From d32859c8368ac25366b156c3247a5b77d9b72ce8 Mon Sep 17 00:00:00 2001 From: Ashutosh Bapat Date: Tue, 18 Aug 2020 11:05:29 +0530 Subject: [PATCH] Print prefix and logical WAL message content in pg_waldump Print logical WAL message prefix which is a null terminated ASCII string. Print the actual message as a space separated hex byte string since it may contain binary data. This is useful for debugging purposes. Ashutosh Bapat, reviewed by Alvaro Herrera --- src/backend/access/rmgrdesc/logicalmsgdesc.c | 16 ++++++++++++++-- src/include/replication/message.h | 4 +++- 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/src/backend/access/rmgrdesc/logicalmsgdesc.c b/src/backend/access/rmgrdesc/logicalmsgdesc.c index bff298c928..5da2625a0b 100644 --- a/src/backend/access/rmgrdesc/logicalmsgdesc.c +++ b/src/backend/access/rmgrdesc/logicalmsgdesc.c @@ -24,10 +24,22 @@ logicalmsg_desc(StringInfo buf, XLogReaderState *record) if (info == XLOG_LOGICAL_MESSAGE) { xl_logical_message *xlrec = (xl_logical_message *) rec; + char *prefix = xlrec->message; + char *message = xlrec->message + xlrec->prefix_size; + int cnt; + char *sep = ""; - appendStringInfo(buf, "%s message size %zu bytes", + Assert(prefix[xlrec->prefix_size] != '\0'); + + appendStringInfo(buf, "%s, prefix \"%s\"; payload (%zu bytes): ", xlrec->transactional ? "transactional" : "nontransactional", - xlrec->message_size); + prefix, xlrec->message_size); + /* Write actual message as a series of hex bytes. */ + for (cnt = 0; cnt < xlrec->message_size; cnt++) + { + appendStringInfo(buf, "%s%02X", sep, (unsigned char)message[cnt]); + sep = " "; + } } } diff --git a/src/include/replication/message.h b/src/include/replication/message.h index 937addde48..7b882296ec 100644 --- a/src/include/replication/message.h +++ b/src/include/replication/message.h @@ -25,7 +25,9 @@ typedef struct xl_logical_message Size message_size; /* size of the message */ char message[FLEXIBLE_ARRAY_MEMBER]; /* message including the null * terminated prefix of length - * prefix_size */ + * prefix_size. Please see + * logicalmsg_desc(), if you + * change this. */ } xl_logical_message; #define SizeOfLogicalMessage (offsetof(xl_logical_message, message)) -- 2.17.1