pdf.js/src/core/evaluator.js

/* Copyright 2012 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.
 */

import {
  AbortException,
  assert,
  CMapCompressionType,
  createPromiseCapability,
  FONT_IDENTITY_MATRIX,
  FormatError,
  IDENTITY_MATRIX,
  info,
  isArrayEqual,
  isNum,
  isString,
  NativeImageDecoding,
  OPS,
  stringToPDFString,
  TextRenderingMode,
  UNSUPPORTED_FEATURES,
  Util,
  warn,
} from "../shared/util.js";
import { CMapFactory, IdentityCMap } from "./cmap.js";
import {
  Cmd,
  Dict,
  EOF,
  isDict,
  isName,
  isRef,
  isStream,
  Name,
  Ref,
} from "./primitives.js";
import {
  ErrorFont,
  Font,
  FontFlags,
  getFontType,
  IdentityToUnicodeMap,
  ToUnicodeMap,
} from "./fonts.js";
import {
  getEncoding,
  MacRomanEncoding,
  StandardEncoding,
  SymbolSetEncoding,
  WinAnsiEncoding,
  ZapfDingbatsEncoding,
} from "./encodings.js";
import {
  getNormalizedUnicodes,
  getUnicodeForGlyph,
  reverseIfRtl,
} from "./unicode.js";
import {
  getSerifFonts,
  getStdFontMap,
  getSymbolsFonts,
} from "./standard_fonts.js";
import { getTilingPatternIR, Pattern } from "./pattern.js";
import { Lexer, Parser } from "./parser.js";
import { bidi } from "./bidi.js";
import { ColorSpace } from "./colorspace.js";
import { DecodeStream } from "./stream.js";
import { getGlyphsUnicode } from "./glyphlist.js";
import { getLookupTableFactory } from "./core_utils.js";
import { getMetrics } from "./metrics.js";
import { isPDFFunction } from "./function.js";
import { JpegStream } from "./jpeg_stream.js";
import { MurmurHash3_64 } from "./murmurhash3.js";
import { NativeImageDecoder } from "./image_utils.js";
import { OperatorList } from "./operator_list.js";
import { PDFImage } from "./image.js";

var PartialEvaluator = (function PartialEvaluatorClosure() {
  const DefaultPartialEvaluatorOptions = {
    forceDataSchema: false,
    maxImageSize: -1,
    disableFontFace: false,
    nativeImageDecoderSupport: NativeImageDecoding.DECODE,
    ignoreErrors: false,
    isEvalSupported: true,
  };

  function PartialEvaluator({
    xref,
    handler,
    pageIndex,
    idFactory,
    fontCache,
    builtInCMapCache,
    options = null,
    pdfFunctionFactory,
  }) {
    this.xref = xref;
    this.handler = handler;
    this.pageIndex = pageIndex;
    this.idFactory = idFactory;
    this.fontCache = fontCache;
    this.builtInCMapCache = builtInCMapCache;
    this.options = options || DefaultPartialEvaluatorOptions;
    this.pdfFunctionFactory = pdfFunctionFactory;
    this.parsingType3Font = false;

    this.fetchBuiltInCMap = async name => {
      if (this.builtInCMapCache.has(name)) {
        return this.builtInCMapCache.get(name);
      }
      const readableStream = this.handler.sendWithStream("FetchBuiltInCMap", {
        name,
      });
      const reader = readableStream.getReader();

      const data = await new Promise(function(resolve, reject) {
        function pump() {
          reader.read().then(function({ value, done }) {
            if (done) {
              return;
            }
            resolve(value);
            pump();
          }, reject);
        }
        pump();
      });

      if (data.compressionType !== CMapCompressionType.NONE) {
        // Given the size of uncompressed CMaps, only cache compressed ones.
        this.builtInCMapCache.set(name, data);
      }
      return data;
    };
  }

  // Trying to minimize Date.now() usage and check every 100 time
  var TIME_SLOT_DURATION_MS = 20;
  var CHECK_TIME_EVERY = 100;
  function TimeSlotManager() {
    this.reset();
  }
  TimeSlotManager.prototype = {
    check: function TimeSlotManager_check() {
      if (++this.checked < CHECK_TIME_EVERY) {
        return false;
      }
      this.checked = 0;
      return this.endTime <= Date.now();
    },
    reset: function TimeSlotManager_reset() {
      this.endTime = Date.now() + TIME_SLOT_DURATION_MS;
      this.checked = 0;
    },
  };

  // Convert PDF blend mode names to HTML5 blend mode names.
  function normalizeBlendMode(value, parsingArray = false) {
    if (Array.isArray(value)) {
      // Use the first *supported* BM value in the Array (fixes issue11279.pdf).
      for (let i = 0, ii = value.length; i < ii; i++) {
        const maybeBM = normalizeBlendMode(value[i], /* parsingArray = */ true);
        if (maybeBM) {
          return maybeBM;
        }
      }
      warn(`Unsupported blend mode Array: ${value}`);
      return "source-over";
    }

    if (!isName(value)) {
      if (parsingArray) {
        return null;
      }
      return "source-over";
    }
    switch (value.name) {
      case "Normal":
      case "Compatible":
        return "source-over";
      case "Multiply":
        return "multiply";
      case "Screen":
        return "screen";
      case "Overlay":
        return "overlay";
      case "Darken":
        return "darken";
      case "Lighten":
        return "lighten";
      case "ColorDodge":
        return "color-dodge";
      case "ColorBurn":
        return "color-burn";
      case "HardLight":
        return "hard-light";
      case "SoftLight":
        return "soft-light";
      case "Difference":
        return "difference";
      case "Exclusion":
        return "exclusion";
      case "Hue":
        return "hue";
      case "Saturation":
        return "saturation";
      case "Color":
        return "color";
      case "Luminosity":
        return "luminosity";
    }
    if (parsingArray) {
      return null;
    }
    warn(`Unsupported blend mode: ${value.name}`);
    return "source-over";
  }

  var deferred = Promise.resolve();

  var TILING_PATTERN = 1,
    SHADING_PATTERN = 2;

  PartialEvaluator.prototype = {
    clone(newOptions = DefaultPartialEvaluatorOptions) {
      var newEvaluator = Object.create(this);
      newEvaluator.options = newOptions;
      return newEvaluator;
    },

    hasBlendModes: function PartialEvaluator_hasBlendModes(resources) {
      if (!(resources instanceof Dict)) {
        return false;
      }

      var processed = Object.create(null);
      if (resources.objId) {
        processed[resources.objId] = true;
      }

      var nodes = [resources],
        xref = this.xref;
      while (nodes.length) {
        var node = nodes.shift();
        // First check the current resources for blend modes.
        var graphicStates = node.get("ExtGState");
        if (graphicStates instanceof Dict) {
          var graphicStatesKeys = graphicStates.getKeys();
          for (let i = 0, ii = graphicStatesKeys.length; i < ii; i++) {
            const key = graphicStatesKeys[i];

            let graphicState = graphicStates.getRaw(key);
            if (graphicState instanceof Ref) {
              if (processed[graphicState.toString()]) {
                continue; // The ExtGState has already been processed.
              }
              graphicState = xref.fetch(graphicState);
            }
            if (!(graphicState instanceof Dict)) {
              continue;
            }
            if (graphicState.objId) {
              processed[graphicState.objId] = true;
            }

            const bm = graphicState.get("BM");
            if (bm instanceof Name) {
              if (bm.name !== "Normal") {
                return true;
              }
              continue;
            }
            if (bm !== undefined && Array.isArray(bm)) {
              for (let j = 0, jj = bm.length; j < jj; j++) {
                if (bm[j] instanceof Name && bm[j].name !== "Normal") {
                  return true;
                }
              }
            }
          }
        }
        // Descend into the XObjects to look for more resources and blend modes.
        var xObjects = node.get("XObject");
        if (!(xObjects instanceof Dict)) {
          continue;
        }
        var xObjectsKeys = xObjects.getKeys();
        for (let i = 0, ii = xObjectsKeys.length; i < ii; i++) {
          const key = xObjectsKeys[i];

          var xObject = xObjects.getRaw(key);
          if (xObject instanceof Ref) {
            if (processed[xObject.toString()]) {
              // The XObject has already been processed, and by avoiding a
              // redundant `xref.fetch` we can *significantly* reduce the load
              // time for badly generated PDF files (fixes issue6961.pdf).
              continue;
            }
            xObject = xref.fetch(xObject);
          }
          if (!isStream(xObject)) {
            continue;
          }
          if (xObject.dict.objId) {
            if (processed[xObject.dict.objId]) {
              continue; // Stream has objId and was processed already.
            }
            processed[xObject.dict.objId] = true;
          }
          var xResources = xObject.dict.get("Resources");
          // Checking objId to detect an infinite loop.
          if (
            xResources instanceof Dict &&
            (!xResources.objId || !processed[xResources.objId])
          ) {
            nodes.push(xResources);
            if (xResources.objId) {
              processed[xResources.objId] = true;
            }
          }
        }
      }
      return false;
    },

    async buildFormXObject(
      resources,
      xobj,
      smask,
      operatorList,
      task,
      initialState
    ) {
      var dict = xobj.dict;
      var matrix = dict.getArray("Matrix");
      var bbox = dict.getArray("BBox");
      if (Array.isArray(bbox) && bbox.length === 4) {
        bbox = Util.normalizeRect(bbox);
      } else {
        bbox = null;
      }
      var group = dict.get("Group");
      if (group) {
        var groupOptions = {
          matrix,
          bbox,
          smask,
          isolated: false,
          knockout: false,
        };

        var groupSubtype = group.get("S");
        var colorSpace = null;
        if (isName(groupSubtype, "Transparency")) {
          groupOptions.isolated = group.get("I") || false;
          groupOptions.knockout = group.get("K") || false;
          if (group.has("CS")) {
            colorSpace = await this.parseColorSpace({
              cs: group.get("CS"),
              resources,
            });
          }
        }

        if (smask && smask.backdrop) {
          colorSpace = colorSpace || ColorSpace.singletons.rgb;
          smask.backdrop = colorSpace.getRgb(smask.backdrop, 0);
        }

        operatorList.addOp(OPS.beginGroup, [groupOptions]);
      }

      operatorList.addOp(OPS.paintFormXObjectBegin, [matrix, bbox]);

      return this.getOperatorList({
        stream: xobj,
        task,
        resources: dict.get("Resources") || resources,
        operatorList,
        initialState,
      }).then(function() {
        operatorList.addOp(OPS.paintFormXObjectEnd, []);

        if (group) {
          operatorList.addOp(OPS.endGroup, [groupOptions]);
        }
      });
    },

    async buildPaintImageXObject({
      resources,
      image,
      isInline = false,
      operatorList,
      cacheKey,
      imageCache,
      forceDisableNativeImageDecoder = false,
    }) {
      var dict = image.dict;
      var w = dict.get("Width", "W");
      var h = dict.get("Height", "H");

      if (!(w && isNum(w)) || !(h && isNum(h))) {
        warn("Image dimensions are missing, or not numbers.");
        return undefined;
      }
      var maxImageSize = this.options.maxImageSize;
      if (maxImageSize !== -1 && w * h > maxImageSize) {
        warn("Image exceeded maximum allowed size and was removed.");
        return undefined;
      }

      var imageMask = dict.get("ImageMask", "IM") || false;
      var imgData, args;
      if (imageMask) {
        // This depends on a tmpCanvas being filled with the
        // current fillStyle, such that processing the pixel
        // data can't be done here. Instead of creating a
        // complete PDFImage, only read the information needed
        // for later.

        var width = dict.get("Width", "W");
        var height = dict.get("Height", "H");
        var bitStrideLength = (width + 7) >> 3;
        var imgArray = image.getBytes(
          bitStrideLength * height,
          /* forceClamped = */ true
        );
        var decode = dict.getArray("Decode", "D");

        imgData = PDFImage.createMask({
          imgArray,
          width,
          height,
          imageIsFromDecodeStream: image instanceof DecodeStream,
          inverseDecode: !!decode && decode[0] > 0,
        });
        imgData.cached = !!cacheKey;
        args = [imgData];

        operatorList.addOp(OPS.paintImageMaskXObject, args);
        if (cacheKey) {
          imageCache[cacheKey] = {
            fn: OPS.paintImageMaskXObject,
            args,
          };
        }
        return undefined;
      }

      var softMask = dict.get("SMask", "SM") || false;
      var mask = dict.get("Mask") || false;

      var SMALL_IMAGE_DIMENSIONS = 200;
      // Inlining small images into the queue as RGB data
      if (
        isInline &&
        !softMask &&
        !mask &&
        !(image instanceof JpegStream) &&
        w + h < SMALL_IMAGE_DIMENSIONS
      ) {
        let imageObj = new PDFImage({
          xref: this.xref,
          res: resources,
          image,
          isInline,
          pdfFunctionFactory: this.pdfFunctionFactory,
        });
        // We force the use of RGBA_32BPP images here, because we can't handle
        // any other kind.
        imgData = imageObj.createImageData(/* forceRGBA = */ true);
        operatorList.addOp(OPS.paintInlineImageXObject, [imgData]);
        return undefined;
      }

      const nativeImageDecoderSupport = forceDisableNativeImageDecoder
        ? NativeImageDecoding.NONE
        : this.options.nativeImageDecoderSupport;
      // If there is no imageMask, create the PDFImage and a lot
      // of image processing can be done here.
      let objId = `img_${this.idFactory.createObjId()}`;

      if (this.parsingType3Font) {
        assert(
          nativeImageDecoderSupport === NativeImageDecoding.NONE,
          "Type3 image resources should be completely decoded in the worker."
        );

        objId = `${this.idFactory.getDocId()}_type3res_${objId}`;
      }

      if (
        nativeImageDecoderSupport !== NativeImageDecoding.NONE &&
        !softMask &&
        !mask &&
        image instanceof JpegStream &&
        NativeImageDecoder.isSupported(
          image,
          this.xref,
          resources,
          this.pdfFunctionFactory
        )
      ) {
        // These JPEGs don't need any more processing so we can just send it.
        return this.handler
          .sendWithPromise("obj", [
            objId,
            this.pageIndex,
            "JpegStream",
            image.getIR(this.options.forceDataSchema),
          ])
          .then(
            function() {
              // Only add the dependency once we know that the native JPEG
              // decoding succeeded, to ensure that rendering will always
              // complete.
              operatorList.addDependency(objId);
              args = [objId, w, h];

              operatorList.addOp(OPS.paintJpegXObject, args);
              if (cacheKey) {
                imageCache[cacheKey] = {
                  fn: OPS.paintJpegXObject,
                  args,
                };
              }
            },
            reason => {
              warn(
                "Native JPEG decoding failed -- trying to recover: " +
                  (reason && reason.message)
              );
              // Try to decode the JPEG image with the built-in decoder instead.
              return this.buildPaintImageXObject({
                resources,
                image,
                isInline,
                operatorList,
                cacheKey,
                imageCache,
                forceDisableNativeImageDecoder: true,
              });
            }
          );
      }

