Make pg_waldump report more detail information about PREPARE TRANSACTION record.

This commit changes xact_desc() so that it reports the detail information about
PREPARE TRANSACTION record, like GID (global transaction identifier),
timestamp at prepare transaction, delete-on-abort/commit relations,
XID of subtransactions, and invalidation messages. These are helpful
when diagnosing 2PC-related troubles.

Author: Fujii Masao
Reviewed-by: Michael Paquier, Andrey Lepikhov, Kyotaro Horiguchi, Julien Rouhaud, Alvaro Herrera
Discussion: https://postgr.es/m/CAHGQGwEvhASad4JJnCv=0dW2TJypZgW_Vpb-oZik2a3utCqcrA@mail.gmail.com

1 files changed, 1 insertions, 55 deletions

diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 712e842b904..b3ad0d08e30 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -910,23 +910,7 @@ TwoPhaseGetDummyProc(TransactionId xid, bool lock_held)
  */
 #define TWOPHASE_MAGIC	0x57F94534	/* format identifier */
 
-typedef struct TwoPhaseFileHeader
-{
-	uint32		magic;			/* format identifier */
-	uint32		total_len;		/* actual file length */
-	TransactionId xid;			/* original transaction XID */
-	Oid			database;		/* OID of database it was in */
-	TimestampTz prepared_at;	/* time of preparation */
-	Oid			owner;			/* user running the transaction */
-	int32		nsubxacts;		/* number of following subxact XIDs */
-	int32		ncommitrels;	/* number of delete-on-commit rels */
-	int32		nabortrels;		/* number of delete-on-abort rels */
-	int32		ninvalmsgs;		/* number of cache invalidation messages */
-	bool		initfileinval;	/* does relcache init file need invalidation? */
-	uint16		gidlen;			/* length of the GID - GID follows the header */
-	XLogRecPtr	origin_lsn;		/* lsn of this record at origin node */
-	TimestampTz origin_timestamp;	/* time of prepare at origin node */
-} TwoPhaseFileHeader;
+typedef xl_xact_prepare TwoPhaseFileHeader;
 
 /*
  * Header for each record in a state file
@@ -1331,44 +1315,6 @@ ReadTwoPhaseFile(TransactionId xid, bool missing_ok)
 	return buf;
 }
 
-/*
- * ParsePrepareRecord
- */
-void
-ParsePrepareRecord(uint8 info, char *xlrec, xl_xact_parsed_prepare *parsed)
-{
-	TwoPhaseFileHeader *hdr;
-	char	   *bufptr;
-
-	hdr = (TwoPhaseFileHeader *) xlrec;
-	bufptr = xlrec + MAXALIGN(sizeof(TwoPhaseFileHeader));
-
-	parsed->origin_lsn = hdr->origin_lsn;
-	parsed->origin_timestamp = hdr->origin_timestamp;
-	parsed->twophase_xid = hdr->xid;
-	parsed->dbId = hdr->database;
-	parsed->nsubxacts = hdr->nsubxacts;
-	parsed->nrels = hdr->ncommitrels;
-	parsed->nabortrels = hdr->nabortrels;
-	parsed->nmsgs = hdr->ninvalmsgs;
-
-	strncpy(parsed->twophase_gid, bufptr, hdr->gidlen);
-	bufptr += MAXALIGN(hdr->gidlen);
-
-	parsed->subxacts = (TransactionId *) bufptr;
-	bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
-
-	parsed->xnodes = (RelFileNode *) bufptr;
-	bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileNode));
-
-	parsed->abortnodes = (RelFileNode *) bufptr;
-	bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileNode));
-
-	parsed->msgs = (SharedInvalidationMessage *) bufptr;
-	bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
-}
-
-
 
 /*
  * Reads 2PC data from xlog. During checkpoint this data will be moved to