1 files changed, 420 insertions, 0 deletions
diff --git a/ext/node/polyfills/internal/async_hooks.ts b/ext/node/polyfills/internal/async_hooks.ts
new file mode 100644
index 000000000..8bf513e46
--- /dev/null
+++ b/ext/node/polyfills/internal/async_hooks.ts
@@ -0,0 +1,420 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// Copyright Joyent and Node contributors. All rights reserved. MIT license.
+
+// deno-lint-ignore camelcase
+import * as async_wrap from "internal:deno_node/polyfills/internal_binding/async_wrap.ts";
+import { ERR_ASYNC_CALLBACK } from "internal:deno_node/polyfills/internal/errors.ts";
+export {
+  asyncIdSymbol,
+  ownerSymbol,
+} from "internal:deno_node/polyfills/internal_binding/symbols.ts";
+
+interface ActiveHooks {
+  array: AsyncHook[];
+  // deno-lint-ignore camelcase
+  call_depth: number;
+  // deno-lint-ignore camelcase
+  tmp_array: AsyncHook[] | null;
+  // deno-lint-ignore camelcase
+  tmp_fields: number[] | null;
+}
+
+// Properties in active_hooks are used to keep track of the set of hooks being
+// executed in case another hook is enabled/disabled. The new set of hooks is
+// then restored once the active set of hooks is finished executing.
+// deno-lint-ignore camelcase
+const active_hooks: ActiveHooks = {
+  // Array of all AsyncHooks that will be iterated whenever an async event
+  // fires. Using var instead of (preferably const) in order to assign
+  // active_hooks.tmp_array if a hook is enabled/disabled during hook
+  // execution.
+  array: [],
+  // Use a counter to track nested calls of async hook callbacks and make sure
+  // the active_hooks.array isn't altered mid execution.
+  // deno-lint-ignore camelcase
+  call_depth: 0,
+  // Use to temporarily store and updated active_hooks.array if the user
+  // enables or disables a hook while hooks are being processed. If a hook is
+  // enabled() or disabled() during hook execution then the current set of
+  // active hooks is duplicated and set equal to active_hooks.tmp_array. Any
+  // subsequent changes are on the duplicated array. When all hooks have
+  // completed executing active_hooks.tmp_array is assigned to
+  // active_hooks.array.
+  // deno-lint-ignore camelcase
+  tmp_array: null,
+  // Keep track of the field counts held in active_hooks.tmp_array. Because the
+  // async_hook_fields can't be reassigned, store each uint32 in an array that
+  // is written back to async_hook_fields when active_hooks.array is restored.
+  // deno-lint-ignore camelcase
+  tmp_fields: null,
+};
+
+export const registerDestroyHook = async_wrap.registerDestroyHook;
+const {
+  // deno-lint-ignore camelcase
+  async_hook_fields,
+  // deno-lint-ignore camelcase
+  asyncIdFields: async_id_fields,
+  newAsyncId,
+  constants,
+} = async_wrap;
+export { newAsyncId };
+const {
+  kInit,
+  kBefore,
+  kAfter,
+  kDestroy,
+  kPromiseResolve,
+  kTotals,
+  kCheck,
+  kDefaultTriggerAsyncId,
+  kStackLength,
+} = constants;
+
+// deno-lint-ignore camelcase
+const resource_symbol = Symbol("resource");
+// deno-lint-ignore camelcase
+export const async_id_symbol = Symbol("trigger_async_id");
+// deno-lint-ignore camelcase
+export const trigger_async_id_symbol = Symbol("trigger_async_id");
+// deno-lint-ignore camelcase
+export const init_symbol = Symbol("init");
+// deno-lint-ignore camelcase
+export const before_symbol = Symbol("before");
+// deno-lint-ignore camelcase
+export const after_symbol = Symbol("after");
+// deno-lint-ignore camelcase
+export const destroy_symbol = Symbol("destroy");
+// deno-lint-ignore camelcase
+export const promise_resolve_symbol = Symbol("promiseResolve");
+
+export const symbols = {
+  // deno-lint-ignore camelcase
+  async_id_symbol,
+  // deno-lint-ignore camelcase
+  trigger_async_id_symbol,
+  // deno-lint-ignore camelcase
+  init_symbol,
+  // deno-lint-ignore camelcase
+  before_symbol,
+  // deno-lint-ignore camelcase
+  after_symbol,
+  // deno-lint-ignore camelcase
+  destroy_symbol,
+  // deno-lint-ignore camelcase
+  promise_resolve_symbol,
+};
+
+// deno-lint-ignore no-explicit-any
+function lookupPublicResource(resource: any) {
+  if (typeof resource !== "object" || resource === null) return resource;
+  // TODO(addaleax): Merge this with owner_symbol and use it across all
+  // AsyncWrap instances.
