Re: PQputCopyEnd doesn't adhere to its API contract

On Thu, May 8, 2014 at 12:53 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> What I'm now thinking I need to do is something like this:
>
>> 1. If PQputCopyEnd returns -1, error.
>> 2. while ((rc = PQflush(conn)) != 0) { if (rc < 0) { error; } else {
>> wait for socket to become read-ready or write-ready; } }
>> 3. while (PQisBusy(conn)) { wait for the socket to become read-ready; }
>> 4. PQgetResult()
>
>> Does that sound right?
>
> Yeah, more or less --- I think you need a PQconsumeInput there somewhere.
>
> There is a PQflush call in PQconsumeInput that is intended to keep clients
> from having to do that for themselves; but I'm not sure that it helps,
> since clients probably only call PQconsumeInput when the socket is
> read-ready --- and it wouldn't be in this situation.

OK.  It still seems to me that there's a doc fix needed here, if
nothing else.  The documentation for PQputCopyEnd() clearly implies
that if you get a return value of 1, the message is sent, and that's
just not true.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company