When I implemented profiler and coverage check to plpgsql_check I had to write a lot of hard maintaining code related to corect finishing some operations (counter incrementing) usually executed by stmt_end and func_end hooks. It is based on the fmgr hook and its own statement call stack. Can be nice if I can throw this code and use some nice buildin API.
Can we enhance dbg API with two hooks stmt_end_err func_end_err ?
These hooks can be called from exception handlers before re raising.
Or we can define new hooks like executor hooks - stmt_exec and func_exec. In custom hooks the exception can be catched.
What do you think about this proposal?
I did quick and ugly benchmark on worst case
CREATE OR REPLACE FUNCTION public.speedtest(i integer) RETURNS void LANGUAGE plpgsql IMMUTABLE AS $function$ declare c int = 0; begin while c < i loop c := c + 1; end loop; raise notice '%', c; end; $function$
and is possible to write some code (see ugly patch) without any performance impacts if the hooks are not used. When hooks are active, then there is 7% performance lost. It is not nice - but this is the worst case. The impact on real code should be significantly lower
