Move worker-thread only functions from src/shared/util.js and into a new src/core/core_utils.js file

The `src/shared/util.js` file is being bundled into both the `pdf.js` and `pdf.worker.js` files, meaning that its code is by definition duplicated.
Some main-thread only utility functions have already been moved to a separate `src/display/display_utils.js` file, and this patch simply extends that concept to utility functions which are used *only* on the worker-thread.

Note in particular the `getInheritableProperty` function, which expects a `Dict` as input and thus *cannot* possibly ever be used on the main-thread.

src/core/annotation.js

@@ -16,12 +16,12 @@
 
 import {
   AnnotationBorderStyleType, AnnotationFieldFlag, AnnotationFlag,
-  AnnotationType, getInheritableProperty, OPS, stringToBytes, stringToPDFString,
-  Util, warn
+  AnnotationType, OPS, stringToBytes, stringToPDFString, Util, warn
 } from '../shared/util';
 import { Catalog, FileSpec, ObjectLoader } from './obj';
 import { Dict, isDict, isName, isRef, isStream } from './primitives';
 import { ColorSpace } from './colorspace';
+import { getInheritableProperty } from './core_utils';
 import { OperatorList } from './operator_list';
 import { Stream } from './stream';
 

src/core/chunked_stream.js

@@ -15,9 +15,9 @@
 /* eslint no-var: error */
 
 import {
-  arrayByteLength, arraysToBytes, createPromiseCapability, isEmptyObj,
-  MissingDataException
+  arrayByteLength, arraysToBytes, createPromiseCapability, isEmptyObj
 } from '../shared/util';
+import { MissingDataException } from './core_utils';
 
 class ChunkedStream {
   constructor(length, chunkSize, manager) {

src/core/cmap.js

@@ -14,11 +14,11 @@
  */
 
 import {
-  CMapCompressionType, FormatError, isString, MissingDataException, unreachable,
-  warn
+  CMapCompressionType, FormatError, isString, unreachable, warn
 } from '../shared/util';
 import { isCmd, isEOF, isName, isStream } from './primitives';
 import { Lexer } from './parser';
+import { MissingDataException } from './core_utils';
 import { Stream } from './stream';
 
