[entity] ensure the .related(entities=False) parameter is honored all the way down (closes #2755994)
As of today, such a call will always fill the relation cache by
calling .entities() on every single related rset entry.
As a consequence, the `limit` parameter handling also had to be fixed.
It was bogus in the following ways:
* not used in the related_rql, hence potentially huge database
requests, but also actually
* foolishly used in the .entities()-calling cache routine we now
bypass (this changeset ticket's main topic)
Now:
* we set a limit on the rql expression, and
* forbid caching if given a non-None limit (as we don't want to make
the cache handling code more complicated than it is already)
With this, entity.unrelated gets a better limit implementation (so the
code in related/unrelated is nice and symmetric)
Risk:
* _cw_relation_cache disappears completely, which is good, but this is
Python, so you never know ...
/* -*- sql -*-
postgres specific registered procedures,
require the plpgsql language installed
*/
DROP FUNCTION IF EXISTS comma_join (anyarray) CASCADE;
CREATE FUNCTION comma_join (anyarray) RETURNS text AS $$
SELECT array_to_string($1, ', ')
$$ LANGUAGE SQL;;
DROP AGGREGATE IF EXISTS group_concat (anyelement) CASCADE;
CREATE AGGREGATE group_concat (
basetype = anyelement,
sfunc = array_append,
stype = anyarray,
finalfunc = comma_join,
initcond = '{}'
);;
DROP FUNCTION IF EXISTS limit_size (fulltext text, format text, maxsize integer);
CREATE FUNCTION limit_size (fulltext text, format text, maxsize integer) RETURNS text AS $$
DECLARE
plaintext text;
BEGIN
IF char_length(fulltext) < maxsize THEN
RETURN fulltext;
END IF;
IF format = 'text/html' OR format = 'text/xhtml' OR format = 'text/xml' THEN
plaintext := regexp_replace(fulltext, '<[\\w/][^>]+>', '', 'g');
ELSE
plaintext := fulltext;
END IF;
IF char_length(plaintext) < maxsize THEN
RETURN plaintext;
ELSE
RETURN substring(plaintext from 1 for maxsize) || '...';
END IF;
END
$$ LANGUAGE plpgsql;;
DROP FUNCTION IF EXISTS text_limit_size (fulltext text, maxsize integer);
CREATE FUNCTION text_limit_size (fulltext text, maxsize integer) RETURNS text AS $$
BEGIN
RETURN limit_size(fulltext, 'text/plain', maxsize);
END
$$ LANGUAGE plpgsql;;