| 1 | import { Context } from '@deepseek-ai/cordis' |
| 2 | import type { Dict } from '@deepseek-ai/cosmokit' |
| 3 | import { Entry } from './entry.ts' |
| 4 | |
| 5 | // Codewhale type-only delta: these dynamically allocated symbol slots hold delimiters. |
| 6 | type DelimitedContext = Context & Record<symbol, symbol> |
| 7 | |
| 8 | declare module './entry.ts' { |
| 9 | interface EntryOptions { |
| 10 | intercept?: Dict | null |
| 11 | isolate?: Dict<true | string> | null |
| 12 | } |
| 13 | |
| 14 | interface Entry { |
| 15 | realm: LocalRealm |
| 16 | } |
| 17 | } |
| 18 | |
| 19 | function swap<T extends {}>(target: T, source?: T | null) { |
| 20 | for (const key of Reflect.ownKeys(target)) { |
| 21 | Reflect.deleteProperty(target, key) |
| 22 | } |
| 23 | for (const key of Reflect.ownKeys(source || {})) { |
| 24 | Reflect.defineProperty(target, key, Reflect.getOwnPropertyDescriptor(source!, key)!) |
| 25 | } |
| 26 | } |
| 27 | |
| 28 | /** Symbol realm used to isolate service implementations by entry or label. */ |
| 29 | export abstract class Realm { |
| 30 | protected store: Dict<symbol> = Object.create(null) |
| 31 | |
| 32 | abstract get suffix(): string |
| 33 | |
| 34 | access(key: string, create = false) { |
| 35 | if (create) { |
| 36 | return this.store[key] ??= Symbol(`${key}${this.suffix}`) |
| 37 | } else { |
| 38 | return this.store[key] ?? Symbol(`${key}${this.suffix}`) |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | delete(key: string) { |
| 43 | delete this.store[key] |
| 44 | } |
| 45 | |
| 46 | get size() { |
| 47 | return Object.keys(this.store).length |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | /** Entry-local isolation realm. */ |
| 52 | export class LocalRealm extends Realm { |
| 53 | constructor(private entry: Entry) { |
| 54 | super() |
| 55 | } |
| 56 | |
| 57 | get suffix() { |
| 58 | return '#' + this.entry.options.id |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | /** Named isolation realm shared by entries that use the same label. */ |
| 63 | export class GlobalRealm extends Realm { |
| 64 | constructor(public label: string) { |
| 65 | super() |
| 66 | } |
| 67 | |
| 68 | get suffix() { |
| 69 | return '@' + this.label |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | /** Install loader hooks that apply `intercept` and `isolate` entry options. */ |
| 74 | export default function isolate(ctx: Context) { |
| 75 | const realms: Dict<GlobalRealm> = Object.create(null) |
| 76 | const delims: Dict<symbol> = Object.create(null) |
| 77 | |
| 78 | function access(entry: Entry, name: string, create: true): symbol |
| 79 | function access(entry: Entry, name: string, create?: boolean): symbol | undefined |
| 80 | function access(entry: Entry, name: string, create = false) { |
| 81 | let realm: Realm | undefined |
| 82 | const label = entry.options.isolate?.[name] |
| 83 | if (!label) return |
| 84 | if (label === true) { |
| 85 | realm = entry.realm ??= new LocalRealm(entry) |
| 86 | } else if (create) { |
| 87 | realm = realms[label] ??= new GlobalRealm(label) |
| 88 | } else { |
| 89 | realm = realms[label] |
| 90 | } |
| 91 | return realm?.access(name, create) |
| 92 | } |
| 93 | |
| 94 | ctx.on('loader/entry-init', (entry) => { |
| 95 | entry.ctx[Context.intercept] = Object.create(entry.ctx[Context.intercept]) |
| 96 | entry.ctx[Context.isolate] = Object.create(entry.ctx[Context.isolate]) |
| 97 | }) |
| 98 | |
| 99 | ctx.on('loader/patch-context', (entry, next) => { |
