openLogOff is not needed anymore

... obviously due to commit c24dcd0. The following patch removes it.

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index ecd12fc53a..0fdd82a287 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -771,13 +771,11 @@ static const char *xlogSourceNames[] = {"any", "archive", "pg_wal", "stream"};

/*
* openLogFile is -1 or a kernel FD for an open log file segment.
- * When it's open, openLogOff is the current seek offset in the file.
- * openLogSegNo identifies the segment. These variables are only
- * used to write the XLOG, and so will normally refer to the active segment.
+ * openLogSegNo identifies the segment. These variables are only used to
+ * write the XLOG, and so will normally refer to the active segment.
*/
static int openLogFile = -1;
static XLogSegNo openLogSegNo = 0;
-static uint32 openLogOff = 0;

/*
* These variables are used similarly to the ones above, but for reading
@@ -2447,7 +2445,6 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible)
/* create/use new log file */
use_existent = true;
openLogFile = XLogFileInit(openLogSegNo, &use_existent, true);
- openLogOff = 0;
}

/* Make sure we have the current logfile open */
@@ -2456,7 +2453,6 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible)
XLByteToPrevSeg(LogwrtResult.Write, openLogSegNo,
wal_segment_size);
openLogFile = XLogFileOpen(openLogSegNo);
- openLogOff = 0;
}

/* Add current page to the set of pending pages-to-dump */
@@ -2508,15 +2504,13 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible)
errmsg("could not write to log file %s "
"at offset %u, length %zu: %m",
XLogFileNameP(ThisTimeLineID, openLogSegNo),
- openLogOff, nbytes)));
+ startoffset, nbytes)));
}
nleft -= written;
from += written;
startoffset += written;
} while (nleft > 0);

- /* Update state for write */
- openLogOff += nbytes;
npages = 0;

/*
@@ -2602,7 +2596,6 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible)
XLByteToPrevSeg(LogwrtResult.Write, openLogSegNo,
wal_segment_size);
openLogFile = XLogFileOpen(openLogSegNo);
- openLogOff = 0;
}

issue_xlog_fsync(openLogFile, openLogSegNo);

--
Antonin Houska
https://www.cybertec-postgresql.com