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