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| 1 | +# frozen_string_literal: true |
| 2 | + |
| 3 | +# Released under the MIT License. |
| 4 | +# Copyright, 2020, by David Ortiz. |
| 5 | +# Copyright, 2023-2024, by Samuel Williams. |
| 6 | + |
| 7 | +require_relative 'client' |
| 8 | +require 'io/stream' |
| 9 | + |
| 10 | +module Async |
| 11 | + module Redis |
| 12 | + class ClusterClient |
| 13 | + class ReloadError < StandardError |
| 14 | + end |
| 15 | + |
| 16 | + Node = Struct.new(:id, :endpoint, :role, :health, :client) |
| 17 | + |
| 18 | + class RangeMap |
| 19 | + def initialize |
| 20 | + @ranges = [] |
| 21 | + end |
| 22 | + |
| 23 | + def add(range, value) |
| 24 | + @ranges << [range, value] |
| 25 | + |
| 26 | + return value |
| 27 | + end |
| 28 | + |
| 29 | + def find(key) |
| 30 | + @ranges.each do |range, value| |
| 31 | + return value if range.include?(key) |
| 32 | + end |
| 33 | + |
| 34 | + if block_given? |
| 35 | + return yield |
| 36 | + end |
| 37 | + |
| 38 | + return nil |
| 39 | + end |
| 40 | + |
| 41 | + def each |
| 42 | + @ranges.each do |range, value| |
| 43 | + yield value |
| 44 | + end |
| 45 | + end |
| 46 | + |
| 47 | + def clear |
| 48 | + @ranges.clear |
| 49 | + end |
| 50 | + end |
| 51 | + |
| 52 | + # Create a new instance of the cluster client. |
| 53 | + # |
| 54 | + # @property endpoints [Array(Endpoint)] The list of cluster endpoints. |
| 55 | + def initialize(endpoints, **options) |
| 56 | + @endpoints = endpoints |
| 57 | + @shards = nil |
| 58 | + end |
| 59 | + |
| 60 | + def clients_for(*keys, attempts: 3) |
| 61 | + slots = slots_for(keys) |
| 62 | + |
| 63 | + slots.map do |slot, keys| |
| 64 | + yield client_for(slot), keys |
| 65 | + end |
| 66 | + rescue ServerError => error |
| 67 | + if error.message =~ /MOVED|ASK/ |
| 68 | + reload_cluster! |
| 69 | + |
| 70 | + attempts -= 1 |
| 71 | + |
| 72 | + retry if attempts > 0 |
| 73 | + else |
| 74 | + raise |
| 75 | + end |
| 76 | + end |
| 77 | + |
| 78 | + def client_for(slot, role = :master) |
| 79 | + unless @nodes |
| 80 | + reload_cluster! |
| 81 | + end |
| 82 | + |
| 83 | + nodes = @shards.find(slot) |
| 84 | + |
| 85 | + nodes = nodes.select{|node| node.role == role} |
| 86 | + |
| 87 | + if node = nodes.sample |
| 88 | + node.client ||= Client.new(node.endpoint) |
| 89 | + end |
| 90 | + end |
| 91 | + |
| 92 | + protected |
| 93 | + |
| 94 | + def reload_cluster!(endpoints = @endpoints) |
| 95 | + @endpoints.each do |endpoint| |
| 96 | + client = Client.new(endpoint) |
| 97 | + |
| 98 | + shards = RangeMap.new |
| 99 | + endpoints = [] |
| 100 | + |
| 101 | + client.call('CLUSTER', 'SHARDS').each do |shard| |
| 102 | + shard = shard.each_slice(2).to_h |
| 103 | + |
| 104 | + slots = shard['slots'] |
| 105 | + range = Range.new(*slots, exclude_end: false) |
| 106 | + |
| 107 | + nodes = shard['nodes'].map do |node| |
| 108 | + node = node.each_slice(2).to_h |
| 109 | + endpoint = Endpoint.remote(node['ip'], node['port']) |
| 110 | + |
| 111 | + # Collect all endpoints: |
| 112 | + endpoints << endpoint |
| 113 | + |
| 114 | + Node.new(node['id'], endpoint, node['role'].to_sym, node['health'].to_sym) |
| 115 | + end |
| 116 | + |
| 117 | + shards.add(range, nodes) |
| 118 | + end |
| 119 | + |
| 120 | + @shards = shards |
| 121 | + # @endpoints = @endpoints | endpoints |
| 122 | + |
| 123 | + return true |
| 124 | + rescue Errno::ECONNREFUSED |
| 125 | + next |
| 126 | + end |
| 127 | + |
| 128 | + raise ReloadError, "Failed to reload cluster configuration." |
| 129 | + end |
| 130 | + |
| 131 | + XMODEM_CRC16_LOOKUP = [ |
| 132 | + 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, |
| 133 | + 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef, |
| 134 | + 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6, |
| 135 | + 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de, |
| 136 | + 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485, |
| 137 | + 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d, |
| 138 | + 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4, |
| 139 | + 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc, |
| 140 | + 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823, |
| 141 | + 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b, |
| 142 | + 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12, |
| 143 | + 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a, |
| 144 | + 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41, |
| 145 | + 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49, |
| 146 | + 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70, |
| 147 | + 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78, |
| 148 | + 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f, |
| 149 | + 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067, |
| 150 | + 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e, |
| 151 | + 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256, |
| 152 | + 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d, |
| 153 | + 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405, |
| 154 | + 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c, |
| 155 | + 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634, |
| 156 | + 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab, |
| 157 | + 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3, |
| 158 | + 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a, |
| 159 | + 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92, |
| 160 | + 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9, |
| 161 | + 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1, |
| 162 | + 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8, |
| 163 | + 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0 |
| 164 | + ].freeze |
| 165 | + |
| 166 | + # This is the CRC16 algorithm used by Redis Cluster to hash keys. |
| 167 | + # Copied from https://github.com/antirez/redis-rb-cluster/blob/master/crc16.rb |
| 168 | + def crc16(bytes) |
| 169 | + crc = 0 |
| 170 | + |
| 171 | + bytes.each_byte do |b| |
| 172 | + crc = ((crc << 8) & 0xffff) ^ XMODEM_CRC16_LOOKUP[((crc >> 8) ^ b) & 0xff] |
| 173 | + end |
| 174 | + |
| 175 | + return crc |
| 176 | + end |
| 177 | + |
| 178 | + HASH_SLOTS = 16_384 |
| 179 | + |
| 180 | + # Return Redis::Client for a given key. |
| 181 | + # Modified from https://github.com/antirez/redis-rb-cluster/blob/master/cluster.rb#L104-L117 |
| 182 | + def slot_for(key) |
| 183 | + key = key.to_s |
| 184 | + |
| 185 | + if s = key.index('{') |
| 186 | + if e = key.index('}', s + 1) and e != s + 1 |
| 187 | + key = key[s + 1..e - 1] |
| 188 | + end |
| 189 | + end |
| 190 | + |
| 191 | + return crc16(key) % HASH_SLOTS |
| 192 | + end |
| 193 | + |
| 194 | + def slots_for(keys) |
| 195 | + slots = Hash.new{|hash, key| hash[key] = []} |
| 196 | + |
| 197 | + keys.each do |key| |
| 198 | + slots[slot_for(key)] << key |
| 199 | + end |
| 200 | + |
| 201 | + return slots |
| 202 | + end |
| 203 | + end |
| 204 | + end |
| 205 | +end |
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