1 files changed, 95 insertions, 0 deletions
diff --git a/util/serialization.lua b/util/serialization.lua
new file mode 100644
index 00000000..8a259184
--- /dev/null
+++ b/util/serialization.lua
@@ -0,0 +1,95 @@
+-- Prosody IM
+-- Copyright (C) 2008-2010 Matthew Wild
+-- Copyright (C) 2008-2010 Waqas Hussain
+-- 
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+
+local string_rep = string.rep;
+local type = type;
+local tostring = tostring;
+local t_insert = table.insert;
+local t_concat = table.concat;
+local error = error;
+local pairs = pairs;
+local next = next;
+
+local loadstring = loadstring;
+local pcall = pcall;
+
+local debug_traceback = debug.traceback;
+local log = require "util.logger".init("serialization");
+local envload = require"util.envload".envload;
+
+module "serialization"
+
+local indent = function(i)
+	return string_rep("\t", i);
+end
+local function basicSerialize (o)
+	if type(o) == "number" or type(o) == "boolean" then
+		-- no need to check for NaN, as that's not a valid table index
+		if o == 1/0 then return "(1/0)";
+		elseif o == -1/0 then return "(-1/0)";
+		else return tostring(o); end
+	else -- assume it is a string -- FIXME make sure it's a string. throw an error otherwise.
+		return (("%q"):format(tostring(o)):gsub("\\\n", "\\n"));
+	end
+end
+local function _simplesave(o, ind, t, func)
+	if type(o) == "number" then
+		if o ~= o then func(t, "(0/0)");
+		elseif o == 1/0 then func(t, "(1/0)");
+		elseif o == -1/0 then func(t, "(-1/0)");
+		else func(t, tostring(o)); end
+	elseif type(o) == "string" then
+		func(t, (("%q"):format(o):gsub("\\\n", "\\n")));
+	elseif type(o) == "table" then
+		if next(o) ~= nil then
+			func(t, "{\n");
+			for k,v in pairs(o) do
+				func(t, indent(ind));
+				func(t, "[");
+				func(t, basicSerialize(k));
+				func(t, "] = ");
+				if ind == 0 then
+					_simplesave(v, 0, t, func);
+				else
+					_simplesave(v, ind+1, t, func);
+				end
+				func(t, ";\n");
+			end
+			func(t, indent(ind-1));
+			func(t, "}");
+		else
+			func(t, "{}");
+		end
+	elseif type(o) == "boolean" then
+		func(t, (o and "true" or "false"));
+	else
+		log("error", "cannot serialize a %s: %s", type(o), debug_traceback())
+		func(t, "nil");
+	end
+end
+
+function append(t, o)
+	_simplesave(o, 1, t, t.write or t_insert);
+	return t;
+end
+
+function serialize(o)
+	return t_concat(append({}, o));
+end
+
+function deserialize(str)
+	if type(str) ~= "string" then return nil; end
+	str = "return "..str;
+	local f, err = envload(str, "@data", {});
+	if not f then return nil, err; end
+	local success, ret = pcall(f);
+	if not success then return nil, ret; end
+	return ret;
+end
+
+return _M;