int
inv_seek(struct lobj *obj_desc, int offset, int whence)
{
ASSERT(PTR_VALID(obj_desc));
switch (whence) {
case SEEK_SET:
if (offset < 0)
elog(ERROR, "invalid seek offset: %d", offset);
obj_desc->offset = offset;
break;
case SEEK_CUR:
if (offset < 0 && obj_desc->offset < ((uint32) (-offset)))
elog(ERROR, "invalid seek offset: %d", offset);
obj_desc->offset += offset;
break;
case SEEK_END: {
uint32 size = inv_getsize(obj_desc);
if (offset < 0 && size < ((uint32) (-offset)))
elog(ERROR, "invalid seek offset: %d", offset);
obj_desc->offset = size + offset;
}
break;
default:
elog(ERROR, "invalid whence: %d", whence);
}
return obj_desc->offset;
}
int
inv_seek(LargeObjectDesc *obj_desc, int offset, int whence)
{
Assert(PointerIsValid(obj_desc));
switch (whence)
{
case SEEK_SET:
if (offset < 0)
elog(ERROR, "invalid seek offset: %d", offset);
obj_desc->offset = offset;
break;
case SEEK_CUR:
if (offset < 0 && obj_desc->offset < ((uint32) (-offset)))
elog(ERROR, "invalid seek offset: %d", offset);
obj_desc->offset += offset;
break;
case SEEK_END:
{
uint32 size = inv_getsize(obj_desc);
if (offset < 0 && size < ((uint32) (-offset)))
elog(ERROR, "invalid seek offset: %d", offset);
obj_desc->offset = size + offset;
}
break;
default:
elog(ERROR, "invalid whence: %d", whence);
}
return obj_desc->offset;
}
int64
inv_seek(LargeObjectDesc *obj_desc, int64 offset, int whence)
{
int64 newoffset;
Assert(PointerIsValid(obj_desc));
/*
* Note: overflow in the additions is possible, but since we will reject
* negative results, we don't need any extra test for that.
*/
switch (whence)
{
case SEEK_SET:
newoffset = offset;
break;
case SEEK_CUR:
newoffset = obj_desc->offset + offset;
break;
case SEEK_END:
newoffset = inv_getsize(obj_desc) + offset;
break;
default:
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("invalid whence setting: %d", whence)));
newoffset = 0; /* keep compiler quiet */
break;
}
/*
* use errmsg_internal here because we don't want to expose INT64_FORMAT
* in translatable strings; doing better is not worth the trouble
*/
if (newoffset < 0 || newoffset > MAX_LARGE_OBJECT_SIZE)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg_internal("invalid large object seek target: " INT64_FORMAT,
newoffset)));
obj_desc->offset = newoffset;
return newoffset;
}