From 9f1cf97bb5387a6243c8a6c9725616ef7447962e Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Thu, 10 Sep 2020 19:37:02 -0300 Subject: [PATCH] Print WAL logical message contents in pg_waldump MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This helps debuggability when looking at WAL streams containing logical messages. Author: Ashutosh Bapat Reviewed-by: Álvaro Herrera Discussion: https://postgr.es/m/CAExHW5sWx49rKmXbg5H1Xc1t+nRv9PaYKQmgw82HPt6vWDVmDg@mail.gmail.com --- src/backend/access/rmgrdesc/logicalmsgdesc.c | 17 ++++++++++++++--- src/backend/replication/logical/message.c | 1 + src/include/replication/message.h | 5 ++--- 3 files changed, 17 insertions(+), 6 deletions(-) diff --git a/src/backend/access/rmgrdesc/logicalmsgdesc.c b/src/backend/access/rmgrdesc/logicalmsgdesc.c index bff298c9287..83ab93a24be 100644 --- a/src/backend/access/rmgrdesc/logicalmsgdesc.c +++ b/src/backend/access/rmgrdesc/logicalmsgdesc.c @@ -24,10 +24,21 @@ 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; + char *sep = ""; - appendStringInfo(buf, "%s message size %zu bytes", - xlrec->transactional ? "transactional" : "nontransactional", - xlrec->message_size); + Assert(prefix[xlrec->prefix_size] != '\0'); + + appendStringInfo(buf, "%s, prefix \"%s\"; payload (%zu bytes): ", + xlrec->transactional ? "transactional" : "non-transactional", + prefix, xlrec->message_size); + /* Write message payload as a series of hex bytes */ + for (int cnt = 0; cnt < xlrec->message_size; cnt++) + { + appendStringInfo(buf, "%s%02X", sep, (unsigned char) message[cnt]); + sep = " "; + } } } diff --git a/src/backend/replication/logical/message.c b/src/backend/replication/logical/message.c index db33cbe5a7a..bd4b08543e6 100644 --- a/src/backend/replication/logical/message.c +++ b/src/backend/replication/logical/message.c @@ -59,6 +59,7 @@ LogLogicalMessage(const char *prefix, const char *message, size_t size, xlrec.dbId = MyDatabaseId; xlrec.transactional = transactional; + /* trailing zero is critical; see logicalmsg_desc */ xlrec.prefix_size = strlen(prefix) + 1; xlrec.message_size = size; diff --git a/src/include/replication/message.h b/src/include/replication/message.h index 937addde485..e97891ebcaf 100644 --- a/src/include/replication/message.h +++ b/src/include/replication/message.h @@ -23,9 +23,8 @@ typedef struct xl_logical_message bool transactional; /* is message transactional? */ Size prefix_size; /* length of prefix */ Size message_size; /* size of the message */ - char message[FLEXIBLE_ARRAY_MEMBER]; /* message including the null - * terminated prefix of length - * prefix_size */ + /* payload, including null-terminated prefix of length prefix_size */ + char message[FLEXIBLE_ARRAY_MEMBER]; } xl_logical_message; #define SizeOfLogicalMessage (offsetof(xl_logical_message, message)) -- 2.39.5