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69 lines
2.2 KiB
JavaScript

import { PACKET_TYPES } from "./commons.js";
const withNativeBlob = typeof Blob === "function" ||
(typeof Blob !== "undefined" &&
Object.prototype.toString.call(Blob) === "[object BlobConstructor]");
const withNativeArrayBuffer = typeof ArrayBuffer === "function";
// ArrayBuffer.isView method is not defined in IE10
const isView = (obj) => {
return typeof ArrayBuffer.isView === "function"
? ArrayBuffer.isView(obj)
: obj && obj.buffer instanceof ArrayBuffer;
};
const encodePacket = ({ type, data }, supportsBinary, callback) => {
if (withNativeBlob && data instanceof Blob) {
if (supportsBinary) {
return callback(data);
}
else {
return encodeBlobAsBase64(data, callback);
}
}
else if (withNativeArrayBuffer &&
(data instanceof ArrayBuffer || isView(data))) {
if (supportsBinary) {
return callback(data);
}
else {
return encodeBlobAsBase64(new Blob([data]), callback);
}
}
// plain string
return callback(PACKET_TYPES[type] + (data || ""));
};
const encodeBlobAsBase64 = (data, callback) => {
const fileReader = new FileReader();
fileReader.onload = function () {
const content = fileReader.result.split(",")[1];
callback("b" + (content || ""));
};
return fileReader.readAsDataURL(data);
};
function toArray(data) {
if (data instanceof Uint8Array) {
return data;
}
else if (data instanceof ArrayBuffer) {
return new Uint8Array(data);
}
else {
return new Uint8Array(data.buffer, data.byteOffset, data.byteLength);
}
}
let TEXT_ENCODER;
export function encodePacketToBinary(packet, callback) {
if (withNativeBlob && packet.data instanceof Blob) {
return packet.data.arrayBuffer().then(toArray).then(callback);
}
else if (withNativeArrayBuffer &&
(packet.data instanceof ArrayBuffer || isView(packet.data))) {
return callback(toArray(packet.data));
}
encodePacket(packet, false, (encoded) => {
if (!TEXT_ENCODER) {
TEXT_ENCODER = new TextEncoder();
}
callback(TEXT_ENCODER.encode(encoded));
});
}
export { encodePacket };