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denoland-deno/core/01_core.js
2022-09-22 10:05:24 +05:30

335 lines
10 KiB
JavaScript

// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
"use strict";
((window) => {
const {
Error,
RangeError,
ReferenceError,
SyntaxError,
TypeError,
URIError,
Map,
Array,
ArrayPrototypeFill,
ArrayPrototypeMap,
ErrorCaptureStackTrace,
Promise,
ObjectFromEntries,
MapPrototypeGet,
MapPrototypeHas,
MapPrototypeDelete,
MapPrototypeSet,
PromisePrototypeThen,
PromisePrototypeFinally,
StringPrototypeSlice,
ObjectAssign,
SymbolFor,
setQueueMicrotask,
} = window.__bootstrap.primordials;
const ops = window.Deno.core.ops;
const errorMap = {};
// Builtin v8 / JS errors
registerErrorClass("Error", Error);
registerErrorClass("RangeError", RangeError);
registerErrorClass("ReferenceError", ReferenceError);
registerErrorClass("SyntaxError", SyntaxError);
registerErrorClass("TypeError", TypeError);
registerErrorClass("URIError", URIError);
let nextPromiseId = 1;
const promiseMap = new Map();
const RING_SIZE = 4 * 1024;
const NO_PROMISE = null; // Alias to null is faster than plain nulls
const promiseRing = ArrayPrototypeFill(new Array(RING_SIZE), NO_PROMISE);
// TODO(bartlomieju): it future use `v8::Private` so it's not visible
// to users. Currently missing bindings.
const promiseIdSymbol = SymbolFor("Deno.core.internalPromiseId");
let opCallTracingEnabled = false;
const opCallTraces = new Map();
function enableOpCallTracing() {
opCallTracingEnabled = true;
}
function isOpCallTracingEnabled() {
return opCallTracingEnabled;
}
function setPromise(promiseId) {
const idx = promiseId % RING_SIZE;
// Move old promise from ring to map
const oldPromise = promiseRing[idx];
if (oldPromise !== NO_PROMISE) {
const oldPromiseId = promiseId - RING_SIZE;
MapPrototypeSet(promiseMap, oldPromiseId, oldPromise);
}
// Set new promise
return promiseRing[idx] = newPromise();
}
function getPromise(promiseId) {
// Check if out of ring bounds, fallback to map
const outOfBounds = promiseId < nextPromiseId - RING_SIZE;
if (outOfBounds) {
const promise = MapPrototypeGet(promiseMap, promiseId);
MapPrototypeDelete(promiseMap, promiseId);
return promise;
}
// Otherwise take from ring
const idx = promiseId % RING_SIZE;
const promise = promiseRing[idx];
promiseRing[idx] = NO_PROMISE;
return promise;
}
function newPromise() {
let resolve, reject;
const promise = new Promise((resolve_, reject_) => {
resolve = resolve_;
reject = reject_;
});
promise.resolve = resolve;
promise.reject = reject;
return promise;
}
function hasPromise(promiseId) {
// Check if out of ring bounds, fallback to map
const outOfBounds = promiseId < nextPromiseId - RING_SIZE;
if (outOfBounds) {
return MapPrototypeHas(promiseMap, promiseId);
}
// Otherwise check it in ring
const idx = promiseId % RING_SIZE;
return promiseRing[idx] != NO_PROMISE;
}
function opresolve() {
for (let i = 0; i < arguments.length; i += 2) {
const promiseId = arguments[i];
const res = arguments[i + 1];
const promise = getPromise(promiseId);
promise.resolve(res);
}
}
function registerErrorClass(className, errorClass) {
registerErrorBuilder(className, (msg) => new errorClass(msg));
}
function registerErrorBuilder(className, errorBuilder) {
if (typeof errorMap[className] !== "undefined") {
throw new TypeError(`Error class for "${className}" already registered`);
}
errorMap[className] = errorBuilder;
}
function buildCustomError(className, message, code) {
const error = errorMap[className]?.(message);
// Strip buildCustomError() calls from stack trace
if (typeof error == "object") {
ErrorCaptureStackTrace(error, buildCustomError);
if (code) {
error.code = code;
}
}
return error;
}
function unwrapOpResult(res) {
// .$err_class_name is a special key that should only exist on errors
if (res?.$err_class_name) {
const className = res.$err_class_name;
const errorBuilder = errorMap[className];
const err = errorBuilder ? errorBuilder(res.message) : new Error(
`Unregistered error class: "${className}"\n ${res.message}\n Classes of errors returned from ops should be registered via Deno.core.registerErrorClass().`,
);
// Set .code if error was a known OS error, see error_codes.rs
if (res.code) {
err.code = res.code;
}
// Strip unwrapOpResult() and errorBuilder() calls from stack trace
ErrorCaptureStackTrace(err, unwrapOpResult);
throw err;
}
return res;
}
function opAsync(opName, ...args) {
const promiseId = nextPromiseId++;
let p = setPromise(promiseId);
try {
ops[opName](promiseId, ...args);
} catch (err) {
// Cleanup the just-created promise
getPromise(promiseId);
// Rethrow the error
throw err;
}
p = PromisePrototypeThen(p, unwrapOpResult);
if (opCallTracingEnabled) {
// Capture a stack trace by creating a new `Error` object. We remove the
// first 6 characters (the `Error\n` prefix) to get just the stack trace.
