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, 15 insertions, 51 deletions

diff --git a/src/interfaces/libpq/fe-misc.c b/src/interfaces/libpq/fe-misc.c
index ce2d24b91fc..082b583c152 100644
--- a/src/interfaces/libpq/fe-misc.c
+++ b/src/interfaces/libpq/fe-misc.c
@@ -84,9 +84,6 @@ pqGetc(char *result, PGconn *conn)
 
 	*result = conn->inBuffer[conn->inCursor++];
 
-	if (conn->Pfdebug)
-		fprintf(conn->Pfdebug, "From backend> %c\n", *result);
-
 	return 0;
 }
 
@@ -100,9 +97,6 @@ pqPutc(char c, PGconn *conn)
 	if (pqPutMsgBytes(&c, 1, conn))
 		return EOF;
 
-	if (conn->Pfdebug)
-		fprintf(conn->Pfdebug, "To backend> %c\n", c);
-
 	return 0;
 }
 
@@ -138,10 +132,6 @@ pqGets_internal(PQExpBuffer buf, PGconn *conn, bool resetbuffer)
 
 	conn->inCursor = ++inCursor;
 
-	if (conn->Pfdebug)
-		fprintf(conn->Pfdebug, "From backend> \"%s\"\n",
-				buf->data);
-
 	return 0;
 }
 
@@ -167,9 +157,6 @@ pqPuts(const char *s, PGconn *conn)
 	if (pqPutMsgBytes(s, strlen(s) + 1, conn))
 		return EOF;
 
-	if (conn->Pfdebug)
-		fprintf(conn->Pfdebug, "To backend> \"%s\"\n", s);
-
 	return 0;
 }
 
@@ -188,13 +175,6 @@ pqGetnchar(char *s, size_t len, PGconn *conn)
 
 	conn->inCursor += len;
 
-	if (conn->Pfdebug)
-	{
-		fprintf(conn->Pfdebug, "From backend (%lu)> ", (unsigned long) len);
-		fwrite(s, 1, len, conn->Pfdebug);
-		fprintf(conn->Pfdebug, "\n");
-	}
-
 	return 0;
 }
 
@@ -212,13 +192,6 @@ pqSkipnchar(size_t len, PGconn *conn)
 	if (len > (size_t) (conn->inEnd - conn->inCursor))
 		return EOF;
 
-	if (conn->Pfdebug)
-	{
-		fprintf(conn->Pfdebug, "From backend (%lu)> ", (unsigned long) len);
-		fwrite(conn->inBuffer + conn->inCursor, 1, len, conn->Pfdebug);
-		fprintf(conn->Pfdebug, "\n");
-	}
-
 	conn->inCursor += len;
 
 	return 0;
@@ -234,13 +207,6 @@ pqPutnchar(const char *s, size_t len, PGconn *conn)
 	if (pqPutMsgBytes(s, len, conn))
 		return EOF;
 
-	if (conn->Pfdebug)
-	{
-		fprintf(conn->Pfdebug, "To backend> ");
-		fwrite(s, 1, len, conn->Pfdebug);
-		fprintf(conn->Pfdebug, "\n");
-	}
-
 	return 0;
 }
 
@@ -278,9 +244,6 @@ pqGetInt(int *result, size_t bytes, PGconn *conn)
 			return EOF;
 	}
 
-	if (conn->Pfdebug)
-		fprintf(conn->Pfdebug, "From backend (#%lu)> %d\n", (unsigned long) bytes, *result);
-
 	return 0;
 }
 
@@ -314,9 +277,6 @@ pqPutInt(int value, size_t bytes, PGconn *conn)
 			return EOF;
 	}
 
-	if (conn->Pfdebug)
-		fprintf(conn->Pfdebug, "To backend (%lu#)> %d\n", (unsigned long) bytes, value);
-
 	return 0;
 }
 
@@ -525,10 +485,6 @@ pqPutMsgStart(char msg_type, PGconn *conn)
 	conn->outMsgEnd = endPos;
 	/* length word, if needed, will be filled in by pqPutMsgEnd */
 
-	if (conn->Pfdebug)
-		fprintf(conn->Pfdebug, "To backend> Msg %c\n",
-				msg_type ? msg_type : ' ');
-
 	return 0;
 }
 
@@ -563,10 +519,6 @@ pqPutMsgBytes(const void *buf, size_t len, PGconn *conn)
 int
 pqPutMsgEnd(PGconn *conn)
 {
-	if (conn->Pfdebug)
-		fprintf(conn->Pfdebug, "To backend> Msg complete, length %u\n",
-				conn->outMsgEnd - conn->outCount);
-
 	/* Fill in length word if needed */
 	if (conn->outMsgStart >= 0)
 	{
@@ -576,6 +528,16 @@ pqPutMsgEnd(PGconn *conn)
 		memcpy(conn->outBuffer + conn->outMsgStart, &msgLen, 4);
 	}
 
+	/* trace client-to-server message */
+	if (conn->Pfdebug)
+	{
+		if (conn->outCount < conn->outMsgStart)
+			pqTraceOutputMessage(conn, conn->outBuffer + conn->outCount, true);
+		else
+			pqTraceOutputNoTypeByteMessage(conn,
+										   conn->outBuffer + conn->outMsgStart);
+	}
+
 	/* Make message eligible to send */
 	conn->outCount = conn->outMsgEnd;
 
@@ -1002,11 +964,13 @@ pqSendSome(PGconn *conn, int len)
 int
 pqFlush(PGconn *conn)
 {
-	if (conn->Pfdebug)
-		fflush(conn->Pfdebug);
-
 	if (conn->outCount > 0)
+	{
+		if (conn->Pfdebug)
+			fflush(conn->Pfdebug);
+
 		return pqSendSome(conn, conn->outCount);
+	}
 
 	return 0;
 }