mod_posix: Move everything to util.startup
This allows greater control over the order of events.
Notably, the internal ordering between daemonization, initialization of
libunbound and setup of signal handling is sensitive.
libunbound starts a separate thread for processing DNS requests.
If this thread is started before signal handling has been set up, it
will not inherit the signal handlers and instead behave as it would have
before signal handlers were set up, i.e. cause the whole process to
immediately exit.
libunbound is usually initialized on the first DNS request, usually
triggered by an outgoing s2s connection attempt.
If daemonization happens before signals have been set up, signals may
not be processed at all.
local it = require "prosody.util.iterators";
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, value)
self.ring = nil;
self.nodes[name] = value == nil and true or value;
table.insert(self.nodes, name);
return true;
end
function hashring_methods:add_nodes(nodes)
self.ring = nil;
local iter = pairs;
if nodes[1] then -- simple array?
iter = it.values;
end
for node_name, node_value in iter(nodes) do
if self.nodes[node_name] == nil then
self.nodes[node_name] = node_value == nil and true or node_value;
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] ~= nil 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);
for node_name, node_value in pairs(self.nodes) do
clone_hashring.nodes[node_name] = node_value;
end
clone_hashring.ring = nil;
return clone_hashring;
end
function hashring_methods:get_node(key)
local node;
local key_hash = self.hash(key);
for _, replica_hash in ipairs(self.ring) do
if key_hash < replica_hash then
node = self.ring[replica_hash];
break;
end
end
if not node then
node = self.ring[self.ring[1]];
end
return node, self.nodes[node];
end
return {
new = new;
}