File

util/hashring.lua @ 11516:83822be7704d

util.xmppstream: Send <?xml?> declaration in same call as stream open If network_settings.opportunistic_writes is enabled then this would previously have resulted in two socket writes, and possibly two packets being sent. This caused some issues in older versions of Gajim, which apparently expected the stream opening in the first packet, and thus it could not connect. With this change and opportunistic_writes enabled, the first packet should contain both the xml declaration and the stream open tag. Without opportunistic_writes, there should be no observable change. Tested with Gajim 1.1.2 (on same machine). Unsure if loopback behaves differently than the network here.
author Kim Alvefur <zash@zash.se>
date Wed, 14 Apr 2021 15:21:13 +0200
parent 11208:96429946a742
child 12795:87424cbedc55
line wrap: on
line source

local function generate_ring(nodes, num_replicas, hash)
	local new_ring = {};
	for _, node_name in ipairs(nodes) do
		for replica = 1, num_replicas do
			local replica_hash = hash(node_name..":"..replica);
			new_ring[replica_hash] = node_name;
			table.insert(new_ring, replica_hash);
		end
	end
	table.sort(new_ring);
	return new_ring;
end

local hashring_methods = {};
local hashring_mt = {
	__index = function (self, k)
		-- Automatically build self.ring if it's missing
		if k == "ring" then
			local ring = generate_ring(self.nodes, self.num_replicas, self.hash);
			rawset(self, "ring", ring);
			return ring;
		end
		return rawget(hashring_methods, k);
	end
};

local function new(num_replicas, hash_function)
	return setmetatable({ nodes = {}, num_replicas = num_replicas, hash = hash_function }, hashring_mt);
end;

function hashring_methods:add_node(name)
	self.ring = nil;
	self.nodes[name] = true;
	table.insert(self.nodes, name);
	return true;
end

function hashring_methods:add_nodes(nodes)
	self.ring = nil;
	for _, node_name in ipairs(nodes) do
		if not self.nodes[node_name] then
			self.nodes[node_name] = true;
			table.insert(self.nodes, node_name);
		end
	end
	return true;
end

function hashring_methods:remove_node(node_name)
	self.ring = nil;
	if self.nodes[node_name] then
		for i, stored_node_name in ipairs(self.nodes) do
			if node_name == stored_node_name then
				self.nodes[node_name] = nil;
				table.remove(self.nodes, i);
				return true;
			end
		end
	end
	return false;
end

function hashring_methods:remove_nodes(nodes)
	self.ring = nil;
	for _, node_name in ipairs(nodes) do
		self:remove_node(node_name);
	end
end

function hashring_methods:clone()
	local clone_hashring = new(self.num_replicas, self.hash);
	clone_hashring:add_nodes(self.nodes);
	return clone_hashring;
end

function hashring_methods:get_node(key)
	local key_hash = self.hash(key);
	for _, replica_hash in ipairs(self.ring) do
		if key_hash < replica_hash then
			return self.ring[replica_hash];
		end
	end
	return self.ring[self.ring[1]];
end

return {
	new = new;
}