biofriction-wp-theme/node_modules/into-stream/index.js

80 lines
1.5 KiB
JavaScript

'use strict';
const from = require('from2');
const pIsPromise = require('p-is-promise');
module.exports = x => {
if (Array.isArray(x)) {
x = x.slice();
}
let promise;
let iterator;
prepare(x);
function prepare(value) {
x = value;
promise = pIsPromise(x) ? x : null;
// we don't iterate on strings and buffers since slicing them is ~7x faster
const shouldIterate = !promise && x[Symbol.iterator] && typeof x !== 'string' && !Buffer.isBuffer(x);
iterator = shouldIterate ? x[Symbol.iterator]() : null;
}
return from(function reader(size, cb) {
if (promise) {
promise.then(prepare).then(() => reader.call(this, size, cb), cb);
return;
}
if (iterator) {
const obj = iterator.next();
setImmediate(cb, null, obj.done ? null : obj.value);
return;
}
if (x.length === 0) {
setImmediate(cb, null, null);
return;
}
const chunk = x.slice(0, size);
x = x.slice(size);
setImmediate(cb, null, chunk);
});
};
module.exports.obj = x => {
if (Array.isArray(x)) {
x = x.slice();
}
let promise;
let iterator;
prepare(x);
function prepare(value) {
x = value;
promise = pIsPromise(x) ? x : null;
iterator = !promise && x[Symbol.iterator] ? x[Symbol.iterator]() : null;
}
return from.obj(function reader(size, cb) {
if (promise) {
promise.then(prepare).then(() => reader.call(this, size, cb), cb);
return;
}
if (iterator) {
const obj = iterator.next();
setImmediate(cb, null, obj.done ? null : obj.value);
return;
}
this.push(x);
setImmediate(cb, null, null);
});
};