/*-------------------------------------------------------------------------
 *
 * xlogdesc.c
 *    rmgr descriptor routines for access/transam/xlog.c
 *
 * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/access/rmgrdesc/xlogdesc.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "access/xlog.h"
#include "access/xlog_internal.h"
#include "catalog/pg_control.h"
#include "utils/guc.h"

/*
 * GUC support
 */
const struct config_enum_entry wal_level_options[] = {
	{"minimal", WAL_LEVEL_MINIMAL, false},
	{"archive", WAL_LEVEL_ARCHIVE, false},
	{"hot_standby", WAL_LEVEL_HOT_STANDBY, false},
	{NULL, 0, false}
};

void
xlog_desc(StringInfo buf, uint8 xl_info, char *rec)
{
	uint8		info = xl_info & ~XLR_INFO_MASK;

	if (info == XLOG_CHECKPOINT_SHUTDOWN ||
		info == XLOG_CHECKPOINT_ONLINE)
	{
		CheckPoint *checkpoint = (CheckPoint *) rec;

		appendStringInfo(buf, "checkpoint: redo %X/%X; "
				   "tli %u; fpw %s; xid %u/%u; oid %u; multi %u; offset %u; "
						 "oldest xid %u in DB %u; oldest running xid %u; %s",
						 (uint32) (checkpoint->redo >> 32), (uint32) checkpoint->redo,
						 checkpoint->ThisTimeLineID,
						 checkpoint->fullPageWrites ? "true" : "false",
						 checkpoint->nextXidEpoch, checkpoint->nextXid,
						 checkpoint->nextOid,
						 checkpoint->nextMulti,
						 checkpoint->nextMultiOffset,
						 checkpoint->oldestXid,
						 checkpoint->oldestXidDB,
						 checkpoint->oldestActiveXid,
				 (info == XLOG_CHECKPOINT_SHUTDOWN) ? "shutdown" : "online");
	}
	else if (info == XLOG_NOOP)
	{
		appendStringInfo(buf, "xlog no-op");
	}
	else if (info == XLOG_NEXTOID)
	{
		Oid			nextOid;

		memcpy(&nextOid, rec, sizeof(Oid));
		appendStringInfo(buf, "nextOid: %u", nextOid);
	}
	else if (info == XLOG_SWITCH)
	{
		appendStringInfo(buf, "xlog switch");
	}
	else if (info == XLOG_RESTORE_POINT)
	{
		xl_restore_point *xlrec = (xl_restore_point *) rec;

		appendStringInfo(buf, "restore point: %s", xlrec->rp_name);

	}
	else if (info == XLOG_BACKUP_END)
	{
		XLogRecPtr	startpoint;

		memcpy(&startpoint, rec, sizeof(XLogRecPtr));
		appendStringInfo(buf, "backup end: %X/%X",
						 (uint32) (startpoint >> 32), (uint32) startpoint);
	}
	else if (info == XLOG_PARAMETER_CHANGE)
	{
		xl_parameter_change xlrec;
		const char *wal_level_str;
		const struct config_enum_entry *entry;

		memcpy(&xlrec, rec, sizeof(xl_parameter_change));

		/* Find a string representation for wal_level */
		wal_level_str = "?";
		for (entry = wal_level_options; entry->name; entry++)
		{
			if (entry->val == xlrec.wal_level)
			{
				wal_level_str = entry->name;
				break;
			}
		}

		appendStringInfo(buf, "parameter change: max_connections=%d max_prepared_xacts=%d max_locks_per_xact=%d wal_level=%s",
						 xlrec.MaxConnections,
						 xlrec.max_prepared_xacts,
						 xlrec.max_locks_per_xact,
						 wal_level_str);
	}
	else if (info == XLOG_FPW_CHANGE)
	{
		bool		fpw;

		memcpy(&fpw, rec, sizeof(bool));
		appendStringInfo(buf, "full_page_writes: %s", fpw ? "true" : "false");
	}
	else
		appendStringInfo(buf, "UNKNOWN");
}