Expand usage of macros for protocol characters.HEADorigin/masterorigin/HEADmaster

This commit makes use of the existing PqMsg_* macros in more places
and adds new PqReplMsg_* and PqBackupMsg_* macros for use in
special replication and backup messages, respectively.

Author: Dave Cramer <davecramer@gmail.com>
Co-authored-by: Fabrízio de Royes Mello <fabriziomello@gmail.com>
Reviewed-by: Jacob Champion <jacob.champion@enterprisedb.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Euler Taveira <euler@eulerto.com>
Discussion: https://postgr.es/m/aIECfYfevCUpenBT@nathan
Discussion: https://postgr.es/m/CAFcNs%2Br73NOUb7%2BqKrV4HHEki02CS96Z%2Bx19WaFgE087BWwEng%40mail.gmail.com

3 files changed, 17 insertions, 14 deletions

diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 55621f35fb6..0a3ca4315de 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -35,6 +35,7 @@
 #include "fe_utils/option_utils.h"
 #include "fe_utils/recovery_gen.h"
 #include "getopt_long.h"
+#include "libpq/protocol.h"
 #include "receivelog.h"
 #include "streamutil.h"
 
@@ -1338,7 +1339,7 @@ ReceiveArchiveStreamChunk(size_t r, char *copybuf, void *callback_data)
 	/* Each CopyData message begins with a type byte. */
 	switch (GetCopyDataByte(r, copybuf, &cursor))
 	{
-		case 'n':
+		case PqBackupMsg_NewArchive:
 			{
 				/* New archive. */
 				char	   *archive_name;
@@ -1410,7 +1411,7 @@ ReceiveArchiveStreamChunk(size_t r, char *copybuf, void *callback_data)
 				break;
 			}
 
-		case 'd':
+		case PqMsg_CopyData:
 			{
 				/* Archive or manifest data. */
 				if (state->manifest_buffer != NULL)
@@ -1446,7 +1447,7 @@ ReceiveArchiveStreamChunk(size_t r, char *copybuf, void *callback_data)
 				break;
 			}
 
-		case 'p':
+		case PqBackupMsg_ProgressReport:
 			{
 				/*
 				 * Progress report.
@@ -1465,7 +1466,7 @@ ReceiveArchiveStreamChunk(size_t r, char *copybuf, void *callback_data)
 				break;
 			}
 
-		case 'm':
+		case PqBackupMsg_Manifest:
 			{
 				/*
 				 * Manifest data will be sent next. This message is not
diff --git a/src/bin/pg_basebackup/pg_recvlogical.c b/src/bin/pg_basebackup/pg_recvlogical.c
index 0e9d2e23947..7a4d1a2d2ca 100644
--- a/src/bin/pg_basebackup/pg_recvlogical.c
+++ b/src/bin/pg_basebackup/pg_recvlogical.c
@@ -24,6 +24,7 @@
 #include "getopt_long.h"
 #include "libpq-fe.h"
 #include "libpq/pqsignal.h"
+#include "libpq/protocol.h"
 #include "pqexpbuffer.h"
 #include "streamutil.h"
 
@@ -149,7 +150,7 @@ sendFeedback(PGconn *conn, TimestampTz now, bool force, bool replyRequested)
 					LSN_FORMAT_ARGS(output_fsync_lsn),
 					replication_slot);
 
-	replybuf[len] = 'r';
+	replybuf[len] = PqReplMsg_StandbyStatusUpdate;
 	len += 1;
 	fe_sendint64(output_written_lsn, &replybuf[len]);	/* write */
 	len += 8;
@@ -454,7 +455,7 @@ StreamLogicalLog(void)
 		}
 
