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.
module:set_global();
local have_unix, unix = pcall(require, "socket.unix");
if have_unix and type(unix) == "function" then
-- COMPAT #1717
-- Before the introduction of datagram support, only the stream socket
-- constructor was exported instead of a module table. Due to the lack of a
-- proper release of LuaSocket, distros have settled on shipping either the
-- last RC tag or some commit since then.
-- Here we accomodate both variants.
unix = { stream = unix };
end
if not have_unix or type(unix) ~= "table" then
module:log_status("error", "LuaSocket unix socket support not available or incompatible, ensure it is up to date");
return;
end
local server = require "net.server";
local adminstream = require "util.adminstream";
local socket_path = module:get_option_path("admin_socket", "prosody.sock", "data");
local sessions = module:shared("sessions");
local function fire_admin_event(session, stanza)
local event_data = {
origin = session, stanza = stanza;
};
local event_name;
if stanza.attr.xmlns then
event_name = "admin/"..stanza.attr.xmlns..":"..stanza.name;
else
event_name = "admin/"..stanza.name;
end
module:log("debug", "Firing %s", event_name);
return module:fire_event(event_name, event_data);
end
module:hook("server-stopping", function ()
for _, session in pairs(sessions) do
session:close("system-shutdown");
end
os.remove(socket_path);
end);
--- Unix domain socket management
local conn, sock;
local listeners = adminstream.server(sessions, fire_admin_event).listeners;
local function accept_connection()
module:log("debug", "accepting...");
local client = sock:accept();
if not client then return; end
server.wrapclient(client, "unix", 0, listeners, "*a");
end
function module.load()
sock = unix.stream();
sock:settimeout(0);
os.remove(socket_path);
local ok, err = sock:bind(socket_path);
if not ok then
module:log_status("error", "Unable to bind admin socket %s: %s", socket_path, err);
return;
end
local ok, err = sock:listen();
if not ok then
module:log_status("error", "Unable to listen on admin socket %s: %s", socket_path, err);
return;
end
if server.wrapserver then
conn = server.wrapserver(sock, socket_path, 0, listeners);
else
conn = server.watchfd(sock:getfd(), accept_connection);
end
end
function module.unload()
if conn then
conn:close();
end
if sock then
sock:close();
end
os.remove(socket_path);
end