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 2³¹ 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.