core/storagemanager.lua

   1
   2 local error, type = error, type;
   3 local setmetatable = setmetatable;
   4
   5 local config = require "core.configmanager";
   6 local datamanager = require "util.datamanager";
   7 local modulemanager = require "core.modulemanager";
   8 local multitable = require "util.multitable";
   9 local hosts = hosts;
  10 local log = require "util.logger".init("storagemanager");
  11
  12 local olddm = {}; -- maintain old datamanager, for backwards compatibility
  13 for k,v in pairs(datamanager) do olddm[k] = v; end
  14 local prosody = prosody;
  15
  16 module("storagemanager")
  17
  18 local null_storage_method = function () return false, "no data storage active"; end
  19 local null_storage_driver = setmetatable(
  20         {
  21                 name = "null",
  22                 open = function (self) return self; end
  23         }, {
  24                 __index = function (self, method)
  25                         return null_storage_method;
  26                 end
  27         }
  28 );
  29
  30 --TODO: Move default driver to mod_auth_internal
  31 local default_driver_mt = { name = "internal" };
  32 default_driver_mt.__index = default_driver_mt;
  33 function default_driver_mt:open(store)
  34         return setmetatable({ host = self.host, store = store }, default_driver_mt);
  35 end
  36 function default_driver_mt:get(user) return olddm.load(user, self.host, self.store); end
  37 function default_driver_mt:set(user, data) return olddm.store(user, self.host, self.store, data); end
  38
  39 local stores_available = multitable.new();
  40
  41 function initialize_host(host)
  42         local host_session = hosts[host];
  43         host_session.events.add_handler("item-added/data-driver", function (event)
  44                 local item = event.item;
  45                 stores_available:set(host, item.name, item);
  46         end);
  47
  48         host_session.events.add_handler("item-removed/data-driver", function (event)
  49                 local item = event.item;
  50                 stores_available:set(host, item.name, nil);
  51         end);
  52 end
  53 prosody.events.add_handler("host-activated", initialize_host, 101);
  54
  55 local function load_driver(host, driver_name)
  56         if not driver_name then
  57                 return;
  58         end
  59         local driver = stores_available:get(host, driver_name);
  60         if driver then return driver; end
  61         if driver_name ~= "internal" then
  62                 local ok, err = modulemanager.load(host, "storage_"..driver_name);
  63                 if not ok then
  64                         log("error", "Failed to load storage driver plugin %s on %s: %s", driver_name, host, err);
  65                 end
  66                 return stores_available:get(host, driver_name);
  67         else
  68                 return setmetatable({host = host}, default_driver_mt);
  69         end
  70 end
  71
  72 function open(host, store, typ)
  73         local storage = config.get(host, "core", "storage");
  74         local driver_name;
  75         local option_type = type(storage);
  76         if option_type == "string" then
  77                 driver_name = storage;
  78         elseif option_type == "table" then
  79                 driver_name = storage[store];
  80         end
  81
  82         local driver = load_driver(host, driver_name);
  83         if not driver then
  84                 driver_name = config.get(host, "core", "default_storage");
  85                 driver = load_driver(host, driver_name);
  86                 if not driver then
  87                         if driver_name or (type(storage) == "string"
  88                         or type(storage) == "table" and storage[store]) then
  89                                 log("warn", "Falling back to null driver for %s storage on %s", store, host);
  90                                 driver_name = "null";
  91                                 driver = null_storage_driver;
  92                         else
  93                                 driver_name = "internal";
  94                                 driver = load_driver(host, driver_name);
  95                         end
  96                 end
  97         end
  98
  99         local ret, err = driver:open(store, typ);
 100         if not ret then
 101                 if err == "unsupported-store" then
 102                         log("debug", "Storage driver %s does not support store %s (%s), falling back to null driver",
 103                                 driver_name, store, typ);
 104                         ret = null_storage_driver;
 105                         err = nil;
 106                 end
 107         end
 108         return ret, err;
 109 end
 110
 111 function datamanager.load(username, host, datastore)
 112         return open(host, datastore):get(username);
 113 end
 114 function datamanager.store(username, host, datastore, data)
 115         return open(host, datastore):set(username, data);
 116 end
 117
 118 return _M;