/* 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 */
}
/* seek to space for attribute (LIBRARY_INTERNAL)
* CsfSeekAttrSpace seeks to the a point in the file where
* the attribute must be stored and update the attribute control
* blocks accordingly.
* Writing can still fail since there is no check if that space is really
* avalaible on the device. After this call returns the file is already
* seeked to the point the functions returns.
* returns the file position or 0 in case of error.
*
* Merrno
* ATTRDUPL
* NOACCESS
* WRITE_ERROR
*/
CSF_FADDR32 CsfSeekAttrSpace(
MAP *m, /* map handle */
CSF_ATTR_ID id, /* attribute identification only for check if avalaible */
size_t size) /* size to be seeked to */
{
ATTR_CNTRL_BLOCK b;
CSF_FADDR32 currBlockPos, prevBlockPos=USED_UNINIT_ZERO, newPos, endBlock, resultPos=0;
int noPosFound;
int i;
if (MattributeAvail(m ,id))
{
M_ERROR(ATTRDUPL);
goto error;
}
if (! WRITE_ENABLE(m))
{
M_ERROR(NOACCESS);
goto error;
}
currBlockPos = m->main.attrTable;
noPosFound = 1;
while (noPosFound)
{
if (currBlockPos == 0)
{
if (m->main.attrTable == 0)
{ /* FIRST BLOCK */
newPos =( (CSF_FADDR)(m->raster.nrRows)*
(CSF_FADDR)(m->raster.nrCols)*
(CSF_FADDR)(CELLSIZE(RgetCellRepr(m))))
+ ADDR_DATA;
m->main.attrTable = newPos;
}
else
{ /* NEW/NEXT BLOCK */
newPos = b.attrs[LAST_ATTR_IN_BLOCK].attrOffset
+
b.attrs[LAST_ATTR_IN_BLOCK].attrSize;
b.next = newPos;
if (CsfWriteAttrBlock(m, prevBlockPos, &b))
{
M_ERROR(WRITE_ERROR);
resultPos = 0;
}
}
InitBlock(&b);
b.attrs[0].attrOffset =
newPos + SIZE_OF_ATTR_CNTRL_BLOCK;
currBlockPos = newPos;
noPosFound = 0;
}
else
CsfReadAttrBlock(m, currBlockPos, &b);
i = 0; /* this is also the right index if a new block
is added ! */
while (noPosFound && i < NR_ATTR_IN_BLOCK)
switch (b.attrs[i].attrId)
{
case END_OF_ATTRS:
POSTCOND(i >= 1);
/* i >= 1 , no block otherwise */
b.attrs[i].attrOffset =
b.attrs[i-1].attrOffset +
b.attrs[i-1].attrSize;
noPosFound = 0;
break;
case ATTR_NOT_USED:
if (i == NR_ATTR_IN_BLOCK)
endBlock = b.next;
else
endBlock = b.attrs[i+1].attrOffset;
if ( (size_t)( endBlock - b.attrs[i].attrOffset) >= size)
/* this position can
hold the attr */
noPosFound = 0;
else
i++;
break;
default:
i++;
} /* switch */
/* if (b.next == 0)
? When did I change this CW
remember this block position since it may be have
to rewritten
*/
prevBlockPos = currBlockPos;
if (noPosFound)
currBlockPos = b.next;
} /* while */
b.attrs[i].attrSize = size;
b.attrs[i].attrId = id;
resultPos = b.attrs[i].attrOffset;
if (CsfWriteAttrBlock(m, currBlockPos, &b))
{
M_ERROR(WRITE_ERROR);
resultPos = 0;
}
fseek(m->fp, (long)resultPos, SEEK_SET); /* fsetpos() is better */
error: return resultPos;
} /* CsfSeekAttrSpace */
