[getdns-api] data structures/arguments to getdns_hostname and getdns_hostname_sync

Paul Hoffman paul.hoffman at vpnc.org
Tue Nov 19 16:36:39 MST 2013

On Nov 19, 2013, at 3:25 PM, Melinda Shore <melinda.shore at nomountain.net> wrote:

> As specified, the address to resolve is passed into getdns_hostname
> and getdns_hostname_sync as a dict containing an address type, encoded
> as a string (or octet sequence - this should be made explicit if it
> stays), and the address itself, also a bindata.  There's an awful lot
> of memory allocation and data movement in the API and I think that
> this (getdns_hostname) is an example of the cost/benefit tradeoff being
> a little sketchy.  If we do hang onto the dict encoding and make the
> address type explicit, I think the address type should be an int (i.e.
> a constant/macro) rather than an octet sequence, but since there are
> reliable heuristics for determining whether a given ASCII octet sequence
> is a v4 or v6 address it strikes me as redundant to pass that in, with
> the additional complexity and execution cost that comes from using a
> getdns_dict rather than just a string.

If we change this from being an admittedly verbose dict to an array, for sanity's sake I would want it to be a array of either 4 or 16 octets. That is, the application prepares whatever input it has into the actual on-the-wire address and ships it. Shipping what is hopefully ASCII text, hopefully null-terminated, seems ripe for errors. With the raw address, the only possible error is "that wasn't exactly 4 or 16 byte long".

--Paul Hoffman

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