Diff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/storage/sqlbasic.lib.lua	Fri Feb 19 22:32:28 2010 +0500
@@ -0,0 +1,97 @@
+
+-- Basic SQL driver
+-- This driver stores data as simple key-values
+
+local ser = require "util.serialization".serialize;
+local deser = function(data)
+	module:log("debug", "deser: %s", tostring(data));
+	if not data then return nil; end
+	local f = loadstring("return "..data);
+	if not f then return nil; end
+	setfenv(f, {});
+	local s, d = pcall(f);
+	if not s then return nil; end
+	return d;
+end;
+
+local driver = {};
+driver.__index = driver;
+
+driver.item_table = "item";
+driver.list_table = "list";
+
+function driver:prepare(sql)
+	module:log("debug", "query: %s", sql);
+	local err;
+	if not self.sqlcache then self.sqlcache = {}; end
+	local r = self.sqlcache[sql];
+	if r then return r; end
+	r, err = self.connection:prepare(sql);
+	if not r then error("Unable to prepare SQL statement: "..err); end
+	self.sqlcache[sql] = r;
+	return r;
+end
+
+function driver:load(username, host, datastore)
+	local select = self:prepare("select data from "..self.item_table.." where username=? and host=? and datastore=?");
+	select:execute(username, host, datastore);
+	local row = select:fetch();
+	return row and deser(row[1]) or nil;
+end
+
+function driver:store(username, host, datastore, data)
+	if not data or next(data) == nil then
+		local delete = self:prepare("delete from "..self.item_table.." where username=? and host=? and datastore=?");
+		delete:execute(username, host, datastore);
+		return true;
+	else
+		local d = self:load(username, host, datastore);
+		if d then -- update
+			local update = self:prepare("update "..self.item_table.." set data=? where username=? and host=? and datastore=?");
+			return update:execute(ser(data), username, host, datastore);
+		else -- insert
+			local insert = self:prepare("insert into "..self.item_table.." values (?, ?, ?, ?)");
+			return insert:execute(username, host, datastore, ser(data));
+		end
+	end
+end
+
+function driver:list_append(username, host, datastore, data)
+	if not data then return; end
+	local insert = self:prepare("insert into "..self.list_table.." values (?, ?, ?, ?)");
+	return insert:execute(username, host, datastore, ser(data));
+end
+
+function driver:list_store(username, host, datastore, data)
+	-- remove existing data
+	local delete = self:prepare("delete from "..self.list_table.." where username=? and host=? and datastore=?");
+	delete:execute(username, host, datastore);
+	if data and next(data) ~= nil then
+		-- add data
+		for _, d in ipairs(data) do
+			self:list_append(username, host, datastore, ser(d));
+		end
+	end
+	return true;
+end
+
+function driver:list_load(username, host, datastore)
+	local select = self:prepare("select data from "..self.list_table.." where username=? and host=? and datastore=?");
+	select:execute(username, host, datastore);
+	local r = {};
+	for row in select:rows() do
+		table.insert(r, deser(row[1]));
+	end
+	return r;
+end
+
+local _M = {};
+function _M.new(dbtype, dbname, ...)
+	local d = {};
+	setmetatable(d, driver);
+	local dbh = get_database(dbtype, dbname, ...);
+	--d:set_connection(dbh);
+	d.connection = dbh;
+	return d;
+end
+return _M;