      // Creates native image decoder only if a JPEG image or mask is present.
      var nativeImageDecoder = null;
      if (
        nativeImageDecoderSupport === NativeImageDecoding.DECODE &&
        (image instanceof JpegStream ||
          mask instanceof JpegStream ||
          softMask instanceof JpegStream)
      ) {
        nativeImageDecoder = new NativeImageDecoder({
          xref: this.xref,
          resources,
          handler: this.handler,
          forceDataSchema: this.options.forceDataSchema,
          pdfFunctionFactory: this.pdfFunctionFactory,
        });
      }

      // Ensure that the dependency is added before the image is decoded.
      operatorList.addDependency(objId);
      args = [objId, w, h];

      const imgPromise = PDFImage.buildImage({
        handler: this.handler,
        xref: this.xref,
        res: resources,
        image,
        isInline,
        nativeDecoder: nativeImageDecoder,
        pdfFunctionFactory: this.pdfFunctionFactory,
      })
        .then(imageObj => {
          var imgData = imageObj.createImageData(/* forceRGBA = */ false);

          if (this.parsingType3Font) {
            return this.handler.sendWithPromise(
              "commonobj",
              [objId, "FontType3Res", imgData],
              [imgData.data.buffer]
            );
          }
          this.handler.send(
            "obj",
            [objId, this.pageIndex, "Image", imgData],
            [imgData.data.buffer]
          );
          return undefined;
        })
        .catch(reason => {
          warn("Unable to decode image: " + reason);

          if (this.parsingType3Font) {
            return this.handler.sendWithPromise("commonobj", [
              objId,
              "FontType3Res",
              null,
            ]);
          }
          this.handler.send("obj", [objId, this.pageIndex, "Image", null]);
          return undefined;
        });

      if (this.parsingType3Font) {
        // In the very rare case where a Type3 image resource is being parsed,
        // wait for the image to be both decoded *and* sent to simplify the
        // rendering code on the main-thread (see issue10717.pdf).
        await imgPromise;
      }

      operatorList.addOp(OPS.paintImageXObject, args);
      if (cacheKey) {
        imageCache[cacheKey] = {
          fn: OPS.paintImageXObject,
          args,
        };
      }
      return undefined;
    },

    handleSMask: function PartialEvaluator_handleSmask(
      smask,
      resources,
      operatorList,
      task,
      stateManager
    ) {
      var smaskContent = smask.get("G");
      var smaskOptions = {
        subtype: smask.get("S").name,
        backdrop: smask.get("BC"),
      };

      // The SMask might have a alpha/luminosity value transfer function --
      // we will build a map of integer values in range 0..255 to be fast.
      var transferObj = smask.get("TR");
      if (isPDFFunction(transferObj)) {
        let transferFn = this.pdfFunctionFactory.create(transferObj);
        var transferMap = new Uint8Array(256);
        var tmp = new Float32Array(1);
        for (var i = 0; i < 256; i++) {
          tmp[0] = i / 255;
          transferFn(tmp, 0, tmp, 0);
          transferMap[i] = (tmp[0] * 255) | 0;
        }
        smaskOptions.transferMap = transferMap;
      }

      return this.buildFormXObject(
        resources,
        smaskContent,
        smaskOptions,
        operatorList,
        task,
        stateManager.state.clone()
      );
    },

    handleTilingType(
      fn,
      args,
      resources,
      pattern,
      patternDict,
      operatorList,
      task
    ) {
      // Create an IR of the pattern code.
      let tilingOpList = new OperatorList();
      // Merge the available resources, to prevent issues when the patternDict
      // is missing some /Resources entries (fixes issue6541.pdf).
      let resourcesArray = [patternDict.get("Resources"), resources];
      let patternResources = Dict.merge(this.xref, resourcesArray);

      return this.getOperatorList({
        stream: pattern,
        task,
        resources: patternResources,
        operatorList: tilingOpList,
      })
        .then(function() {
          return getTilingPatternIR(
            {
              fnArray: tilingOpList.fnArray,
              argsArray: tilingOpList.argsArray,
            },
            patternDict,
            args
          );
        })
        .then(
          function(tilingPatternIR) {
            // Add the dependencies to the parent operator list so they are
            // resolved before the sub operator list is executed synchronously.
            operatorList.addDependencies(tilingOpList.dependencies);
            operatorList.addOp(fn, tilingPatternIR);
          },
          reason => {
            if (reason instanceof AbortException) {
              return;
            }
            if (this.options.ignoreErrors) {
              // Error(s) in the TilingPattern -- sending unsupported feature
              // notification and allow rendering to continue.
              this.handler.send("UnsupportedFeature", {
                featureId: UNSUPPORTED_FEATURES.unknown,
              });
              warn(`handleTilingType - ignoring pattern: "${reason}".`);
              return;
            }
            throw reason;
          }
        );
    },

    handleSetFont: function PartialEvaluator_handleSetFont(
      resources,
      fontArgs,
      fontRef,
      operatorList,
      task,
      state
    ) {
      // TODO(mack): Not needed?
      var fontName;
      if (fontArgs) {
        fontArgs = fontArgs.slice();
        fontName = fontArgs[0].name;
      }

      return this.loadFont(fontName, fontRef, resources)
        .then(translated => {
          if (!translated.font.isType3Font) {
            return translated;
          }
          return translated
            .loadType3Data(this, resources, operatorList, task)
            .then(function() {
              return translated;
            })
            .catch(reason => {
              // Error in the font data -- sending unsupported feature
              // notification.
              this.handler.send("UnsupportedFeature", {
                featureId: UNSUPPORTED_FEATURES.font,
              });
              return new TranslatedFont(
                "g_font_error",
                new ErrorFont("Type3 font load error: " + reason),
                translated.font
              );
            });
        })
        .then(translated => {
          state.font = translated.font;
          translated.send(this.handler);
          return translated.loadedName;
        });
    },

    handleText(chars, state) {
      const font = state.font;
      const glyphs = font.charsToGlyphs(chars);

      if (font.data) {
        const isAddToPathSet = !!(
          state.textRenderingMode & TextRenderingMode.ADD_TO_PATH_FLAG
        );
        if (
          isAddToPathSet ||
          state.fillColorSpace.name === "Pattern" ||
          font.disableFontFace ||
          this.options.disableFontFace
        ) {
          PartialEvaluator.buildFontPaths(font, glyphs, this.handler);
        }
      }
      return glyphs;
    },

    setGState: function PartialEvaluator_setGState(
      resources,
      gState,
      operatorList,
      task,
      stateManager
    ) {
      // This array holds the converted/processed state data.
      var gStateObj = [];
      var gStateKeys = gState.getKeys();
      var promise = Promise.resolve();
      for (var i = 0, ii = gStateKeys.length; i < ii; i++) {
        let key = gStateKeys[i];
        let value = gState.get(key);
        switch (key) {
          case "Type":
            break;
          case "LW":
          case "LC":
          case "LJ":
          case "ML":
          case "D":
          case "RI":
          case "FL":
          case "CA":
          case "ca":
            gStateObj.push([key, value]);
            break;
          case "Font":
            promise = promise.then(() => {
              return this.handleSetFont(
                resources,
                null,
                value[0],
                operatorList,
                task,
                stateManager.state
              ).then(function(loadedName) {
                operatorList.addDependency(loadedName);
                gStateObj.push([key, [loadedName, value[1]]]);
              });
            });
            break;
          case "BM":
            gStateObj.push([key, normalizeBlendMode(value)]);
            break;
          case "SMask":
            if (isName(value, "None")) {
              gStateObj.push([key, false]);
              break;
            }
            if (isDict(value)) {
              promise = promise.then(() => {
                return this.handleSMask(
                  value,
                  resources,
                  operatorList,
                  task,
                  stateManager
                );
              });
              gStateObj.push([key, true]);
            } else {
              warn("Unsupported SMask type");
            }

            break;
          // Only generate info log messages for the following since
          // they are unlikely to have a big impact on the rendering.
          case "OP":
          case "op":
          case "OPM":
          case "BG":
          case "BG2":
          case "UCR":
          case "UCR2":
          case "TR":
          case "TR2":
          case "HT":
          case "SM":
          case "SA":
          case "AIS":
          case "TK":
            // TODO implement these operators.
            info("graphic state operator " + key);
            break;
          default:
            info("Unknown graphic state operator " + key);
            break;
        }
      }
      return promise.then(function() {
        if (gStateObj.length > 0) {
          operatorList.addOp(OPS.setGState, [gStateObj]);
        }
      });
    },

    loadFont: function PartialEvaluator_loadFont(fontName, font, resources) {
      function errorFont() {
        return Promise.resolve(
          new TranslatedFont(
            "g_font_error",
            new ErrorFont("Font " + fontName + " is not available"),
            font
          )
        );
      }

      var fontRef,
        xref = this.xref;
      if (font) {
        // Loading by ref.
        if (!isRef(font)) {
          throw new FormatError('The "font" object should be a reference.');
        }
        fontRef = font;
      } else {
        // Loading by name.
        var fontRes = resources.get("Font");
        if (fontRes) {
          fontRef = fontRes.getRaw(fontName);
        }
      }
      if (!fontRef) {
        const partialMsg = `Font "${fontName ||
          (font && font.toString())}" is not available`;

        if (!this.options.ignoreErrors && !this.parsingType3Font) {
          warn(`${partialMsg}.`);
          return errorFont();
        }
        // Font not found -- sending unsupported feature notification.
        this.handler.send("UnsupportedFeature", {
          featureId: UNSUPPORTED_FEATURES.font,
        });
        warn(`${partialMsg} -- attempting to fallback to a default font.`);

        // Falling back to a default font to avoid completely broken rendering,
        // but note that there're no guarantees that things will look "correct".
        fontRef = new Dict();
        fontRef.set("BaseFont", Name.get("PDFJS-FallbackFont"));
        fontRef.set("Type", Name.get("FallbackType"));
        fontRef.set("Subtype", Name.get("FallbackType"));
        fontRef.set("Encoding", Name.get("WinAnsiEncoding"));
      }

      if (this.fontCache.has(fontRef)) {
        return this.fontCache.get(fontRef);
      }

      font = xref.fetchIfRef(fontRef);
      if (!isDict(font)) {
        return errorFont();
      }

      // We are holding `font.translated` references just for `fontRef`s that
      // are not actually `Ref`s, but rather `Dict`s. See explanation below.
      if (font.translated) {
        return font.translated;
      }

      var fontCapability = createPromiseCapability();

      var preEvaluatedFont = this.preEvaluateFont(font);
      const { descriptor, hash } = preEvaluatedFont;

      var fontRefIsRef = isRef(fontRef),
        fontID;
      if (fontRefIsRef) {
        fontID = fontRef.toString();
      }

      if (hash && isDict(descriptor)) {
        if (!descriptor.fontAliases) {
          descriptor.fontAliases = Object.create(null);
        }
        var fontAliases = descriptor.fontAliases;

        if (fontAliases[hash]) {
          var aliasFontRef = fontAliases[hash].aliasRef;
          if (
            fontRefIsRef &&
            aliasFontRef &&
            this.fontCache.has(aliasFontRef)
          ) {
            this.fontCache.putAlias(fontRef, aliasFontRef);
            return this.fontCache.get(fontRef);
          }
        } else {
          fontAliases[hash] = {
            fontID: Font.getFontID(),
          };
        }

        if (fontRefIsRef) {
          fontAliases[hash].aliasRef = fontRef;
        }
        fontID = fontAliases[hash].fontID;
      }

      // Workaround for bad PDF generators that reference fonts incorrectly,
      // where `fontRef` is a `Dict` rather than a `Ref` (fixes bug946506.pdf).
      // In this case we should not put the font into `this.fontCache` (which is
      // a `RefSetCache`), since it's not meaningful to use a `Dict` as a key.
      //
      // However, if we don't cache the font it's not possible to remove it
      // when `cleanup` is triggered from the API, which causes issues on
      // subsequent rendering operations (see issue7403.pdf).
      // A simple workaround would be to just not hold `font.translated`
      // references in this case, but this would force us to unnecessarily load
      // the same fonts over and over.
      //
      // Instead, we cheat a bit by attempting to use a modified `fontID` as a
      // key in `this.fontCache`, to allow the font to be cached.
      // NOTE: This works because `RefSetCache` calls `toString()` on provided
      //       keys. Also, since `fontRef` is used when getting cached fonts,
      //       we'll not accidentally match fonts cached with the `fontID`.
      if (fontRefIsRef) {
        this.fontCache.put(fontRef, fontCapability.promise);
      } else {
        if (!fontID) {
          fontID = this.idFactory.createObjId();
        }
        this.fontCache.put(`id_${fontID}`, fontCapability.promise);
      }
      assert(fontID, 'The "fontID" must be defined.');

      // Keep track of each font we translated so the caller can
      // load them asynchronously before calling display on a page.
      font.loadedName = `${this.idFactory.getDocId()}_f${fontID}`;

      font.translated = fontCapability.promise;

