pdfjs-dist/lib/display/transport_stream.js

/**
 * @licstart The following is the entire license notice for the
 * Javascript code in this page
 *
 * Copyright 2018 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";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.PDFDataTransportStream = void 0;

var _regenerator = _interopRequireDefault(require("@babel/runtime/regenerator"));

var _util = require("../shared/util");

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function asyncGeneratorStep(gen, resolve, reject, _next, _throw, key, arg) { try { var info = gen[key](arg); var value = info.value; } catch (error) { reject(error); return; } if (info.done) { resolve(value); } else { Promise.resolve(value).then(_next, _throw); } }

function _asyncToGenerator(fn) { return function () { var self = this, args = arguments; return new Promise(function (resolve, reject) { var gen = fn.apply(self, args); function _next(value) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "next", value); } function _throw(err) { asyncGeneratorStep(gen, resolve, reject, _next, _throw, "throw", err); } _next(undefined); }); }; }

var PDFDataTransportStream = function PDFDataTransportStreamClosure() {
  function PDFDataTransportStream(params, pdfDataRangeTransport) {
    var _this = this;

    (0, _util.assert)(pdfDataRangeTransport);
    this._queuedChunks = [];
    var initialData = params.initialData;

    if (initialData && initialData.length > 0) {
      var buffer = new Uint8Array(initialData).buffer;

      this._queuedChunks.push(buffer);
    }

    this._pdfDataRangeTransport = pdfDataRangeTransport;
    this._isStreamingSupported = !params.disableStream;
    this._isRangeSupported = !params.disableRange;
    this._contentLength = params.length;
    this._fullRequestReader = null;
    this._rangeReaders = [];

    this._pdfDataRangeTransport.addRangeListener(function (begin, chunk) {
      _this._onReceiveData({
        begin: begin,
        chunk: chunk
      });
    });

    this._pdfDataRangeTransport.addProgressListener(function (loaded) {
      _this._onProgress({
        loaded: loaded
      });
    });

    this._pdfDataRangeTransport.addProgressiveReadListener(function (chunk) {
      _this._onReceiveData({
        chunk: chunk
      });
    });

    this._pdfDataRangeTransport.transportReady();
  }

  PDFDataTransportStream.prototype = {
    _onReceiveData: function PDFDataTransportStream_onReceiveData(args) {
      var buffer = new Uint8Array(args.chunk).buffer;

      if (args.begin === undefined) {
        if (this._fullRequestReader) {
          this._fullRequestReader._enqueue(buffer);
        } else {
          this._queuedChunks.push(buffer);
        }
      } else {
        var found = this._rangeReaders.some(function (rangeReader) {
          if (rangeReader._begin !== args.begin) {
            return false;
          }

          rangeReader._enqueue(buffer);

          return true;
        });

        (0, _util.assert)(found);
      }
    },
    _onProgress: function PDFDataTransportStream_onDataProgress(evt) {
      if (this._rangeReaders.length > 0) {
        var firstReader = this._rangeReaders[0];

        if (firstReader.onProgress) {
          firstReader.onProgress({
            loaded: evt.loaded
          });
        }
      }
    },
    _removeRangeReader: function PDFDataTransportStream_removeRangeReader(reader) {
      var i = this._rangeReaders.indexOf(reader);

      if (i >= 0) {
        this._rangeReaders.splice(i, 1);
      }
    },
    getFullReader: function PDFDataTransportStream_getFullReader() {
      (0, _util.assert)(!this._fullRequestReader);
      var queuedChunks = this._queuedChunks;
      this._queuedChunks = null;
      return new PDFDataTransportStreamReader(this, queuedChunks);
    },
    getRangeReader: function PDFDataTransportStream_getRangeReader(begin, end) {
      var reader = new PDFDataTransportStreamRangeReader(this, begin, end);

      this._pdfDataRangeTransport.requestDataRange(begin, end);

      this._rangeReaders.push(reader);

      return reader;
    },
    cancelAllRequests: function PDFDataTransportStream_cancelAllRequests(reason) {
      if (this._fullRequestReader) {
        this._fullRequestReader.cancel(reason);
      }

      var readers = this._rangeReaders.slice(0);

      readers.forEach(function (rangeReader) {
        rangeReader.cancel(reason);
      });

      this._pdfDataRangeTransport.abort();
    }
  };

  function PDFDataTransportStreamReader(stream, queuedChunks) {
    this._stream = stream;
    this._done = false;
    this._filename = null;
    this._queuedChunks = queuedChunks || [];
    this._requests = [];
    this._headersReady = Promise.resolve();
    stream._fullRequestReader = this;
    this.onProgress = null;
  }

