/* delete attribute from map
* MdelAttribute deletes an attribute
* from a map, if the attribute is available.
* returns
* the id argument if the attribute is succesfully deleted,
* or 0 in case of error or if the attribute is not found.
*
* Merrno
* NOACCESS
* WRITE_ERROR
*/
CSF_ATTR_ID MdelAttribute(
MAP *m, /* map handle */
CSF_ATTR_ID id) /* identification of attribute */
{
ATTR_CNTRL_BLOCK b;
CSF_FADDR32 pos;
if (! WRITE_ENABLE(m))
{
M_ERROR(NOACCESS);
goto error;
}
pos = CsfGetAttrBlock(m, id, &b);
if (pos == 0)
goto error;
b.attrs[CsfGetAttrIndex(id, &b)].attrId = ATTR_NOT_USED;
if (CsfWriteAttrBlock(m, pos, &b))
{
M_ERROR(WRITE_ERROR);
goto error;
}
return id ;
error: return 0 ; /* not found or an error */
}
/* get the size of an attribute (LIBRARY_INTERNAL)
* returns
* 0 if the attribute is not available,
* or the nonzero size if the attribute is available.
*/
size_t CsfAttributeSize(
MAP *m, /* map handle */
CSF_ATTR_ID id) /* identification of attribute */
{
ATTR_CNTRL_BLOCK b;
if (CsfGetAttrBlock(m, id, &b) != 0)
return b.attrs[CsfGetAttrIndex(id, &b)].attrSize;
return 0;
}
/* read an attribute (LIBRARY_INTERNAL)
* MgetAttribute reads an attribute if it is available.
* Be aware that you can't pass a simple pointer to some
* (array of) structure(s) due to alignment en endian problems.
* At some time there will be a separate get function for each attribute
* returns 0 if the attribute is not found, arg id if
* the attribute is found.
*/
CSF_ATTR_ID CsfGetAttribute(
MAP *m, /* map handle */
CSF_ATTR_ID id, /* id of attribute to be read */
size_t elSize, /* size of each data-element */
size_t *nmemb, /* write-only. How many elSize members are read. */
void *attr) /* write-only. buffer where attribute is read in.
* Must be big enough to hold buffer.
*/
{
ATTR_CNTRL_BLOCK b;
CSF_FADDR pos;
PRECOND(CsfValidSize(elSize));
CHECKHANDLE_GOTO(m, error);
if (! READ_ENABLE(m))
{
M_ERROR(NOACCESS);
goto error;
}
if (CsfGetAttrBlock(m, id, &b) != 0)
{
int i = CsfGetAttrIndex(id, &b);
*nmemb = b.attrs[i].attrSize;
POSTCOND( ((*nmemb) % elSize) == 0);
*nmemb /= elSize;
POSTCOND( (*nmemb) > 0);
pos = b.attrs[i].attrOffset;
(void)fseek(m->fp, (long)pos, SEEK_SET);
m->read(attr,elSize, (size_t)(*nmemb),m->fp);
return(id);
}
else
*nmemb = 0;
error: return(0); /* not available or an error */
} /* MgetAttribute */
