plugins/muc/history.lib.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2010 Matthew Wild
   3 -- Copyright (C) 2008-2010 Waqas Hussain
   4 -- Copyright (C) 2014 Daurnimator
   5 --
   6 -- This project is MIT/X11 licensed. Please see the
   7 -- COPYING file in the source package for more information.
   8 --
   9
  10 local gettime = os.time;
  11 local datetime = require "util.datetime";
  12 local st = require "util.stanza";
  13
  14 local default_history_length = 20;
  15 local max_history_length = module:get_option_number("max_history_messages", math.huge);
  16
  17 local function set_max_history_length(_max_history_length)
  18         max_history_length = _max_history_length or math.huge;
  19 end
  20
  21 local function get_historylength(room)
  22         return math.min(room._data.history_length or default_history_length, max_history_length);
  23 end
  24
  25 local function set_historylength(room, length)
  26         if length then
  27                 length = assert(tonumber(length), "Length not a valid number");
  28         end
  29         if length == default_history_length then length = nil; end
  30         room._data.history_length = length;
  31         return true;
  32 end
  33
  34 module:hook("muc-config-form", function(event)
  35         table.insert(event.form, {
  36                 name = "muc#roomconfig_historylength";
  37                 type = "text-single";
  38                 label = "Maximum Number of History Messages Returned by Room";
  39                 value = tostring(get_historylength(event.room));
  40         });
  41 end);
  42
  43 module:hook("muc-config-submitted/muc#roomconfig_historylength", function(event)
  44         if set_historylength(event.room, event.value) then
  45                 event.status_codes["104"] = true;
  46         end
  47 end);
  48
  49 local function parse_history(stanza)
  50         local x_tag = stanza:get_child("x", "http://jabber.org/protocol/muc");
  51         local history_tag = x_tag and x_tag:get_child("history", "http://jabber.org/protocol/muc");
  52         if not history_tag then
  53                 return nil, default_history_length, nil;
  54         end
  55
  56         local maxchars = tonumber(history_tag.attr.maxchars);
  57
  58         local maxstanzas = tonumber(history_tag.attr.maxstanzas);
  59
  60         -- messages received since the UTC datetime specified
  61         local since = history_tag.attr.since;
  62         if since then
  63                 since = datetime.parse(since);
  64         end
  65
  66         -- messages received in the last "X" seconds.
  67         local seconds = tonumber(history_tag.attr.seconds);
  68         if seconds then
  69                 seconds = gettime() - seconds;
  70                 if since then
  71                         since = math.max(since, seconds);
  72                 else
  73                         since = seconds;
  74                 end
  75         end
  76
  77         return maxchars, maxstanzas, since;
  78 end
  79
  80 module:hook("muc-get-history", function(event)
  81         local room = event.room;
  82         local history = room._history; -- send discussion history
  83         if not history then return nil end
  84         local history_len = #history;
  85
  86         local to = event.to;
  87         local maxchars = event.maxchars;
  88         local maxstanzas = event.maxstanzas or history_len;
  89         local since = event.since;
  90         local n = 0;
  91         local charcount = 0;
  92         for i=history_len,1,-1 do
  93                 local entry = history[i];
  94                 if maxchars then
  95                         if not entry.chars then
  96                                 entry.stanza.attr.to = "";
  97                                 entry.chars = #tostring(entry.stanza);
  98                         end
  99                         charcount = charcount + entry.chars + #to;
 100                         if charcount > maxchars then break; end
 101                 end
 102                 if since and since > entry.timestamp then break; end
 103                 if n + 1 > maxstanzas then break; end
 104                 n = n + 1;
 105         end
 106
 107         local i = history_len-n+1
 108         function event.next_stanza()
 109                 if i > history_len then return nil end
 110                 local entry = history[i];
 111                 local msg = entry.stanza;
 112                 msg.attr.to = to;
 113                 i = i + 1;
 114                 return msg;
 115         end
 116         return true;
 117 end);
 118
 119 local function send_history(room, stanza)
 120         local maxchars, maxstanzas, since = parse_history(stanza);
 121         local event = {
 122                 room = room;
 123                 to = stanza.attr.from; -- `to` is required to calculate the character count for `maxchars`
 124                 maxchars = maxchars, maxstanzas = maxstanzas, since = since;
 125                 next_stanza = function() end; -- events should define this iterator
 126         };
 127         module:fire_event("muc-get-history", event);
 128         for msg in event.next_stanza, event do
 129                 room:route_stanza(msg);
 130         end
 131 end
 132
 133 -- Send history on join
 134 module:hook("muc-occupant-session-new", function(event)
 135         send_history(event.room, event.stanza);
 136 end, 50); -- Before subject(20)
 137
 138 -- add to history
 139 module:hook("muc-add-history", function(event)
 140         local historic = event.stanza:get_child("body");
 141         if historic then
 142                 local room = event.room
 143                 local history = room._history;
 144                 if not history then history = {}; room._history = history; end
 145                 local stanza = st.clone(event.stanza);
 146                 stanza.attr.to = "";
 147                 local ts = gettime();
 148                 local stamp = datetime.datetime(ts);
 149                 stanza:tag("delay", {xmlns = "urn:xmpp:delay", from = module.host, stamp = stamp}):up(); -- XEP-0203
 150                 stanza:tag("x", {xmlns = "jabber:x:delay", from = module.host, stamp = datetime.legacy()}):up(); -- XEP-0091 (deprecated)
 151                 local entry = { stanza = stanza, timestamp = ts };
 152                 table.insert(history, entry);
 153                 while #history > get_historylength(room) do table.remove(history, 1) end
 154         end
 155         return true;
 156 end, -1);
 157
 158 -- Have a single muc-add-history event, so that plugins can mark it
 159 -- as handled without stopping other muc-broadcast-message handlers
 160 module:hook("muc-broadcast-message", function(event)
 161         module:fire_event("muc-add-history", event);
 162 end);
 163
 164 return {
 165         set_max_length = set_max_history_length;
 166         parse_history = parse_history;
 167         send = send_history;
 168         get_length = get_historylength;
 169         set_length = set_historylength;
 170 };