dicom-microscopy-viewer-changed
Version:
Interactive web-based viewer for DICOM Microscopy Images
78 lines (71 loc) • 2.01 kB
JavaScript
;
var forEach = require('for-each');
var callBind = require('call-bind');
var typedArrays = [
'Float32Array',
'Float64Array',
'Int8Array',
'Int16Array',
'Int32Array',
'Uint8Array',
'Uint8ClampedArray',
'Uint16Array',
'Uint32Array',
'BigInt64Array',
'BigUint64Array'
];
var getters = {};
var hasProto = [].__proto__ === Array.prototype; // eslint-disable-line no-proto
var gOPD = Object.getOwnPropertyDescriptor;
var oDP = Object.defineProperty;
if (gOPD) {
var getLength = function (x) {
return x.length;
};
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;
var descriptor = gOPD(Proto, 'length');
if (!descriptor && hasProto) {
var superProto = Proto.__proto__; // eslint-disable-line no-proto
descriptor = gOPD(superProto, 'length');
}
// Opera 12.16 has a magic length 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 length data property
var arr = new global[typedArray](2);
descriptor = gOPD(arr, 'length');
if (descriptor && descriptor.configurable) {
oDP(arr, 'length', { value: 3 });
}
if (arr.length === 2) {
getters[typedArray] = getLength;
}
}
}
});
}
var tryTypedArrays = function tryAllTypedArrays(value) {
var foundLength;
forEach(getters, function (getter) {
if (typeof foundLength !== 'number') {
try {
var length = getter(value);
if (typeof length === 'number') {
foundLength = length;
}
} catch (e) {}
}
});
return foundLength;
};
var isTypedArray = require('is-typed-array');
module.exports = function typedArrayLength(value) {
if (!isTypedArray(value)) {
return false;
}
return tryTypedArrays(value);
};