Improve PQtrace() output format

Transform the PQtrace output format from its ancient (and mostly
useless) byte-level output format to a logical-message-level output,
making it much more usable.  This implementation allows the printing
code to be written (as it indeed was) by looking at the protocol
documentation, which gives more confidence that the three (docs, trace
code and actual code) actually match.

Author: 岩田 彩 (Aya Iwata) <iwata.aya@fujitsu.com>
Reviewed-by: 綱川 貴之 (Takayuki Tsunakawa) <tsunakawa.takay@fujitsu.com>
Reviewed-by: Kirk Jamison <k.jamison@fujitsu.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: 黒田 隼人 (Hayato Kuroda) <kuroda.hayato@fujitsu.com>
Reviewed-by: "Nagaura, Ryohei" <nagaura.ryohei@jp.fujitsu.com>
Reviewed-by: Ryo Matsumura <matsumura.ryo@fujitsu.com>
Reviewed-by: Greg Nancarrow <gregn4422@gmail.com>
Reviewed-by: Jim Doty <jdoty@pivotal.io>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/71E660EB361DF14299875B198D4CE5423DE3FBA4@g01jpexmbkw25

1 files changed, 13 insertions, 0 deletions

diff --git a/src/interfaces/libpq/fe-protocol3.c b/src/interfaces/libpq/fe-protocol3.c
index 306e89acfd2..b45fb7e7059 100644
--- a/src/interfaces/libpq/fe-protocol3.c
+++ b/src/interfaces/libpq/fe-protocol3.c
@@ -457,6 +457,10 @@ pqParseInput3(PGconn *conn)
 		/* Successfully consumed this message */
 		if (conn->inCursor == conn->inStart + 5 + msgLength)
 		{
+			/* trace server-to-client message */
+			if (conn->Pfdebug)
+				pqTraceOutputMessage(conn, conn->inBuffer + conn->inStart, false);
+
 			/* Normal case: parsing agrees with specified length */
 			conn->inStart = conn->inCursor;
 		}
@@ -1660,6 +1664,10 @@ getCopyDataMessage(PGconn *conn)
 				return -1;
 		}
 
+		/* trace server-to-client message */
+		if (conn->Pfdebug)
+			pqTraceOutputMessage(conn, conn->inBuffer + conn->inStart, false);
+
 		/* Drop the processed message and loop around for another */
 		conn->inStart = conn->inCursor;
 	}
@@ -2119,6 +2127,11 @@ pqFunctionCall3(PGconn *conn, Oid fnid,
 				conn->inStart += 5 + msgLength;
 				return pqPrepareAsyncResult(conn);
 		}
+
+		/* trace server-to-client message */
+		if (conn->Pfdebug)
+			pqTraceOutputMessage(conn, conn->inBuffer + conn->inStart, false);
+
 		/* Completed this message, keep going */
 		/* trust the specified message length as what to skip */
 		conn->inStart += 5 + msgLength;