  PDFDataTransportStreamReader.prototype = {
    _enqueue: function PDFDataTransportStreamReader_enqueue(chunk) {
      if (this._done) {
        return;
      }

      if (this._requests.length > 0) {
        var requestCapability = this._requests.shift();

        requestCapability.resolve({
          value: chunk,
          done: false
        });
        return;
      }

      this._queuedChunks.push(chunk);
    },

    get headersReady() {
      return this._headersReady;
    },

    get filename() {
      return this._filename;
    },

    get isRangeSupported() {
      return this._stream._isRangeSupported;
    },

    get isStreamingSupported() {
      return this._stream._isStreamingSupported;
    },

    get contentLength() {
      return this._stream._contentLength;
    },

    read: function () {
      var _read = _asyncToGenerator(
      /*#__PURE__*/
      _regenerator.default.mark(function _callee() {
        var chunk, requestCapability;
        return _regenerator.default.wrap(function _callee$(_context) {
          while (1) {
            switch (_context.prev = _context.next) {
              case 0:
                if (!(this._queuedChunks.length > 0)) {
                  _context.next = 3;
                  break;
                }

                chunk = this._queuedChunks.shift();
                return _context.abrupt("return", {
                  value: chunk,
                  done: false
                });

              case 3:
                if (!this._done) {
                  _context.next = 5;
                  break;
                }

                return _context.abrupt("return", {
                  value: undefined,
                  done: true
                });

              case 5:
                requestCapability = (0, _util.createPromiseCapability)();

                this._requests.push(requestCapability);

                return _context.abrupt("return", requestCapability.promise);

              case 8:
              case "end":
                return _context.stop();
            }
          }
        }, _callee, this);
      }));

      function read() {
        return _read.apply(this, arguments);
      }

      return read;
    }(),
    cancel: function PDFDataTransportStreamReader_cancel(reason) {
      this._done = true;

      this._requests.forEach(function (requestCapability) {
        requestCapability.resolve({
          value: undefined,
          done: true
        });
      });

      this._requests = [];
    }
  };

  function PDFDataTransportStreamRangeReader(stream, begin, end) {
    this._stream = stream;
    this._begin = begin;
    this._end = end;
    this._queuedChunk = null;
    this._requests = [];
    this._done = false;
    this.onProgress = null;
  }

  PDFDataTransportStreamRangeReader.prototype = {
    _enqueue: function PDFDataTransportStreamRangeReader_enqueue(chunk) {
      if (this._done) {
        return;
      }

      if (this._requests.length === 0) {
        this._queuedChunk = chunk;
      } else {
        var requestsCapability = this._requests.shift();

        requestsCapability.resolve({
          value: chunk,
          done: false
        });

        this._requests.forEach(function (requestCapability) {
          requestCapability.resolve({
            value: undefined,
            done: true
          });
        });

        this._requests = [];
      }

      this._done = true;

      this._stream._removeRangeReader(this);
    },

    get isStreamingSupported() {
      return false;
    },

    read: function () {
      var _read2 = _asyncToGenerator(
      /*#__PURE__*/
      _regenerator.default.mark(function _callee2() {
        var chunk, requestCapability;
        return _regenerator.default.wrap(function _callee2$(_context2) {
          while (1) {
            switch (_context2.prev = _context2.next) {
              case 0:
                if (!this._queuedChunk) {
                  _context2.next = 4;
                  break;
                }

                chunk = this._queuedChunk;
                this._queuedChunk = null;
                return _context2.abrupt("return", {
                  value: chunk,
                  done: false
                });

              case 4:
                if (!this._done) {
                  _context2.next = 6;
                  break;
                }

                return _context2.abrupt("return", {
                  value: undefined,
                  done: true
                });

              case 6:
                requestCapability = (0, _util.createPromiseCapability)();

                this._requests.push(requestCapability);

                return _context2.abrupt("return", requestCapability.promise);

              case 9:
              case "end":
                return _context2.stop();
            }
          }
        }, _callee2, this);
      }));

      function read() {
        return _read2.apply(this, arguments);
      }

      return read;
    }(),
    cancel: function PDFDataTransportStreamRangeReader_cancel(reason) {
      this._done = true;

      this._requests.forEach(function (requestCapability) {
        requestCapability.resolve({
          value: undefined,
          done: true
        });
      });

      this._requests = [];

      this._stream._removeRangeReader(this);
    }
  };
  return PDFDataTransportStream;
}();

exports.PDFDataTransportStream = PDFDataTransportStream;