 var BUILT_IN_CMAPS = [

src/core/core_utils.js

@@ -0,0 +1,160 @@
+/* Copyright 2019 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.
+ */
+/* eslint no-var: error */
+
+import { assert, warn } from '../shared/util';
+
+function getLookupTableFactory(initializer) {
+  let lookup;
+  return function() {
+    if (initializer) {
+      lookup = Object.create(null);
+      initializer(lookup);
+      initializer = null;
+    }
+    return lookup;
+  };
+}
+
+const MissingDataException = (function MissingDataExceptionClosure() {
+  function MissingDataException(begin, end) {
+    this.begin = begin;
+    this.end = end;
+    this.message = `Missing data [${begin}, ${end})`;
+  }
+
+  MissingDataException.prototype = new Error();
+  MissingDataException.prototype.name = 'MissingDataException';
+  MissingDataException.constructor = MissingDataException;
+
+  return MissingDataException;
+})();
+
+const XRefEntryException = (function XRefEntryExceptionClosure() {
+  function XRefEntryException(msg) {
+    this.message = msg;
+  }
+
+  XRefEntryException.prototype = new Error();
+  XRefEntryException.prototype.name = 'XRefEntryException';
+  XRefEntryException.constructor = XRefEntryException;
+
+  return XRefEntryException;
+})();
+
+const XRefParseException = (function XRefParseExceptionClosure() {
+  function XRefParseException(msg) {
+    this.message = msg;
+  }
+
+  XRefParseException.prototype = new Error();
+  XRefParseException.prototype.name = 'XRefParseException';
+  XRefParseException.constructor = XRefParseException;
+
+  return XRefParseException;
+})();
+
+/**
+ * Get the value of an inheritable property.
+ *
+ * If the PDF specification explicitly lists a property in a dictionary as
+ * inheritable, then the value of the property may be present in the dictionary
+ * itself or in one or more parents of the dictionary.
+ *
+ * If the key is not found in the tree, `undefined` is returned. Otherwise,
+ * the value for the key is returned or, if `stopWhenFound` is `false`, a list
+ * of values is returned. To avoid infinite loops, the traversal is stopped when
+ * the loop limit is reached.
+ *
+ * @param {Dict} dict - Dictionary from where to start the traversal.
+ * @param {string} key - The key of the property to find the value for.
+ * @param {boolean} getArray - Whether or not the value should be fetched as an
+ *   array. The default value is `false`.
+ * @param {boolean} stopWhenFound - Whether or not to stop the traversal when
+ *   the key is found. If set to `false`, we always walk up the entire parent
+ *   chain, for example to be able to find `\Resources` placed on multiple
+ *   levels of the tree. The default value is `true`.
+ */
+function getInheritableProperty({ dict, key, getArray = false,
+                                  stopWhenFound = true, }) {
+  const LOOP_LIMIT = 100;
+  let loopCount = 0;
+  let values;
+
+  while (dict) {
+    const value = getArray ? dict.getArray(key) : dict.get(key);
+    if (value !== undefined) {
+      if (stopWhenFound) {
+        return value;
+      }
+      if (!values) {
+        values = [];
+      }
+      values.push(value);
+    }
+    if (++loopCount > LOOP_LIMIT) {
+      warn(`getInheritableProperty: maximum loop count exceeded for "${key}"`);
+      break;
+    }
+    dict = dict.get('Parent');
+  }
+  return values;
+}
+
+const ROMAN_NUMBER_MAP = [
+  '', 'C', 'CC', 'CCC', 'CD', 'D', 'DC', 'DCC', 'DCCC', 'CM',
+  '', 'X', 'XX', 'XXX', 'XL', 'L', 'LX', 'LXX', 'LXXX', 'XC',
+  '', 'I', 'II', 'III', 'IV', 'V', 'VI', 'VII', 'VIII', 'IX'
+];
+
+/**
+ * Converts positive integers to (upper case) Roman numerals.
+ * @param {integer} number - The number that should be converted.
+ * @param {boolean} lowerCase - Indicates if the result should be converted
+ *   to lower case letters. The default value is `false`.
+ * @return {string} The resulting Roman number.
+ */
+function toRomanNumerals(number, lowerCase = false) {
+  assert(Number.isInteger(number) && number > 0,
+         'The number should be a positive integer.');
+  let pos, romanBuf = [];
+  // Thousands
+  while (number >= 1000) {
+    number -= 1000;
+    romanBuf.push('M');
+  }
+  // Hundreds
+  pos = (number / 100) | 0;
+  number %= 100;
+  romanBuf.push(ROMAN_NUMBER_MAP[pos]);
+  // Tens
+  pos = (number / 10) | 0;
+  number %= 10;
+  romanBuf.push(ROMAN_NUMBER_MAP[10 + pos]);
+  // Ones
+  romanBuf.push(ROMAN_NUMBER_MAP[20 + number]);
+
+  const romanStr = romanBuf.join('');
+  return (lowerCase ? romanStr.toLowerCase() : romanStr);
+}
+
+export {
+  getLookupTableFactory,
+  MissingDataException,
+  XRefEntryException,
+  XRefParseException,
+  getInheritableProperty,
+  toRomanNumerals,
+};

src/core/document.js

@@ -15,12 +15,15 @@
 /* eslint no-var: error */
 
 import {
-  assert, FormatError, getInheritableProperty, info, isArrayBuffer, isBool,
-  isNum, isSpace, isString, MissingDataException, OPS, shadow, stringToBytes,
-  stringToPDFString, Util, warn, XRefEntryException, XRefParseException
+  assert, FormatError, info, isArrayBuffer, isBool, isNum, isSpace, isString,
+  OPS, shadow, stringToBytes, stringToPDFString, Util, warn
 } from '../shared/util';
 import { Catalog, ObjectLoader, XRef } from './obj';
 import { Dict, isDict, isName, isStream, Ref } from './primitives';
+import {
+  getInheritableProperty, MissingDataException, XRefEntryException,
+  XRefParseException
+} from './core_utils';
 import { NullStream, Stream, StreamsSequenceStream } from './stream';
 import { AnnotationFactory } from './annotation';
 import { calculateMD5 } from './crypto';

