util.dbuffer: Add efficient shortcuts for discard() in certain cases
If the buffer is already empty, nothing to do. If we're throwing away the
whole buffer, we can just empty it and avoid read_chunk() (which in turn
may collapse()). These shortcuts are much more efficient.
local st = require "util.stanza"
local jid_split = require "util.jid".split;
local mod_pep = module:depends("pep");
module:hook("account-disco-info", function (event)
event.reply:tag("feature", { var = "urn:ietf:params:xml:ns:vcard-4.0" }):up();
end);
module:hook("iq-get/bare/urn:ietf:params:xml:ns:vcard-4.0:vcard", function (event)
local origin, stanza = event.origin, event.stanza;
local pep_service = mod_pep.get_pep_service(jid_split(stanza.attr.to) or origin.username);
local ok, id, item = pep_service:get_last_item("urn:xmpp:vcard4", stanza.attr.from);
if ok and item then
origin.send(st.reply(stanza):add_child(item.tags[1]));
elseif id == "item-not-found" or not id then
origin.send(st.error_reply(stanza, "cancel", "item-not-found"));
elseif id == "forbidden" then
origin.send(st.error_reply(stanza, "auth", "forbidden"));
else
origin.send(st.error_reply(stanza, "modify", "undefined-condition"));
end
return true;
end);
module:hook("iq-set/self/urn:ietf:params:xml:ns:vcard-4.0:vcard", function (event)
local origin, stanza = event.origin, event.stanza;
local vcard4 = st.stanza("item", { xmlns = "http://jabber.org/protocol/pubsub", id = "current" })
:add_child(stanza.tags[1]);
local pep_service = mod_pep.get_pep_service(origin.username);
local ok, err = pep_service:publish("urn:xmpp:vcard4", origin.full_jid, "current", vcard4);
if ok then
origin.send(st.reply(stanza));
elseif err == "forbidden" then
origin.send(st.error_reply(stanza, "auth", "forbidden"));
else
origin.send(st.error_reply(stanza, "modify", "undefined-condition", err));
end
return true;
end);