1 files changed, 105 insertions, 0 deletions
diff --git a/src/backend/access/rmgrdesc/mxactdesc.c b/src/backend/access/rmgrdesc/mxactdesc.c
new file mode 100644
index 0000000..4dd6d7d
--- /dev/null
+++ b/src/backend/access/rmgrdesc/mxactdesc.c
@@ -0,0 +1,105 @@
+/*-------------------------------------------------------------------------
+ *
+ * mxactdesc.c
+ *	  rmgr descriptor routines for access/transam/multixact.c
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/access/rmgrdesc/mxactdesc.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/multixact.h"
+
+static void
+out_member(StringInfo buf, MultiXactMember *member)
+{
+	appendStringInfo(buf, "%u ", member->xid);
+	switch (member->status)
+	{
+		case MultiXactStatusForKeyShare:
+			appendStringInfoString(buf, "(keysh) ");
+			break;
+		case MultiXactStatusForShare:
+			appendStringInfoString(buf, "(sh) ");
+			break;
+		case MultiXactStatusForNoKeyUpdate:
+			appendStringInfoString(buf, "(fornokeyupd) ");
+			break;
+		case MultiXactStatusForUpdate:
+			appendStringInfoString(buf, "(forupd) ");
+			break;
+		case MultiXactStatusNoKeyUpdate:
+			appendStringInfoString(buf, "(nokeyupd) ");
+			break;
+		case MultiXactStatusUpdate:
+			appendStringInfoString(buf, "(upd) ");
+			break;
+		default:
+			appendStringInfoString(buf, "(unk) ");
+			break;
+	}
+}
+
+void
+multixact_desc(StringInfo buf, XLogReaderState *record)
+{
+	char	   *rec = XLogRecGetData(record);
+	uint8		info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
+
+	if (info == XLOG_MULTIXACT_ZERO_OFF_PAGE ||
+		info == XLOG_MULTIXACT_ZERO_MEM_PAGE)
+	{
+		int			pageno;
+
+		memcpy(&pageno, rec, sizeof(int));
+		appendStringInfo(buf, "%d", pageno);
+	}
+	else if (info == XLOG_MULTIXACT_CREATE_ID)
+	{
+		xl_multixact_create *xlrec = (xl_multixact_create *) rec;
+		int			i;
+
+		appendStringInfo(buf, "%u offset %u nmembers %d: ", xlrec->mid,
+						 xlrec->moff, xlrec->nmembers);
+		for (i = 0; i < xlrec->nmembers; i++)
+			out_member(buf, &xlrec->members[i]);
+	}
+	else if (info == XLOG_MULTIXACT_TRUNCATE_ID)
+	{
+		xl_multixact_truncate *xlrec = (xl_multixact_truncate *) rec;
+
+		appendStringInfo(buf, "offsets [%u, %u), members [%u, %u)",
+						 xlrec->startTruncOff, xlrec->endTruncOff,
+						 xlrec->startTruncMemb, xlrec->endTruncMemb);
+	}
+}
+
+const char *
+multixact_identify(uint8 info)
+{
+	const char *id = NULL;
+
+	switch (info & ~XLR_INFO_MASK)
+	{
+		case XLOG_MULTIXACT_ZERO_OFF_PAGE:
+			id = "ZERO_OFF_PAGE";
+			break;
+		case XLOG_MULTIXACT_ZERO_MEM_PAGE:
+			id = "ZERO_MEM_PAGE";
+			break;
+		case XLOG_MULTIXACT_CREATE_ID:
+			id = "CREATE_ID";
+			break;
+		case XLOG_MULTIXACT_TRUNCATE_ID:
+			id = "TRUNCATE_ID";
+			break;
+	}
+
+	return id;
+}