File

util.hashring: Support associating arbitrary data with nodes In this API, a 'node' is always a simple text string. Sometimes the caller may have a more complex structure representing a node, but the hash ring is really only concerned with the node's name. This API change allows :add_nodes() to take a table of `node_name = value` pairs, as well as the simple array of node names previously accepted. The 'value' of the selected node is returned as a new second result from :get_node(). If no value is passed when a node is added, it defaults to `true` (as before, but this was never previously exposed).

local s_char = string.char;
local s_format = string.format;
local s_gsub = string.gsub;
local s_lower = string.lower;

local char_to_hex = {};
local hex_to_char = {};

do
	local char, hex;
	for i = 0,255 do
		char, hex = s_char(i), s_format("%02x", i);
		char_to_hex[char] = hex;
		hex_to_char[hex] = char;
	end
end

local function to(s)
	return (s_gsub(s, ".", char_to_hex));
end

local function from(s)
	return (s_gsub(s_lower(s), "%X*(%x%x)%X*", hex_to_char));
end

return {
	encode = to, decode = from;
	-- COMPAT w/pre-0.12:
	to = to, from = from;
};