      // TODO move promises into translate font
      var translatedPromise;
      try {
        translatedPromise = this.translateFont(preEvaluatedFont);
      } catch (e) {
        translatedPromise = Promise.reject(e);
      }

      translatedPromise
        .then(function(translatedFont) {
          if (translatedFont.fontType !== undefined) {
            var xrefFontStats = xref.stats.fontTypes;
            xrefFontStats[translatedFont.fontType] = true;
          }

          fontCapability.resolve(
            new TranslatedFont(font.loadedName, translatedFont, font)
          );
        })
        .catch(reason => {
          // TODO fontCapability.reject?
          // Error in the font data -- sending unsupported feature notification.
          this.handler.send("UnsupportedFeature", {
            featureId: UNSUPPORTED_FEATURES.font,
          });

          try {
            // error, but it's still nice to have font type reported
            var fontFile3 = descriptor && descriptor.get("FontFile3");
            var subtype = fontFile3 && fontFile3.get("Subtype");
            var fontType = getFontType(
              preEvaluatedFont.type,
              subtype && subtype.name
            );
            var xrefFontStats = xref.stats.fontTypes;
            xrefFontStats[fontType] = true;
          } catch (ex) {}

          fontCapability.resolve(
            new TranslatedFont(
              font.loadedName,
              new ErrorFont(reason instanceof Error ? reason.message : reason),
              font
            )
          );
        });
      return fontCapability.promise;
    },

    buildPath(operatorList, fn, args, parsingText = false) {
      var lastIndex = operatorList.length - 1;
      if (!args) {
        args = [];
      }
      if (
        lastIndex < 0 ||
        operatorList.fnArray[lastIndex] !== OPS.constructPath
      ) {
        // Handle corrupt PDF documents that contains path operators inside of
        // text objects, which may shift subsequent text, by enclosing the path
        // operator in save/restore operators (fixes issue10542_reduced.pdf).
        //
        // Note that this will effectively disable the optimization in the
        // `else` branch below, but given that this type of corruption is
        // *extremely* rare that shouldn't really matter much in practice.
        if (parsingText) {
          warn(`Encountered path operator "${fn}" inside of a text object.`);
          operatorList.addOp(OPS.save, null);
        }

        operatorList.addOp(OPS.constructPath, [[fn], args]);

        if (parsingText) {
          operatorList.addOp(OPS.restore, null);
        }
      } else {
        var opArgs = operatorList.argsArray[lastIndex];
        opArgs[0].push(fn);
        Array.prototype.push.apply(opArgs[1], args);
      }
    },

    parseColorSpace({ cs, resources }) {
      return new Promise(resolve => {
        resolve(
          ColorSpace.parse(cs, this.xref, resources, this.pdfFunctionFactory)
        );
      }).catch(reason => {
        if (reason instanceof AbortException) {
          return null;
        }
        if (this.options.ignoreErrors) {
          // Error(s) in the ColorSpace -- sending unsupported feature
          // notification and allow rendering to continue.
          this.handler.send("UnsupportedFeature", {
            featureId: UNSUPPORTED_FEATURES.unknown,
          });
          warn(`parseColorSpace - ignoring ColorSpace: "${reason}".`);
          return null;
        }
        throw reason;
      });
    },

    async handleColorN(operatorList, fn, args, cs, patterns, resources, task) {
      // compile tiling patterns
      var patternName = args[args.length - 1];
      // SCN/scn applies patterns along with normal colors
      var pattern;
      if (isName(patternName) && (pattern = patterns.get(patternName.name))) {
        var dict = isStream(pattern) ? pattern.dict : pattern;
        var typeNum = dict.get("PatternType");

        if (typeNum === TILING_PATTERN) {
          var color = cs.base ? cs.base.getRgb(args, 0) : null;
          return this.handleTilingType(
            fn,
            color,
            resources,
            pattern,
            dict,
            operatorList,
            task
          );
        } else if (typeNum === SHADING_PATTERN) {
          var shading = dict.get("Shading");
          var matrix = dict.getArray("Matrix");
          pattern = Pattern.parseShading(
            shading,
            matrix,
            this.xref,
            resources,
            this.handler,
            this.pdfFunctionFactory
          );
          operatorList.addOp(fn, pattern.getIR());
          return undefined;
        }
        throw new FormatError(`Unknown PatternType: ${typeNum}`);
      }
      throw new FormatError(`Unknown PatternName: ${patternName}`);
    },

    getOperatorList({
      stream,
      task,
      resources,
      operatorList,
      initialState = null,
    }) {
      // Ensure that `resources`/`initialState` is correctly initialized,
      // even if the provided parameter is e.g. `null`.
      resources = resources || Dict.empty;
      initialState = initialState || new EvalState();

      if (!operatorList) {
        throw new Error('getOperatorList: missing "operatorList" parameter');
      }

      var self = this;
      var xref = this.xref;
      let parsingText = false;
      var imageCache = Object.create(null);

      var xobjs = resources.get("XObject") || Dict.empty;
      var patterns = resources.get("Pattern") || Dict.empty;
      var stateManager = new StateManager(initialState);
      var preprocessor = new EvaluatorPreprocessor(stream, xref, stateManager);
      var timeSlotManager = new TimeSlotManager();

      function closePendingRestoreOPS(argument) {
        for (var i = 0, ii = preprocessor.savedStatesDepth; i < ii; i++) {
          operatorList.addOp(OPS.restore, []);
        }
      }

      return new Promise(function promiseBody(resolve, reject) {
        let next = function(promise) {
          Promise.all([promise, operatorList.ready]).then(function() {
            try {
              promiseBody(resolve, reject);
            } catch (ex) {
              reject(ex);
            }
          }, reject);
        };
        task.ensureNotTerminated();
        timeSlotManager.reset();
        var stop,
          operation = {},
          i,
          ii,
          cs;
        while (!(stop = timeSlotManager.check())) {
          // The arguments parsed by read() are used beyond this loop, so we
          // cannot reuse the same array on each iteration. Therefore we pass
          // in |null| as the initial value (see the comment on
          // EvaluatorPreprocessor_read() for why).
          operation.args = null;
          if (!preprocessor.read(operation)) {
            break;
          }
          var args = operation.args;
          var fn = operation.fn;

          switch (fn | 0) {
            case OPS.paintXObject:
              // eagerly compile XForm objects
              var name = args[0].name;
              if (name && imageCache[name] !== undefined) {
                operatorList.addOp(imageCache[name].fn, imageCache[name].args);
                args = null;
                continue;
              }

              next(
                new Promise(function(resolveXObject, rejectXObject) {
                  if (!name) {
                    throw new FormatError(
                      "XObject must be referred to by name."
                    );
                  }

                  let xobj = xobjs.get(name);
                  if (!xobj) {
                    operatorList.addOp(fn, args);
                    resolveXObject();
                    return;
                  }
                  if (!isStream(xobj)) {
                    throw new FormatError("XObject should be a stream");
                  }

                  let type = xobj.dict.get("Subtype");
                  if (!isName(type)) {
                    throw new FormatError("XObject should have a Name subtype");
                  }

                  if (type.name === "Form") {
                    stateManager.save();
                    self
                      .buildFormXObject(
                        resources,
                        xobj,
                        null,
                        operatorList,
                        task,
                        stateManager.state.clone()
                      )
                      .then(function() {
                        stateManager.restore();
                        resolveXObject();
                      }, rejectXObject);
                    return;
                  } else if (type.name === "Image") {
                    self
                      .buildPaintImageXObject({
                        resources,
                        image: xobj,
                        operatorList,
                        cacheKey: name,
                        imageCache,
                      })
                      .then(resolveXObject, rejectXObject);
                    return;
                  } else if (type.name === "PS") {
                    // PostScript XObjects are unused when viewing documents.
                    // See section 4.7.1 of Adobe's PDF reference.
                    info("Ignored XObject subtype PS");
                  } else {
                    throw new FormatError(
                      `Unhandled XObject subtype ${type.name}`
                    );
                  }
                  resolveXObject();
                }).catch(function(reason) {
                  if (reason instanceof AbortException) {
                    return;
                  }
                  if (self.options.ignoreErrors) {
                    // Error(s) in the XObject -- sending unsupported feature
                    // notification and allow rendering to continue.
                    self.handler.send("UnsupportedFeature", {
                      featureId: UNSUPPORTED_FEATURES.unknown,
                    });
                    warn(`getOperatorList - ignoring XObject: "${reason}".`);
                    return;
                  }
                  throw reason;
                })
              );
              return;
            case OPS.setFont:
              var fontSize = args[1];
              // eagerly collect all fonts
              next(
                self
                  .handleSetFont(
                    resources,
                    args,
                    null,
                    operatorList,
                    task,
                    stateManager.state
                  )
                  .then(function(loadedName) {
                    operatorList.addDependency(loadedName);
                    operatorList.addOp(OPS.setFont, [loadedName, fontSize]);
                  })
              );
              return;
            case OPS.beginText:
              parsingText = true;
              break;
            case OPS.endText:
              parsingText = false;
              break;
            case OPS.endInlineImage:
              var cacheKey = args[0].cacheKey;
              if (cacheKey) {
                var cacheEntry = imageCache[cacheKey];
                if (cacheEntry !== undefined) {
                  operatorList.addOp(cacheEntry.fn, cacheEntry.args);
                  args = null;
                  continue;
                }
              }
              next(
                self.buildPaintImageXObject({
                  resources,
                  image: args[0],
                  isInline: true,
                  operatorList,
                  cacheKey,
                  imageCache,
                })
              );
              return;
            case OPS.showText:
              args[0] = self.handleText(args[0], stateManager.state);
              break;
            case OPS.showSpacedText:
              var arr = args[0];
              var combinedGlyphs = [];
              var arrLength = arr.length;
              var state = stateManager.state;
              for (i = 0; i < arrLength; ++i) {
                var arrItem = arr[i];
                if (isString(arrItem)) {
                  Array.prototype.push.apply(
                    combinedGlyphs,
                    self.handleText(arrItem, state)
                  );
                } else if (isNum(arrItem)) {
                  combinedGlyphs.push(arrItem);
                }
              }
              args[0] = combinedGlyphs;
              fn = OPS.showText;
              break;
            case OPS.nextLineShowText:
              operatorList.addOp(OPS.nextLine);
              args[0] = self.handleText(args[0], stateManager.state);
              fn = OPS.showText;
              break;
            case OPS.nextLineSetSpacingShowText:
              operatorList.addOp(OPS.nextLine);
              operatorList.addOp(OPS.setWordSpacing, [args.shift()]);
              operatorList.addOp(OPS.setCharSpacing, [args.shift()]);
              args[0] = self.handleText(args[0], stateManager.state);
              fn = OPS.showText;
              break;
            case OPS.setTextRenderingMode:
              stateManager.state.textRenderingMode = args[0];
              break;

            case OPS.setFillColorSpace:
              next(
                self
                  .parseColorSpace({
                    cs: args[0],
                    resources,
                  })
                  .then(function(colorSpace) {
                    if (colorSpace) {
                      stateManager.state.fillColorSpace = colorSpace;
                    }
                  })
              );
              return;
            case OPS.setStrokeColorSpace:
              next(
                self
                  .parseColorSpace({
                    cs: args[0],
                    resources,
                  })
                  .then(function(colorSpace) {
                    if (colorSpace) {
                      stateManager.state.strokeColorSpace = colorSpace;
                    }
                  })
              );
              return;
            case OPS.setFillColor:
              cs = stateManager.state.fillColorSpace;
              args = cs.getRgb(args, 0);
              fn = OPS.setFillRGBColor;
              break;
            case OPS.setStrokeColor:
              cs = stateManager.state.strokeColorSpace;
              args = cs.getRgb(args, 0);
              fn = OPS.setStrokeRGBColor;
              break;
            case OPS.setFillGray:
              stateManager.state.fillColorSpace = ColorSpace.singletons.gray;
              args = ColorSpace.singletons.gray.getRgb(args, 0);
              fn = OPS.setFillRGBColor;
              break;
            case OPS.setStrokeGray:
              stateManager.state.strokeColorSpace = ColorSpace.singletons.gray;
              args = ColorSpace.singletons.gray.getRgb(args, 0);
              fn = OPS.setStrokeRGBColor;
              break;
            case OPS.setFillCMYKColor:
              stateManager.state.fillColorSpace = ColorSpace.singletons.cmyk;
              args = ColorSpace.singletons.cmyk.getRgb(args, 0);
              fn = OPS.setFillRGBColor;
              break;
            case OPS.setStrokeCMYKColor:
              stateManager.state.strokeColorSpace = ColorSpace.singletons.cmyk;
              args = ColorSpace.singletons.cmyk.getRgb(args, 0);
              fn = OPS.setStrokeRGBColor;
              break;
            case OPS.setFillRGBColor:
              stateManager.state.fillColorSpace = ColorSpace.singletons.rgb;
              args = ColorSpace.singletons.rgb.getRgb(args, 0);
              break;
            case OPS.setStrokeRGBColor:
              stateManager.state.strokeColorSpace = ColorSpace.singletons.rgb;
              args = ColorSpace.singletons.rgb.getRgb(args, 0);
              break;
            case OPS.setFillColorN:
              cs = stateManager.state.fillColorSpace;
              if (cs.name === "Pattern") {
                next(
                  self.handleColorN(
                    operatorList,
                    OPS.setFillColorN,
                    args,
                    cs,
                    patterns,
                    resources,
                    task
                  )
                );
                return;
              }
              args = cs.getRgb(args, 0);
              fn = OPS.setFillRGBColor;
              break;
            case OPS.setStrokeColorN:
              cs = stateManager.state.strokeColorSpace;
              if (cs.name === "Pattern") {
                next(
                  self.handleColorN(
                    operatorList,
                    OPS.setStrokeColorN,
                    args,
                    cs,
                    patterns,
                    resources,
                    task
                  )
                );
                return;
              }
              args = cs.getRgb(args, 0);
              fn = OPS.setStrokeRGBColor;
              break;

            case OPS.shadingFill:
              var shadingRes = resources.get("Shading");
              if (!shadingRes) {
                throw new FormatError("No shading resource found");
              }

              var shading = shadingRes.get(args[0].name);
              if (!shading) {
                throw new FormatError("No shading object found");
              }

