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 default_driver_mt = { name = "internal" };
  19 default_driver_mt.__index = default_driver_mt;
  20 function default_driver_mt:open(store)
  21         return setmetatable({ host = self.host, store = store }, default_driver_mt);
  22 end
  23 function default_driver_mt:get(user) return olddm.load(user, self.host, self.store); end
  24 function default_driver_mt:set(user, data) return olddm.store(user, self.host, self.store, data); end
  25
  26 local stores_available = multitable.new();
  27
  28 function initialize_host(host)
  29         local host_session = hosts[host];
  30         host_session.events.add_handler("item-added/data-driver", function (event)
  31                 local item = event.item;
  32                 stores_available:set(host, item.name, item);
  33         end);
  34
  35         host_session.events.add_handler("item-removed/data-driver", function (event)
  36                 local item = event.item;
  37                 stores_available:set(host, item.name, nil);
  38         end);
  39 end
  40 prosody.events.add_handler("host-activated", initialize_host, 101);
  41
  42 local function load_driver(host, driver_name)
  43         if not driver_name then
  44                 return;
  45         end
  46         local driver = stores_available:get(host, driver_name);
  47         if driver then return driver; end
  48         if driver_name ~= "internal" then
  49                 local ok, err = modulemanager.load(host, "storage_"..driver_name);
  50                 if not ok then
  51                         log("error", "Failed to load storage driver plugin %s on %s: %s", driver_name, host, err);
  52                 end
  53                 return stores_available:get(host, driver_name);
  54         else
  55                 return setmetatable({host = host}, default_driver_mt);
  56         end
  57 end
  58
  59 function open(host, store, typ)
  60         local storage = config.get(host, "core", "storage");
  61         local driver_name;
  62         local option_type = type(storage);
  63         if option_type == "string" then
  64                 driver_name = storage;
  65         elseif option_type == "table" then
  66                 driver_name = storage[store];
  67         end
  68
  69         local driver = load_driver(host, driver_name);
  70         if not driver then
  71                 driver_name = config.get(host, "core", "default_storage");
  72                 driver = load_driver(host, driver_name);
  73                 if not driver then
  74                         if driver_name or (type(storage) == "string"
  75                         or type(storage) == "table" and storage[store]) then
  76                                 log("warn", "Falling back to default driver for %s storage on %s", store, host);
  77                         end
  78                         driver_name = "internal";
  79                         driver = load_driver(host, driver_name);
  80                 end
  81         end
  82
  83         local ret, err = driver:open(store, typ);
  84         if not ret then
  85                 if err == "unsupported-store" then
  86                         log("debug", "Storage driver %s does not support store %s (%s), falling back to internal driver",
  87                                 driver_name, store, typ);
  88                         ret = setmetatable({ host = host, store = store }, default_driver_mt); -- default to default driver
  89                         err = nil;
  90                 end
  91         end
  92         return ret, err;
  93 end
  94
  95 function datamanager.load(username, host, datastore)
  96         return open(host, datastore):get(username);
  97 end
  98 function datamanager.store(username, host, datastore, data)
  99         return open(host, datastore):set(username, data);
 100 end
 101
 102 return _M;