lemmy/crates/db_schema/replaceable_schema/utils.sql
dullbananas 78702b59fd
Use trigger to generate apub URL in insert instead of update, and fix query planner options not being set when TLS is disabled (#4797)
* Update create.rs

* Update utils.rs

* Update utils.sql

* Update triggers.sql

* Update utils.sql

* Update create.rs

* Update create.rs

* Update create.rs

* Update create.rs

* Update create.rs

* Update create.rs

* Update create.rs

* Update create.rs

* Create up.sql

* Update up.sql

* Update triggers.sql

* Update utils.rs

* stuff

* stuff

* revert some changed files

* Revert "revert some changed files"

This reverts commit 028eabb4bd.

* revert the correct files

* partial reverts

* migration, tests, fix establish_connection

* lint

* pg_format
2024-07-02 11:23:21 -04:00

154 lines
5.7 KiB
PL/PgSQL

-- Each calculation used in triggers should be a single SQL language
-- expression so it can be inlined in migrations.
CREATE FUNCTION r.controversy_rank (upvotes numeric, downvotes numeric)
RETURNS float
LANGUAGE sql
IMMUTABLE PARALLEL SAFE RETURN CASE WHEN downvotes <= 0
OR upvotes <= 0 THEN
0
ELSE
(
upvotes + downvotes) ^ CASE WHEN upvotes > downvotes THEN
downvotes::float / upvotes::float
ELSE
upvotes::float / downvotes::float
END
END;
CREATE FUNCTION r.hot_rank (score numeric, published timestamp with time zone)
RETURNS double precision
LANGUAGE sql
IMMUTABLE PARALLEL SAFE RETURN
-- after a week, it will default to 0.
CASE WHEN (
now() - published) > '0 days'
AND (
now() - published) < '7 days' THEN
-- Use greatest(2,score), so that the hot_rank will be positive and not ignored.
log (
greatest (2, score + 2)) / power (((EXTRACT(EPOCH FROM (now() - published)) / 3600) + 2), 1.8)
ELSE
-- if the post is from the future, set hot score to 0. otherwise you can game the post to
-- always be on top even with only 1 vote by setting it to the future
0.0
END;
CREATE FUNCTION r.scaled_rank (score numeric, published timestamp with time zone, users_active_month numeric)
RETURNS double precision
LANGUAGE sql
IMMUTABLE PARALLEL SAFE
-- Add 2 to avoid divide by zero errors
-- Default for score = 1, active users = 1, and now, is (0.1728 / log(2 + 1)) = 0.3621
-- There may need to be a scale factor multiplied to users_active_month, to make
-- the log curve less pronounced. This can be tuned in the future.
RETURN (
r.hot_rank (score, published) / log(2 + users_active_month)
);
-- For tables with `deleted` and `removed` columns, this function determines which rows to include in a count.
CREATE FUNCTION r.is_counted (item record)
RETURNS bool
LANGUAGE plpgsql
IMMUTABLE PARALLEL SAFE
AS $$
BEGIN
RETURN COALESCE(NOT (item.deleted
OR item.removed), FALSE);
END;
$$;
CREATE FUNCTION r.local_url (url_path text)
RETURNS text
LANGUAGE sql
STABLE PARALLEL SAFE RETURN (
current_setting('lemmy.protocol_and_hostname') || url_path
);
-- 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 trigger function body given as the 2nd argument
-- and can contain these names, which are replaced with a `SELECT` statement in parenthesis if needed:
-- * `select_old_rows`
-- * `select_new_rows`
-- * `select_old_and_new_rows` with 2 columns:
-- 1. `count_diff`: `-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. (same name as the trigger's table): the old or new row as a composite value
CREATE PROCEDURE r.create_triggers (table_name text, function_body text)
LANGUAGE plpgsql
AS $a$
DECLARE
defs text := $$
-- Delete
CREATE FUNCTION r.thing_delete_statement ()
RETURNS TRIGGER
LANGUAGE plpgsql
AS function_body_delete;
CREATE TRIGGER delete_statement
AFTER DELETE ON thing REFERENCING OLD TABLE AS select_old_rows
FOR EACH STATEMENT
EXECUTE FUNCTION r.thing_delete_statement ( );
-- Insert
CREATE FUNCTION r.thing_insert_statement ( )
RETURNS TRIGGER
LANGUAGE plpgsql
AS function_body_insert;
CREATE TRIGGER insert_statement
AFTER INSERT ON thing REFERENCING NEW TABLE AS select_new_rows
FOR EACH STATEMENT
EXECUTE FUNCTION r.thing_insert_statement ( );
-- Update
CREATE FUNCTION r.thing_update_statement ( )
RETURNS TRIGGER
LANGUAGE plpgsql
AS function_body_update;
CREATE TRIGGER update_statement
AFTER UPDATE ON thing REFERENCING OLD TABLE AS select_old_rows NEW TABLE AS select_new_rows
FOR EACH STATEMENT
EXECUTE FUNCTION r.thing_update_statement ( );
$$;
select_old_and_new_rows text := $$ (
SELECT
-1 AS count_diff,
old_table::thing AS thing
FROM
select_old_rows AS old_table
UNION ALL
SELECT
1 AS count_diff,
new_table::thing AS thing
FROM
select_new_rows AS new_table) $$;
empty_select_new_rows text := $$ (
SELECT
*
FROM
-- Real transition table
select_old_rows
WHERE
FALSE) $$;
empty_select_old_rows text := $$ (
SELECT
*
FROM
-- Real transition table
select_new_rows
WHERE
FALSE) $$;
BEGIN
function_body := replace(function_body, 'select_old_and_new_rows', select_old_and_new_rows);
-- `select_old_rows` and `select_new_rows` are made available as empty tables if they don't already exist
defs := replace(defs, 'function_body_delete', quote_literal(replace(function_body, 'select_new_rows', empty_select_new_rows)));
defs := replace(defs, 'function_body_insert', quote_literal(replace(function_body, 'select_old_rows', empty_select_old_rows)));
defs := replace(defs, 'function_body_update', quote_literal(function_body));
defs := replace(defs, 'thing', table_name);
EXECUTE defs;
END;
$a$;