              var shadingFill = Pattern.parseShading(
                shading,
                null,
                xref,
                resources,
                self.handler,
                self.pdfFunctionFactory
              );
              var patternIR = shadingFill.getIR();
              args = [patternIR];
              fn = OPS.shadingFill;
              break;
            case OPS.setGState:
              var dictName = args[0];
              var extGState = resources.get("ExtGState");

              if (!isDict(extGState) || !extGState.has(dictName.name)) {
                break;
              }

              var gState = extGState.get(dictName.name);
              next(
                self.setGState(
                  resources,
                  gState,
                  operatorList,
                  task,
                  stateManager
                )
              );
              return;
            case OPS.moveTo:
            case OPS.lineTo:
            case OPS.curveTo:
            case OPS.curveTo2:
            case OPS.curveTo3:
            case OPS.closePath:
            case OPS.rectangle:
              self.buildPath(operatorList, fn, args, parsingText);
              continue;
            case OPS.markPoint:
            case OPS.markPointProps:
            case OPS.beginMarkedContent:
            case OPS.beginMarkedContentProps:
            case OPS.endMarkedContent:
            case OPS.beginCompat:
            case OPS.endCompat:
              // Ignore operators where the corresponding handlers are known to
              // be no-op in CanvasGraphics (display/canvas.js). This prevents
              // serialization errors and is also a bit more efficient.
              // We could also try to serialize all objects in a general way,
              // e.g. as done in https://github.com/mozilla/pdf.js/pull/6266,
              // but doing so is meaningless without knowing the semantics.
              continue;
            default:
              // Note: Ignore the operator if it has `Dict` arguments, since
              // those are non-serializable, otherwise postMessage will throw
              // "An object could not be cloned.".
              if (args !== null) {
                for (i = 0, ii = args.length; i < ii; i++) {
                  if (args[i] instanceof Dict) {
                    break;
                  }
                }
                if (i < ii) {
                  warn("getOperatorList - ignoring operator: " + fn);
                  continue;
                }
              }
          }
          operatorList.addOp(fn, args);
        }
        if (stop) {
          next(deferred);
          return;
        }
        // Some PDFs don't close all restores inside object/form.
        // Closing those for them.
        closePendingRestoreOPS();
        resolve();
      }).catch(reason => {
        if (reason instanceof AbortException) {
          return;
        }
        if (this.options.ignoreErrors) {
          // Error(s) in the OperatorList -- sending unsupported feature
          // notification and allow rendering to continue.
          this.handler.send("UnsupportedFeature", {
            featureId: UNSUPPORTED_FEATURES.unknown,
          });
          warn(
            `getOperatorList - ignoring errors during "${task.name}" ` +
              `task: "${reason}".`
          );

          closePendingRestoreOPS();
          return;
        }
        throw reason;
      });
    },

    getTextContent({
      stream,
      task,
      resources,
      stateManager = null,
      normalizeWhitespace = false,
      combineTextItems = false,
      sink,
      seenStyles = Object.create(null),
    }) {
      // Ensure that `resources`/`stateManager` is correctly initialized,
      // even if the provided parameter is e.g. `null`.
      resources = resources || Dict.empty;
      stateManager = stateManager || new StateManager(new TextState());

      var WhitespaceRegexp = /\s/g;

      var textContent = {
        items: [],
        styles: Object.create(null),
      };
      var textContentItem = {
        initialized: false,
        str: [],
        width: 0,
        height: 0,
        vertical: false,
        lastAdvanceWidth: 0,
        lastAdvanceHeight: 0,
        textAdvanceScale: 0,
        spaceWidth: 0,
        fakeSpaceMin: Infinity,
        fakeMultiSpaceMin: Infinity,
        fakeMultiSpaceMax: -0,
        textRunBreakAllowed: false,
        transform: null,
        fontName: null,
      };
      var SPACE_FACTOR = 0.3;
      var MULTI_SPACE_FACTOR = 1.5;
      var MULTI_SPACE_FACTOR_MAX = 4;

      var self = this;
      var xref = this.xref;

      // The xobj is parsed iff it's needed, e.g. if there is a `DO` cmd.
      var xobjs = null;
      var skipEmptyXObjs = Object.create(null);

      var preprocessor = new EvaluatorPreprocessor(stream, xref, stateManager);

      var textState;

      function ensureTextContentItem() {
        if (textContentItem.initialized) {
          return textContentItem;
        }
        var font = textState.font;
        if (!(font.loadedName in seenStyles)) {
          seenStyles[font.loadedName] = true;
          textContent.styles[font.loadedName] = {
            fontFamily: font.fallbackName,
            ascent: font.ascent,
            descent: font.descent,
            vertical: !!font.vertical,
          };
        }
        textContentItem.fontName = font.loadedName;

        // 9.4.4 Text Space Details
        var tsm = [
          textState.fontSize * textState.textHScale,
          0,
          0,
          textState.fontSize,
          0,
          textState.textRise,
        ];

        if (
          font.isType3Font &&
          textState.fontSize <= 1 &&
          !isArrayEqual(textState.fontMatrix, FONT_IDENTITY_MATRIX)
        ) {
          const glyphHeight = font.bbox[3] - font.bbox[1];
          if (glyphHeight > 0) {
            tsm[3] *= glyphHeight * textState.fontMatrix[3];
          }
        }

        var trm = Util.transform(
          textState.ctm,
          Util.transform(textState.textMatrix, tsm)
        );
        textContentItem.transform = trm;
        if (!font.vertical) {
          textContentItem.width = 0;
          textContentItem.height = Math.sqrt(trm[2] * trm[2] + trm[3] * trm[3]);
          textContentItem.vertical = false;
        } else {
          textContentItem.width = Math.sqrt(trm[0] * trm[0] + trm[1] * trm[1]);
          textContentItem.height = 0;
          textContentItem.vertical = true;
        }

        var a = textState.textLineMatrix[0];
        var b = textState.textLineMatrix[1];
        var scaleLineX = Math.sqrt(a * a + b * b);
        a = textState.ctm[0];
        b = textState.ctm[1];
        var scaleCtmX = Math.sqrt(a * a + b * b);
        textContentItem.textAdvanceScale = scaleCtmX * scaleLineX;
        textContentItem.lastAdvanceWidth = 0;
        textContentItem.lastAdvanceHeight = 0;

        var spaceWidth = (font.spaceWidth / 1000) * textState.fontSize;
        if (spaceWidth) {
          textContentItem.spaceWidth = spaceWidth;
          textContentItem.fakeSpaceMin = spaceWidth * SPACE_FACTOR;
          textContentItem.fakeMultiSpaceMin = spaceWidth * MULTI_SPACE_FACTOR;
          textContentItem.fakeMultiSpaceMax =
            spaceWidth * MULTI_SPACE_FACTOR_MAX;
          // It's okay for monospace fonts to fake as much space as needed.
          textContentItem.textRunBreakAllowed = !font.isMonospace;
        } else {
          textContentItem.spaceWidth = 0;
          textContentItem.fakeSpaceMin = Infinity;
          textContentItem.fakeMultiSpaceMin = Infinity;
          textContentItem.fakeMultiSpaceMax = 0;
          textContentItem.textRunBreakAllowed = false;
        }

        textContentItem.initialized = true;
        return textContentItem;
      }

      function replaceWhitespace(str) {
        // Replaces all whitespaces with standard spaces (0x20), to avoid
        // alignment issues between the textLayer and the canvas if the text
        // contains e.g. tabs (fixes issue6612.pdf).
        var i = 0,
          ii = str.length,
          code;
        while (i < ii && (code = str.charCodeAt(i)) >= 0x20 && code <= 0x7f) {
          i++;
        }
        return i < ii ? str.replace(WhitespaceRegexp, " ") : str;
      }

      function runBidiTransform(textChunk) {
        var str = textChunk.str.join("");
        var bidiResult = bidi(str, -1, textChunk.vertical);
        return {
          str: normalizeWhitespace
            ? replaceWhitespace(bidiResult.str)
            : bidiResult.str,
          dir: bidiResult.dir,
          width: textChunk.width,
          height: textChunk.height,
          transform: textChunk.transform,
          fontName: textChunk.fontName,
        };
      }

      function handleSetFont(fontName, fontRef) {
        return self
          .loadFont(fontName, fontRef, resources)
          .then(function(translated) {
            textState.font = translated.font;
            textState.fontMatrix =
              translated.font.fontMatrix || FONT_IDENTITY_MATRIX;
          });
      }

      function buildTextContentItem(chars) {
        var font = textState.font;
        var textChunk = ensureTextContentItem();
        var width = 0;
        var height = 0;
        var glyphs = font.charsToGlyphs(chars);
        for (var i = 0; i < glyphs.length; i++) {
          var glyph = glyphs[i];
          var glyphWidth = null;
          if (font.vertical && glyph.vmetric) {
            glyphWidth = glyph.vmetric[0];
          } else {
            glyphWidth = glyph.width;
          }

          var glyphUnicode = glyph.unicode;
          var NormalizedUnicodes = getNormalizedUnicodes();
          if (NormalizedUnicodes[glyphUnicode] !== undefined) {
            glyphUnicode = NormalizedUnicodes[glyphUnicode];
          }
          glyphUnicode = reverseIfRtl(glyphUnicode);

          var charSpacing = textState.charSpacing;
          if (glyph.isSpace) {
            var wordSpacing = textState.wordSpacing;
            charSpacing += wordSpacing;
            if (wordSpacing > 0) {
              addFakeSpaces(wordSpacing, textChunk.str);
            }
          }

          var tx = 0;
          var ty = 0;
          if (!font.vertical) {
            var w0 = glyphWidth * textState.fontMatrix[0];
            tx = (w0 * textState.fontSize + charSpacing) * textState.textHScale;
            width += tx;
          } else {
            var w1 = glyphWidth * textState.fontMatrix[0];
            ty = w1 * textState.fontSize + charSpacing;
            height += ty;
          }
          textState.translateTextMatrix(tx, ty);

          textChunk.str.push(glyphUnicode);
        }

        if (!font.vertical) {
          textChunk.lastAdvanceWidth = width;
          textChunk.width += width;
        } else {
          textChunk.lastAdvanceHeight = height;
          textChunk.height += Math.abs(height);
        }

        return textChunk;
      }

      function addFakeSpaces(width, strBuf) {
        if (width < textContentItem.fakeSpaceMin) {
          return;
        }
        if (width < textContentItem.fakeMultiSpaceMin) {
          strBuf.push(" ");
          return;
        }
        var fakeSpaces = Math.round(width / textContentItem.spaceWidth);
        while (fakeSpaces-- > 0) {
          strBuf.push(" ");
        }
      }

      function flushTextContentItem() {
        if (!textContentItem.initialized) {
          return;
        }

        // Do final text scaling.
        if (!textContentItem.vertical) {
          textContentItem.width *= textContentItem.textAdvanceScale;
        } else {
          textContentItem.height *= textContentItem.textAdvanceScale;
        }
        textContent.items.push(runBidiTransform(textContentItem));

        textContentItem.initialized = false;
        textContentItem.str.length = 0;
      }

      function enqueueChunk() {
        let length = textContent.items.length;
        if (length > 0) {
          sink.enqueue(textContent, length);
          textContent.items = [];
          textContent.styles = Object.create(null);
        }
      }

      var timeSlotManager = new TimeSlotManager();

      return new Promise(function promiseBody(resolve, reject) {
        let next = function(promise) {
          enqueueChunk();
          Promise.all([promise, sink.ready]).then(function() {
            try {
              promiseBody(resolve, reject);
            } catch (ex) {
              reject(ex);
            }
          }, reject);
        };
        task.ensureNotTerminated();
        timeSlotManager.reset();
        var stop,
          operation = {},
          args = [];
        while (!(stop = timeSlotManager.check())) {
          // The arguments parsed by read() are not used beyond this loop, so
          // we can reuse the same array on every iteration, thus avoiding
          // unnecessary allocations.
          args.length = 0;
          operation.args = args;
          if (!preprocessor.read(operation)) {
            break;
          }
          textState = stateManager.state;
          var fn = operation.fn;
          args = operation.args;
          var advance, diff;

          switch (fn | 0) {
            case OPS.setFont:
              // Optimization to ignore multiple identical Tf commands.
              var fontNameArg = args[0].name,
                fontSizeArg = args[1];
              if (
                textState.font &&
                fontNameArg === textState.fontName &&
                fontSizeArg === textState.fontSize
              ) {
                break;
              }

              flushTextContentItem();
              textState.fontName = fontNameArg;
              textState.fontSize = fontSizeArg;
              next(handleSetFont(fontNameArg, null));
              return;
            case OPS.setTextRise:
              flushTextContentItem();
              textState.textRise = args[0];
              break;
            case OPS.setHScale:
              flushTextContentItem();
              textState.textHScale = args[0] / 100;
              break;
            case OPS.setLeading:
              flushTextContentItem();
              textState.leading = args[0];
              break;
            case OPS.moveText:
              // Optimization to treat same line movement as advance
              var isSameTextLine = !textState.font
                ? false
                : (textState.font.vertical ? args[0] : args[1]) === 0;
              advance = args[0] - args[1];
              if (
                combineTextItems &&
                isSameTextLine &&
                textContentItem.initialized &&
                advance > 0 &&
                advance <= textContentItem.fakeMultiSpaceMax
              ) {
                textState.translateTextLineMatrix(args[0], args[1]);
                textContentItem.width +=
                  args[0] - textContentItem.lastAdvanceWidth;
                textContentItem.height +=
                  args[1] - textContentItem.lastAdvanceHeight;
                diff =
                  args[0] -
                  textContentItem.lastAdvanceWidth -
                  (args[1] - textContentItem.lastAdvanceHeight);
                addFakeSpaces(diff, textContentItem.str);
                break;
              }

              flushTextContentItem();
              textState.translateTextLineMatrix(args[0], args[1]);
              textState.textMatrix = textState.textLineMatrix.slice();
              break;
            case OPS.setLeadingMoveText:
              flushTextContentItem();
              textState.leading = -args[1];
              textState.translateTextLineMatrix(args[0], args[1]);
              textState.textMatrix = textState.textLineMatrix.slice();
              break;
            case OPS.nextLine:
              flushTextContentItem();
              textState.carriageReturn();
              break;
            case OPS.setTextMatrix:
              // Optimization to treat same line movement as advance.
              advance = textState.calcTextLineMatrixAdvance(
                args[0],
                args[1],
                args[2],
                args[3],
                args[4],
                args[5]
              );
              if (
                combineTextItems &&
                advance !== null &&
                textContentItem.initialized &&
                advance.value > 0 &&
                advance.value <= textContentItem.fakeMultiSpaceMax
              ) {
                textState.translateTextLineMatrix(
                  advance.width,
                  advance.height
                );
                textContentItem.width +=
                  advance.width - textContentItem.lastAdvanceWidth;
                textContentItem.height +=
                  advance.height - textContentItem.lastAdvanceHeight;
                diff =
                  advance.width -
                  textContentItem.lastAdvanceWidth -
                  (advance.height - textContentItem.lastAdvanceHeight);
                addFakeSpaces(diff, textContentItem.str);
                break;
              }

              flushTextContentItem();
              textState.setTextMatrix(
                args[0],
                args[1],
                args[2],
                args[3],
                args[4],
                args[5]
              );
              textState.setTextLineMatrix(
                args[0],
                args[1],
                args[2],
                args[3],
                args[4],
                args[5]
              );
              break;
            case OPS.setCharSpacing:
              textState.charSpacing = args[0];
              break;
            case OPS.setWordSpacing:
              textState.wordSpacing = args[0];
              break;
            case OPS.beginText:
              flushTextContentItem();
              textState.textMatrix = IDENTITY_MATRIX.slice();
              textState.textLineMatrix = IDENTITY_MATRIX.slice();
              break;
            case OPS.showSpacedText:
              var items = args[0];
              var offset;
              for (var j = 0, jj = items.length; j < jj; j++) {
                if (typeof items[j] === "string") {
                  buildTextContentItem(items[j]);
                } else if (isNum(items[j])) {
                  ensureTextContentItem();

