| 1 | import fs from 'node:fs'; |
| 2 | |
| 3 | import type { ChargingStation } from './ChargingStation'; |
| 4 | import { ChargingStationUtils } from './ChargingStationUtils'; |
| 5 | import { FileType, IdTagDistribution } from '../types'; |
| 6 | import { Utils, handleFileException, logger, watchJsonFile } from '../utils'; |
| 7 | |
| 8 | type IdTagsCacheValueType = { |
| 9 | idTags: string[]; |
| 10 | idTagsFileWatcher: fs.FSWatcher | undefined; |
| 11 | }; |
| 12 | |
| 13 | export class IdTagsCache { |
| 14 | private static instance: IdTagsCache | null = null; |
| 15 | private readonly idTagsCaches: Map<string, IdTagsCacheValueType>; |
| 16 | private readonly idTagsCachesAddressableIndexes: Map<string, number>; |
| 17 | |
| 18 | private constructor() { |
| 19 | this.idTagsCaches = new Map<string, IdTagsCacheValueType>(); |
| 20 | this.idTagsCachesAddressableIndexes = new Map<string, number>(); |
| 21 | } |
| 22 | |
| 23 | public static getInstance(): IdTagsCache { |
| 24 | if (IdTagsCache.instance === null) { |
| 25 | IdTagsCache.instance = new IdTagsCache(); |
| 26 | } |
| 27 | return IdTagsCache.instance; |
| 28 | } |
| 29 | |
| 30 | /** |
| 31 | * Get one idtag from the cache given the distribution |
| 32 | * Must be called after checking the cache is not an empty array |
| 33 | * |
| 34 | * @param distribution - |
| 35 | * @param chargingStation - |
| 36 | * @param connectorId - |
| 37 | * @returns |
| 38 | */ |
| 39 | public getIdTag( |
| 40 | distribution: IdTagDistribution, |
| 41 | chargingStation: ChargingStation, |
| 42 | connectorId: number |
| 43 | ): string { |
| 44 | const hashId = chargingStation.stationInfo.hashId; |
| 45 | const idTagsFile = ChargingStationUtils.getIdTagsFile(chargingStation.stationInfo); |
| 46 | switch (distribution) { |
| 47 | case IdTagDistribution.RANDOM: |
| 48 | return this.getRandomIdTag(hashId, idTagsFile); |
| 49 | case IdTagDistribution.ROUND_ROBIN: |
| 50 | return this.getRoundRobinIdTag(hashId, idTagsFile); |
| 51 | case IdTagDistribution.CONNECTOR_AFFINITY: |
| 52 | return this.getConnectorAffinityIdTag(chargingStation, connectorId); |
| 53 | default: |
| 54 | return this.getRoundRobinIdTag(hashId, idTagsFile); |
| 55 | } |
| 56 | } |
| 57 | |
| 58 | /** |
| 59 | * Get all idtags from the cache |
| 60 | * Must be called after checking the cache is not an empty array |
| 61 | * |
| 62 | * @param file - |
| 63 | * @returns |
| 64 | */ |
| 65 | public getIdTags(file: string): string[] | undefined { |
| 66 | if (this.hasIdTagsCache(file) === false) { |
| 67 | this.setIdTagsCache(file, this.getIdTagsFromFile(file)); |
| 68 | } |
| 69 | return this.getIdTagsCache(file); |
| 70 | } |
| 71 | |
| 72 | public deleteIdTags(file: string): boolean { |
| 73 | return this.deleteIdTagsCache(file); |
| 74 | } |
| 75 | |
| 76 | private getRandomIdTag(hashId: string, file: string): string { |
| 77 | const idTags = this.getIdTags(file); |
| 78 | const addressableKey = this.getIdTagsCacheIndexesAddressableKey(file, hashId); |
| 79 | this.idTagsCachesAddressableIndexes.set( |
| 80 | addressableKey, |
| 81 | Math.floor(Utils.secureRandom() * idTags.length) |
| 82 | ); |
| 83 | return idTags[this.idTagsCachesAddressableIndexes.get(addressableKey)]; |
| 84 | } |
| 85 | |
| 86 | private getRoundRobinIdTag(hashId: string, file: string): string { |
| 87 | const idTags = this.getIdTags(file); |
| 88 | const addressableKey = this.getIdTagsCacheIndexesAddressableKey(file, hashId); |
