Horton

Re: libpq debug log

Kyotaro Horiguchi <horikyota.ntt@gmail.com>

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From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
To: tsunakawa.takay@fujitsu.com
Cc: iwata.aya@fujitsu.com, k.jamison@fujitsu.com, alvherre@alvh.no-ip.org, pgsql-hackers@lists.postgresql.org
Date: 2021-02-03T02:18:05Z
Lists: pgsql-hackers 
At Wed, 3 Feb 2021 01:26:41 +0000, "tsunakawa.takay@fujitsu.com" <tsunakawa.takay@fujitsu.com> wrote in 
> (41)
> +void
> +PQtraceEx(PGconn *conn, FILE *debug_port, int flags)
> +{
> +	if (conn == NULL)
> +		return;
> ...
> +	if (!debug_port)
> +		return;
> 
> The if should better be as follows to match the style of existing surrounding code.
> 
> +	if (debug_port == NULL)

I don't have particular preference here, but FWIW the current
PQuntrace is doing this:

> void
> PQuntrace(PGconn *conn)
> {
> 	if (conn == NULL)
> 		return;
> 	if (conn->Pfdebug)
> 	{
> 		fflush(conn->Pfdebug);

> (44)
> +	if ((conn->traceFlags & PQTRACE_OUTPUT_TIMESTAMPS) == 0)
> +		timestr_p = pqLogFormatTimestamp(timestr, sizeof(timestr));
> 
> == 0 should be removed.

Looking the doc mentioned in the comment #39:

+      <literal>flags</literal> contains flag bits describing the operating mode
+      of tracing.  If (<literal>flags</literal> &amp; <literal>PQTRACE_OUTPUT_TIMESTAMPS</literal>) is
+      true, then timestamp is not printed with each message.

PQTRACE_OUTPUT_TIMESTAMPS is designed to *inhibit* timestamps from
being prepended. If that is actually intended, the symbol name should
be PQTRACE_NOOUTPUT_TIMESTAMP. Otherwise, the doc need to be fixed.

By the way removing "== 0" makes it difficult to tell whether the
condition is correct or not; I recommend to use '!= 0" rather than
removing '== 0'.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center

Commits

  1. Rename PQtraceSetFlags() to PQsetTraceFlags().

  2. Suppress length of Notice/Error msgs in PQtrace regress mode

  3. Strip file names reported in error messages on Windows, too.

  4. Fix setvbuf()-induced crash in libpq_pipeline

  5. libpq_pipeline: Must strdup(optarg) to avoid crash

  6. Remove setvbuf() call from PQtrace()

  7. Initialize conn->Pfdebug to NULL when creating a connection

  8. Disable force_parallel_mode in libpq_pipeline

  9. libpq_pipeline: add PQtrace() support and tests

  10. Improve PQtrace() output format

  11. Re-simplify management of inStart in pqParseInput3's subroutines.