                  // PDF Specification 5.3.2 states:
                  // The number is expressed in thousandths of a unit of text
                  // space.
                  // This amount is subtracted from the current horizontal or
                  // vertical coordinate, depending on the writing mode.
                  // In the default coordinate system, a positive adjustment
                  // has the effect of moving the next glyph painted either to
                  // the left or down by the given amount.
                  advance = (items[j] * textState.fontSize) / 1000;
                  var breakTextRun = false;
                  if (textState.font.vertical) {
                    offset = advance;
                    textState.translateTextMatrix(0, offset);
                    breakTextRun =
                      textContentItem.textRunBreakAllowed &&
                      advance > textContentItem.fakeMultiSpaceMax;
                    if (!breakTextRun) {
                      // Value needs to be added to height to paint down.
                      textContentItem.height += offset;
                    }
                  } else {
                    advance = -advance;
                    offset = advance * textState.textHScale;
                    textState.translateTextMatrix(offset, 0);
                    breakTextRun =
                      textContentItem.textRunBreakAllowed &&
                      advance > textContentItem.fakeMultiSpaceMax;
                    if (!breakTextRun) {
                      // Value needs to be subtracted from width to paint left.
                      textContentItem.width += offset;
                    }
                  }
                  if (breakTextRun) {
                    flushTextContentItem();
                  } else if (advance > 0) {
                    addFakeSpaces(advance, textContentItem.str);
                  }
                }
              }
              break;
            case OPS.showText:
              buildTextContentItem(args[0]);
              break;
            case OPS.nextLineShowText:
              flushTextContentItem();
              textState.carriageReturn();
              buildTextContentItem(args[0]);
              break;
            case OPS.nextLineSetSpacingShowText:
              flushTextContentItem();
              textState.wordSpacing = args[0];
              textState.charSpacing = args[1];
              textState.carriageReturn();
              buildTextContentItem(args[2]);
              break;
            case OPS.paintXObject:
              flushTextContentItem();
              if (!xobjs) {
                xobjs = resources.get("XObject") || Dict.empty;
              }

              var name = args[0].name;
              if (name && skipEmptyXObjs[name] !== undefined) {
                break;
              }

              next(
                new Promise(function(resolveXObject, rejectXObject) {
                  if (!name) {
                    throw new FormatError(
                      "XObject must be referred to by name."
                    );
                  }

                  let xobj = xobjs.get(name);
                  if (!xobj) {
                    resolveXObject();
                    return;
                  }
                  if (!isStream(xobj)) {
                    throw new FormatError("XObject should be a stream");
                  }

                  let type = xobj.dict.get("Subtype");
                  if (!isName(type)) {
                    throw new FormatError("XObject should have a Name subtype");
                  }

                  if (type.name !== "Form") {
                    skipEmptyXObjs[name] = true;
                    resolveXObject();
                    return;
                  }

                  // Use a new `StateManager` to prevent incorrect positioning
                  // of textItems *after* the Form XObject, since errors in the
                  // data can otherwise prevent `restore` operators from
                  // executing.
                  // NOTE: Only an issue when `options.ignoreErrors === true`.
                  let currentState = stateManager.state.clone();
                  let xObjStateManager = new StateManager(currentState);

                  let matrix = xobj.dict.getArray("Matrix");
                  if (Array.isArray(matrix) && matrix.length === 6) {
                    xObjStateManager.transform(matrix);
                  }

                  // Enqueue the `textContent` chunk before parsing the /Form
                  // XObject.
                  enqueueChunk();
                  let sinkWrapper = {
                    enqueueInvoked: false,

                    enqueue(chunk, size) {
                      this.enqueueInvoked = true;
                      sink.enqueue(chunk, size);
                    },

                    get desiredSize() {
                      return sink.desiredSize;
                    },

                    get ready() {
                      return sink.ready;
                    },
                  };

                  self
                    .getTextContent({
                      stream: xobj,
                      task,
                      resources: xobj.dict.get("Resources") || resources,
                      stateManager: xObjStateManager,
                      normalizeWhitespace,
                      combineTextItems,
                      sink: sinkWrapper,
                      seenStyles,
                    })
                    .then(function() {
                      if (!sinkWrapper.enqueueInvoked) {
                        skipEmptyXObjs[name] = true;
                      }
                      resolveXObject();
                    }, rejectXObject);
                }).catch(function(reason) {
                  if (reason instanceof AbortException) {
                    return;
                  }
                  if (self.options.ignoreErrors) {
                    // Error(s) in the XObject -- allow text-extraction to
                    // continue.
                    warn(`getTextContent - ignoring XObject: "${reason}".`);
                    return;
                  }
                  throw reason;
                })
              );
              return;
            case OPS.setGState:
              flushTextContentItem();
              var dictName = args[0];
              var extGState = resources.get("ExtGState");

              if (!isDict(extGState) || !isName(dictName)) {
                break;
              }
              var gState = extGState.get(dictName.name);
              if (!isDict(gState)) {
                break;
              }
              var gStateFont = gState.get("Font");
              if (gStateFont) {
                textState.fontName = null;
                textState.fontSize = gStateFont[1];
                next(handleSetFont(null, gStateFont[0]));
                return;
              }
              break;
          } // switch
          if (textContent.items.length >= sink.desiredSize) {
            // Wait for ready, if we reach highWaterMark.
            stop = true;
            break;
          }
        } // while
        if (stop) {
          next(deferred);
          return;
        }
        flushTextContentItem();
        enqueueChunk();
        resolve();
      }).catch(reason => {
        if (reason instanceof AbortException) {
          return;
        }
        if (this.options.ignoreErrors) {
          // Error(s) in the TextContent -- allow text-extraction to continue.
          warn(
            `getTextContent - ignoring errors during "${task.name}" ` +
              `task: "${reason}".`
          );

          flushTextContentItem();
          enqueueChunk();
          return;
        }
        throw reason;
      });
    },

    extractDataStructures: function PartialEvaluator_extractDataStructures(
      dict,
      baseDict,
      properties
    ) {
      let xref = this.xref,
        cidToGidBytes;
      // 9.10.2
      var toUnicode = dict.get("ToUnicode") || baseDict.get("ToUnicode");
      var toUnicodePromise = toUnicode
        ? this.readToUnicode(toUnicode)
        : Promise.resolve(undefined);

      if (properties.composite) {
        // CIDSystemInfo helps to match CID to glyphs
        var cidSystemInfo = dict.get("CIDSystemInfo");
        if (isDict(cidSystemInfo)) {
          properties.cidSystemInfo = {
            registry: stringToPDFString(cidSystemInfo.get("Registry")),
            ordering: stringToPDFString(cidSystemInfo.get("Ordering")),
            supplement: cidSystemInfo.get("Supplement"),
          };
        }

        var cidToGidMap = dict.get("CIDToGIDMap");
        if (isStream(cidToGidMap)) {
          cidToGidBytes = cidToGidMap.getBytes();
        }
      }

      // Based on 9.6.6 of the spec the encoding can come from multiple places
      // and depends on the font type. The base encoding and differences are
      // read here, but the encoding that is actually used is chosen during
      // glyph mapping in the font.
      // TODO: Loading the built in encoding in the font would allow the
      // differences to be merged in here not require us to hold on to it.
      var differences = [];
      var baseEncodingName = null;
      var encoding;
      if (dict.has("Encoding")) {
        encoding = dict.get("Encoding");
        if (isDict(encoding)) {
          baseEncodingName = encoding.get("BaseEncoding");
          baseEncodingName = isName(baseEncodingName)
            ? baseEncodingName.name
            : null;
          // Load the differences between the base and original
          if (encoding.has("Differences")) {
            var diffEncoding = encoding.get("Differences");
            var index = 0;
            for (var j = 0, jj = diffEncoding.length; j < jj; j++) {
              var data = xref.fetchIfRef(diffEncoding[j]);
              if (isNum(data)) {
                index = data;
              } else if (isName(data)) {
                differences[index++] = data.name;
              } else {
                throw new FormatError(
                  `Invalid entry in 'Differences' array: ${data}`
                );
              }
            }
          }
        } else if (isName(encoding)) {
          baseEncodingName = encoding.name;
        } else {
          throw new FormatError("Encoding is not a Name nor a Dict");
        }
        // According to table 114 if the encoding is a named encoding it must be
        // one of these predefined encodings.
        if (
          baseEncodingName !== "MacRomanEncoding" &&
          baseEncodingName !== "MacExpertEncoding" &&
          baseEncodingName !== "WinAnsiEncoding"
        ) {
          baseEncodingName = null;
        }
      }

      if (baseEncodingName) {
        properties.defaultEncoding = getEncoding(baseEncodingName).slice();
      } else {
        var isSymbolicFont = !!(properties.flags & FontFlags.Symbolic);
        var isNonsymbolicFont = !!(properties.flags & FontFlags.Nonsymbolic);
        // According to "Table 114" in section "9.6.6.1 General" (under
        // "9.6.6 Character Encoding") of the PDF specification, a Nonsymbolic
        // font should use the `StandardEncoding` if no encoding is specified.
        encoding = StandardEncoding;
        if (properties.type === "TrueType" && !isNonsymbolicFont) {
          encoding = WinAnsiEncoding;
        }
        // The Symbolic attribute can be misused for regular fonts
        // Heuristic: we have to check if the font is a standard one also
        if (isSymbolicFont) {
          encoding = MacRomanEncoding;
          if (!properties.file) {
            if (/Symbol/i.test(properties.name)) {
              encoding = SymbolSetEncoding;
            } else if (/Dingbats/i.test(properties.name)) {
              encoding = ZapfDingbatsEncoding;
            }
          }
        }
        properties.defaultEncoding = encoding;
      }

      properties.differences = differences;
      properties.baseEncodingName = baseEncodingName;
      properties.hasEncoding = !!baseEncodingName || differences.length > 0;
      properties.dict = dict;
      return toUnicodePromise
        .then(toUnicode => {
          properties.toUnicode = toUnicode;
          return this.buildToUnicode(properties);
        })
        .then(toUnicode => {
          properties.toUnicode = toUnicode;
          if (cidToGidBytes) {
            properties.cidToGidMap = this.readCidToGidMap(
              cidToGidBytes,
              toUnicode
            );
          }
          return properties;
        });
    },

    /**
     * @returns {ToUnicodeMap}
     * @private
     */
    _buildSimpleFontToUnicode(properties, forceGlyphs = false) {
      assert(!properties.composite, "Must be a simple font.");

      let toUnicode = [],
        charcode,
        glyphName;
      let encoding = properties.defaultEncoding.slice();
      let baseEncodingName = properties.baseEncodingName;
      // Merge in the differences array.
      let differences = properties.differences;
      for (charcode in differences) {
        glyphName = differences[charcode];
        if (glyphName === ".notdef") {
          // Skip .notdef to prevent rendering errors, e.g. boxes appearing
          // where there should be spaces (fixes issue5256.pdf).
          continue;
        }
        encoding[charcode] = glyphName;
      }
      let glyphsUnicodeMap = getGlyphsUnicode();
      for (charcode in encoding) {
        // a) Map the character code to a character name.
        glyphName = encoding[charcode];
        // b) Look up the character name in the Adobe Glyph List (see the
        //    Bibliography) to obtain the corresponding Unicode value.
        if (glyphName === "") {
          continue;
        } else if (glyphsUnicodeMap[glyphName] === undefined) {
          // (undocumented) c) Few heuristics to recognize unknown glyphs
          // NOTE: Adobe Reader does not do this step, but OSX Preview does
          let code = 0;
          switch (glyphName[0]) {
            case "G": // Gxx glyph
              if (glyphName.length === 3) {
                code = parseInt(glyphName.substring(1), 16);
              }
              break;
            case "g": // g00xx glyph
              if (glyphName.length === 5) {
                code = parseInt(glyphName.substring(1), 16);
              }
              break;
            case "C": // Cdd{d} glyph
            case "c": // cdd{d} glyph
              if (glyphName.length >= 3 && glyphName.length <= 4) {
                const codeStr = glyphName.substring(1);

                if (forceGlyphs) {
                  code = parseInt(codeStr, 16);
                  break;
                }
                // Normally the Cdd{d}/cdd{d} glyphName format will contain
                // regular, i.e. base 10, charCodes (see issue4550.pdf)...
                code = +codeStr;

