InnoDB portability fix: new function os_file_set_eof()

innobase/include/os0file.h:
  Add os_file_set_eof()
innobase/os/os0file.c:
  Add os_file_set_eof()
innobase/srv/srv0srv.c:
  Replace chsize() or ftruncate() with os_file_set_eof()
sql/ha_innodb.cc:
  Replace my_chsize() with os_file_set_eof()

innobase/include/os0file.h

@@ -227,6 +227,14 @@ os_file_set_size(
 				size */
 	ulint		size_high);/* in: most significant 32 bits of size */
 /***************************************************************************
+Truncates a file at its current position. */
+
+ibool
+os_file_set_eof(
+/*============*/
+				/* out: TRUE if success */
+	FILE*		file);	/* in: file to be truncated */
+/***************************************************************************
 Flushes the write buffers of a given file to the disk. */
 
 ibool

innobase/os/os0file.c

@@ -1031,6 +1031,23 @@ error_handling:
 	return(FALSE);
 }
 
+/***************************************************************************
+Truncates a file at its current position. */
+
+ibool
+os_file_set_eof(
+/*============*/
+				/* out: TRUE if success */
+	FILE*		file)	/* in: file to be truncated */
+{
+#ifdef __WIN__
+	HANDLE h = (HANDLE) _get_osfhandle(fileno(file));
+	return(SetEndOfFile(h));
+#else /* __WIN__ */
+	return(!ftruncate(fileno(file), ftell(file)));
+#endif /* __WIN__ */
+}
+
 /***************************************************************************
 Flushes the write buffers of a given file to the disk. */
 

innobase/srv/srv0srv.c

@@ -1609,11 +1609,7 @@ loop:
 	    mutex_enter(&srv_monitor_file_mutex);
 	    rewind(srv_monitor_file);
 	    srv_printf_innodb_monitor(srv_monitor_file);
-#ifdef __WIN__
-	    chsize(fileno(srv_monitor_file), ftell(srv_monitor_file));
-#else /* __WIN__ */
-	    ftruncate(fileno(srv_monitor_file), ftell(srv_monitor_file));
-#endif /* __WIN__ */
+	    os_file_set_eof(srv_monitor_file);
 	    mutex_exit(&srv_monitor_file_mutex);
 
 	    if (srv_print_innodb_tablespace_monitor

sql/ha_innodb.cc

@@ -4648,7 +4648,7 @@ innodb_show_status(
 	rewind(srv_monitor_file);
 	srv_printf_innodb_monitor(srv_monitor_file);
 	flen = ftell(srv_monitor_file);
-	my_chsize(fileno(srv_monitor_file), flen, 0, MYF(0));
+	os_file_set_eof(srv_monitor_file);
 	if(flen > 64000 - 1) {
 		flen = 64000 - 1;
 	}