pdfjs-dist/lib/display/node_stream.js

/**
 * @licstart The following is the entire license notice for the
 * Javascript code in this page
 *
 * Copyright 2021 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.PDFNodeStream = void 0;

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

var _network_utils = require("./network_utils.js");

;

const fs = require("fs");

const http = require("http");

const https = require("https");

const url = require("url");

const fileUriRegex = /^file:\/\/\/[a-zA-Z]:\//;

function parseUrl(sourceUrl) {
  const parsedUrl = url.parse(sourceUrl);

  if (parsedUrl.protocol === "file:" || parsedUrl.host) {
    return parsedUrl;
  }

  if (/^[a-z]:[/\\]/i.test(sourceUrl)) {
    return url.parse(`file:///${sourceUrl}`);
  }

  if (!parsedUrl.host) {
    parsedUrl.protocol = "file:";
  }

  return parsedUrl;
}

class PDFNodeStream {
  constructor(source) {
    this.source = source;
    this.url = parseUrl(source.url);
    this.isHttp = this.url.protocol === "http:" || this.url.protocol === "https:";
    this.isFsUrl = this.url.protocol === "file:";
    this.httpHeaders = this.isHttp && source.httpHeaders || {};
    this._fullRequestReader = null;
    this._rangeRequestReaders = [];
  }

  get _progressiveDataLength() {
    return this._fullRequestReader?._loaded ?? 0;
  }

  getFullReader() {
    (0, _util.assert)(!this._fullRequestReader, "PDFNodeStream.getFullReader can only be called once.");
    this._fullRequestReader = this.isFsUrl ? new PDFNodeStreamFsFullReader(this) : new PDFNodeStreamFullReader(this);
    return this._fullRequestReader;
  }

  getRangeReader(start, end) {
    if (end <= this._progressiveDataLength) {
      return null;
    }

    const rangeReader = this.isFsUrl ? new PDFNodeStreamFsRangeReader(this, start, end) : new PDFNodeStreamRangeReader(this, start, end);

    this._rangeRequestReaders.push(rangeReader);

    return rangeReader;
  }

  cancelAllRequests(reason) {
    if (this._fullRequestReader) {
      this._fullRequestReader.cancel(reason);
    }

    for (const reader of this._rangeRequestReaders.slice(0)) {
      reader.cancel(reason);
    }
  }

}

exports.PDFNodeStream = PDFNodeStream;

class BaseFullReader {
  constructor(stream) {
    this._url = stream.url;
    this._done = false;
    this._storedError = null;
    this.onProgress = null;
    const source = stream.source;
    this._contentLength = source.length;
    this._loaded = 0;
    this._filename = null;
    this._disableRange = source.disableRange || false;
    this._rangeChunkSize = source.rangeChunkSize;

    if (!this._rangeChunkSize && !this._disableRange) {
      this._disableRange = true;
    }

    this._isStreamingSupported = !source.disableStream;
    this._isRangeSupported = !source.disableRange;
    this._readableStream = null;
    this._readCapability = (0, _util.createPromiseCapability)();
    this._headersCapability = (0, _util.createPromiseCapability)();
  }

  get headersReady() {
    return this._headersCapability.promise;
  }

  get filename() {
    return this._filename;
  }

  get contentLength() {
    return this._contentLength;
  }

  get isRangeSupported() {
    return this._isRangeSupported;
  }

  get isStreamingSupported() {
    return this._isStreamingSupported;
  }

  async read() {
    await this._readCapability.promise;

    if (this._done) {
      return {
        value: undefined,
        done: true
      };
    }

    if (this._storedError) {
      throw this._storedError;
    }

    const chunk = this._readableStream.read();

    if (chunk === null) {
      this._readCapability = (0, _util.createPromiseCapability)();
      return this.read();
    }

    this._loaded += chunk.length;

    if (this.onProgress) {
      this.onProgress({
        loaded: this._loaded,
        total: this._contentLength
      });
    }

    const buffer = new Uint8Array(chunk).buffer;
    return {
      value: buffer,
      done: false
    };
  }

  cancel(reason) {
    if (!this._readableStream) {
      this._error(reason);

      return;
    }

    this._readableStream.destroy(reason);
  }

  _error(reason) {
    this._storedError = reason;

    this._readCapability.resolve();
  }

  _setReadableStream(readableStream) {
    this._readableStream = readableStream;
    readableStream.on("readable", () => {
      this._readCapability.resolve();
    });
    readableStream.on("end", () => {
      readableStream.destroy();
      this._done = true;

      this._readCapability.resolve();
    });
    readableStream.on("error", reason => {
      this._error(reason);
    });

    if (!this._isStreamingSupported && this._isRangeSupported) {
      this._error(new _util.AbortException("streaming is disabled"));
    }

    if (this._storedError) {
      this._readableStream.destroy(this._storedError);
    }
  }

