array-buffer-view-core.js

'use strict';
var NATIVE_ARRAY_BUFFER = require('../internals/array-buffer-native');
var DESCRIPTORS = require('../internals/descriptors');
var global = require('../internals/global');
var isObject = require('../internals/is-object');
var has = require('../internals/has');
var classof = require('../internals/classof');
var createNonEnumerableProperty = require('../internals/create-non-enumerable-property');
var redefine = require('../internals/redefine');
var defineProperty = require('../internals/object-define-property').f;
var getPrototypeOf = require('../internals/object-get-prototype-of');
var setPrototypeOf = require('../internals/object-set-prototype-of');
var wellKnownSymbol = require('../internals/well-known-symbol');
var uid = require('../internals/uid');

var Int8Array = global.Int8Array;
var Int8ArrayPrototype = Int8Array && Int8Array.prototype;
var Uint8ClampedArray = global.Uint8ClampedArray;
var Uint8ClampedArrayPrototype = Uint8ClampedArray && Uint8ClampedArray.prototype;
var TypedArray = Int8Array && getPrototypeOf(Int8Array);
var TypedArrayPrototype = Int8ArrayPrototype && getPrototypeOf(Int8ArrayPrototype);
var ObjectPrototype = Object.prototype;
var isPrototypeOf = ObjectPrototype.isPrototypeOf;

var TO_STRING_TAG = wellKnownSymbol('toStringTag');
var TYPED_ARRAY_TAG = uid('TYPED_ARRAY_TAG');
// Fixing native typed arrays in Opera Presto crashes the browser, see #595
var NATIVE_ARRAY_BUFFER_VIEWS = NATIVE_ARRAY_BUFFER && !!setPrototypeOf && classof(global.opera) !== 'Opera';
var TYPED_ARRAY_TAG_REQIRED = false;
var NAME;

var TypedArrayConstructorsList = {
  Int8Array: 1,
  Uint8Array: 1,
  Uint8ClampedArray: 1,
  Int16Array: 2,
  Uint16Array: 2,
  Int32Array: 4,
  Uint32Array: 4,
  Float32Array: 4,
  Float64Array: 8
};

var isView = function isView(it) {
  var klass = classof(it);
  return klass === 'DataView' || has(TypedArrayConstructorsList, klass);
};

var isTypedArray = function (it) {
  return isObject(it) && has(TypedArrayConstructorsList, classof(it));
};

var aTypedArray = function (it) {
  if (isTypedArray(it)) return it;
  throw TypeError('Target is not a typed array');
};

var aTypedArrayConstructor = function (C) {
  if (setPrototypeOf) {
    if (isPrototypeOf.call(TypedArray, C)) return C;
  } else for (var ARRAY in TypedArrayConstructorsList) if (has(TypedArrayConstructorsList, NAME)) {
    var TypedArrayConstructor = global[ARRAY];
    if (TypedArrayConstructor && (C === TypedArrayConstructor || isPrototypeOf.call(TypedArrayConstructor, C))) {
      return C;
    }
  } throw TypeError('Target is not a typed array constructor');
};

var exportTypedArrayMethod = function (KEY, property, forced) {
  if (!DESCRIPTORS) return;
  if (forced) for (var ARRAY in TypedArrayConstructorsList) {
    var TypedArrayConstructor = global[ARRAY];
    if (TypedArrayConstructor && has(TypedArrayConstructor.prototype, KEY)) {
      delete TypedArrayConstructor.prototype[KEY];
    }
  }
  if (!TypedArrayPrototype[KEY] || forced) {
    redefine(TypedArrayPrototype, KEY, forced ? property
      : NATIVE_ARRAY_BUFFER_VIEWS && Int8ArrayPrototype[KEY] || property);
  }
};

var exportTypedArrayStaticMethod = function (KEY, property, forced) {
  var ARRAY, TypedArrayConstructor;
  if (!DESCRIPTORS) return;
  if (setPrototypeOf) {
    if (forced) for (ARRAY in TypedArrayConstructorsList) {
      TypedArrayConstructor = global[ARRAY];
      if (TypedArrayConstructor && has(TypedArrayConstructor, KEY)) {
        delete TypedArrayConstructor[KEY];
      }
    }
    if (!TypedArray[KEY] || forced) {
      // V8 ~ Chrome 49-50 `%TypedArray%` methods are non-writable non-configurable
      try {
        return redefine(TypedArray, KEY, forced ? property : NATIVE_ARRAY_BUFFER_VIEWS && Int8Array[KEY] || property);
      } catch (error) { /* empty */ }
    } else return;
  }
  for (ARRAY in TypedArrayConstructorsList) {
    TypedArrayConstructor = global[ARRAY];
    if (TypedArrayConstructor && (!TypedArrayConstructor[KEY] || forced)) {
      redefine(TypedArrayConstructor, KEY, property);
    }
  }
};

for (NAME in TypedArrayConstructorsList) {
  if (!global[NAME]) NATIVE_ARRAY_BUFFER_VIEWS = false;
}

// WebKit bug - typed arrays constructors prototype is Object.prototype
if (!NATIVE_ARRAY_BUFFER_VIEWS || typeof TypedArray != 'function' || TypedArray === Function.prototype) {
  // eslint-disable-next-line no-shadow
  TypedArray = function TypedArray() {
    throw TypeError('Incorrect invocation');
  };
  if (NATIVE_ARRAY_BUFFER_VIEWS) for (NAME in TypedArrayConstructorsList) {
    if (global[NAME]) setPrototypeOf(global[NAME], TypedArray);
  }
}

if (!NATIVE_ARRAY_BUFFER_VIEWS || !TypedArrayPrototype || TypedArrayPrototype === ObjectPrototype) {
  TypedArrayPrototype = TypedArray.prototype;
  if (NATIVE_ARRAY_BUFFER_VIEWS) for (NAME in TypedArrayConstructorsList) {
    if (global[NAME]) setPrototypeOf(global[NAME].prototype, TypedArrayPrototype);
  }
}

// WebKit bug - one more object in Uint8ClampedArray prototype chain
if (NATIVE_ARRAY_BUFFER_VIEWS && getPrototypeOf(Uint8ClampedArrayPrototype) !== TypedArrayPrototype) {
  setPrototypeOf(Uint8ClampedArrayPrototype, TypedArrayPrototype);
}

if (DESCRIPTORS && !has(TypedArrayPrototype, TO_STRING_TAG)) {
  TYPED_ARRAY_TAG_REQIRED = true;
  defineProperty(TypedArrayPrototype, TO_STRING_TAG, { get: function () {
    return isObject(this) ? this[TYPED_ARRAY_TAG] : undefined;
  } });
  for (NAME in TypedArrayConstructorsList) if (global[NAME]) {
    createNonEnumerableProperty(global[NAME], TYPED_ARRAY_TAG, NAME);
  }
}

module.exports = {
  NATIVE_ARRAY_BUFFER_VIEWS: NATIVE_ARRAY_BUFFER_VIEWS,
  TYPED_ARRAY_TAG: TYPED_ARRAY_TAG_REQIRED && TYPED_ARRAY_TAG,
  aTypedArray: aTypedArray,
  aTypedArrayConstructor: aTypedArrayConstructor,
  exportTypedArrayMethod: exportTypedArrayMethod,
  exportTypedArrayStaticMethod: exportTypedArrayStaticMethod,
  isView: isView,
  isTypedArray: isTypedArray,
  TypedArray: TypedArray,
  TypedArrayPrototype: TypedArrayPrototype
};