From cca186348929cd75f23ef1b25922386bf38cf99c Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Tue, 20 Dec 2022 13:36:27 +0900 Subject: Add pg_dissect_walfile_name() This function takes in input a WAL segment name and returns a tuple made of the segment sequence number (dependent on the WAL segment size of the cluster) and its timeline, as of a thin SQL wrapper around the existing XLogFromFileName(). This function has multiple usages, like being able to compile a LSN from a file name and an offset, or finding the timeline of a segment without having to do to some maths based on the first eight characters of the segment. Bump catalog version. Author: Bharath Rupireddy Reviewed-by: Nathan Bossart, Kyotaro Horiguchi, Maxim Orlov, Michael Paquier Discussion: https://postgr.es/m/CALj2ACWV=FCddsxcGbVOA=cvPyMr75YCFbSQT6g4KDj=gcJK4g@mail.gmail.com --- src/backend/access/transam/xlogfuncs.c | 53 ++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) (limited to 'src/backend/access/transam/xlogfuncs.c') diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c index 487d5d9cac7..0a31837ef18 100644 --- a/src/backend/access/transam/xlogfuncs.c +++ b/src/backend/access/transam/xlogfuncs.c @@ -432,6 +432,59 @@ pg_walfile_name(PG_FUNCTION_ARGS) PG_RETURN_TEXT_P(cstring_to_text(xlogfilename)); } +/* + * Extract the sequence number and the timeline ID from given a WAL file + * name. + */ +Datum +pg_dissect_walfile_name(PG_FUNCTION_ARGS) +{ +#define PG_DISSECT_WALFILE_NAME_COLS 2 + char *fname = text_to_cstring(PG_GETARG_TEXT_PP(0)); + char *fname_upper; + char *p; + TimeLineID tli; + XLogSegNo segno; + Datum values[PG_DISSECT_WALFILE_NAME_COLS] = {0}; + bool isnull[PG_DISSECT_WALFILE_NAME_COLS] = {0}; + TupleDesc tupdesc; + HeapTuple tuple; + char buf[256]; + Datum result; + + fname_upper = pstrdup(fname); + + /* Capitalize WAL file name. */ + for (p = fname_upper; *p; p++) + *p = pg_toupper((unsigned char) *p); + + if (!IsXLogFileName(fname_upper)) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("invalid WAL file name \"%s\"", fname))); + + XLogFromFileName(fname_upper, &tli, &segno, wal_segment_size); + + if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) + elog(ERROR, "return type must be a row type"); + + /* Convert to numeric. */ + snprintf(buf, sizeof buf, UINT64_FORMAT, segno); + values[0] = DirectFunctionCall3(numeric_in, + CStringGetDatum(buf), + ObjectIdGetDatum(0), + Int32GetDatum(-1)); + + values[1] = Int64GetDatum(tli); + + tuple = heap_form_tuple(tupdesc, values, isnull); + result = HeapTupleGetDatum(tuple); + + PG_RETURN_DATUM(result); + +#undef PG_DISSECT_WALFILE_NAME_COLS +} + /* * pg_wal_replay_pause - Request to pause recovery * -- cgit v1.2.3