plucky (3) gd_close.3.gz

NAME

       gd_close, gd_discard — close a Dirfile and free associated memory

SYNOPSIS

       #include <getdata.h>

       int gd_close(DIRFILE *dirfile);

       int gd_discard(DIRFILE *dirfile);

DESCRIPTION

       The  gd_close() and gd_discard() attempt to close the open Dirfile dirfile and free all memory associated
       with it.

       The gd_close() function first flushes all pending metadata updates to disk.   This  step  is  skipped  by
       gd_discard(), which simply discards metadata changes.  For dirfiles opened read-only, these two functions
       are equivalent.

       Next, all pending data is flushed to disk and all open data  files  closed.   In  order  to  ensure  that
       modified  data  files  associated  with RAW fields are properly terminated, changes to RAW data files are
       still flushed to disk by gd_discard().

       Finally, if the above didn't encounter an error, these functions free memory associated with the  DIRFILE
       object.

       If dirfile is NULL, nothing happens, and the call succeeds.

       One  of  these  functions  should  be  called  on  all pointers returned by gd_cbopen(3), gd_open(3), and
       gd_invalid_dirfile(3), even if the call to those  function  failed.   After  gd_close()  or  gd_discard()
       returns successfully, the pointer dirfile should be considered invalid.

       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, Standards non-compliant metadata will be written.

RETURN VALUE

       gd_close()  and  gd_discard()  return  zero  on  success.   On error, they do not de-allocate dirfile and
       instead return a negative-valued error code.  Possible error codes are:

       GD_E_ALLOC
               The library was unable to allocate memory.

       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_IO An I/O error occurred while trying to write modified data or metadata to  disk.   In  this  case,
               another call to gd_close() or gd_discard() may be attempted.

       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 function dirfile_close() appeared in GetData-0.3.0.

       The function dirfile_discard() appeared in GetData-0.6.0.

       In GetData-0.7.0 these functions were renamed to gd_close() and gd_discard().

       In GetData-0.10.0, the error return from these functions changed from -1 to a negative-valued error code.

SEE ALSO

       gd_dirfile_standards(3), gd_error(3), gd_error_string(3), gd_flush(3), gd_invalid_dirfile(3), gd_open(3)