const stack = StringPrototypeSlice(new Error().stack, 6);
MapPrototypeSet(opCallTraces, promiseId, { opName, stack });
p = PromisePrototypeFinally(
p,
() => MapPrototypeDelete(opCallTraces, promiseId),
);
}
// Save the id on the promise so it can later be ref'ed or unref'ed
p[promiseIdSymbol] = promiseId;
return p;
}
function opSync(opName, ...args) {
return ops[opName](...args);
}
function refOp(promiseId) {
if (!hasPromise(promiseId)) {
return;
}
ops.op_ref_op(promiseId);
}
function unrefOp(promiseId) {
if (!hasPromise(promiseId)) {
return;
}
ops.op_unref_op(promiseId);
}
function resources() {
return ObjectFromEntries(ops.op_resources());
}
function metrics() {
const [aggregate, perOps] = ops.op_metrics();
aggregate.ops = ObjectFromEntries(ArrayPrototypeMap(
ops.op_op_names(),
(opName, opId) => [opName, perOps[opId]],
));
return aggregate;
}
let reportExceptionCallback = undefined;
// Used to report errors thrown from functions passed to `queueMicrotask()`.
// The callback will be passed the thrown error. For example, you can use this
// to dispatch an error event to the global scope.
// In other words, set the implementation for
// https://html.spec.whatwg.org/multipage/webappapis.html#report-the-exception
function setReportExceptionCallback(cb) {
if (typeof cb != "function") {
throw new TypeError("expected a function");
}
reportExceptionCallback = cb;
}
function queueMicrotask(cb) {
if (typeof cb != "function") {
throw new TypeError("expected a function");
}
return ops.op_queue_microtask(() => {
try {
cb();
} catch (error) {
if (reportExceptionCallback) {
reportExceptionCallback(error);
} else {
throw error;
}
}
});
}
// Some "extensions" rely on "BadResource" and "Interrupted" errors in the
// JS code (eg. "deno_net") so they are provided in "Deno.core" but later
// reexported on "Deno.errors"
class BadResource extends Error {
constructor(msg) {
super(msg);
this.name = "BadResource";
}
}
const BadResourcePrototype = BadResource.prototype;
class Interrupted extends Error {
constructor(msg) {
super(msg);
this.name = "Interrupted";
}
}
const InterruptedPrototype = Interrupted.prototype;
// Extra Deno.core.* exports
const core = ObjectAssign(globalThis.Deno.core, {
opAsync,
opSync,
resources,
metrics,
registerErrorBuilder,
registerErrorClass,
buildCustomError,
opresolve,
BadResource,
BadResourcePrototype,
Interrupted,
InterruptedPrototype,
enableOpCallTracing,
isOpCallTracingEnabled,
opCallTraces,
refOp,
unrefOp,
setReportExceptionCallback,
close: (rid) => ops.op_close(rid),
tryClose: (rid) => ops.op_try_close(rid),
read: opAsync.bind(null, "op_read"),
write: opAsync.bind(null, "op_write"),
shutdown: opAsync.bind(null, "op_shutdown"),
print: (msg, isErr) => ops.op_print(msg, isErr),
setMacrotaskCallback: (fn) => ops.op_set_macrotask_callback(fn),
setNextTickCallback: (fn) => ops.op_set_next_tick_callback(fn),
runMicrotasks: () => ops.op_run_microtasks(),
hasTickScheduled: () => ops.op_has_tick_scheduled(),
setHasTickScheduled: (bool) => ops.op_set_has_tick_scheduled(bool),
evalContext: (
source,
specifier,
) => ops.op_eval_context(source, specifier),
createHostObject: () => ops.op_create_host_object(),
encode: (text) => ops.op_encode(text),
decode: (buffer) => ops.op_decode(buffer),
serialize: (
value,
options,
errorCallback,
) => ops.op_serialize(value, options, errorCallback),
deserialize: (buffer, options) => ops.op_deserialize(buffer, options),
getPromiseDetails: (promise) => ops.op_get_promise_details(promise),
getProxyDetails: (proxy) => ops.op_get_proxy_details(proxy),
isProxy: (value) => ops.op_is_proxy(value),
memoryUsage: () => ops.op_memory_usage(),
setWasmStreamingCallback: (fn) => ops.op_set_wasm_streaming_callback(fn),
abortWasmStreaming: (
rid,
error,
) => ops.op_abort_wasm_streaming(rid, error),
destructureError: (error) => ops.op_destructure_error(error),
opNames: () => ops.op_op_names(),
eventLoopHasMoreWork: () => ops.op_event_loop_has_more_work(),
setPromiseRejectCallback: (fn) => ops.op_set_promise_reject_callback(fn),
byteLength: (str) => ops.op_str_byte_length(str),
});
ObjectAssign(globalThis.__bootstrap, { core });
ObjectAssign(globalThis.Deno, { core });
// Direct bindings on `globalThis`
ObjectAssign(globalThis, { queueMicrotask });
setQueueMicrotask(queueMicrotask);
})(globalThis);