1 files changed, 100 insertions, 0 deletions
diff --git a/core/storagemanager.lua b/core/storagemanager.lua
new file mode 100644
index 00000000..c96ef3ec
--- /dev/null
+++ b/core/storagemanager.lua
@@ -0,0 +1,100 @@
+
+local error, type, pairs = error, type, pairs;
+local setmetatable = setmetatable;
+
+local config = require "core.configmanager";
+local datamanager = require "util.datamanager";
+local modulemanager = require "core.modulemanager";
+local multitable = require "util.multitable";
+local hosts = hosts;
+local log = require "util.logger".init("storagemanager");
+
+local prosody = prosody;
+
+module("storagemanager")
+
+local olddm = {}; -- maintain old datamanager, for backwards compatibility
+for k,v in pairs(datamanager) do olddm[k] = v; end
+_M.olddm = olddm;
+
+local null_storage_method = function () return false, "no data storage active"; end
+local null_storage_driver = setmetatable(
+	{
+		name = "null",
+		open = function (self) return self; end
+	}, {
+		__index = function (self, method)
+			return null_storage_method;
+		end
+	}
+);
+
+local stores_available = multitable.new();
+
+function initialize_host(host)
+	local host_session = hosts[host];
+	host_session.events.add_handler("item-added/data-driver", function (event)
+		local item = event.item;
+		stores_available:set(host, item.name, item);
+	end);
+	
+	host_session.events.add_handler("item-removed/data-driver", function (event)
+		local item = event.item;
+		stores_available:set(host, item.name, nil);
+	end);
+end
+prosody.events.add_handler("host-activated", initialize_host, 101);
+
+function load_driver(host, driver_name)
+	if driver_name == "null" then
+		return null_storage_provider;
+	end
+	local driver = stores_available:get(host, driver_name);
+	if driver then return driver; end
+	local ok, err = modulemanager.load(host, "storage_"..driver_name);
+	if not ok then
+		log("error", "Failed to load storage driver plugin %s on %s: %s", driver_name, host, err);
+	end
+	return stores_available:get(host, driver_name);
+end
+
+function open(host, store, typ)
+	local storage = config.get(host, "core", "storage");
+	local driver_name;
+	local option_type = type(storage);
+	if option_type == "string" then
+		driver_name = storage;
+	elseif option_type == "table" then
+		driver_name = storage[store];
+	end
+	if not driver_name then
+		driver_name = config.get(host, "core", "default_storage") or "internal";
+	end
+	
+	local driver = load_driver(host, driver_name);
+	if not driver then
+		log("warn", "Falling back to null driver for %s storage on %s", store, host);
+		driver_name = "null";
+		driver = null_storage_driver;
+	end
+	
+	local ret, err = driver:open(store, typ);
+	if not ret then
+		if err == "unsupported-store" then
+			log("debug", "Storage driver %s does not support store %s (%s), falling back to null driver",
+				driver_name, store, typ);
+			ret = null_storage_driver;
+			err = nil;
+		end
+	end
+	return ret, err;
+end
+
+function datamanager.load(username, host, datastore)
+	return open(host, datastore):get(username);
+end
+function datamanager.store(username, host, datastore, data)
+	return open(host, datastore):set(username, data);
+end
+
+return _M;