"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Scope = exports.WeakLifetime = exports.StaticLifetime = exports.Lifetime = void 0;
const asyncify_helpers_1 = require("./asyncify-helpers");
const debug_1 = require("./debug");
const errors_1 = require("./errors");
/**
* A lifetime prevents access to a value after the lifetime has been
* [[dispose]]ed.
*
* Typically, quickjs-emscripten uses Lifetimes to protect C memory pointers.
*/
class Lifetime {
/**
* When the Lifetime is disposed, it will call `disposer(_value)`. Use the
* disposer function to implement whatever cleanup needs to happen at the end
* of `value`'s lifetime.
*
* `_owner` is not used or controlled by the lifetime. It's just metadata for
* the creator.
*/
constructor(_value, copier, disposer, _owner) {
this._value = _value;
this.copier = copier;
this.disposer = disposer;
this._owner = _owner;
this._alive = true;
this._constructorStack = debug_1.QTS_DEBUG ? new Error("Lifetime constructed").stack : undefined;
}
get alive() {
return this._alive;
}
/**
* The value this Lifetime protects. You must never retain the value - it
* may become invalid, leading to memory errors.
*
* @throws If the lifetime has been [[dispose]]d already.
*/
get value() {
this.assertAlive();
return this._value;
}
get owner() {
return this._owner;
}
get dupable() {
return !!this.copier;
}
/**
* Create a new handle pointing to the same [[value]].
*/
dup() {
this.assertAlive();
if (!this.copier) {
throw new Error("Non-dupable lifetime");
}
return new Lifetime(this.copier(this._value), this.copier, this.disposer, this._owner);
}
consume(map) {
this.assertAlive();
const result = map(this);
this.dispose();
return result;
}
/**
* Dispose of [[value]] and perform cleanup.
*/
dispose() {
this.assertAlive();
if (this.disposer) {
this.disposer(this._value);
}
this._alive = false;
}
assertAlive() {
if (!this.alive) {
if (this._constructorStack) {
throw new errors_1.QuickJSUseAfterFree(`Lifetime not alive\n${this._constructorStack}\nLifetime used`);
}
throw new errors_1.QuickJSUseAfterFree("Lifetime not alive");
}
}
}
exports.Lifetime = Lifetime;
/**
* A Lifetime that lives forever. Used for constants.
*/
class StaticLifetime extends Lifetime {
constructor(value, owner) {
super(value, undefined, undefined, owner);
}
// Static lifetime doesn't need a copier to be copiable
get dupable() {
return true;
}
// Copy returns the same instance.
dup() {
return this;
}
// Dispose does nothing.
dispose() { }
}
exports.StaticLifetime = StaticLifetime;
/**
* A Lifetime that does not own its `value`. A WeakLifetime never calls its
* `disposer` function, but can be `dup`ed to produce regular lifetimes that
* do.
*
* Used for function arguments.
*/
class WeakLifetime extends Lifetime {
constructor(value, copier, disposer, owner) {
// We don't care if the disposer doesn't support freeing T
super(value, copier, disposer, owner);
}
dispose() {
this._alive = false;
}
}
exports.WeakLifetime = WeakLifetime;
function scopeFinally(scope, blockError) {
// console.log('scopeFinally', scope, blockError)
let disposeError;
try {
scope.dispose();
}
catch (error) {
disposeError = error;
}
if (blockError && disposeError) {
Object.assign(blockError, {
message: `${blockError.message}\n Then, failed to dispose scope: ${disposeError.message}`,
disposeError,
});
throw blockError;
}
if (blockError || disposeError) {
throw blockError || disposeError;
}
}
/**
* Scope helps reduce the burden of manually tracking and disposing of
* Lifetimes. See [[withScope]]. and [[withScopeAsync]].
*/
class Scope {
constructor() {
this._disposables = new Lifetime(new Set());
}
/**
* Run `block` with a new Scope instance that will be disposed after the block returns.
* Inside `block`, call `scope.manage` on each lifetime you create to have the lifetime
* automatically disposed after the block returns.
*
* @warning Do not use with async functions. Instead, use [[withScopeAsync]].
*/
static withScope(block) {
const scope = new Scope();
let blockError;
try {
return block(scope);
}
catch (error) {
blockError = error;
throw error;
}
finally {
scopeFinally(scope, blockError);
}
}
static withScopeMaybeAsync(_this, block) {
return (0, asyncify_helpers_1.maybeAsync)(undefined, function* (awaited) {
const scope = new Scope();
let blockError;
try {
return yield* awaited.of(block.call(_this, awaited, scope));
}
catch (error) {
blockError = error;
throw error;
}
finally {
scopeFinally(scope, blockError);
}
});
}
/**
* Run `block` with a new Scope instance that will be disposed after the
* block's returned promise settles. Inside `block`, call `scope.manage` on each
* lifetime you create to have the lifetime automatically disposed after the
* block returns.
*/
static async withScopeAsync(block) {
const scope = new Scope();
let blockError;
try {
return await block(scope);
}
catch (error) {
blockError = error;
throw error;
}
finally {
scopeFinally(scope, blockError);
}
}
/**
* Track `lifetime` so that it is disposed when this scope is disposed.
*/
manage(lifetime) {
this._disposables.value.add(lifetime);
return lifetime;
}
get alive() {
return this._disposables.alive;
}
dispose() {
const lifetimes = Array.from(this._disposables.value.values()).reverse();
for (const lifetime of lifetimes) {
if (lifetime.alive) {
lifetime.dispose();
}
}
this._disposables.dispose();
}
}
exports.Scope = Scope;
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