src/core/evaluator.js

@@ -15,9 +15,9 @@
 
 import {
   AbortException, assert, CMapCompressionType, createPromiseCapability,
-  FONT_IDENTITY_MATRIX, FormatError, getLookupTableFactory, IDENTITY_MATRIX,
-  info, isNum, isString, NativeImageDecoding, OPS, stringToPDFString,
-  TextRenderingMode, UNSUPPORTED_FEATURES, Util, warn
+  FONT_IDENTITY_MATRIX, FormatError, IDENTITY_MATRIX, info, isNum, isString,
+  NativeImageDecoding, OPS, stringToPDFString, TextRenderingMode,
+  UNSUPPORTED_FEATURES, Util, warn
 } from '../shared/util';
 import { CMapFactory, IdentityCMap } from './cmap';
 import { DecodeStream, Stream } from './stream';
@@ -42,6 +42,7 @@ import { Lexer, Parser } from './parser';
 import { bidi } from './bidi';
 import { ColorSpace } from './colorspace';
 import { getGlyphsUnicode } from './glyphlist';
+import { getLookupTableFactory } from './core_utils';
 import { getMetrics } from './metrics';
 import { isPDFFunction } from './function';
 import { JpegStream } from './jpeg_stream';

src/core/fonts.js

@@ -15,8 +15,7 @@
 
 import {
   assert, bytesToString, FONT_IDENTITY_MATRIX, FontType, FormatError, info,
-  isNum, isSpace, MissingDataException, readUint32, shadow, string32,
-  unreachable, warn
+  isNum, isSpace, readUint32, shadow, string32, unreachable, warn
 } from '../shared/util';
 import {
   CFF, CFFCharset, CFFCompiler, CFFHeader, CFFIndex, CFFParser, CFFPrivateDict,
@@ -36,6 +35,7 @@ import {
 } from './unicode';
 import { FontRendererFactory } from './font_renderer';
 import { IdentityCMap } from './cmap';
+import { MissingDataException } from './core_utils';
 import { Stream } from './stream';
 import { Type1Parser } from './type1_parser';
 

src/core/glyphlist.js

@@ -14,7 +14,7 @@
  */
 /* no-babel-preset */
 
-var getLookupTableFactory = require('../shared/util').getLookupTableFactory;
+var getLookupTableFactory = require('./core_utils').getLookupTableFactory;
 
 var getGlyphsUnicode = getLookupTableFactory(function (t) {
   t['A'] = 0x0041;

src/core/metrics.js

@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-import { getLookupTableFactory } from '../shared/util';
+import { getLookupTableFactory } from './core_utils';
 
 // The Metrics object contains glyph widths (in glyph space units).
 // As per PDF spec, for most fonts (Type 3 being an exception) a glyph

src/core/obj.js

@@ -15,15 +15,17 @@
 
 import {
   bytesToString, createPromiseCapability, createValidAbsoluteUrl, FormatError,
-  info, InvalidPDFException, isBool, isNum, isString, MissingDataException,
-  PermissionFlag, shadow, stringToPDFString, stringToUTF8String,
-  toRomanNumerals, unreachable, warn, XRefEntryException, XRefParseException
+  info, InvalidPDFException, isBool, isNum, isString, PermissionFlag, shadow,
+  stringToPDFString, stringToUTF8String, unreachable, warn
 } from '../shared/util';
 import {
   Dict, isCmd, isDict, isName, isRef, isRefsEqual, isStream, Ref, RefSet,
   RefSetCache
 } from './primitives';
 import { Lexer, Parser } from './parser';
+import {
+  MissingDataException, toRomanNumerals, XRefEntryException, XRefParseException
+} from './core_utils';
 import { ChunkedStream } from './chunked_stream';
 import { CipherTransformFactory } from './crypto';
 import { ColorSpace } from './colorspace';

src/core/parser.js

@@ -19,7 +19,7 @@ import {
 } from './stream';
 import {
   assert, bytesToString, FormatError, info, isNum, isSpace, isString,
-  MissingDataException, StreamType, warn
+  StreamType, warn
 } from '../shared/util';
 import {
   Cmd, Dict, EOF, isCmd, isDict, isEOF, isName, Name, Ref
@@ -28,6 +28,7 @@ import { CCITTFaxStream } from './ccitt_stream';
 import { Jbig2Stream } from './jbig2_stream';
 import { JpegStream } from './jpeg_stream';
 import { JpxStream } from './jpx_stream';
+import { MissingDataException } from './core_utils';
 
