File size: 1,715 Bytes
dbda22c | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 | export var hasFetch = isFunction(global.fetch) && isFunction(global.ReadableStream)
var _blobConstructor;
export function blobConstructor() {
if (typeof _blobConstructor !== 'undefined') {
return _blobConstructor;
}
try {
new global.Blob([new ArrayBuffer(1)])
_blobConstructor = true
} catch (e) {
_blobConstructor = false
}
return _blobConstructor
}
var xhr;
function checkTypeSupport(type) {
if (!xhr) {
xhr = new global.XMLHttpRequest()
// If location.host is empty, e.g. if this page/worker was loaded
// from a Blob, then use example.com to avoid an error
xhr.open('GET', global.location.host ? '/' : 'https://example.com')
}
try {
xhr.responseType = type
return xhr.responseType === type
} catch (e) {
return false
}
}
// For some strange reason, Safari 7.0 reports typeof global.ArrayBuffer === 'object'.
// Safari 7.1 appears to have fixed this bug.
var haveArrayBuffer = typeof global.ArrayBuffer !== 'undefined'
var haveSlice = haveArrayBuffer && isFunction(global.ArrayBuffer.prototype.slice)
export var arraybuffer = haveArrayBuffer && checkTypeSupport('arraybuffer')
// These next two tests unavoidably show warnings in Chrome. Since fetch will always
// be used if it's available, just return false for these to avoid the warnings.
export var msstream = !hasFetch && haveSlice && checkTypeSupport('ms-stream')
export var mozchunkedarraybuffer = !hasFetch && haveArrayBuffer &&
checkTypeSupport('moz-chunked-arraybuffer')
export var overrideMimeType = isFunction(xhr.overrideMimeType)
export var vbArray = isFunction(global.VBArray)
function isFunction(value) {
return typeof value === 'function'
}
xhr = null // Help gc
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