79 lines
2.6 KiB
JavaScript
79 lines
2.6 KiB
JavaScript
|
'use strict';
|
||
|
|
|
||
|
|
var forEach = require('for-each');
|
||
|
|
var callBind = require('call-bind');
|
||
|
|
|
||
|
|
var typedArrays = require('available-typed-arrays')();
|
||
|
|
|
||
|
|
/** @typedef {Int8Array | Uint8Array | Uint8ClampedArray | Int16Array | Uint16Array | Int32Array | Uint32Array | Float32Array | Float64Array | BigInt64Array | BigUint64Array} TypedArray */
|
||
|
|
/** @typedef {(x: TypedArray) => number} ByteOffsetGetter */
|
||
|
|
|
||
|
|
/** @type {Object.<typeof typedArrays, ByteOffsetGetter>} */
|
||
|
|
var getters = {};
|
||
|
|
var hasProto = require('has-proto')();
|
||
|
|
|
||
|
|
var gOPD = require('gopd');
|
||
|
|
var oDP = Object.defineProperty;
|
||
|
|
if (gOPD) {
|
||
|
|
/** @type {ByteOffsetGetter} */
|
||
|
|
var getByteOffset = function (x) {
|
||
|
|
return x.byteOffset;
|
||
|
|
};
|
||
|
|
forEach(typedArrays, function (typedArray) {
|
||
|
|
// In Safari 7, Typed Array constructors are typeof object
|
||
|
|
if (typeof global[typedArray] === 'function' || typeof global[typedArray] === 'object') {
|
||
|
|
var Proto = global[typedArray].prototype;
|
||
|
|
// @ts-expect-error TS can't guarantee the callback is invoked sync
|
||
|
|
var descriptor = gOPD(Proto, 'byteOffset');
|
||
|
|
if (!descriptor && hasProto) {
|
||
|
|
// @ts-expect-error hush, TS, every object has a dunder proto
|
||
|
|
var superProto = Proto.__proto__; // eslint-disable-line no-proto
|
||
|
|
// @ts-expect-error TS can't guarantee the callback is invoked sync
|
||
|
|
descriptor = gOPD(superProto, 'byteOffset');
|
||
|
|
}
|
||
|
|
// Opera 12.16 has a magic byteOffset data property on instances AND on Proto
|
||
|
|
if (descriptor && descriptor.get) {
|
||
|
|
getters[typedArray] = callBind(descriptor.get);
|
||
|
|
} else if (oDP) {
|
||
|
|
// this is likely an engine where instances have a magic byteOffset data property
|
||
|
|
var arr = new global[typedArray](2);
|
||
|
|
// @ts-expect-error TS can't guarantee the callback is invoked sync
|
||
|
|
descriptor = gOPD(arr, 'byteOffset');
|
||
|
|
if (descriptor && descriptor.configurable) {
|
||
|
|
oDP(arr, 'length', { value: 3 });
|
||
|
|
}
|
||
|
|
if (arr.length === 2) {
|
||
|
|
getters[typedArray] = getByteOffset;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
/** @type {ByteOffsetGetter} */
|
||
|
|
var tryTypedArrays = function tryAllTypedArrays(value) {
|
||
|
|
/** @type {number} */ var foundOffset;
|
||
|
|
forEach(getters, /** @type {(getter: ByteOffsetGetter) => void} */ function (getter) {
|
||
|
|
if (typeof foundOffset !== 'number') {
|
||
|
|
try {
|
||
|
|
var offset = getter(value);
|
||
|
|
if (typeof offset === 'number') {
|
||
|
|
foundOffset = offset;
|
||
|
|
}
|
||
|
|
} catch (e) {}
|
||
|
|
}
|
||
|
|
});
|
||
|
|
// @ts-expect-error TS can't guarantee the callback is invoked sync
|
||
|
|
return foundOffset;
|
||
|
|
};
|
||
|
|
|
||
|
|
var isTypedArray = require('is-typed-array');
|
||
|
|
|
||
|
|
/** @type {import('.')} */
|
||
|
|
module.exports = function typedArrayByteOffset(value) {
|
||
|
|
if (!isTypedArray(value)) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
return tryTypedArrays(value);
|
||
|
|
};
|