gd_alter_encoding(3) GETDATA gd_alter_encoding(3)NAMEgd_alter_encoding — modify the binary encoding of data in a dirfile
SYNOPSIS
#include <getdata.h>
int gd_alter_encoding(DIRFILE *dirfile, unsigned int encoding, int
fragment_index, int recode);
DESCRIPTION
The gd_alter_encoding() function sets the binary encoding of the format
specification fragment given by fragment_index to byte_sex in the
dirfile(5) database specified by dirfile. The binary encoding of a
fragment indicate the encoding of data stored in binary files associat‐
ed with RAW fields defined in the specified fragment. The binary en‐
coding of a fragment containing no RAW fields is ignored.
The byte_sex argument should be one of the following:
GD_UNENCODED, GD_BZIP2_ENCODED, GD_GZIP_ENCODED,
GD_LZMA_ENCODED, GD_SLIM_ENCODED, GD_TEXT_ENCODED.
See gd_cbopen(3) and dirfile-encoding(5) for the meanings of these sym‐
bols and details on the supported encoding schemes.
In addition to being simply a valid fragment index, fragment_index may
also be the special value GD_ALL_FRAGMENTS, which indicates that the
encoding of all fragments in the database should be changed.
If the recode argument is non-zero, this call will recode the binary
data of affected RAW fields to account for the change in binary encod‐
ing. If the encoding of the fragment is encoding insensitive, or if
the data type is only one byte in size, no change is made. If recode
is zero, affected binary files are left untouched.
RETURN VALUE
Upon successful completion, gd_alter_encoding() returns zero. On er‐
ror, it returns -1 and sets the dirfile error to a non-zero error val‐
ue. Possible error values are:
GD_E_ACCMODE
The specified dirfile was opened read-only.
GD_E_ALLOC
The library was unable to allocate memory.
GD_E_BAD_DIRFILE
The supplied dirfile was invalid.
GD_E_BAD_INDEX
The supplied index was out of range.
GD_E_PROTECTED
The metadata of the given format specification fragment was
protected from change, or the binary data of the fragment was
protected from change and binary file recoding was requested.
GD_E_RAW_IO
An I/O error occurred while attempting to recode a binary file.
GD_E_UNCLEAN_DB
An error occurred while moving the recoded file into place. As
a result, the database may be in an unclean state. See the
NOTES section below for recovery instructions. In this case,
the dirfile will be flagged as invalid, to prevent further
database corruption. It should be immediately closed.
GD_E_UNKNOWN_ENCODING
The encoding scheme of the fragment is unknown.
GD_E_UNSUPPORTED
The encoding scheme of the fragment does not support binary
file recoding.
The dirfile error may be retrieved by calling gd_error(3). A descrip‐
tive error string for the last error encountered can be obtained from a
call to gd_error_string(3).
NOTES
A binary file recoding occurs out-of-place. As a result, sufficient
space must be present on the filesystem for the binary files of all RAW
fields in the fragment both before and after translation. If all frag‐
ments are updated by specifying GD_ALL_FRAGMENTS, the recoding occurs
one fragment at a time.
An error code of GD_E_UNCLEAN_DB indicates a system error occurred
while moving the re-encoded binary data into place or when deleting the
old data. If this happens, the database may be left in an unclean
state. The caller should check the filesystem directly to ascertain
the state of the dirfile data before continuing. For recovery instruc‐
tions, see the file /usr/share/doc/getdata/unclean_database_recov‐
ery.txt.
SEE ALSOgd_cbopen(3), gd_error(3), gd_error_string(3), gd_encoding(3),
dirfile(5), dirfile-format(5)Version 0.7.0 20 July 2010 gd_alter_encoding(3)
