mirror of
https://github.com/denoland/deno.git
synced 2024-12-25 08:39:09 -05:00
103 lines
2.6 KiB
TypeScript
103 lines
2.6 KiB
TypeScript
|
// Copyright Node.js contributors. All rights reserved. MIT License.
|
||
|
import { Buffer } from "../buffer.ts";
|
||
|
import Readable from "./readable.ts";
|
||
|
import type { ReadableOptions } from "./readable.ts";
|
||
|
import { ERR_INVALID_ARG_TYPE, ERR_STREAM_NULL_VALUES } from "../_errors.ts";
|
||
|
|
||
|
export default function from(
|
||
|
// deno-lint-ignore no-explicit-any
|
||
|
iterable: Iterable<any> | AsyncIterable<any>,
|
||
|
opts?: ReadableOptions,
|
||
|
) {
|
||
|
let iterator:
|
||
|
// deno-lint-ignore no-explicit-any
|
||
|
| Iterator<any, any, undefined>
|
||
|
// deno-lint-ignore no-explicit-any
|
||
|
| AsyncIterator<any, any, undefined>;
|
||
|
if (typeof iterable === "string" || iterable instanceof Buffer) {
|
||
|
return new Readable({
|
||
|
objectMode: true,
|
||
|
...opts,
|
||
|
read() {
|
||
|
this.push(iterable);
|
||
|
this.push(null);
|
||
|
},
|
||
|
});
|
||
|
}
|
||
|
|
||
|
if (Symbol.asyncIterator in iterable) {
|
||
|
// deno-lint-ignore no-explicit-any
|
||
|
iterator = (iterable as AsyncIterable<any>)[Symbol.asyncIterator]();
|
||
|
} else if (Symbol.iterator in iterable) {
|
||
|
// deno-lint-ignore no-explicit-any
|
||
|
iterator = (iterable as Iterable<any>)[Symbol.iterator]();
|
||
|
} else {
|
||
|
throw new ERR_INVALID_ARG_TYPE("iterable", ["Iterable"], iterable);
|
||
|
}
|
||
|
|
||
|
const readable = new Readable({
|
||
|
objectMode: true,
|
||
|
highWaterMark: 1,
|
||
|
...opts,
|
||
|
});
|
||
|
|
||
|
// Reading boolean to protect against _read
|
||
|
// being called before last iteration completion.
|
||
|
let reading = false;
|
||
|
|
||
|
// needToClose boolean if iterator needs to be explicitly closed
|
||
|
let needToClose = false;
|
||
|
|
||
|
readable._read = function () {
|
||
|
if (!reading) {
|
||
|
reading = true;
|
||
|
next();
|
||
|
}
|
||
|
};
|
||
|
|
||
|
readable._destroy = function (error, cb) {
|
||
|
if (needToClose) {
|
||
|
needToClose = false;
|
||
|
close().then(
|
||
|
() => queueMicrotask(() => cb(error)),
|
||
|
(e) => queueMicrotask(() => cb(error || e)),
|
||
|
);
|
||
|
} else {
|
||
|
cb(error);
|
||
|
}
|
||
|
};
|
||
|
|
||
|
async function close() {
|
||
|
if (typeof iterator.return === "function") {
|
||
|
const { value } = await iterator.return();
|
||
|
await value;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
async function next() {
|
||
|
try {
|
||
|
needToClose = false;
|
||
|
const { value, done } = await iterator.next();
|
||
|
needToClose = !done;
|
||
|
if (done) {
|
||
|
readable.push(null);
|
||
|
} else if (readable.destroyed) {
|
||
|
await close();
|
||
|
} else {
|
||
|
const res = await value;
|
||
|
if (res === null) {
|
||
|
reading = false;
|
||
|
throw new ERR_STREAM_NULL_VALUES();
|
||
|
} else if (readable.push(res)) {
|
||
|
next();
|
||
|
} else {
|
||
|
reading = false;
|
||
|
}
|
||
|
}
|
||
|
} catch (err) {
|
||
|
readable.destroy(err);
|
||
|
}
|
||
|
}
|
||
|
return readable;
|
||
|
}
|