util/pubsub.lua

   1 module("pubsub", package.seeall);
   2
   3 local service = {};
   4 local service_mt = { __index = service };
   5
   6 function new(cb)
   7         return setmetatable({ cb = cb or {}, nodes = {} }, service_mt);
   8 end
   9
  10 function service:add_subscription(node, actor, jid)
  11         local node_obj = self.nodes[node];
  12         if not node_obj then
  13                 return false, "item-not-found";
  14         end
  15         node_obj.subscribers[jid] = true;
  16         return true;
  17 end
  18
  19 function service:remove_subscription(node, actor, jid)
  20         local node_obj = self.nodes[node];
  21         if not node_obj then
  22                 return false, "item-not-found";
  23         end
  24         if not node_obj.subscribers[jid] then
  25                 return false, "not-subscribed";
  26         end
  27         node_obj.subscribers[jid] = nil;
  28         return true;
  29 end
  30
  31 function service:get_subscription(node, actor, jid)
  32         local node_obj = self.nodes[node];
  33         if node_obj then
  34                 return node_obj.subscribers[jid];
  35         end
  36 end
  37
  38 function service:create(node, actor)
  39         if not self.nodes[node] then
  40                 self.nodes[node] = { name = node, subscribers = {}, config = {}, data = {} };
  41                 return true;
  42         end
  43         return false, "conflict";
  44 end
  45
  46 function service:publish(node, actor, id, item)
  47         local node_obj = self.nodes[node];
  48         if not node_obj then
  49                 node_obj = { name = node, subscribers = {}, config = {}, data = {} };
  50                 self.nodes[node] = node_obj;
  51         end
  52         node_obj.data[id] = item;
  53         self.cb.broadcaster(node, node_obj.subscribers, item);
  54         return true;
  55 end
  56
  57 function service:retract(node, actor, id, retract)
  58         local node_obj = self.nodes[node];
  59         if (not node_obj) or (not node_obj.data[id]) then
  60                 return false, "item-not-found";
  61         end
  62         node_obj.data[id] = nil;
  63         if retract then
  64                 self.cb.broadcaster(node, node_obj.subscribers, retract);
  65         end
  66         return true
  67 end
  68
  69 function service:get(node, actor, id)
  70         local node_obj = self.nodes[node];
  71         if node_obj then
  72                 if id then
  73                         return { node_obj.data[id] };
  74                 else
  75                         return node_obj.data;
  76                 end
  77         end
  78 end
  79
  80 function service:get_nodes(actor)
  81         return true, self.nodes;
  82 end
  83
  84 return _M;