                // ... however some PDF generators violate that assumption by
                // containing glyph, i.e. base 16, codes instead.
                // In that case we need to re-parse the *entire* encoding to
                // prevent broken text-selection (fixes issue9655_reduced.pdf).
                if (
                  Number.isNaN(code) &&
                  Number.isInteger(parseInt(codeStr, 16))
                ) {
                  return this._buildSimpleFontToUnicode(
                    properties,
                    /* forceGlyphs */ true
                  );
                }
              }
              break;
            default:
              // 'uniXXXX'/'uXXXX{XX}' glyphs
              let unicode = getUnicodeForGlyph(glyphName, glyphsUnicodeMap);
              if (unicode !== -1) {
                code = unicode;
              }
          }
          if (code) {
            // If `baseEncodingName` is one the predefined encodings, and `code`
            // equals `charcode`, using the glyph defined in the baseEncoding
            // seems to yield a better `toUnicode` mapping (fixes issue 5070).
            if (baseEncodingName && code === +charcode) {
              let baseEncoding = getEncoding(baseEncodingName);
              if (baseEncoding && (glyphName = baseEncoding[charcode])) {
                toUnicode[charcode] = String.fromCharCode(
                  glyphsUnicodeMap[glyphName]
                );
                continue;
              }
            }
            toUnicode[charcode] = String.fromCodePoint(code);
          }
          continue;
        }
        toUnicode[charcode] = String.fromCharCode(glyphsUnicodeMap[glyphName]);
      }
      return new ToUnicodeMap(toUnicode);
    },

    /**
     * Builds a char code to unicode map based on section 9.10 of the spec.
     * @param {Object} properties Font properties object.
     * @returns {Promise} A Promise that is resolved with a
     *   {ToUnicodeMap|IdentityToUnicodeMap} object.
     */
    buildToUnicode(properties) {
      properties.hasIncludedToUnicodeMap =
        !!properties.toUnicode && properties.toUnicode.length > 0;

      // Section 9.10.2 Mapping Character Codes to Unicode Values
      if (properties.hasIncludedToUnicodeMap) {
        // Some fonts contain incomplete ToUnicode data, causing issues with
        // text-extraction. For simple fonts, containing encoding information,
        // use a fallback ToUnicode map to improve this (fixes issue8229.pdf).
        if (!properties.composite && properties.hasEncoding) {
          properties.fallbackToUnicode = this._buildSimpleFontToUnicode(
            properties
          );
        }

        return Promise.resolve(properties.toUnicode);
      }

      // According to the spec if the font is a simple font we should only map
      // to unicode if the base encoding is MacRoman, MacExpert, or WinAnsi or
      // the differences array only contains adobe standard or symbol set names,
      // in pratice it seems better to always try to create a toUnicode map
      // based of the default encoding.
      if (!properties.composite /* is simple font */) {
        return Promise.resolve(this._buildSimpleFontToUnicode(properties));
      }

      // If the font is a composite font that uses one of the predefined CMaps
      // listed in Table 118 (except Identity–H and Identity–V) or whose
      // descendant CIDFont uses the Adobe-GB1, Adobe-CNS1, Adobe-Japan1, or
      // Adobe-Korea1 character collection:
      if (
        properties.composite &&
        ((properties.cMap.builtInCMap &&
          !(properties.cMap instanceof IdentityCMap)) ||
          (properties.cidSystemInfo.registry === "Adobe" &&
            (properties.cidSystemInfo.ordering === "GB1" ||
              properties.cidSystemInfo.ordering === "CNS1" ||
              properties.cidSystemInfo.ordering === "Japan1" ||
              properties.cidSystemInfo.ordering === "Korea1")))
      ) {
        // Then:
        // a) Map the character code to a character identifier (CID) according
        // to the font’s CMap.
        // b) Obtain the registry and ordering of the character collection used
        // by the font’s CMap (for example, Adobe and Japan1) from its
        // CIDSystemInfo dictionary.
        let registry = properties.cidSystemInfo.registry;
        let ordering = properties.cidSystemInfo.ordering;
        // c) Construct a second CMap name by concatenating the registry and
        // ordering obtained in step (b) in the format registry–ordering–UCS2
        // (for example, Adobe–Japan1–UCS2).
        let ucs2CMapName = Name.get(registry + "-" + ordering + "-UCS2");
        // d) Obtain the CMap with the name constructed in step (c) (available
        // from the ASN Web site; see the Bibliography).
        return CMapFactory.create({
          encoding: ucs2CMapName,
          fetchBuiltInCMap: this.fetchBuiltInCMap,
          useCMap: null,
        }).then(function(ucs2CMap) {
          let cMap = properties.cMap;
          let toUnicode = [];
          cMap.forEach(function(charcode, cid) {
            if (cid > 0xffff) {
              throw new FormatError("Max size of CID is 65,535");
            }
            // e) Map the CID obtained in step (a) according to the CMap
            // obtained in step (d), producing a Unicode value.
            let ucs2 = ucs2CMap.lookup(cid);
            if (ucs2) {
              toUnicode[charcode] = String.fromCharCode(
                (ucs2.charCodeAt(0) << 8) + ucs2.charCodeAt(1)
              );
            }
          });
          return new ToUnicodeMap(toUnicode);
        });
      }

      // The viewer's choice, just use an identity map.
      return Promise.resolve(
        new IdentityToUnicodeMap(properties.firstChar, properties.lastChar)
      );
    },

    readToUnicode: function PartialEvaluator_readToUnicode(toUnicode) {
      var cmapObj = toUnicode;
      if (isName(cmapObj)) {
        return CMapFactory.create({
          encoding: cmapObj,
          fetchBuiltInCMap: this.fetchBuiltInCMap,
          useCMap: null,
        }).then(function(cmap) {
          if (cmap instanceof IdentityCMap) {
            return new IdentityToUnicodeMap(0, 0xffff);
          }
          return new ToUnicodeMap(cmap.getMap());
        });
      } else if (isStream(cmapObj)) {
        return CMapFactory.create({
          encoding: cmapObj,
          fetchBuiltInCMap: this.fetchBuiltInCMap,
          useCMap: null,
        }).then(function(cmap) {
          if (cmap instanceof IdentityCMap) {
            return new IdentityToUnicodeMap(0, 0xffff);
          }
          var map = new Array(cmap.length);
          // Convert UTF-16BE
          // NOTE: cmap can be a sparse array, so use forEach instead of for(;;)
          // to iterate over all keys.
          cmap.forEach(function(charCode, token) {
            var str = [];
            for (var k = 0; k < token.length; k += 2) {
              var w1 = (token.charCodeAt(k) << 8) | token.charCodeAt(k + 1);
              if ((w1 & 0xf800) !== 0xd800) {
                // w1 < 0xD800 || w1 > 0xDFFF
                str.push(w1);
                continue;
              }
              k += 2;
              var w2 = (token.charCodeAt(k) << 8) | token.charCodeAt(k + 1);
              str.push(((w1 & 0x3ff) << 10) + (w2 & 0x3ff) + 0x10000);
            }
            map[charCode] = String.fromCodePoint.apply(String, str);
          });
          return new ToUnicodeMap(map);
        });
      }
      return Promise.resolve(null);
    },

    readCidToGidMap(glyphsData, toUnicode) {
      // Extract the encoding from the CIDToGIDMap

      // Set encoding 0 to later verify the font has an encoding
      var result = [];
      for (var j = 0, jj = glyphsData.length; j < jj; j++) {
        var glyphID = (glyphsData[j++] << 8) | glyphsData[j];
        const code = j >> 1;
        if (glyphID === 0 && !toUnicode.has(code)) {
          continue;
        }
        result[code] = glyphID;
      }
      return result;
    },

    extractWidths: function PartialEvaluator_extractWidths(
      dict,
      descriptor,
      properties
    ) {
      var xref = this.xref;
      var glyphsWidths = [];
      var defaultWidth = 0;
      var glyphsVMetrics = [];
      var defaultVMetrics;
      var i, ii, j, jj, start, code, widths;
      if (properties.composite) {
        defaultWidth = dict.has("DW") ? dict.get("DW") : 1000;

        widths = dict.get("W");
        if (widths) {
          for (i = 0, ii = widths.length; i < ii; i++) {
            start = xref.fetchIfRef(widths[i++]);
            code = xref.fetchIfRef(widths[i]);
            if (Array.isArray(code)) {
              for (j = 0, jj = code.length; j < jj; j++) {
                glyphsWidths[start++] = xref.fetchIfRef(code[j]);
              }
            } else {
              var width = xref.fetchIfRef(widths[++i]);
              for (j = start; j <= code; j++) {
                glyphsWidths[j] = width;
              }
            }
          }
        }

        if (properties.vertical) {
          var vmetrics = dict.getArray("DW2") || [880, -1000];
          defaultVMetrics = [vmetrics[1], defaultWidth * 0.5, vmetrics[0]];
          vmetrics = dict.get("W2");
          if (vmetrics) {
            for (i = 0, ii = vmetrics.length; i < ii; i++) {
              start = xref.fetchIfRef(vmetrics[i++]);
              code = xref.fetchIfRef(vmetrics[i]);
              if (Array.isArray(code)) {
                for (j = 0, jj = code.length; j < jj; j++) {
                  glyphsVMetrics[start++] = [
                    xref.fetchIfRef(code[j++]),
                    xref.fetchIfRef(code[j++]),
                    xref.fetchIfRef(code[j]),
                  ];
                }
              } else {
                var vmetric = [
                  xref.fetchIfRef(vmetrics[++i]),
                  xref.fetchIfRef(vmetrics[++i]),
                  xref.fetchIfRef(vmetrics[++i]),
                ];
                for (j = start; j <= code; j++) {
                  glyphsVMetrics[j] = vmetric;
                }
              }
            }
          }
        }
      } else {
        var firstChar = properties.firstChar;
        widths = dict.get("Widths");
        if (widths) {
          j = firstChar;
          for (i = 0, ii = widths.length; i < ii; i++) {
            glyphsWidths[j++] = xref.fetchIfRef(widths[i]);
          }
          defaultWidth = parseFloat(descriptor.get("MissingWidth")) || 0;
        } else {
          // Trying get the BaseFont metrics (see comment above).
          var baseFontName = dict.get("BaseFont");
          if (isName(baseFontName)) {
            var metrics = this.getBaseFontMetrics(baseFontName.name);

            glyphsWidths = this.buildCharCodeToWidth(
              metrics.widths,
              properties
            );
            defaultWidth = metrics.defaultWidth;
          }
        }
      }

      // Heuristic: detection of monospace font by checking all non-zero widths
      var isMonospace = true;
      var firstWidth = defaultWidth;
      for (var glyph in glyphsWidths) {
        var glyphWidth = glyphsWidths[glyph];
        if (!glyphWidth) {
          continue;
        }
        if (!firstWidth) {
          firstWidth = glyphWidth;
          continue;
        }
        if (firstWidth !== glyphWidth) {
          isMonospace = false;
          break;
        }
      }
      if (isMonospace) {
        properties.flags |= FontFlags.FixedPitch;
      }

      properties.defaultWidth = defaultWidth;
      properties.widths = glyphsWidths;
      properties.defaultVMetrics = defaultVMetrics;
      properties.vmetrics = glyphsVMetrics;
    },

    isSerifFont: function PartialEvaluator_isSerifFont(baseFontName) {
      // Simulating descriptor flags attribute
      var fontNameWoStyle = baseFontName.split("-")[0];
      return (
        fontNameWoStyle in getSerifFonts() ||
        fontNameWoStyle.search(/serif/gi) !== -1
      );
    },

    getBaseFontMetrics: function PartialEvaluator_getBaseFontMetrics(name) {
      var defaultWidth = 0;
      var widths = [];
      var monospace = false;
      var stdFontMap = getStdFontMap();
      var lookupName = stdFontMap[name] || name;
      var Metrics = getMetrics();

      if (!(lookupName in Metrics)) {
        // Use default fonts for looking up font metrics if the passed
        // font is not a base font
        if (this.isSerifFont(name)) {
          lookupName = "Times-Roman";
        } else {
          lookupName = "Helvetica";
        }
      }
      var glyphWidths = Metrics[lookupName];

      if (isNum(glyphWidths)) {
        defaultWidth = glyphWidths;
        monospace = true;
      } else {
        widths = glyphWidths(); // expand lazy widths array
      }

      return {
        defaultWidth,
        monospace,
        widths,
      };
    },

    buildCharCodeToWidth: function PartialEvaluator_bulildCharCodeToWidth(
      widthsByGlyphName,
      properties
    ) {
      var widths = Object.create(null);
      var differences = properties.differences;
      var encoding = properties.defaultEncoding;
      for (var charCode = 0; charCode < 256; charCode++) {
        if (
          charCode in differences &&
          widthsByGlyphName[differences[charCode]]
        ) {
          widths[charCode] = widthsByGlyphName[differences[charCode]];
          continue;
        }
        if (charCode in encoding && widthsByGlyphName[encoding[charCode]]) {
          widths[charCode] = widthsByGlyphName[encoding[charCode]];
          continue;
        }
      }
      return widths;
    },

    preEvaluateFont: function PartialEvaluator_preEvaluateFont(dict) {
      var baseDict = dict;
      var type = dict.get("Subtype");
      if (!isName(type)) {
        throw new FormatError("invalid font Subtype");
      }

      var composite = false;
      var uint8array;
      if (type.name === "Type0") {
        // If font is a composite
        //  - get the descendant font
        //  - set the type according to the descendant font
        //  - get the FontDescriptor from the descendant font
        var df = dict.get("DescendantFonts");
        if (!df) {
          throw new FormatError("Descendant fonts are not specified");
        }
        dict = Array.isArray(df) ? this.xref.fetchIfRef(df[0]) : df;

        type = dict.get("Subtype");
        if (!isName(type)) {
          throw new FormatError("invalid font Subtype");
        }
        composite = true;
      }

