table of contents
gd_flush(3) | GETDATA | gd_flush(3) |
NAME¶
gd_flush gd_raw_close gd_sync — write all pending Dirfile changes to disk or close open raw fields
SYNOPSIS¶
#include <getdata.h>
int gd_flush(DIRFILE *dirfile, const char *field_code);
int gd_raw_close(DIRFILE *dirfile, const char *field_code);
int gd_sync(DIRFILE *dirfile, const char *field_code);
DESCRIPTION¶
The gd_sync() function flushes all pending writes to disk of raw data files associated with field_code, or its input(s), in the dirfile specified by dirfile. If the field_code contains a valid representation suffix, it will be ignored.
As a special case, if NULL is passed to gd_sync() as field_code, all fields in dirfile will be flushed. In this special case, modified metadata will also be flushed to disk as if gd_metaflush(3) had been called. If the dirfile has been opened read-only, this function does nothing. Additionally, some encoding schemes may implement this as a NOP.
The gd_raw_close() function closes any raw data files which GetData has opened associated with field_code, or its input(s). Again, if field_code is NULL, all open data files are closed. The I/O pointer of any RAW field which is closed is reset to the beginning-of-field.
Calling gd_flush() is essentially equivalent to calling first gd_sync() and then gd_raw_close() (ie. it does both tasks), although, if field_code is NULL, the order of operations if may be different than making the two explicit calls.
RETURN VALUE¶
On success, these functions return zero. On error, a negative-valued error code is returned. Possible error codes are:
- GD_E_ALLOC
- The library was unable to allocate memory.
- GD_E_BAD_CODE
- The field specified by field_code was not found in the database.
- GD_E_BAD_DIRFILE
- The supplied dirfile was invalid.
- GD_E_IO
- An I/O error occurred while trying to write modified data or metadata to disk.
- GD_E_LINE_TOO_LONG
- 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.
- GD_E_RECURSE_LEVEL
- Too many levels of recursion were encountered while trying to resolve field_code. This usually indicates a circular dependency in field specification in the dirfile.
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).
HISTORY¶
The dirfile_flush() function appeared in GetData-0.3.0.
In GetData-0.7.0, this function was renamed to gd_flush().
The gd_raw_close() and gd_sync() functions appeared in GetData-0.8.0.
In GetData-0.10.0, the error return from these functions changed from -1 to a negative-valued error code.
SEE ALSO¶
gd_close(3), gd_dirfile_standards(3), gd_error(3), gd_error_string(3), gd_metaflush(3), gd_open(3)
25 December 2016 | Version 0.10.0 |