mod_mam/fallback_archive.lib.lua

   1 -- luacheck: ignore 212/self
   2
   3 local uuid = require "util.uuid".generate;
   4 local store = module:shared("archive");
   5 local archive_store = { _provided_by = "mam"; name = "fallback"; };
   6
   7 function archive_store:append(username, key, value, when, with)
   8         local archive = store[username];
   9         if not archive then
  10                 archive = { [0] = 0 };
  11                 store[username] = archive;
  12         end
  13         local index = (archive[0] or #archive)+1;
  14         local item = { key = key, when = when, with = with, value = value };
  15         if not key or archive[key] then
  16                 key = uuid();
  17                 item.key = key;
  18         end
  19         archive[index] = item;
  20         archive[key] = index;
  21         archive[0] = index;
  22         return key;
  23 end
  24
  25 function archive_store:find(username, query)
  26         local archive = store[username] or {};
  27         local start, stop, step = 1, archive[0] or #archive, 1;
  28         local qstart, qend, qwith = -math.huge, math.huge;
  29         local limit;
  30
  31         if query then
  32                 if query.reverse then
  33                         start, stop, step = stop, start, -1;
  34                         if query.before and archive[query.before] then
  35                                 start = archive[query.before] - 1;
  36                         end
  37                 elseif query.after and archive[query.after] then
  38                         start = archive[query.after] + 1;
  39                 end
  40                 qwith = query.with;
  41                 limit = query.limit;
  42                 qstart = query.start or qstart;
  43                 qend = query["end"] or qend;
  44         end
  45
  46         return function ()
  47                 if limit and limit <= 0 then return end
  48                 for i = start, stop, step do
  49                         local item = archive[i];
  50                         if (not qwith or qwith == item.with) and item.when >= qstart and item.when <= qend then
  51                                 if limit then limit = limit - 1; end
  52                                 start = i + step; -- Start on next item
  53                                 return item.key, item.value, item.when, item.with;
  54                         end
  55                 end
  56         end
  57 end
  58
  59 function archive_store:delete(username, query)
  60         if not query or next(query) == nil then
  61                 -- no specifics, delete everything
  62                 store[username] = nil;
  63                 return true;
  64         end
  65         local archive = store[username];
  66         if not archive then return true; end -- no messages, nothing to delete
  67
  68         local qstart = query.start or -math.huge;
  69         local qend = query["end"] or math.huge;
  70         local qwith = query.with;
  71         store[username] = nil;
  72         for i = 1, #archive do
  73                 local item = archive[i];
  74                 local when, with = item.when, item.when;
  75                 -- Add things that don't match the query
  76                 if not ((not qwith or qwith == item.with) and item.when >= qstart and item.when <= qend) then
  77                         self:append(username, item.key, item.value, when, with);
  78                 end
  79         end
  80         return true;
  81 end
  82
  83 return archive_store;