Re: There doesn't seem to be any case where PQputCopyEnd() returns 0
On Fri, Feb 5, 2021 at 11:01 PM Fujii Masao wrote: > > > > On 2021/02/05 16:52, Kasahara Tatsuhito wrote: > > Hi, > > > > The following is written in the comments of PQputCopyEnd(). > > > > (snip) > > * Returns 1 if successful, 0 if data could not be sent (only possible > > * in nonblock mode), or -1 if an error occurs. > > (snip) > > > > The PQputCopyEnd() section of the manual (libpq.sgml) describes the > > following. > > > > The result is 1 if the termination message was sent; or in > > nonblocking mode, this may only indicate that the termination > > message was successfully queued. (In nonblocking mode, to be > > certain that the data has been sent, you should next wait for > > write-ready and call , repeating > > until it > > returns zero.) Zero indicates that the function could not queue > > the termination message because of full buffers; this will only > > happen in nonblocking mode. (In this case, wait for > > write-ready and try the call > > again.) If a hard error occurs, -1 is returned; you can use > > to retrieve details. > > > > > > These says that 0 may be returned if a non-blocking mode is used, but > > there doesn't seem to be any case where 0 is returned in the code of > > PQputCopyEnd(). > > I found the past discussion [1] about this issue. > > [1] > https://www.postgresql.org/message-id/CA+Tgmobjj+0modbnmjy7ezeBFOBo9d2mAVcSPkzLx4LtZmc==g...@mail.gmail.com Oh, thank you. I understood what was unclear. Best regards, > > Regards, > > -- > Fujii Masao > Advanced Computing Technology Center > Research and Development Headquarters > NTT DATA CORPORATION -- Tatsuhito Kasahara kasahara.tatsuhito _at_ gmail.com
Re: There doesn't seem to be any case where PQputCopyEnd() returns 0
On 2021/02/05 16:52, Kasahara Tatsuhito wrote: Hi, The following is written in the comments of PQputCopyEnd(). (snip) * Returns 1 if successful, 0 if data could not be sent (only possible * in nonblock mode), or -1 if an error occurs. (snip) The PQputCopyEnd() section of the manual (libpq.sgml) describes the following. The result is 1 if the termination message was sent; or in nonblocking mode, this may only indicate that the termination message was successfully queued. (In nonblocking mode, to be certain that the data has been sent, you should next wait for write-ready and call , repeating until it returns zero.) Zero indicates that the function could not queue the termination message because of full buffers; this will only happen in nonblocking mode. (In this case, wait for write-ready and try the call again.) If a hard error occurs, -1 is returned; you can use to retrieve details. These says that 0 may be returned if a non-blocking mode is used, but there doesn't seem to be any case where 0 is returned in the code of PQputCopyEnd(). I found the past discussion [1] about this issue. [1] https://www.postgresql.org/message-id/CA+Tgmobjj+0modbnmjy7ezeBFOBo9d2mAVcSPkzLx4LtZmc==g...@mail.gmail.com Regards, -- Fujii Masao Advanced Computing Technology Center Research and Development Headquarters NTT DATA CORPORATION
There doesn't seem to be any case where PQputCopyEnd() returns 0
Hi,
The following is written in the comments of PQputCopyEnd().
(snip)
* Returns 1 if successful, 0 if data could not be sent (only possible
* in nonblock mode), or -1 if an error occurs.
(snip)
The PQputCopyEnd() section of the manual (libpq.sgml) describes the following.
The result is 1 if the termination message was sent; or in
nonblocking mode, this may only indicate that the termination
message was successfully queued. (In nonblocking mode, to be
certain that the data has been sent, you should next wait for
write-ready and call , repeating until it
returns zero.) Zero indicates that the function could not queue
the termination message because of full buffers; this will only
happen in nonblocking mode. (In this case, wait for
write-ready and try the call
again.) If a hard error occurs, -1 is returned; you can use
to retrieve details.
These says that 0 may be returned if a non-blocking mode is used, but
there doesn't seem to be any case where 0 is returned in the code of
PQputCopyEnd().
I may have missed something, but is it a mistake in the comments or
documentation?
Or should it return 0 when sending a COPY exit message fails
in non-blocking mode, like this?
@@ -2370,7 +2370,7 @@ PQputCopyEnd(PGconn *conn, const char *errormsg)
/* Send COPY DONE */
if (pqPutMsgStart('c', false, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
- return -1;
+ return pqIsnonblocking(conn) ? 0 : -1;
}
/*
@@ -2399,7 +2399,7 @@ PQputCopyEnd(PGconn *conn, const char *errormsg)
if (pqPutMsgStart(0, false, conn) < 0 ||
pqPutnchar("\\.\n", 3, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
- return -1;
+ return pqIsnonblocking(conn) ? 0 : -1;
}
}
Best regards,
--
Tatsuhito Kasahara
kasahara.tatsuhito _at_ gmail.com
