core/storagemanager.lua

   1
   2 local type, pairs = type, pairs;
   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 prosody = prosody;
  13
  14 module("storagemanager")
  15
  16 local olddm = {}; -- maintain old datamanager, for backwards compatibility
  17 for k,v in pairs(datamanager) do olddm[k] = v; end
  18 _M.olddm = olddm;
  19
  20 local null_storage_method = function () return false, "no data storage active"; end
  21 local null_storage_driver = setmetatable(
  22         {
  23                 name = "null",
  24                 open = function (self) return self; end
  25         }, {
  26                 __index = function (self, method) --luacheck: ignore 212
  27                         return null_storage_method;
  28                 end
  29         }
  30 );
  31
  32 local stores_available = multitable.new();
  33
  34 function initialize_host(host)
  35         local host_session = hosts[host];
  36         host_session.events.add_handler("item-added/storage-provider", function (event)
  37                 local item = event.item;
  38                 stores_available:set(host, item.name, item);
  39         end);
  40
  41         host_session.events.add_handler("item-removed/storage-provider", function (event)
  42                 local item = event.item;
  43                 stores_available:set(host, item.name, nil);
  44         end);
  45 end
  46 prosody.events.add_handler("host-activated", initialize_host, 101);
  47
  48 function load_driver(host, driver_name)
  49         if driver_name == "null" then
  50                 return null_storage_driver;
  51         end
  52         local driver = stores_available:get(host, driver_name);
  53         if driver then return driver; end
  54         local ok, err = modulemanager.load(host, "storage_"..driver_name);
  55         if not ok then
  56                 log("error", "Failed to load storage driver plugin %s on %s: %s", driver_name, host, err);
  57         end
  58         return stores_available:get(host, driver_name);
  59 end
  60
  61 function get_driver(host, store)
  62         local storage = config.get(host, "storage");
  63         local driver_name;
  64         local option_type = type(storage);
  65         if option_type == "string" then
  66                 driver_name = storage;
  67         elseif option_type == "table" then
  68                 driver_name = storage[store];
  69         end
  70         if not driver_name then
  71                 driver_name = config.get(host, "default_storage") or "internal";
  72         end
  73
  74         local driver = load_driver(host, driver_name);
  75         if not driver then
  76                 log("warn", "Falling back to null driver for %s storage on %s", store, host);
  77                 driver_name = "null";
  78                 driver = null_storage_driver;
  79         end
  80         return driver, driver_name;
  81 end
  82
  83 local map_shim_mt = {
  84         __index = {
  85                 get = function(self, username, key)
  86                         local ret, err = self.keyval_store:get(username);
  87                         if ret == nil then return nil, err end
  88                         return ret[key];
  89                 end;
  90                 set = function(self, username, key, data)
  91                         local current, err = self.keyval_store:get(username);
  92                         if current == nil then
  93                                 if err then
  94                                         return nil, err;
  95                                 else
  96                                         current = {};
  97                                 end
  98                         end
  99                         current[key] = data;
 100                         return self.keyval_store:set(username, current);
 101                 end;
 102         };
 103 }
 104 local function create_map_shim(host, store)
 105         local keyval_store, err = open(host, store, "keyval");
 106         if keyval_store == nil then return nil, err end
 107         return setmetatable({
 108                 keyval_store = keyval_store;
 109         }, map_shim_mt);
 110 end
 111
 112 function open(host, store, typ)
 113         local driver, driver_name = get_driver(host, store);
 114         local ret, err = driver:open(store, typ);
 115         if not ret then
 116                 if err == "unsupported-store" then
 117                         if typ == "map" then -- Use shim on top of keyval store
 118                                 log("debug", "map storage driver unavailable, using shim on top of keyval store.");
 119                                 return create_map_shim(host, store);
 120                         end
 121                         log("debug", "Storage driver %s does not support store %s (%s), falling back to null driver",
 122                                 driver_name, store, typ or "<nil>");
 123                         ret = null_storage_driver;
 124                         err = nil;
 125                 end
 126         end
 127         return ret, err;
 128 end
 129
 130 function purge(user, host)
 131         local storage = config.get(host, "storage");
 132         if type(storage) == "table" then
 133                 -- multiple storage backends in use that we need to purge
 134                 local purged = {};
 135                 for store, driver in pairs(storage) do
 136                         if not purged[driver] then
 137                                 purged[driver] = get_driver(host, store):purge(user);
 138                         end
 139                 end
 140         end
 141         get_driver(host):purge(user); -- and the default driver
 142
 143         olddm.purge(user, host); -- COMPAT list stores, like offline messages end up in the old datamanager
 144
 145         return true;
 146 end
 147
 148 function datamanager.load(username, host, datastore)
 149         return open(host, datastore):get(username);
 150 end
 151 function datamanager.store(username, host, datastore, data)
 152         return open(host, datastore):set(username, data);
 153 end
 154 function datamanager.users(host, datastore, typ)
 155         local driver = open(host, datastore, typ);
 156         if not driver.users then
 157                 return function() log("warn", "storage driver %s does not support listing users", driver.name) end
 158         end
 159         return driver:users();
 160 end
 161 function datamanager.stores(username, host, typ)
 162         return get_driver(host):stores(username, typ);
 163 end
 164 function datamanager.purge(username, host)
 165         return purge(username, host);
 166 end
 167
 168 return _M;