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util/hashring.lua @ 13107:9c4dc1e6d2c9
mod_http: Add way to retrieve internal URL instead of external
This could be of help when configuring reverse proxies, as it is the
internal URL the proxy must point at.
Argument treated as an enum "internal" "external"(default) to allow for
future extensibility.
author | Kim Alvefur <zash@zash.se> |
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date | Wed, 24 May 2023 14:43:45 +0200 |
parent | 12975:d10957394a3c |
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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; }