      var descriptor = dict.get("FontDescriptor");
      if (descriptor) {
        var hash = new MurmurHash3_64();
        var encoding = baseDict.getRaw("Encoding");
        if (isName(encoding)) {
          hash.update(encoding.name);
        } else if (isRef(encoding)) {
          hash.update(encoding.toString());
        } else if (isDict(encoding)) {
          var keys = encoding.getKeys();
          for (var i = 0, ii = keys.length; i < ii; i++) {
            var entry = encoding.getRaw(keys[i]);
            if (isName(entry)) {
              hash.update(entry.name);
            } else if (isRef(entry)) {
              hash.update(entry.toString());
            } else if (Array.isArray(entry)) {
              // 'Differences' array (fixes bug1157493.pdf).
              var diffLength = entry.length,
                diffBuf = new Array(diffLength);

              for (var j = 0; j < diffLength; j++) {
                var diffEntry = entry[j];
                if (isName(diffEntry)) {
                  diffBuf[j] = diffEntry.name;
                } else if (isNum(diffEntry) || isRef(diffEntry)) {
                  diffBuf[j] = diffEntry.toString();
                }
              }
              hash.update(diffBuf.join());
            }
          }
        }

        const firstChar = dict.get("FirstChar") || 0;
        const lastChar = dict.get("LastChar") || (composite ? 0xffff : 0xff);
        hash.update(`${firstChar}-${lastChar}`);

        var toUnicode = dict.get("ToUnicode") || baseDict.get("ToUnicode");
        if (isStream(toUnicode)) {
          var stream = toUnicode.str || toUnicode;
          uint8array = stream.buffer
            ? new Uint8Array(stream.buffer.buffer, 0, stream.bufferLength)
            : new Uint8Array(
                stream.bytes.buffer,
                stream.start,
                stream.end - stream.start
              );
          hash.update(uint8array);
        } else if (isName(toUnicode)) {
          hash.update(toUnicode.name);
        }

        var widths = dict.get("Widths") || baseDict.get("Widths");
        if (widths) {
          uint8array = new Uint8Array(new Uint32Array(widths).buffer);
          hash.update(uint8array);
        }
      }

      return {
        descriptor,
        dict,
        baseDict,
        composite,
        type: type.name,
        hash: hash ? hash.hexdigest() : "",
      };
    },

    translateFont: function PartialEvaluator_translateFont(preEvaluatedFont) {
      var baseDict = preEvaluatedFont.baseDict;
      var dict = preEvaluatedFont.dict;
      var composite = preEvaluatedFont.composite;
      var descriptor = preEvaluatedFont.descriptor;
      var type = preEvaluatedFont.type;
      var maxCharIndex = composite ? 0xffff : 0xff;
      var properties;

      if (!descriptor) {
        if (type === "Type3") {
          // FontDescriptor is only required for Type3 fonts when the document
          // is a tagged pdf. Create a barbebones one to get by.
          descriptor = new Dict(null);
          descriptor.set("FontName", Name.get(type));
          descriptor.set("FontBBox", dict.getArray("FontBBox"));
        } else {
          // Before PDF 1.5 if the font was one of the base 14 fonts, having a
          // FontDescriptor was not required.
          // This case is here for compatibility.
          var baseFontName = dict.get("BaseFont");
          if (!isName(baseFontName)) {
            throw new FormatError("Base font is not specified");
          }

          // Using base font name as a font name.
          baseFontName = baseFontName.name.replace(/[,_]/g, "-");
          var metrics = this.getBaseFontMetrics(baseFontName);

          // Simulating descriptor flags attribute
          var fontNameWoStyle = baseFontName.split("-")[0];
          var flags =
            (this.isSerifFont(fontNameWoStyle) ? FontFlags.Serif : 0) |
            (metrics.monospace ? FontFlags.FixedPitch : 0) |
            (getSymbolsFonts()[fontNameWoStyle]
              ? FontFlags.Symbolic
              : FontFlags.Nonsymbolic);

          properties = {
            type,
            name: baseFontName,
            widths: metrics.widths,
            defaultWidth: metrics.defaultWidth,
            flags,
            firstChar: 0,
            lastChar: maxCharIndex,
          };
          return this.extractDataStructures(dict, dict, properties).then(
            properties => {
              properties.widths = this.buildCharCodeToWidth(
                metrics.widths,
                properties
              );
              return new Font(baseFontName, null, properties);
            }
          );
        }
      }

      // According to the spec if 'FontDescriptor' is declared, 'FirstChar',
      // 'LastChar' and 'Widths' should exist too, but some PDF encoders seem
      // to ignore this rule when a variant of a standard font is used.
      // TODO Fill the width array depending on which of the base font this is
      // a variant.
      var firstChar = dict.get("FirstChar") || 0;
      var lastChar = dict.get("LastChar") || maxCharIndex;

      var fontName = descriptor.get("FontName");
      var baseFont = dict.get("BaseFont");
      // Some bad PDFs have a string as the font name.
      if (isString(fontName)) {
        fontName = Name.get(fontName);
      }
      if (isString(baseFont)) {
        baseFont = Name.get(baseFont);
      }

      if (type !== "Type3") {
        var fontNameStr = fontName && fontName.name;
        var baseFontStr = baseFont && baseFont.name;
        if (fontNameStr !== baseFontStr) {
          info(
            `The FontDescriptor\'s FontName is "${fontNameStr}" but ` +
              `should be the same as the Font\'s BaseFont "${baseFontStr}".`
          );
          // Workaround for cases where e.g. fontNameStr = 'Arial' and
          // baseFontStr = 'Arial,Bold' (needed when no font file is embedded).
          if (
            fontNameStr &&
            baseFontStr &&
            baseFontStr.startsWith(fontNameStr)
          ) {
            fontName = baseFont;
          }
        }
      }
      fontName = fontName || baseFont;

      if (!isName(fontName)) {
        throw new FormatError("invalid font name");
      }

      var fontFile = descriptor.get("FontFile", "FontFile2", "FontFile3");
      if (fontFile) {
        if (fontFile.dict) {
          var subtype = fontFile.dict.get("Subtype");
          if (subtype) {
            subtype = subtype.name;
          }
          var length1 = fontFile.dict.get("Length1");
          var length2 = fontFile.dict.get("Length2");
          var length3 = fontFile.dict.get("Length3");
        }
      }

      properties = {
        type,
        name: fontName.name,
        subtype,
        file: fontFile,
        length1,
        length2,
        length3,
        loadedName: baseDict.loadedName,
        composite,
        wideChars: composite,
        fixedPitch: false,
        fontMatrix: dict.getArray("FontMatrix") || FONT_IDENTITY_MATRIX,
        firstChar: firstChar || 0,
        lastChar: lastChar || maxCharIndex,
        bbox: descriptor.getArray("FontBBox"),
        ascent: descriptor.get("Ascent"),
        descent: descriptor.get("Descent"),
        xHeight: descriptor.get("XHeight"),
        capHeight: descriptor.get("CapHeight"),
        flags: descriptor.get("Flags"),
        italicAngle: descriptor.get("ItalicAngle"),
        isType3Font: false,
      };

      var cMapPromise;
      if (composite) {
        var cidEncoding = baseDict.get("Encoding");
        if (isName(cidEncoding)) {
          properties.cidEncoding = cidEncoding.name;
        }
        cMapPromise = CMapFactory.create({
          encoding: cidEncoding,
          fetchBuiltInCMap: this.fetchBuiltInCMap,
          useCMap: null,
        }).then(function(cMap) {
          properties.cMap = cMap;
          properties.vertical = properties.cMap.vertical;
        });
      } else {
        cMapPromise = Promise.resolve(undefined);
      }

      return cMapPromise
        .then(() => {
          return this.extractDataStructures(dict, baseDict, properties);
        })
        .then(properties => {
          this.extractWidths(dict, descriptor, properties);

          if (type === "Type3") {
            properties.isType3Font = true;
          }
          return new Font(fontName.name, fontFile, properties);
        });
    },
  };

  PartialEvaluator.buildFontPaths = function(font, glyphs, handler) {
    function buildPath(fontChar) {
      if (font.renderer.hasBuiltPath(fontChar)) {
        return;
      }
      handler.send("commonobj", [
        `${font.loadedName}_path_${fontChar}`,
        "FontPath",
        font.renderer.getPathJs(fontChar),
      ]);
    }

    for (const glyph of glyphs) {
      buildPath(glyph.fontChar);

      // If the glyph has an accent we need to build a path for its
      // fontChar too, otherwise CanvasGraphics_paintChar will fail.
      const accent = glyph.accent;
      if (accent && accent.fontChar) {
        buildPath(accent.fontChar);
      }
    }
  };

  return PartialEvaluator;
})();

var TranslatedFont = (function TranslatedFontClosure() {
  function TranslatedFont(loadedName, font, dict) {
    this.loadedName = loadedName;
    this.font = font;
    this.dict = dict;
    this.type3Loaded = null;
    this.sent = false;
  }
  TranslatedFont.prototype = {
    send(handler) {
      if (this.sent) {
        return;
      }
      this.sent = true;

      handler.send("commonobj", [
        this.loadedName,
        "Font",
        this.font.exportData(),
      ]);
    },

    fallback(handler) {
      if (!this.font.data) {
        return;
      }
      // When font loading failed, fall back to the built-in font renderer.
      this.font.disableFontFace = true;
      // An arbitrary number of text rendering operators could have been
      // encountered between the point in time when the 'Font' message was sent
      // to the main-thread, and the point in time when the 'FontFallback'
      // message was received on the worker-thread.
      // To ensure that all 'FontPath's are available on the main-thread, when
      // font loading failed, attempt to resend *all* previously parsed glyphs.
      const glyphs = this.font.glyphCacheValues;
      PartialEvaluator.buildFontPaths(this.font, glyphs, handler);
    },

    loadType3Data(evaluator, resources, parentOperatorList, task) {
      if (!this.font.isType3Font) {
        throw new Error("Must be a Type3 font.");
      }

      if (this.type3Loaded) {
        return this.type3Loaded;
      }
      // When parsing Type3 glyphs, always ignore them if there are errors.
      // Compared to the parsing of e.g. an entire page, it doesn't really
      // make sense to only be able to render a Type3 glyph partially.
      //
      // Also, ensure that any Type3 image resources (which should be very rare
      // in practice) are completely decoded on the worker-thread, to simplify
      // the rendering code on the main-thread (see issue10717.pdf).
      var type3Options = Object.create(evaluator.options);
      type3Options.ignoreErrors = false;
      type3Options.nativeImageDecoderSupport = NativeImageDecoding.NONE;
      var type3Evaluator = evaluator.clone(type3Options);
      type3Evaluator.parsingType3Font = true;

      var translatedFont = this.font;
      var loadCharProcsPromise = Promise.resolve();
      var charProcs = this.dict.get("CharProcs");
      var fontResources = this.dict.get("Resources") || resources;
      var charProcKeys = charProcs.getKeys();
      var charProcOperatorList = Object.create(null);

      for (var i = 0, n = charProcKeys.length; i < n; ++i) {
        let key = charProcKeys[i];
        loadCharProcsPromise = loadCharProcsPromise.then(function() {
          var glyphStream = charProcs.get(key);
          var operatorList = new OperatorList();
          return type3Evaluator
            .getOperatorList({
              stream: glyphStream,
              task,
              resources: fontResources,
              operatorList,
            })
            .then(function() {
              charProcOperatorList[key] = operatorList.getIR();

              // Add the dependencies to the parent operator list so they are
              // resolved before sub operator list is executed synchronously.
              parentOperatorList.addDependencies(operatorList.dependencies);
            })
            .catch(function(reason) {
              warn(`Type3 font resource "${key}" is not available.`);
              var operatorList = new OperatorList();
              charProcOperatorList[key] = operatorList.getIR();
            });
        });
      }
      this.type3Loaded = loadCharProcsPromise.then(function() {
        translatedFont.charProcOperatorList = charProcOperatorList;
      });
      return this.type3Loaded;
    },
  };
  return TranslatedFont;
})();

var StateManager = (function StateManagerClosure() {
  function StateManager(initialState) {
    this.state = initialState;
    this.stateStack = [];
  }
  StateManager.prototype = {
    save() {
      var old = this.state;
      this.stateStack.push(this.state);
      this.state = old.clone();
    },
    restore() {
      var prev = this.stateStack.pop();
      if (prev) {
        this.state = prev;
      }
    },
    transform(args) {
      this.state.ctm = Util.transform(this.state.ctm, args);
    },
  };
  return StateManager;
})();

var TextState = (function TextStateClosure() {
  function TextState() {
    this.ctm = new Float32Array(IDENTITY_MATRIX);
    this.fontName = null;
    this.fontSize = 0;
    this.font = null;
    this.fontMatrix = FONT_IDENTITY_MATRIX;
    this.textMatrix = IDENTITY_MATRIX.slice();
    this.textLineMatrix = IDENTITY_MATRIX.slice();
    this.charSpacing = 0;
    this.wordSpacing = 0;
    this.leading = 0;
    this.textHScale = 1;
    this.textRise = 0;
  }