| 89 | const idTagIndex = this.idTagsCachesAddressableIndexes.get(addressableKey) ?? 0; |
| 90 | const idTag = idTags[idTagIndex]; |
| 91 | this.idTagsCachesAddressableIndexes.set( |
| 92 | addressableKey, |
| 93 | idTagIndex === idTags.length - 1 ? 0 : idTagIndex + 1 |
| 94 | ); |
| 95 | return idTag; |
| 96 | } |
| 97 | |
| 98 | private getConnectorAffinityIdTag(chargingStation: ChargingStation, connectorId: number): string { |
| 99 | const file = ChargingStationUtils.getIdTagsFile(chargingStation.stationInfo); |
| 100 | const idTags = this.getIdTags(file); |
| 101 | const addressableKey = this.getIdTagsCacheIndexesAddressableKey( |
| 102 | file, |
| 103 | chargingStation.stationInfo.hashId |
| 104 | ); |
| 105 | this.idTagsCachesAddressableIndexes.set( |
| 106 | addressableKey, |
| 107 | (chargingStation.index - 1 + (connectorId - 1)) % idTags.length |
| 108 | ); |
| 109 | return idTags[this.idTagsCachesAddressableIndexes.get(addressableKey)]; |
| 110 | } |
| 111 | |
| 112 | private hasIdTagsCache(file: string): boolean { |
| 113 | return this.idTagsCaches.has(file); |
| 114 | } |
| 115 | |
| 116 | private setIdTagsCache(file: string, idTags: string[]) { |
| 117 | return this.idTagsCaches.set(file, { |
| 118 | idTags, |
| 119 | idTagsFileWatcher: watchJsonFile( |
| 120 | file, |
| 121 | FileType.Authorization, |
| 122 | this.logPrefix(file), |
| 123 | undefined, |
| 124 | (event, filename) => { |
| 125 | if (Utils.isNotEmptyString(filename) && event === 'change') { |
| 126 | try { |
| 127 | logger.debug( |
| 128 | `${this.logPrefix(file)} ${FileType.Authorization} file have changed, reload` |
| 129 | ); |
| 130 | this.deleteIdTagsCache(file); |
| 131 | this.deleteIdTagsCacheIndexes(file); |
| 132 | } catch (error) { |
| 133 | handleFileException( |
| 134 | file, |
| 135 | FileType.Authorization, |
| 136 | error as NodeJS.ErrnoException, |
| 137 | this.logPrefix(file), |
| 138 | { |
| 139 | throwError: false, |
| 140 | } |
| 141 | ); |
| 142 | } |
| 143 | } |
| 144 | } |
| 145 | ), |
| 146 | }); |
| 147 | } |
| 148 | |
| 149 | private getIdTagsCache(file: string): string[] | undefined { |
| 150 | return this.idTagsCaches.get(file)?.idTags; |
| 151 | } |
| 152 | |
| 153 | private deleteIdTagsCache(file: string): boolean { |
| 154 | this.idTagsCaches.get(file)?.idTagsFileWatcher?.close(); |
| 155 | return this.idTagsCaches.delete(file); |
| 156 | } |
| 157 | |
| 158 | private deleteIdTagsCacheIndexes(file: string): void { |
| 159 | for (const [key] of this.idTagsCachesAddressableIndexes) { |
| 160 | if (key.startsWith(file)) { |
| 161 | this.idTagsCachesAddressableIndexes.delete(key); |
| 162 | } |
| 163 | } |
| 164 | } |
| 165 | |
| 166 | private getIdTagsCacheIndexesAddressableKey(prefix: string, uid: string): string { |
| 167 | return `${prefix}${uid}`; |
| 168 | } |
| 169 | |
| 170 | private getIdTagsFromFile(file: string): string[] { |
| 171 | if (Utils.isNotEmptyString(file)) { |
| 172 | try { |
| 173 | return JSON.parse(fs.readFileSync(file, 'utf8')) as string[]; |
| 174 | } catch (error) { |
| 175 | handleFileException( |
| 176 | file, |
| 177 | FileType.Authorization, |
| 178 | error as NodeJS.ErrnoException, |
| 179 | this.logPrefix(file) |
| 180 | ); |
| 181 | } |
| 182 | } |
| 183 | return []; |
| 184 | } |
| 185 | |
| 186 | private logPrefix = (file: string): string => { |
| 187 | return Utils.logPrefix(` Id tags cache for id tags file '${file}' |`); |
| 188 | }; |
| 189 | } |