 		/* Check the message type. */
-		if (copybuf[0] == 'k')
+		if (copybuf[0] == PqReplMsg_Keepalive)
 		{
 			int			pos;
 			bool		replyRequested;
@@ -466,7 +467,7 @@ StreamLogicalLog(void)
 			 * We just check if the server requested a reply, and ignore the
 			 * rest.
 			 */
-			pos = 1;			/* skip msgtype 'k' */
+			pos = 1;			/* skip msgtype PqReplMsg_Keepalive */
 			walEnd = fe_recvint64(&copybuf[pos]);
 			output_written_lsn = Max(walEnd, output_written_lsn);
 
@@ -509,7 +510,7 @@ StreamLogicalLog(void)
 
 			continue;
 		}
-		else if (copybuf[0] != 'w')
+		else if (copybuf[0] != PqReplMsg_WALData)
 		{
 			pg_log_error("unrecognized streaming header: \"%c\"",
 						 copybuf[0]);
@@ -521,7 +522,7 @@ StreamLogicalLog(void)
 		 * message. We only need the WAL location field (dataStart), the rest
 		 * of the header is ignored.
 		 */
-		hdr_len = 1;			/* msgtype 'w' */
+		hdr_len = 1;			/* msgtype PqReplMsg_WALData */
 		hdr_len += 8;			/* dataStart */
 		hdr_len += 8;			/* walEnd */
 		hdr_len += 8;			/* sendTime */
diff --git a/src/bin/pg_basebackup/receivelog.c b/src/bin/pg_basebackup/receivelog.c
index f2b54d3c501..25b13c7f55c 100644
--- a/src/bin/pg_basebackup/receivelog.c
+++ b/src/bin/pg_basebackup/receivelog.c
@@ -21,6 +21,7 @@
 #include "access/xlog_internal.h"
 #include "common/logging.h"
 #include "libpq-fe.h"
+#include "libpq/protocol.h"
 #include "receivelog.h"
 #include "streamutil.h"
 
@@ -338,7 +339,7 @@ sendFeedback(PGconn *conn, XLogRecPtr blockpos, TimestampTz now, bool replyReque
 	char		replybuf[1 + 8 + 8 + 8 + 8 + 1];
 	int			len = 0;
 
-	replybuf[len] = 'r';
+	replybuf[len] = PqReplMsg_StandbyStatusUpdate;
 	len += 1;
 	fe_sendint64(blockpos, &replybuf[len]); /* write */
 	len += 8;
@@ -823,13 +824,13 @@ HandleCopyStream(PGconn *conn, StreamCtl *stream,
 			}
 
 			/* Check the message type. */
-			if (copybuf[0] == 'k')
+			if (copybuf[0] == PqReplMsg_Keepalive)
 			{
 				if (!ProcessKeepaliveMsg(conn, stream, copybuf, r, blockpos,
 										 &last_status))
 					goto error;
 			}
-			else if (copybuf[0] == 'w')
+			else if (copybuf[0] == PqReplMsg_WALData)
 			{
 				if (!ProcessWALDataMsg(conn, stream, copybuf, r, &blockpos))
 					goto error;
@@ -1001,7 +1002,7 @@ ProcessKeepaliveMsg(PGconn *conn, StreamCtl *stream, char *copybuf, int len,
 	 * Parse the keepalive message, enclosed in the CopyData message. We just
 	 * check if the server requested a reply, and ignore the rest.
 	 */
-	pos = 1;					/* skip msgtype 'k' */
+	pos = 1;					/* skip msgtype PqReplMsg_Keepalive */
 	pos += 8;					/* skip walEnd */
 	pos += 8;					/* skip sendTime */
 
@@ -1064,7 +1065,7 @@ ProcessWALDataMsg(PGconn *conn, StreamCtl *stream, char *copybuf, int len,
 	 * message. We only need the WAL location field (dataStart), the rest of
 	 * the header is ignored.
 	 */
-	hdr_len = 1;				/* msgtype 'w' */
+	hdr_len = 1;				/* msgtype PqReplMsg_WALData */
 	hdr_len += 8;				/* dataStart */
 	hdr_len += 8;				/* walEnd */
 	hdr_len += 8;				/* sendTime */