 const MAX_LENGTH_TO_CACHE = 1000;
 const MAX_ADLER32_LENGTH = 5552;

src/core/pattern.js

@@ -15,11 +15,11 @@
 /* eslint-disable no-multi-spaces */
 
 import {
-  assert, FormatError, info, MissingDataException, unreachable,
-  UNSUPPORTED_FEATURES, Util, warn
+  assert, FormatError, info, unreachable, UNSUPPORTED_FEATURES, Util, warn
 } from '../shared/util';
 import { ColorSpace } from './colorspace';
 import { isStream } from './primitives';
+import { MissingDataException } from './core_utils';
 
 var ShadingType = {
   FUNCTION_BASED: 1,

src/core/pdf_manager.js

@@ -14,9 +14,10 @@
  */
 
 import {
-  createValidAbsoluteUrl, MissingDataException, shadow, unreachable, warn
+  createValidAbsoluteUrl, shadow, unreachable, warn
 } from '../shared/util';
 import { ChunkedStreamManager } from './chunked_stream';
+import { MissingDataException } from './core_utils';
 import { PDFDocument } from './document';
 import { Stream } from './stream';
 

src/core/standard_fonts.js

@@ -14,7 +14,7 @@
  */
 /* eslint no-var: error */
 
-import { getLookupTableFactory } from '../shared/util';
+import { getLookupTableFactory } from './core_utils';
 
 /**
  * Hold a map of decoded fonts and of the standard fourteen Type1

src/core/unicode.js

@@ -14,7 +14,7 @@
  */
 /* no-babel-preset */
 
-var getLookupTableFactory = require('../shared/util').getLookupTableFactory;
+var getLookupTableFactory = require('./core_utils').getLookupTableFactory;
 
 // Some characters, e.g. copyrightserif, are mapped to the private use area
 // and might not be displayed using standard fonts. Mapping/hacking well-known

src/core/worker.js

@@ -17,12 +17,13 @@ import {
   arrayByteLength, arraysToBytes, assert, createPromiseCapability, info,
   InvalidPDFException, MissingPDFException, PasswordException,
   setVerbosityLevel, UnexpectedResponseException, UnknownErrorException,
-  UNSUPPORTED_FEATURES, warn, XRefParseException
+  UNSUPPORTED_FEATURES, warn
 } from '../shared/util';
 import { LocalPdfManager, NetworkPdfManager } from './pdf_manager';
 import isNodeJS from '../shared/is_node';
 import { MessageHandler } from '../shared/message_handler';
 import { Ref } from './primitives';
+import { XRefParseException } from './core_utils';
 
 var WorkerTask = (function WorkerTaskClosure() {
   function WorkerTask(name) {

src/shared/util.js

@@ -382,18 +382,6 @@ function shadow(obj, prop, value) {
   return value;
 }
 
-function getLookupTableFactory(initializer) {
-  var lookup;
-  return function () {
-    if (initializer) {
-      lookup = Object.create(null);
-      initializer(lookup);
-      initializer = null;
-    }
-    return lookup;
-  };
-}
-
 var PasswordException = (function PasswordExceptionClosure() {
   function PasswordException(msg, code) {
     this.name = 'PasswordException';
@@ -458,44 +446,6 @@ var UnexpectedResponseException =
   return UnexpectedResponseException;
 })();
 
-var MissingDataException = (function MissingDataExceptionClosure() {
-  function MissingDataException(begin, end) {
-    this.begin = begin;
-    this.end = end;
-    this.message = 'Missing data [' + begin + ', ' + end + ')';
-  }
-
-  MissingDataException.prototype = new Error();
-  MissingDataException.prototype.name = 'MissingDataException';
-  MissingDataException.constructor = MissingDataException;
-
-  return MissingDataException;
-})();
-
-const XRefEntryException = (function XRefEntryExceptionClosure() {
-  function XRefEntryException(msg) {
-    this.message = msg;
-  }
-
-  XRefEntryException.prototype = new Error();
-  XRefEntryException.prototype.name = 'XRefEntryException';
-  XRefEntryException.constructor = XRefEntryException;
-
-  return XRefEntryException;
-})();
-
-var XRefParseException = (function XRefParseExceptionClosure() {
-  function XRefParseException(msg) {
-    this.message = msg;
-  }
-
-  XRefParseException.prototype = new Error();
-  XRefParseException.prototype.name = 'XRefParseException';
-  XRefParseException.constructor = XRefParseException;
-
-  return XRefParseException;
-})();
-
 /**
  * Error caused during parsing PDF data.
  */
@@ -659,53 +609,6 @@ function isEvalSupported() {
   }
 }
 