| 100 | // step 1: generate new isolate map |
| 101 | const newMap: Dict<symbol> = Object.create(entry.parent.ctx[Context.isolate]) |
| 102 | for (const name of Object.keys(entry.options.isolate ?? {})) { |
| 103 | newMap[name] = access(entry, name, true) |
| 104 | } |
| 105 | |
| 106 | // step 2: generate service diff |
| 107 | const diff: Dict<[symbol, symbol, symbol, symbol]> = Object.create(null) |
| 108 | const oldMap = entry.ctx[Context.isolate] |
| 109 | for (const name in { ...newMap, ...delims }) { |
| 110 | if (newMap[name] === oldMap[name]) continue |
| 111 | const delim = delims[name] ??= Symbol(`delim:${name}`) |
| 112 | ;(entry.ctx as DelimitedContext)[delim] = Symbol(`${name}#${entry.id}`) |
| 113 | for (const symbol of [oldMap[name], newMap[name]]) { |
| 114 | const impl = symbol && entry.ctx.reflect.store[symbol] |
| 115 | if (!impl) continue |
| 116 | if (!impl.fiber) { |
| 117 | entry.ctx.logger.warn(new Error(`expected service ${name} to be implemented`)) |
| 118 | continue |
| 119 | } |
| 120 | diff[name] = [oldMap[name], newMap[name], (entry.ctx as DelimitedContext)[delim], (impl.fiber.ctx as DelimitedContext)[delim]] |
| 121 | if ((entry.ctx as DelimitedContext)[delim] !== (impl.fiber.ctx as DelimitedContext)[delim]) break |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | // step 3: set prototype for transferred context |
| 126 | Object.setPrototypeOf(entry.ctx[Context.isolate], entry.parent.ctx[Context.isolate]) |
| 127 | Object.setPrototypeOf(entry.ctx[Context.intercept], entry.parent.ctx[Context.intercept]) |
| 128 | swap(entry.ctx[Context.isolate], newMap) |
| 129 | swap(entry.ctx[Context.intercept], entry.options.intercept) |
| 130 | |
| 131 | // step 4: reload fiber |
| 132 | next() |
| 133 | |
| 134 | // step 5: replace service impl |
| 135 | for (const [symbol1, symbol2, flag1, flag2] of Object.values(diff)) { |
| 136 | if (flag1 === flag2 && entry.ctx.reflect.store[symbol1] && !entry.ctx.reflect.store[symbol2]) { |
| 137 | entry.ctx.reflect.store[symbol2] = entry.ctx.reflect.store[symbol1] |
| 138 | delete entry.ctx.reflect.store[symbol1] |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | // step 6: reflect notify |
| 143 | ctx.reflect.notify(Object.keys(diff), (ctx, name) => { |
| 144 | const [symbol1, symbol2, flag1, flag2] = diff[name] |
| 145 | const symbol3 = ctx[Context.isolate][name] |
| 146 | const flag3 = (ctx as DelimitedContext)[delims[name]] |
| 147 | return (symbol1 === symbol3 || symbol2 === symbol3) && (flag1 === flag3) !== (flag1 === flag2) |
| 148 | }) |
| 149 | |
| 150 | // step 7: clean up delimiters |
| 151 | for (const name in delims) { |
| 152 | if (!Reflect.ownKeys(newMap).includes(name)) { |
| 153 | delete (entry.ctx as DelimitedContext)[delims[name]] |
| 154 | } |
| 155 | } |
| 156 | }) |
| 157 | |
| 158 | ctx.on('loader/partial-dispose', (entry, legacy, active) => { |
| 159 | for (const [name, label] of Object.entries(legacy.isolate ?? {})) { |
| 160 | if (label === true) continue |
| 161 | if (active && entry.options.isolate?.[name] === label) continue |
| 162 | const realm = realms[label] |
| 163 | if (!realm) continue |
| 164 | |
| 165 | // realm garbage collection |
| 166 | for (const entry of ctx.loader.entries()) { |
| 167 | // has reference to this realm |
| 168 | if (entry.options.isolate?.[name] === realm.label) return |
| 169 | } |
| 170 | realm.delete(name) |
| 171 | if (!realm.size) { |
| 172 | delete realms[realm.label] |
| 173 | } |
| 174 | } |
| 175 | }) |
| 176 | } |
| 177 |