provided to the trigger function, not to functions that it calls.
--
-- This function can only be called once per table. The command to run is given as the 2nd argument
-- and has access to these tables:
-- * `old_table` with old rows
-- * `new_table` with new rows
-- * `combined_transition_tables` with both old and new rows, with 2 columns:
-- 1. `-1` for old rows and `1` for new rows, which can be used with `sum` to get the number
-- to add to a count
-- 2. the old or new row as a composite value
CREATE PROCEDURE r.create_triggers (table_name text, command text)
LANGUAGE plpgsql
AS $$
AS $a$
DECLARE
defs text := $b$
CREATE FUNCTION r.thing_delete_statement ()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
BEGIN
PERFORM (
WITH
combined_transition_tables AS (
select_old_table
),
trigger_result AS command
SELECT
1
);
RETURN NULL;
END
$$;
CREATE TRIGGER delete_statement
AFTER DELETE ON thing REFERENCING OLD TABLE AS old_table
FOR EACH STATEMENT
EXECUTE FUNCTION r.thing_delete_statement ();
CREATE FUNCTION r.thing_insert_statement ()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
BEGIN
PERFORM (
WITH
combined_transition_tables AS (
select_new_table
),
trigger_result AS command
SELECT
1
);
RETURN NULL;
END
$$;
CREATE TRIGGER insert_statement
AFTER DELETE ON thing REFERENCING NEW TABLE AS new_table
FOR EACH STATEMENT
EXECUTE FUNCTION r.thing_insert_statement ();
CREATE FUNCTION r.thing_update_statement ()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
BEGIN
PERFORM (
WITH
combined_transition_tables AS (
select_old_table
UNION ALL
select_new_table
),
trigger_result AS command
SELECT
1
);
RETURN NULL;
END
$$;
CREATE TRIGGER update_statement
AFTER UPDATE ON thing REFERENCING OLD TABLE AS old_table NEW TABLE AS new_table
FOR EACH STATEMENT
EXECUTE FUNCTION r.thing_update_statement ();
$b$;
BEGIN
EXECUTE format('CREATE TRIGGER %2$s_insert AFTER INSERT ON %1$s REFERENCING NEW TABLE AS new_table FOR EACH STATEMENT EXECUTE FUNCTION r.%2$s ();', table_name, function_name);
EXECUTE format('CREATE TRIGGER %2$s_delete AFTER DELETE ON %1$s REFERENCING OLD TABLE AS old_table FOR EACH STATEMENT EXECUTE FUNCTION r.%2$s ();', table_name, function_name);
EXECUTE format('CREATE TRIGGER %2$s_update AFTER UPDATE ON %1$s REFERENCING OLD TABLE AS old_table NEW TABLE AS new_table FOR EACH STATEMENT EXECUTE FUNCTION r.%2$s ();', table_name, function_name);
defs := replace(defs, 'select_old_table', $$
SELECT -1 AS count_diff, old_table AS thing FROM old_table
$$);
defs := replace(defs, 'select_new_table', $$
SELECT 1 AS count_diff, new_table AS thing FROM new_table
$$);
defs := replace(defs, 'thing', table_name);
defs := replace(defs, 'command', format('(%s)', command));
EXECUTE defs;
END
$$;
$a$;
-- Define functions
CREATE FUNCTION r.creator_id_from_post_aggregates (agg post_aggregates)
@ -119,12 +180,8 @@ BEGIN
FOR EACH STATEMENT
EXECUTE FUNCTION r.resolve_reports_when_thing_removed ( );
-- When a thing gets a vote, update its aggregates and its creator's aggregates
CREATE FUNCTION r.thing_aggregates_from_like ( )
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
BEGIN
WITH thing_diff AS (
CALL r.create_triggers ('thing_like', $$
WITH thing_diff AS (
UPDATE
thing_aggregates AS a
SET
@ -138,7 +195,7 @@ BEGIN
sum(count_diff) FILTER (WHERE (thing_like).score = 1) AS upvotes,
sum(count_diff) FILTER (WHERE (thing_like).score != 1) AS downvotes
FROM
r.combine_transition_tables (TG_OP)
combined_transition_tables
AS (count_diff bigint,
thing_like thing_like)
GROUP BY
@ -161,13 +218,8 @@ BEGIN
GROUP BY
creator_id) AS diff
WHERE
a.person_id = diff.creator_id;
RETURN NULL;
END $$;
CALL r.create_triggers ('thing_like', 'thing_aggregates_from_like');
$b$,
'thing',
thing_type);
a.person_id = diff.creator_id
$$);
END
$a$;
@ -176,11 +228,7 @@ CALL r.post_or_comment ('post');
CALL r.post_or_comment ('comment');
-- Create triggers that update counts in parent aggregates
CREATE FUNCTION r.parent_aggregates_from_comment ()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
