v001-0001-Adds-separate-dest-field-to-log-protocol-PipeProtoHe.patch

From d5b3f5fe44e91d35aefdd570758d5b2a9e9c1a36 Mon Sep 17 00:00:00 2001
From: Sehrope Sarkuni <sehrope@jackdb.com>
Date: Wed, 10 Jul 2019 10:02:31 -0400
Subject: [PATCH 1/3] Adds separate dest field to log protocol PipeProtoHeader

Adds a separate dest field to PipeProtoHeader to store the log destination
requested by the sending process. Also changes the is_last field to only
store whether the chunk is the last one for a message rather than also
including whether the destination is csvlog.
---
 src/backend/postmaster/syslogger.c | 15 ++++++---------
 src/backend/utils/error/elog.c     |  4 +++-
 src/include/postmaster/syslogger.h |  4 ++--
 3 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/src/backend/postmaster/syslogger.c b/src/backend/postmaster/syslogger.c
index cad43bdef2..edd8f33204 100644
--- a/src/backend/postmaster/syslogger.c
+++ b/src/backend/postmaster/syslogger.c
@@ -878,7 +878,6 @@ process_pipe_input(char *logbuffer, int *bytes_in_logbuffer)
 {
 	char	   *cursor = logbuffer;
 	int			count = *bytes_in_logbuffer;
-	int			dest = LOG_DESTINATION_STDERR;
 
 	/* While we have enough for a header, process data... */
 	while (count >= (int) (offsetof(PipeProtoHeader, data) + 1))
@@ -891,8 +890,9 @@ process_pipe_input(char *logbuffer, int *bytes_in_logbuffer)
 		if (p.nuls[0] == '\0' && p.nuls[1] == '\0' &&
 			p.len > 0 && p.len <= PIPE_MAX_PAYLOAD &&
 			p.pid != 0 &&
-			(p.is_last == 't' || p.is_last == 'f' ||
-			 p.is_last == 'T' || p.is_last == 'F'))
+			(p.is_last == 't' || p.is_last == 'f') &&
+			(p.dest == LOG_DESTINATION_CSVLOG ||
+			 p.dest == LOG_DESTINATION_STDERR))
 		{
 			List	   *buffer_list;
 			ListCell   *cell;
@@ -906,9 +906,6 @@ process_pipe_input(char *logbuffer, int *bytes_in_logbuffer)
 			if (count < chunklen)
 				break;
 
-			dest = (p.is_last == 'T' || p.is_last == 'F') ?
-				LOG_DESTINATION_CSVLOG : LOG_DESTINATION_STDERR;
-
 			/* Locate any existing buffer for this source pid */
 			buffer_list = buffer_lists[p.pid % NBUFFER_LISTS];
 			foreach(cell, buffer_list)
@@ -924,7 +921,7 @@ process_pipe_input(char *logbuffer, int *bytes_in_logbuffer)
 					free_slot = buf;
 			}
 
-			if (p.is_last == 'f' || p.is_last == 'F')
+			if (p.is_last == 'f')
 			{
 				/*
 				 * Save a complete non-final chunk in a per-pid buffer
@@ -970,7 +967,7 @@ process_pipe_input(char *logbuffer, int *bytes_in_logbuffer)
 					appendBinaryStringInfo(str,
 										   cursor + PIPE_HEADER_SIZE,
 										   p.len);
-					write_syslogger_file(str->data, str->len, dest);
+					write_syslogger_file(str->data, str->len, p.dest);
 					/* Mark the buffer unused, and reclaim string storage */
 					existing_slot->pid = 0;
 					pfree(str->data);
@@ -979,7 +976,7 @@ process_pipe_input(char *logbuffer, int *bytes_in_logbuffer)
 				{
 					/* The whole message was one chunk, evidently. */
 					write_syslogger_file(cursor + PIPE_HEADER_SIZE, p.len,
-										 dest);
+										 p.dest);
 				}
 			}
 
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index a3e1c59a82..cd13111708 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -3250,6 +3250,8 @@ write_pipe_chunks(char *data, int len, int dest)
 
 	p.proto.nuls[0] = p.proto.nuls[1] = '\0';
 	p.proto.pid = MyProcPid;
+	p.proto.dest = (int32) dest;
+	p.proto.is_last = 'f';
 
 	/* write all but the last chunk */
 	while (len > PIPE_MAX_PAYLOAD)
@@ -3264,7 +3266,7 @@ write_pipe_chunks(char *data, int len, int dest)
 	}
 
 	/* write the last chunk */
-	p.proto.is_last = (dest == LOG_DESTINATION_CSVLOG ? 'T' : 't');
+	p.proto.is_last = 't';
 	p.proto.len = len;
 	memcpy(p.proto.data, data, len);
 	rc = write(fd, &p, PIPE_HEADER_SIZE + len);
diff --git a/src/include/postmaster/syslogger.h b/src/include/postmaster/syslogger.h
index 1491eecb0f..41d026a474 100644
--- a/src/include/postmaster/syslogger.h
+++ b/src/include/postmaster/syslogger.h
@@ -46,8 +46,8 @@ typedef struct
 	char		nuls[2];		/* always \0\0 */
 	uint16		len;			/* size of this chunk (counts data only) */
 	int32		pid;			/* writer's pid */
-	char		is_last;		/* last chunk of message? 't' or 'f' ('T' or
-								 * 'F' for CSV case) */
+	int32		dest;			/* log destination */
+	char		is_last;        /* last chunk of message? 't' or 'f'*/
 	char		data[FLEXIBLE_ARRAY_MEMBER];	/* data payload starts here */
 } PipeProtoHeader;
 
-- 
2.17.1