table of contents
gd_metaflush — write modified Dirfile metadata to disk
int gd_metaflush(DIRFILE *dirfile);
The gd_metaflush() function flushes all pending metadata changes in the dirfile specified by dirfile to disk. This is accomplished by re-writing the format specification fragments containing modified metadata, overwriting the existing files. Format file fragments which are unchanged are not touched.
Metadata is written to disk using the current Standards Version as stored in the dirfile object. See gd_dirfile_standards(3) to change or report the current Standards Version. If the dirfile metadata conforms to no known Standards Version, a Standards non-compliant fragment will be written.
This function flushes only metadata. To flush the field data as well, call gd_sync(3) instead.
On success, zero is returned. On error, a negative-valued error code is returned. Possible error codes are:
- The supplied dirfile was opened in read-only mode.
- The library was unable to allocate memory.
- The supplied dirfile was invalid.
- An I/O error occurred while trying to write modified metadata to disk.
- While attempting to flush modified metadata to disk, a field specification line exceeded the maximum allowed length. On most platforms, the maximum length is at least 2**31 bytes, so this typically indicates something pathological happening.
The error code is also stored in the DIRFILE object and may be retrieved after this function returns by calling gd_error(3). A descriptive error string for the error may be obtained by calling gd_error_string(3).
When writing metadata using Standards Version 4 or earlier, the reference field may change, owing to the lack of a /REFERENCE directive. A work-around is to upgrade to Standards Version 5 or later.
The dirfile_metaflush() function appeared in GetData-0.4.0.
In GetData-0.7.0, this function was renamed to gd_metaflush().
in GetData-0.10.0, the error return from this function changed from -1 to a negative-valued error code.
gd_close(3), gd_dirfile_standards(3), gd_error(3), gd_error_string(3), gd_open(3), gd_rewrite_fragment(3), gd_sync(3)
|25 December 2016||Version 0.10.0|