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 local _ENV = nil;
  15
  16 local olddm = {}; -- maintain old datamanager, for backwards compatibility
  17 for k,v in pairs(datamanager) do olddm[k] = v; end
  18
  19 local null_storage_method = function () return false, "no data storage active"; end
  20 local null_storage_driver = setmetatable(
  21         {
  22                 name = "null",
  23                 open = function (self) return self; end
  24         }, {
  25                 __index = function (self, method) --luacheck: ignore 212
  26                         return null_storage_method;
  27                 end
  28         }
  29 );
  30
  31 local stores_available = multitable.new();
  32
  33 local function initialize_host(host)
  34         local host_session = hosts[host];
  35         host_session.events.add_handler("item-added/storage-provider", function (event)
  36                 local item = event.item;
  37                 stores_available:set(host, item.name, item);
  38         end);
  39
  40         host_session.events.add_handler("item-removed/storage-provider", function (event)
  41                 local item = event.item;
  42                 stores_available:set(host, item.name, nil);
  43         end);
  44 end
  45 prosody.events.add_handler("host-activated", initialize_host, 101);
  46
  47 local function load_driver(host, driver_name)
  48         if driver_name == "null" then
  49                 return null_storage_driver;
  50         end
  51         local driver = stores_available:get(host, driver_name);
  52         if driver then return driver; end
  53         local ok, err = modulemanager.load(host, "storage_"..driver_name);
  54         if not ok then
  55                 log("error", "Failed to load storage driver plugin %s on %s: %s", driver_name, host, err);
  56         end
  57         return stores_available:get(host, driver_name);
  58 end
  59
  60 local function get_driver(host, store)
  61         local storage = config.get(host, "storage");
  62         local driver_name;
  63         local option_type = type(storage);
  64         if option_type == "string" then
  65                 driver_name = storage;
  66         elseif option_type == "table" then
  67                 driver_name = storage[store];
  68         end
  69         if not driver_name then
  70                 driver_name = config.get(host, "default_storage") or "internal";
  71         end
  72
  73         local driver = load_driver(host, driver_name);
  74         if not driver then
  75                 log("warn", "Falling back to null driver for %s storage on %s", store, host);
  76                 driver_name = "null";
  77                 driver = null_storage_driver;
  78         end
  79         return driver, driver_name;
  80 end
  81
  82 local map_shim_mt = {
  83         __index = {
  84                 get = function(self, username, key)
  85                         local ret, err = self.keyval_store:get(username);
  86                         if ret == nil then return nil, err end
  87                         return ret[key];
  88                 end;
  89                 set = function(self, username, key, data)
  90                         local current, err = self.keyval_store:get(username);
  91                         if current == nil then
  92                                 if err then
  93                                         return nil, err;
  94                                 else
  95                                         current = {};
  96                                 end
  97                         end
  98                         current[key] = data;
  99                         return self.keyval_store:set(username, current);
 100                 end;
 101         };
 102 }
 103 local function create_map_shim(host, store)
 104         local keyval_store, err = open(host, store, "keyval");
 105         if keyval_store == nil then return nil, err end
 106         return setmetatable({
 107                 keyval_store = keyval_store;
 108         }, map_shim_mt);
 109 end
 110
 111 local function open(host, store, typ)
 112         local driver, driver_name = get_driver(host, store);
 113         local ret, err = driver:open(store, typ);
 114         if not ret then
 115                 if err == "unsupported-store" then
 116                         if typ == "map" then -- Use shim on top of keyval store
 117                                 log("debug", "map storage driver unavailable, using shim on top of keyval store.");
 118                                 return create_map_shim(host, store);
 119                         end
 120                         log("debug", "Storage driver %s does not support store %s (%s), falling back to null driver",
 121                                 driver_name, store, typ or "<nil>");
 122                         ret = null_storage_driver;
 123                         err = nil;
 124                 end
 125         end
 126         return ret, err;
 127 end
 128
 129 local function purge(user, host)
 130         local storage = config.get(host, "storage");
 131         if type(storage) == "table" then
 132                 -- multiple storage backends in use that we need to purge
 133                 local purged = {};
 134                 for store, driver in pairs(storage) do
 135                         if not purged[driver] then
 136                                 purged[driver] = get_driver(host, store):purge(user);
 137                         end
 138                 end
 139         end
 140         get_driver(host):purge(user); -- and the default driver
 141
 142         olddm.purge(user, host); -- COMPAT list stores, like offline messages end up in the old datamanager
 143
 144         return true;
 145 end
 146
 147 function datamanager.load(username, host, datastore)
 148         return open(host, datastore):get(username);
 149 end
 150 function datamanager.store(username, host, datastore, data)
 151         return open(host, datastore):set(username, data);
 152 end
 153 function datamanager.users(host, datastore, typ)
 154         local driver = open(host, datastore, typ);
 155         if not driver.users then
 156                 return function() log("warn", "storage driver %s does not support listing users", driver.name) end
 157         end
 158         return driver:users();
 159 end
 160 function datamanager.stores(username, host, typ)
 161         return get_driver(host):stores(username, typ);
 162 end
 163 function datamanager.purge(username, host)
 164         return purge(username, host);
 165 end
 166
 167 return {
 168         initialize_host = initialize_host;
 169         load_driver = load_driver;
 170         get_driver = get_driver;
 171         open = open;
 172
 173         olddm = olddm;
 174 };