BEGIN
CALL r.create_triggers('comment', $$
WITH comment_group AS (
SELECT
(comment).post_id,
@ -188,7 +236,7 @@ BEGIN
(comment).local,
sum(count_diff) AS comments
FROM
r.combine_transition_tables (TG_OP)
combined_transition_tables
AS (count_diff bigint,
comment comment)
WHERE
@ -272,18 +320,10 @@ FROM (
GROUP BY
community_id) AS diff
WHERE
a.community_id = diff.community_id;
RETURN NULL;
END
$$;
a.community_id = diff.community_id
$$);
CALL r.create_triggers ('comment', 'parent_aggregates_from_comment');
CREATE FUNCTION r.parent_aggregates_from_post ()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
BEGIN
CALL r.create_triggers('post', $$
WITH post_group AS (
SELECT
(post).community_id,
@ -291,7 +331,7 @@ BEGIN
(post).local,
sum(count_diff) AS posts
FROM
r.combine_transition_tables (TG_OP)
combined_post_transition_tables
AS (count_diff bigint,
post post)
WHERE
@ -327,18 +367,10 @@ SET
FROM
post_group
WHERE
a.community_id = post_group.community_id;
RETURN NULL;
END
$$;
a.community_id = post_group.community_id
$$);
CALL r.create_triggers ('post', 'parent_aggregates_from_post');
CREATE FUNCTION r.site_aggregates_from_community ()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
BEGIN
CALL r.create_triggers('community', $$
UPDATE
site_aggregates AS a
SET
@ -347,20 +379,12 @@ BEGIN
SELECT
sum(count_diff) AS communities
FROM
r.combine_transition_tables (TG_OP)
combined_transition_tables
AS (count_diff bigint, community community)
WHERE (community).local AND NOT ((community).deleted OR (community).removed)) AS diff;
RETURN NULL;
END
$$;
WHERE (community).local AND NOT ((community).deleted OR (community).removed)) AS diff
$$);
CALL r.create_triggers ('community', 'site_aggregates_from_community');
CREATE FUNCTION r.site_aggregates_from_person ()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
BEGIN
CALL r.create_triggers('person', $$
UPDATE
site_aggregates AS a
SET
@ -369,14 +393,10 @@ BEGIN
SELECT
sum(count_diff) AS users
FROM
r.combine_transition_tables (TG_OP)
combined_transition_tables
AS (count_diff bigint, person person)
WHERE (person).local) AS diff;
RETURN NULL;
END
$$;
CALL r.create_triggers ('person', 'site_aggregates_from_person');
WHERE (person).local) AS diff
$$);
-- For community_aggregates.comments, don't include comments of deleted or removed posts
CREATE FUNCTION r.update_comment_count_from_post ()
@ -426,11 +446,7 @@ CREATE TRIGGER comment_count
EXECUTE FUNCTION r.update_comment_count_from_post ();
-- Count subscribers for local communities
CREATE FUNCTION r.community_aggregates_from_subscriber ()
RETURNS TRIGGER
LANGUAGE plpgsql
AS $$
BEGIN
CALL r.create_triggers ('community_follower', $$
UPDATE
community_aggregates AS a
SET
@ -440,7 +456,7 @@ BEGIN
(community_follower).community_id,
sum(count_diff) AS subscribers
FROM
r.combine_transition_tables (TG_OP)
combine_transition_tables
AS (count_diff bigint, community_follower community_follower)
WHERE (
SELECT
@ -453,12 +469,8 @@ BEGIN
GROUP BY
(community_follower).community_id) AS diff
WHERE
a.community_id = diff.community_id;
RETURN NULL;
END
$$;
CALL r.create_triggers ('community_follower', 'community_aggregates_from_subscriber');
a.community_id = diff.community_id
$$);
-- These triggers create and update rows in each aggregates table to match its associated table's rows.
-- Deleting rows and updating IDs are already handled by `CASCADE` in foreign key constraints.
@ -551,6 +563,11 @@ BEGIN
END
$$;
CREATE TRIGGER aggregates
AFTER INSERT ON post REFERENCING NEW TABLE AS new_post
FOR EACH STATEMENT
EXECUTE FUNCTION r.post_aggregates_from_post ();
CREATE FUNCTION r.post_aggregates_from_post_update ()
RETURNS TRIGGER
LANGUAGE plpgsql
@ -569,11 +586,6 @@ BEGIN
END
$$;
CREATE TRIGGER aggregates
AFTER INSERT ON post REFERENCING NEW TABLE AS new_post
FOR EACH STATEMENT
EXECUTE FUNCTION r.post_aggregates_from_post ();
CREATE TRIGGER aggregates_update
AFTER UPDATE ON post REFERENCING NEW TABLE AS new_post
FOR EACH STATEMENT