added simple serializer, use lua instead of SQLite

settings.lua

@@ -1,38 +1,66 @@
 DocSettings = {}
 
 function DocSettings:open(docfile)
-	local new = {}
-	new.docdb, errno, errstr = sqlite3.open(docfile..".kpdfview")
-	if new.docdb ~= nil then
-		new.docdb:exec("CREATE TABLE IF NOT EXISTS settings (key TEXT PRIMARY KEY, value TEXT);")
-		new.stmt_readsetting = new.docdb:prepare("SELECT value FROM settings WHERE key = ?;")
-		new.stmt_savesetting = new.docdb:prepare("INSERT OR REPLACE INTO settings (key, value) VALUES (?, ?);")
+	local new = { file = docfile..".kpdfview.lua", data = {} }
+	local ok, stored = pcall(dofile,new.file)
+	if ok then
+		new.data = stored
 	end
 	return setmetatable(new, { __index = DocSettings})
 end
 
 function DocSettings:readsetting(key)
-	if self.docdb ~= nil then
-		self.stmt_readsetting:reset()
-		self.stmt_readsetting:bind_values(key)
-		local result = self.stmt_readsetting:step()
-		if result == sqlite3.ROW then
-			return self.stmt_readsetting:get_value(0)
+	return self.data[key]
+end
+
+function DocSettings:savesetting(key, value)
+	self.data[key] = value
+end
+
+-- simple serialization function, won't do uservalues, functions, loops
+function DocSettings:_serialize(what, outt, indent)
+	if type(what) == "table" then
+		local didrun = false
+		table.insert(outt, "{")
+		for k, v in pairs(what) do
+			if didrun then
+				table.insert(outt, ",")
+			end
+			table.insert(outt, "\n")
+			table.insert(outt, string.rep("\t", indent+1))
+			table.insert(outt, "[")
+			self:_serialize(k, outt, indent+1)
+			table.insert(outt, "] = ")
+			self:_serialize(v, outt, indent+1)
+			didrun = true
 		end
+		if didrun then
+			table.insert(outt, "\n")
+			table.insert(outt, string.rep("\t", indent))
+		end
+		table.insert(outt, "}")
+	elseif type(what) == "string" then
+		table.insert(outt, string.format("%q", what))
+	elseif type(what) == "number" or type(what) == "boolean" then
+		table.insert(outt, tostring(what))
 	end
 end
 
-function DocSettings:savesetting(key, value)
-	if self.docdb ~= nil then
-		self.stmt_savesetting:reset()
-		self.stmt_savesetting:bind_values(key, value)
-		self.stmt_savesetting:step()
+function DocSettings:flush()
+	-- write a serialized version of the data table
+	if not self.file then
+		return
+	end
+	local f_out = io.open(self.file, "w")
+	if f_out ~= nil then
+		local out = {"-- we can read Lua syntax here!\nreturn "}
+		self:_serialize(self.data, out, 0)
+		table.insert(out, "\n")
+		f_out:write(table.concat(out))
+		f_out:close()
 	end
 end
 
 function DocSettings:close()
-	if self.docdb ~= nil then
-		self.docdb:close()
-		self.docdb = nil
-	end
+	self:flush()
 end