pdfjs-dist/lib/test/unit/fetch_stream_spec.js

/**
 * @licstart The following is the entire license notice for the
 * JavaScript code in this page
 *
 * Copyright 2022 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * @licend The above is the entire license notice for the
 * JavaScript code in this page
 */
"use strict";

var _util = require("../../shared/util.js");
var _fetch_stream = require("../../display/fetch_stream.js");
describe("fetch_stream", function () {
  const pdfUrl = new URL("../pdfs/tracemonkey.pdf", window.location).href;
  const pdfLength = 1016315;
  it("read with streaming", async function () {
    const stream = new _fetch_stream.PDFFetchStream({
      url: pdfUrl,
      disableStream: false,
      disableRange: true
    });
    const fullReader = stream.getFullReader();
    let isStreamingSupported, isRangeSupported;
    const promise = fullReader.headersReady.then(function () {
      isStreamingSupported = fullReader.isStreamingSupported;
      isRangeSupported = fullReader.isRangeSupported;
    });
    let len = 0;
    const read = function () {
      return fullReader.read().then(function (result) {
        if (result.done) {
          return undefined;
        }
        len += result.value.byteLength;
        return read();
      });
    };
    await Promise.all([read(), promise]);
    expect(len).toEqual(pdfLength);
    expect(isStreamingSupported).toEqual(true);
    expect(isRangeSupported).toEqual(false);
  });
  it("read ranges with streaming", async function () {
    const rangeSize = 32768;
    const stream = new _fetch_stream.PDFFetchStream({
      url: pdfUrl,
      rangeChunkSize: rangeSize,
      disableStream: false,
      disableRange: false
    });
    const fullReader = stream.getFullReader();
    let isStreamingSupported, isRangeSupported, fullReaderCancelled;
    const promise = fullReader.headersReady.then(function () {
      isStreamingSupported = fullReader.isStreamingSupported;
      isRangeSupported = fullReader.isRangeSupported;
      fullReader.cancel(new _util.AbortException("Don't need fullReader."));
      fullReaderCancelled = true;
    });
    const tailSize = pdfLength % rangeSize || rangeSize;
    const rangeReader1 = stream.getRangeReader(pdfLength - tailSize - rangeSize, pdfLength - tailSize);
    const rangeReader2 = stream.getRangeReader(pdfLength - tailSize, pdfLength);
    const result1 = {
        value: 0
      },
      result2 = {
        value: 0
      };
    const read = function (reader, lenResult) {
      return reader.read().then(function (result) {
        if (result.done) {
          return undefined;
        }
        lenResult.value += result.value.byteLength;
        return read(reader, lenResult);
      });
    };
    await Promise.all([read(rangeReader1, result1), read(rangeReader2, result2), promise]);
    expect(isStreamingSupported).toEqual(true);
    expect(isRangeSupported).toEqual(true);
    expect(fullReaderCancelled).toEqual(true);
    expect(result1.value).toEqual(rangeSize);
    expect(result2.value).toEqual(tailSize);
  });
});