}

class BaseRangeReader {
  constructor(stream) {
    this._url = stream.url;
    this._done = false;
    this._storedError = null;
    this.onProgress = null;
    this._loaded = 0;
    this._readableStream = null;
    this._readCapability = (0, _util.createPromiseCapability)();
    const source = stream.source;
    this._isStreamingSupported = !source.disableStream;
  }

  get isStreamingSupported() {
    return this._isStreamingSupported;
  }

  async read() {
    await this._readCapability.promise;

    if (this._done) {
      return {
        value: undefined,
        done: true
      };
    }

    if (this._storedError) {
      throw this._storedError;
    }

    const chunk = this._readableStream.read();

    if (chunk === null) {
      this._readCapability = (0, _util.createPromiseCapability)();
      return this.read();
    }

    this._loaded += chunk.length;

    if (this.onProgress) {
      this.onProgress({
        loaded: this._loaded
      });
    }

    const buffer = new Uint8Array(chunk).buffer;
    return {
      value: buffer,
      done: false
    };
  }

  cancel(reason) {
    if (!this._readableStream) {
      this._error(reason);

      return;
    }

    this._readableStream.destroy(reason);
  }

  _error(reason) {
    this._storedError = reason;

    this._readCapability.resolve();
  }

  _setReadableStream(readableStream) {
    this._readableStream = readableStream;
    readableStream.on("readable", () => {
      this._readCapability.resolve();
    });
    readableStream.on("end", () => {
      readableStream.destroy();
      this._done = true;

      this._readCapability.resolve();
    });
    readableStream.on("error", reason => {
      this._error(reason);
    });

    if (this._storedError) {
      this._readableStream.destroy(this._storedError);
    }
  }

}

function createRequestOptions(parsedUrl, headers) {
  return {
    protocol: parsedUrl.protocol,
    auth: parsedUrl.auth,
    host: parsedUrl.hostname,
    port: parsedUrl.port,
    path: parsedUrl.path,
    method: "GET",
    headers
  };
}

class PDFNodeStreamFullReader extends BaseFullReader {
  constructor(stream) {
    super(stream);

    const handleResponse = response => {
      if (response.statusCode === 404) {
        const error = new _util.MissingPDFException(`Missing PDF "${this._url}".`);
        this._storedError = error;

        this._headersCapability.reject(error);

        return;
      }

      this._headersCapability.resolve();

      this._setReadableStream(response);

      const getResponseHeader = name => {
        return this._readableStream.headers[name.toLowerCase()];
      };

      const {
        allowRangeRequests,
        suggestedLength
      } = (0, _network_utils.validateRangeRequestCapabilities)({
        getResponseHeader,
        isHttp: stream.isHttp,
        rangeChunkSize: this._rangeChunkSize,
        disableRange: this._disableRange
      });
      this._isRangeSupported = allowRangeRequests;
      this._contentLength = suggestedLength || this._contentLength;
      this._filename = (0, _network_utils.extractFilenameFromHeader)(getResponseHeader);
    };

    this._request = null;

    if (this._url.protocol === "http:") {
      this._request = http.request(createRequestOptions(this._url, stream.httpHeaders), handleResponse);
    } else {
      this._request = https.request(createRequestOptions(this._url, stream.httpHeaders), handleResponse);
    }

    this._request.on("error", reason => {
      this._storedError = reason;

      this._headersCapability.reject(reason);
    });

    this._request.end();
  }

}

class PDFNodeStreamRangeReader extends BaseRangeReader {
  constructor(stream, start, end) {
    super(stream);
    this._httpHeaders = {};

    for (const property in stream.httpHeaders) {
      const value = stream.httpHeaders[property];

      if (typeof value === "undefined") {
        continue;
      }

      this._httpHeaders[property] = value;
    }

    this._httpHeaders.Range = `bytes=${start}-${end - 1}`;

    const handleResponse = response => {
      if (response.statusCode === 404) {
        const error = new _util.MissingPDFException(`Missing PDF "${this._url}".`);
        this._storedError = error;
        return;
      }

      this._setReadableStream(response);
    };

    this._request = null;

    if (this._url.protocol === "http:") {
      this._request = http.request(createRequestOptions(this._url, this._httpHeaders), handleResponse);
    } else {
      this._request = https.request(createRequestOptions(this._url, this._httpHeaders), handleResponse);
    }

    this._request.on("error", reason => {
      this._storedError = reason;
    });

    this._request.end();
  }

}

class PDFNodeStreamFsFullReader extends BaseFullReader {
  constructor(stream) {
    super(stream);
    let path = decodeURIComponent(this._url.path);

    if (fileUriRegex.test(this._url.href)) {
      path = path.replace(/^\//, "");
    }

    fs.lstat(path, (error, stat) => {
      if (error) {
        if (error.code === "ENOENT") {
          error = new _util.MissingPDFException(`Missing PDF "${path}".`);
        }

        this._storedError = error;

        this._headersCapability.reject(error);

        return;
      }

      this._contentLength = stat.size;

      this._setReadableStream(fs.createReadStream(path));

      this._headersCapability.resolve();
    });
  }

}

class PDFNodeStreamFsRangeReader extends BaseRangeReader {
  constructor(stream, start, end) {
    super(stream);
    let path = decodeURIComponent(this._url.path);

    if (fileUriRegex.test(this._url.href)) {
      path = path.replace(/^\//, "");
    }

    this._setReadableStream(fs.createReadStream(path, {
      start,
      end: end - 1
    }));
  }

}