+  const publicResource = resource[resource_symbol];
+  if (publicResource !== undefined) {
+    return publicResource;
+  }
+  return resource;
+}
+
+// Used by C++ to call all init() callbacks. Because some state can be setup
+// from C++ there's no need to perform all the same operations as in
+// emitInitScript.
+function emitInitNative(
+  asyncId: number,
+  // deno-lint-ignore no-explicit-any
+  type: any,
+  triggerAsyncId: number,
+  // deno-lint-ignore no-explicit-any
+  resource: any,
+) {
+  active_hooks.call_depth += 1;
+  resource = lookupPublicResource(resource);
+  // Use a single try/catch for all hooks to avoid setting up one per iteration.
+  try {
+    for (let i = 0; i < active_hooks.array.length; i++) {
+      if (typeof active_hooks.array[i][init_symbol] === "function") {
+        active_hooks.array[i][init_symbol](
+          asyncId,
+          type,
+          triggerAsyncId,
+          resource,
+        );
+      }
+    }
+  } catch (e) {
+    throw e;
+  } finally {
+    active_hooks.call_depth -= 1;
+  }
+
+  // Hooks can only be restored if there have been no recursive hook calls.
+  // Also the active hooks do not need to be restored if enable()/disable()
+  // weren't called during hook execution, in which case active_hooks.tmp_array
+  // will be null.
+  if (active_hooks.call_depth === 0 && active_hooks.tmp_array !== null) {
+    restoreActiveHooks();
+  }
+}
+
+function getHookArrays(): [AsyncHook[], number[] | Uint32Array] {
+  if (active_hooks.call_depth === 0) {
+    return [active_hooks.array, async_hook_fields];
+  }
+  // If this hook is being enabled while in the middle of processing the array
+  // of currently active hooks then duplicate the current set of active hooks
+  // and store this there. This shouldn't fire until the next time hooks are
+  // processed.
+  if (active_hooks.tmp_array === null) {
+    storeActiveHooks();
+  }
+  return [active_hooks.tmp_array!, active_hooks.tmp_fields!];
+}
+
+function storeActiveHooks() {
+  active_hooks.tmp_array = active_hooks.array.slice();
+  // Don't want to make the assumption that kInit to kDestroy are indexes 0 to
+  // 4. So do this the long way.
+  active_hooks.tmp_fields = [];
+  copyHooks(active_hooks.tmp_fields, async_hook_fields);
+}
+
+function copyHooks(
+  destination: number[] | Uint32Array,
+  source: number[] | Uint32Array,
+) {
+  destination[kInit] = source[kInit];
+  destination[kBefore] = source[kBefore];
+  destination[kAfter] = source[kAfter];
+  destination[kDestroy] = source[kDestroy];
+  destination[kPromiseResolve] = source[kPromiseResolve];
+}
+
+// Then restore the correct hooks array in case any hooks were added/removed
+// during hook callback execution.
