Thread: Error handling expectations
I'm working on adding a tuple_data_record function to pageinspect to parallel tuple_data_split (returning the record type of the relation being examined rather than an array of attributes as on-disk byte data).
This my first real foray into the Postgres codebase, so an beginner question: I noticed that existing C functions in pageinspect often do error checking and then report the error with ereport but still continue on to execute the rest of the function instead of early returning. Is this standard practice? Or should I be reporting the error and then cleaning up and returning rather than continuing to execute?
Thanks,
James Coleman
Hi, On 2018-10-15 13:21:04 -0400, James Coleman wrote: > This my first real foray into the Postgres codebase, so an beginner > question: I noticed that existing C functions in pageinspect often do error > checking and then report the error with ereport but still continue on to > execute the rest of the function instead of early returning. Is this > standard practice? Or should I be reporting the error and then cleaning up > and returning rather than continuing to execute? ereport basically throws an exception when elevel >= ERROR. I suggest looking at elog.h's comments above elog and PG_TRY(). Greetings, Andres Freund
Perfect. Thanks for the pointer, Andres, that's exactly what I was looking for.
On Mon, Oct 15, 2018 at 1:28 PM Andres Freund <andres@anarazel.de> wrote:
Hi,
On 2018-10-15 13:21:04 -0400, James Coleman wrote:
> This my first real foray into the Postgres codebase, so an beginner
> question: I noticed that existing C functions in pageinspect often do error
> checking and then report the error with ereport but still continue on to
> execute the rest of the function instead of early returning. Is this
> standard practice? Or should I be reporting the error and then cleaning up
> and returning rather than continuing to execute?
ereport basically throws an exception when elevel >= ERROR. I suggest
looking at elog.h's comments above elog and PG_TRY().
Greetings,
Andres Freund