From 56bdddaebbfb3ccede367a0f10dbd2d91c381206 Mon Sep 17 00:00:00 2001
From: Waqas Hussain <waqas20@gmail.com>
Date: Fri, 23 Jul 2010 23:09:58 +0500
Subject: storagemanager: Initial commit.

---
 core/storagemanager.lua | 68 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 core/storagemanager.lua

(limited to 'core/storagemanager.lua')

diff --git a/core/storagemanager.lua b/core/storagemanager.lua
new file mode 100644
index 00000000..9e966037
--- /dev/null
+++ b/core/storagemanager.lua
@@ -0,0 +1,68 @@
+
+local error = error;
+local setmetatable = setmetatable;
+
+local config = require "core.configmanager";
+local datamanager = require "util.datamanager";
+local multitable = require "util.multitable";
+local modulemanager = require "core.modulemanager";
+local hosts = hosts;
+local log = require "util.logger".init("storagemanager");
+
+local olddm = {}; -- maintain old datamanager, for backwards compatibility
+for k,v in pairs(datamanager) do olddm[k] = v; end
+
+local driver_cache = multitable.new();
+local store_cache = multitable.new();
+
+module("storagemanager")
+
+local default_driver_mt = {};
+default_driver_mt.__index = default_driver_mt;
+function default_driver_mt:open(store)
+	return setmetatable({ host = self.host, store = self.store }, default_driver_mt);
+end
+function default_driver_mt:get(user) return olddm.load(user, self.host, self.store); end
+function default_driver_mt:set(user, data) return olddm.store(user, self.host, self.store, data); end
+
+local function load_driver_for_host(host)
+	if driver_cache:get(host) then return driver_cache:get(host); end
+	
+	local host_session = hosts[host];
+	if not host_session then error("No such host"); end
+	
+	local driver_plugin = config.get(host, "core", "datastore");
+	if not driver_plugin then return setmetatable({ host = host }, default_driver_mt); end
+	
+	local provider;
+	local function handler(event) provider = event.item; end
+	host_session.events.add_handler("item-added/data-driver", handler);
+	local success, err = modulemanager.load(host, driver_plugin);
+	host_session.events.remove_handler("item-added/data-driver", handler);
+	if not success then error(err); end
+	if not provider then error("Module didn't add a provider"); end
+	
+	driver_cache:set(host, provider);
+	log("debug", "Data driver '%s' loaded for host '%s'", driver_plugin, host);
+	return provider;
+end
+
+function open(host, store, typ)
+	local ret = store_cache:get(host, store);
+	if not ret then
+		local driver = load_driver_for_host(host);
+		ret = driver:open(store, typ);
+		if not ret then ret = setmetatable({ host = host, store = store }, default_driver_mt); end -- default to default driver
+		store_cache:set(host, store, ret);
+	end
+	return ret;
+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;
-- 
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