+function restoreActiveHooks() {
+  active_hooks.array = active_hooks.tmp_array!;
+  copyHooks(async_hook_fields, active_hooks.tmp_fields!);
+
+  active_hooks.tmp_array = null;
+  active_hooks.tmp_fields = null;
+}
+
+// deno-lint-ignore no-unused-vars
+let wantPromiseHook = false;
+function enableHooks() {
+  async_hook_fields[kCheck] += 1;
+
+  // TODO(kt3k): Uncomment this
+  // setCallbackTrampoline(callbackTrampoline);
+}
+
+function disableHooks() {
+  async_hook_fields[kCheck] -= 1;
+
+  wantPromiseHook = false;
+
+  // TODO(kt3k): Uncomment the below
+  // setCallbackTrampoline();
+
+  // Delay the call to `disablePromiseHook()` because we might currently be
+  // between the `before` and `after` calls of a Promise.
+  // TODO(kt3k): Uncomment the below
+  // enqueueMicrotask(disablePromiseHookIfNecessary);
+}
+
+// Return the triggerAsyncId meant for the constructor calling it. It's up to
+// the user to safeguard this call and make sure it's zero'd out when the
+// constructor is complete.
+export function getDefaultTriggerAsyncId() {
+  const defaultTriggerAsyncId =
+    async_id_fields[async_wrap.UidFields.kDefaultTriggerAsyncId];
+  // If defaultTriggerAsyncId isn't set, use the executionAsyncId
+  if (defaultTriggerAsyncId < 0) {
+    return async_id_fields[async_wrap.UidFields.kExecutionAsyncId];
+  }
+  return defaultTriggerAsyncId;
+}
+
+export function defaultTriggerAsyncIdScope(
+  triggerAsyncId: number | undefined,
+  // deno-lint-ignore no-explicit-any
+  block: (...arg: any[]) => void,
+  ...args: unknown[]
+) {
+  if (triggerAsyncId === undefined) {
+    return block.apply(null, args);
+  }
+  // CHECK(NumberIsSafeInteger(triggerAsyncId))
+  // CHECK(triggerAsyncId > 0)
+  const oldDefaultTriggerAsyncId = async_id_fields[kDefaultTriggerAsyncId];
+  async_id_fields[kDefaultTriggerAsyncId] = triggerAsyncId;
+
+  try {
+    return block.apply(null, args);
+  } finally {
+    async_id_fields[kDefaultTriggerAsyncId] = oldDefaultTriggerAsyncId;
+  }
+}
+
+function hasHooks(key: number) {
+  return async_hook_fields[key] > 0;
+}
+
+export function enabledHooksExist() {
+  return hasHooks(kCheck);
+}
+
+export function initHooksExist() {
+  return hasHooks(kInit);
+}
+
+export function afterHooksExist() {
+  return hasHooks(kAfter);
+}
+
+export function destroyHooksExist() {
+  return hasHooks(kDestroy);
+}
+
+export function promiseResolveHooksExist() {
+  return hasHooks(kPromiseResolve);
+}
+
+function emitInitScript(
+  asyncId: number,
+  // deno-lint-ignore no-explicit-any
+  type: any,
+  triggerAsyncId: number,
+  // deno-lint-ignore no-explicit-any
+  resource: any,
+) {
+  // Short circuit all checks for the common case. Which is that no hooks have
+  // been set. Do this to remove performance impact for embedders (and core).