  TextState.prototype = {
    setTextMatrix: function TextState_setTextMatrix(a, b, c, d, e, f) {
      var m = this.textMatrix;
      m[0] = a;
      m[1] = b;
      m[2] = c;
      m[3] = d;
      m[4] = e;
      m[5] = f;
    },
    setTextLineMatrix: function TextState_setTextMatrix(a, b, c, d, e, f) {
      var m = this.textLineMatrix;
      m[0] = a;
      m[1] = b;
      m[2] = c;
      m[3] = d;
      m[4] = e;
      m[5] = f;
    },
    translateTextMatrix: function TextState_translateTextMatrix(x, y) {
      var m = this.textMatrix;
      m[4] = m[0] * x + m[2] * y + m[4];
      m[5] = m[1] * x + m[3] * y + m[5];
    },
    translateTextLineMatrix: function TextState_translateTextMatrix(x, y) {
      var m = this.textLineMatrix;
      m[4] = m[0] * x + m[2] * y + m[4];
      m[5] = m[1] * x + m[3] * y + m[5];
    },
    calcTextLineMatrixAdvance: function TextState_calcTextLineMatrixAdvance(
      a,
      b,
      c,
      d,
      e,
      f
    ) {
      var font = this.font;
      if (!font) {
        return null;
      }
      var m = this.textLineMatrix;
      if (!(a === m[0] && b === m[1] && c === m[2] && d === m[3])) {
        return null;
      }
      var txDiff = e - m[4],
        tyDiff = f - m[5];
      if ((font.vertical && txDiff !== 0) || (!font.vertical && tyDiff !== 0)) {
        return null;
      }
      var tx,
        ty,
        denominator = a * d - b * c;
      if (font.vertical) {
        tx = (-tyDiff * c) / denominator;
        ty = (tyDiff * a) / denominator;
      } else {
        tx = (txDiff * d) / denominator;
        ty = (-txDiff * b) / denominator;
      }
      return { width: tx, height: ty, value: font.vertical ? ty : tx };
    },
    calcRenderMatrix: function TextState_calcRendeMatrix(ctm) {
      // 9.4.4 Text Space Details
      var tsm = [
        this.fontSize * this.textHScale,
        0,
        0,
        this.fontSize,
        0,
        this.textRise,
      ];
      return Util.transform(ctm, Util.transform(this.textMatrix, tsm));
    },
    carriageReturn: function TextState_carriageReturn() {
      this.translateTextLineMatrix(0, -this.leading);
      this.textMatrix = this.textLineMatrix.slice();
    },
    clone: function TextState_clone() {
      var clone = Object.create(this);
      clone.textMatrix = this.textMatrix.slice();
      clone.textLineMatrix = this.textLineMatrix.slice();
      clone.fontMatrix = this.fontMatrix.slice();
      return clone;
    },
  };
  return TextState;
})();

var EvalState = (function EvalStateClosure() {
  function EvalState() {
    this.ctm = new Float32Array(IDENTITY_MATRIX);
    this.font = null;
    this.textRenderingMode = TextRenderingMode.FILL;
    this.fillColorSpace = ColorSpace.singletons.gray;
    this.strokeColorSpace = ColorSpace.singletons.gray;
  }
  EvalState.prototype = {
    clone: function CanvasExtraState_clone() {
      return Object.create(this);
    },
  };
  return EvalState;
})();

var EvaluatorPreprocessor = (function EvaluatorPreprocessorClosure() {
  // Specifies properties for each command
  //
  // If variableArgs === true: [0, `numArgs`] expected
  // If variableArgs === false: exactly `numArgs` expected
  var getOPMap = getLookupTableFactory(function(t) {
    // Graphic state
    t["w"] = { id: OPS.setLineWidth, numArgs: 1, variableArgs: false };
    t["J"] = { id: OPS.setLineCap, numArgs: 1, variableArgs: false };
    t["j"] = { id: OPS.setLineJoin, numArgs: 1, variableArgs: false };
    t["M"] = { id: OPS.setMiterLimit, numArgs: 1, variableArgs: false };
    t["d"] = { id: OPS.setDash, numArgs: 2, variableArgs: false };
    t["ri"] = { id: OPS.setRenderingIntent, numArgs: 1, variableArgs: false };
    t["i"] = { id: OPS.setFlatness, numArgs: 1, variableArgs: false };
    t["gs"] = { id: OPS.setGState, numArgs: 1, variableArgs: false };
    t["q"] = { id: OPS.save, numArgs: 0, variableArgs: false };
    t["Q"] = { id: OPS.restore, numArgs: 0, variableArgs: false };
    t["cm"] = { id: OPS.transform, numArgs: 6, variableArgs: false };

    // Path
    t["m"] = { id: OPS.moveTo, numArgs: 2, variableArgs: false };
    t["l"] = { id: OPS.lineTo, numArgs: 2, variableArgs: false };
    t["c"] = { id: OPS.curveTo, numArgs: 6, variableArgs: false };
    t["v"] = { id: OPS.curveTo2, numArgs: 4, variableArgs: false };
    t["y"] = { id: OPS.curveTo3, numArgs: 4, variableArgs: false };
    t["h"] = { id: OPS.closePath, numArgs: 0, variableArgs: false };
    t["re"] = { id: OPS.rectangle, numArgs: 4, variableArgs: false };
    t["S"] = { id: OPS.stroke, numArgs: 0, variableArgs: false };
    t["s"] = { id: OPS.closeStroke, numArgs: 0, variableArgs: false };
    t["f"] = { id: OPS.fill, numArgs: 0, variableArgs: false };
    t["F"] = { id: OPS.fill, numArgs: 0, variableArgs: false };
    t["f*"] = { id: OPS.eoFill, numArgs: 0, variableArgs: false };
    t["B"] = { id: OPS.fillStroke, numArgs: 0, variableArgs: false };
    t["B*"] = { id: OPS.eoFillStroke, numArgs: 0, variableArgs: false };
    t["b"] = { id: OPS.closeFillStroke, numArgs: 0, variableArgs: false };
    t["b*"] = { id: OPS.closeEOFillStroke, numArgs: 0, variableArgs: false };
    t["n"] = { id: OPS.endPath, numArgs: 0, variableArgs: false };

    // Clipping
    t["W"] = { id: OPS.clip, numArgs: 0, variableArgs: false };
    t["W*"] = { id: OPS.eoClip, numArgs: 0, variableArgs: false };

    // Text
    t["BT"] = { id: OPS.beginText, numArgs: 0, variableArgs: false };
    t["ET"] = { id: OPS.endText, numArgs: 0, variableArgs: false };
    t["Tc"] = { id: OPS.setCharSpacing, numArgs: 1, variableArgs: false };
    t["Tw"] = { id: OPS.setWordSpacing, numArgs: 1, variableArgs: false };
    t["Tz"] = { id: OPS.setHScale, numArgs: 1, variableArgs: false };
    t["TL"] = { id: OPS.setLeading, numArgs: 1, variableArgs: false };
    t["Tf"] = { id: OPS.setFont, numArgs: 2, variableArgs: false };
    t["Tr"] = { id: OPS.setTextRenderingMode, numArgs: 1, variableArgs: false };
    t["Ts"] = { id: OPS.setTextRise, numArgs: 1, variableArgs: false };
    t["Td"] = { id: OPS.moveText, numArgs: 2, variableArgs: false };
    t["TD"] = { id: OPS.setLeadingMoveText, numArgs: 2, variableArgs: false };
    t["Tm"] = { id: OPS.setTextMatrix, numArgs: 6, variableArgs: false };
    t["T*"] = { id: OPS.nextLine, numArgs: 0, variableArgs: false };
    t["Tj"] = { id: OPS.showText, numArgs: 1, variableArgs: false };
    t["TJ"] = { id: OPS.showSpacedText, numArgs: 1, variableArgs: false };
    t["'"] = { id: OPS.nextLineShowText, numArgs: 1, variableArgs: false };
    t['"'] = {
      id: OPS.nextLineSetSpacingShowText,
      numArgs: 3,
      variableArgs: false,
    };

    // Type3 fonts
    t["d0"] = { id: OPS.setCharWidth, numArgs: 2, variableArgs: false };
    t["d1"] = {
      id: OPS.setCharWidthAndBounds,
      numArgs: 6,
      variableArgs: false,
    };

    // Color
    t["CS"] = { id: OPS.setStrokeColorSpace, numArgs: 1, variableArgs: false };
    t["cs"] = { id: OPS.setFillColorSpace, numArgs: 1, variableArgs: false };
    t["SC"] = { id: OPS.setStrokeColor, numArgs: 4, variableArgs: true };
    t["SCN"] = { id: OPS.setStrokeColorN, numArgs: 33, variableArgs: true };
    t["sc"] = { id: OPS.setFillColor, numArgs: 4, variableArgs: true };
    t["scn"] = { id: OPS.setFillColorN, numArgs: 33, variableArgs: true };
    t["G"] = { id: OPS.setStrokeGray, numArgs: 1, variableArgs: false };
    t["g"] = { id: OPS.setFillGray, numArgs: 1, variableArgs: false };
    t["RG"] = { id: OPS.setStrokeRGBColor, numArgs: 3, variableArgs: false };
    t["rg"] = { id: OPS.setFillRGBColor, numArgs: 3, variableArgs: false };
    t["K"] = { id: OPS.setStrokeCMYKColor, numArgs: 4, variableArgs: false };
    t["k"] = { id: OPS.setFillCMYKColor, numArgs: 4, variableArgs: false };

    // Shading
    t["sh"] = { id: OPS.shadingFill, numArgs: 1, variableArgs: false };

    // Images
    t["BI"] = { id: OPS.beginInlineImage, numArgs: 0, variableArgs: false };
    t["ID"] = { id: OPS.beginImageData, numArgs: 0, variableArgs: false };
    t["EI"] = { id: OPS.endInlineImage, numArgs: 1, variableArgs: false };

    // XObjects
    t["Do"] = { id: OPS.paintXObject, numArgs: 1, variableArgs: false };
    t["MP"] = { id: OPS.markPoint, numArgs: 1, variableArgs: false };
    t["DP"] = { id: OPS.markPointProps, numArgs: 2, variableArgs: false };
    t["BMC"] = { id: OPS.beginMarkedContent, numArgs: 1, variableArgs: false };
    t["BDC"] = {
      id: OPS.beginMarkedContentProps,
      numArgs: 2,
      variableArgs: false,
    };
    t["EMC"] = { id: OPS.endMarkedContent, numArgs: 0, variableArgs: false };

    // Compatibility
    t["BX"] = { id: OPS.beginCompat, numArgs: 0, variableArgs: false };
    t["EX"] = { id: OPS.endCompat, numArgs: 0, variableArgs: false };

    // (reserved partial commands for the lexer)
    t["BM"] = null;
    t["BD"] = null;
    t["true"] = null;
    t["fa"] = null;
    t["fal"] = null;
    t["fals"] = null;
    t["false"] = null;
    t["nu"] = null;
    t["nul"] = null;
    t["null"] = null;
  });

  const MAX_INVALID_PATH_OPS = 20;

  function EvaluatorPreprocessor(stream, xref, stateManager) {
    this.opMap = getOPMap();
    // TODO(mduan): pass array of knownCommands rather than this.opMap
    // dictionary
    this.parser = new Parser({
      lexer: new Lexer(stream, this.opMap),
      xref,
    });
    this.stateManager = stateManager;
    this.nonProcessedArgs = [];
    this._numInvalidPathOPS = 0;
  }

  EvaluatorPreprocessor.prototype = {
    get savedStatesDepth() {
      return this.stateManager.stateStack.length;
    },

    // |operation| is an object with two fields:
    //
    // - |fn| is an out param.
    //
    // - |args| is an inout param. On entry, it should have one of two values.
    //
    //   - An empty array. This indicates that the caller is providing the
    //     array in which the args will be stored in. The caller should use
    //     this value if it can reuse a single array for each call to read().
    //
    //   - |null|. This indicates that the caller needs this function to create
    //     the array in which any args are stored in. If there are zero args,
    //     this function will leave |operation.args| as |null| (thus avoiding
    //     allocations that would occur if we used an empty array to represent
    //     zero arguments). Otherwise, it will replace |null| with a new array
    //     containing the arguments. The caller should use this value if it
    //     cannot reuse an array for each call to read().
    //
    // These two modes are present because this function is very hot and so
    // avoiding allocations where possible is worthwhile.
    //
    read: function EvaluatorPreprocessor_read(operation) {
      var args = operation.args;
      while (true) {
        var obj = this.parser.getObj();
        if (obj instanceof Cmd) {
          var cmd = obj.cmd;
          // Check that the command is valid
          var opSpec = this.opMap[cmd];
          if (!opSpec) {
            warn(`Unknown command "${cmd}".`);
            continue;
          }

          var fn = opSpec.id;
          var numArgs = opSpec.numArgs;
          var argsLength = args !== null ? args.length : 0;

          if (!opSpec.variableArgs) {
            // Postscript commands can be nested, e.g. /F2 /GS2 gs 5.711 Tf
            if (argsLength !== numArgs) {
              var nonProcessedArgs = this.nonProcessedArgs;
              while (argsLength > numArgs) {
                nonProcessedArgs.push(args.shift());
                argsLength--;
              }
              while (argsLength < numArgs && nonProcessedArgs.length !== 0) {
                if (args === null) {
                  args = [];
                }
                args.unshift(nonProcessedArgs.pop());
                argsLength++;
              }
            }

            if (argsLength < numArgs) {
              const partialMsg =
                `command ${cmd}: expected ${numArgs} args, ` +
                `but received ${argsLength} args.`;

              // Incomplete path operators, in particular, can result in fairly
              // chaotic rendering artifacts. Hence the following heuristics is
              // used to error, rather than just warn, once a number of invalid
              // path operators have been encountered (fixes bug1443140.pdf).
              if (
                fn >= OPS.moveTo &&
                fn <= OPS.endPath && // Path operator
                ++this._numInvalidPathOPS > MAX_INVALID_PATH_OPS
              ) {
                throw new FormatError(`Invalid ${partialMsg}`);
              }
              // If we receive too few arguments, it's not possible to execute
              // the command, hence we skip the command.
              warn(`Skipping ${partialMsg}`);
              if (args !== null) {
                args.length = 0;
              }
              continue;
            }
          } else if (argsLength > numArgs) {
            info(
              `Command ${cmd}: expected [0, ${numArgs}] args, ` +
                `but received ${argsLength} args.`
            );
          }

          // TODO figure out how to type-check vararg functions
          this.preprocessCommand(fn, args);

          operation.fn = fn;
          operation.args = args;
          return true;
        }
        if (obj === EOF) {
          return false; // no more commands
        }
        // argument
        if (obj !== null) {
          if (args === null) {
            args = [];
          }
          args.push(obj);
          if (args.length > 33) {
            throw new FormatError("Too many arguments");
          }
        }
      }
    },

    preprocessCommand: function EvaluatorPreprocessor_preprocessCommand(
      fn,
      args
    ) {
      switch (fn | 0) {
        case OPS.save:
          this.stateManager.save();
          break;
        case OPS.restore:
          this.stateManager.restore();
          break;
        case OPS.transform:
          this.stateManager.transform(args);
          break;
      }
    },
  };
  return EvaluatorPreprocessor;
})();

export { PartialEvaluator };