Software /
code /
prosody
Annotate
util/hashring.lua @ 10380:18685a5e362e
mod_dialback: Fix potential traceback in case of missing addressing
Not tested. Assuming nothing good comes from continuing the program flow
after this. The connection should get closed and the event gets aborted
by a traceback anyways.
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Sat, 02 Nov 2019 15:40:20 +0100 |
parent | 10005:409ff72c501c |
child | 11208:96429946a742 |
rev | line source |
---|---|
10005
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
1 local function generate_ring(nodes, num_replicas, hash) |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
2 local new_ring = {}; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
3 for _, node_name in ipairs(nodes) do |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
4 for replica = 1, num_replicas do |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
5 local replica_hash = hash(node_name..":"..replica); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
6 new_ring[replica_hash] = node_name; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
7 table.insert(new_ring, replica_hash); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
8 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
9 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
10 table.sort(new_ring); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
11 return new_ring; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
12 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
13 |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
14 local hashring_methods = {}; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
15 local hashring_mt = { |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
16 __index = function (self, k) |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
17 -- Automatically build self.ring if it's missing |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
18 if k == "ring" then |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
19 local ring = generate_ring(self.nodes, self.num_replicas, self.hash); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
20 rawset(self, "ring", ring); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
21 return ring; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
22 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
23 return rawget(hashring_methods, k); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
24 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
25 }; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
26 |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
27 local function new(num_replicas, hash_function) |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
28 return setmetatable({ nodes = {}, num_replicas = num_replicas, hash = hash_function }, hashring_mt); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
29 end; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
30 |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
31 function hashring_methods:add_node(name) |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
32 self.ring = nil; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
33 self.nodes[name] = true; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
34 table.insert(self.nodes, name); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
35 return true; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
36 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
37 |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
38 function hashring_methods:add_nodes(nodes) |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
39 self.ring = nil; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
40 for _, node_name in ipairs(nodes) do |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
41 if not self.nodes[node_name] then |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
42 self.nodes[node_name] = true; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
43 table.insert(self.nodes, node_name); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
44 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
45 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
46 return true; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
47 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
48 |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
49 function hashring_methods:remove_node(node_name) |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
50 self.ring = nil; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
51 if self.nodes[node_name] then |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
52 for i, stored_node_name in ipairs(self.nodes) do |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
53 if node_name == stored_node_name then |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
54 self.nodes[node_name] = nil; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
55 table.remove(self.nodes, i); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
56 return true; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
57 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
58 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
59 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
60 return false; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
61 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
62 |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
63 function hashring_methods:remove_nodes(nodes) |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
64 self.ring = nil; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
65 for _, node_name in ipairs(nodes) do |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
66 self:remove_node(node_name); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
67 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
68 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
69 |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
70 function hashring_methods:clone() |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
71 local clone_hashring = new(self.num_replicas, self.hash); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
72 clone_hashring:add_nodes(self.nodes); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
73 return clone_hashring; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
74 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
75 |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
76 function hashring_methods:get_node(key) |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
77 local key_hash = self.hash(key); |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
78 for _, replica_hash in ipairs(self.ring) do |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
79 if key_hash < replica_hash then |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
80 return self.ring[replica_hash]; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
81 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
82 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
83 return self.ring[self.ring[1]]; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
84 end |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
85 |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
86 return { |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
87 new = new; |
409ff72c501c
util.hashring: Implementation of hashring data structure
Matthew Wild <mwild1@gmail.com>
parents:
diff
changeset
|
88 } |