+  if (!hasHooks(kInit)) {
+    return;
+  }
+
+  if (triggerAsyncId === null) {
+    triggerAsyncId = getDefaultTriggerAsyncId();
+  }
+
+  emitInitNative(asyncId, type, triggerAsyncId, resource);
+}
+export { emitInitScript as emitInit };
+
+export function hasAsyncIdStack() {
+  return hasHooks(kStackLength);
+}
+
+export { constants };
+
+type Fn = (...args: unknown[]) => unknown;
+
+export class AsyncHook {
+  [init_symbol]: Fn;
+  [before_symbol]: Fn;
+  [after_symbol]: Fn;
+  [destroy_symbol]: Fn;
+  [promise_resolve_symbol]: Fn;
+
+  constructor({
+    init,
+    before,
+    after,
+    destroy,
+    promiseResolve,
+  }: {
+    init: Fn;
+    before: Fn;
+    after: Fn;
+    destroy: Fn;
+    promiseResolve: Fn;
+  }) {
+    if (init !== undefined && typeof init !== "function") {
+      throw new ERR_ASYNC_CALLBACK("hook.init");
+    }
+    if (before !== undefined && typeof before !== "function") {
+      throw new ERR_ASYNC_CALLBACK("hook.before");
+    }
+    if (after !== undefined && typeof after !== "function") {
+      throw new ERR_ASYNC_CALLBACK("hook.after");
+    }
+    if (destroy !== undefined && typeof destroy !== "function") {
+      throw new ERR_ASYNC_CALLBACK("hook.destroy");
+    }
+    if (promiseResolve !== undefined && typeof promiseResolve !== "function") {
+      throw new ERR_ASYNC_CALLBACK("hook.promiseResolve");
+    }
+
+    this[init_symbol] = init;
+    this[before_symbol] = before;
+    this[after_symbol] = after;
+    this[destroy_symbol] = destroy;
+    this[promise_resolve_symbol] = promiseResolve;
+  }
+
+  enable() {
+    // The set of callbacks for a hook should be the same regardless of whether
+    // enable()/disable() are run during their execution. The following
+    // references are reassigned to the tmp arrays if a hook is currently being
+    // processed.
+    // deno-lint-ignore camelcase
+    const { 0: hooks_array, 1: hook_fields } = getHookArrays();
+
+    // Each hook is only allowed to be added once.
+    if (hooks_array.includes(this)) {
+      return this;
+    }
+
+    // deno-lint-ignore camelcase
+    const prev_kTotals = hook_fields[kTotals];
+
+    // createHook() has already enforced that the callbacks are all functions,
+    // so here simply increment the count of whether each callbacks exists or
+    // not.
+    hook_fields[kTotals] = hook_fields[kInit] += +!!this[init_symbol];
+    hook_fields[kTotals] += hook_fields[kBefore] += +!!this[before_symbol];
+    hook_fields[kTotals] += hook_fields[kAfter] += +!!this[after_symbol];
+    hook_fields[kTotals] += hook_fields[kDestroy] += +!!this[destroy_symbol];
+    hook_fields[kTotals] += hook_fields[kPromiseResolve] +=
+      +!!this[promise_resolve_symbol];
+    hooks_array.push(this);
+
+    if (prev_kTotals === 0 && hook_fields[kTotals] > 0) {
+      enableHooks();
+    }
+
+    // TODO(kt3k): Uncomment the below
+    // updatePromiseHookMode();
+
+    return this;
+  }
+
+  disable() {
+    // deno-lint-ignore camelcase
+    const { 0: hooks_array, 1: hook_fields } = getHookArrays();
+
+    const index = hooks_array.indexOf(this);
+    if (index === -1) {
+      return this;
+    }
+
+    // deno-lint-ignore camelcase
+    const prev_kTotals = hook_fields[kTotals];
+
+    hook_fields[kTotals] = hook_fields[kInit] -= +!!this[init_symbol];
+    hook_fields[kTotals] += hook_fields[kBefore] -= +!!this[before_symbol];
+    hook_fields[kTotals] += hook_fields[kAfter] -= +!!this[after_symbol];
+    hook_fields[kTotals] += hook_fields[kDestroy] -= +!!this[destroy_symbol];
+    hook_fields[kTotals] += hook_fields[kPromiseResolve] -=
+      +!!this[promise_resolve_symbol];
+    hooks_array.splice(index, 1);
+
+    if (prev_kTotals > 0 && hook_fields[kTotals] === 0) {
+      disableHooks();
+    }
+
+    return this;
+  }
+}