-/**
- * Get the value of an inheritable property.
- *
- * If the PDF specification explicitly lists a property in a dictionary as
- * inheritable, then the value of the property may be present in the dictionary
- * itself or in one or more parents of the dictionary.
- *
- * If the key is not found in the tree, `undefined` is returned. Otherwise,
- * the value for the key is returned or, if `stopWhenFound` is `false`, a list
- * of values is returned. To avoid infinite loops, the traversal is stopped when
- * the loop limit is reached.
- *
- * @param {Dict} dict - Dictionary from where to start the traversal.
- * @param {string} key - The key of the property to find the value for.
- * @param {boolean} getArray - Whether or not the value should be fetched as an
- *   array. The default value is `false`.
- * @param {boolean} stopWhenFound - Whether or not to stop the traversal when
- *   the key is found. If set to `false`, we always walk up the entire parent
- *   chain, for example to be able to find `\Resources` placed on multiple
- *   levels of the tree. The default value is `true`.
- */
-function getInheritableProperty({ dict, key, getArray = false,
-                                  stopWhenFound = true, }) {
-  const LOOP_LIMIT = 100;
-  let loopCount = 0;
-  let values;
-
-  while (dict) {
-    const value = getArray ? dict.getArray(key) : dict.get(key);
-    if (value !== undefined) {
-      if (stopWhenFound) {
-        return value;
-      }
-      if (!values) {
-        values = [];
-      }
-      values.push(value);
-    }
-    if (++loopCount > LOOP_LIMIT) {
-      warn(`getInheritableProperty: maximum loop count exceeded for "${key}"`);
-      break;
-    }
-    dict = dict.get('Parent');
-  }
-  return values;
-}
-
 var Util = (function UtilClosure() {
   function Util() {}
 
@@ -866,43 +769,6 @@ var Util = (function UtilClosure() {
   return Util;
 })();
 
-const ROMAN_NUMBER_MAP = [
-  '', 'C', 'CC', 'CCC', 'CD', 'D', 'DC', 'DCC', 'DCCC', 'CM',
-  '', 'X', 'XX', 'XXX', 'XL', 'L', 'LX', 'LXX', 'LXXX', 'XC',
-  '', 'I', 'II', 'III', 'IV', 'V', 'VI', 'VII', 'VIII', 'IX'
-];
-
-/**
- * Converts positive integers to (upper case) Roman numerals.
- * @param {integer} number - The number that should be converted.
- * @param {boolean} lowerCase - Indicates if the result should be converted
- *   to lower case letters. The default value is `false`.
- * @return {string} The resulting Roman number.
- */
-function toRomanNumerals(number, lowerCase = false) {
-  assert(Number.isInteger(number) && number > 0,
-         'The number should be a positive integer.');
-  let pos, romanBuf = [];
-  // Thousands
-  while (number >= 1000) {
-    number -= 1000;
-    romanBuf.push('M');
-  }
-  // Hundreds
-  pos = (number / 100) | 0;
-  number %= 100;
-  romanBuf.push(ROMAN_NUMBER_MAP[pos]);
-  // Tens
-  pos = (number / 10) | 0;
-  number %= 10;
-  romanBuf.push(ROMAN_NUMBER_MAP[10 + pos]);
-  // Ones
-  romanBuf.push(ROMAN_NUMBER_MAP[20 + number]);
-
-  const romanStr = romanBuf.join('');
-  return (lowerCase ? romanStr.toLowerCase() : romanStr);
-}
-
 const PDFStringTranslateTable = [
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
   0x2D8, 0x2C7, 0x2C6, 0x2D9, 0x2DD, 0x2DB, 0x2DA, 0x2DC, 0, 0, 0, 0, 0, 0, 0,
@@ -1046,7 +912,6 @@ export {
   CMapCompressionType,
   AbortException,
   InvalidPDFException,
-  MissingDataException,
   MissingPDFException,
   NativeImageDecoding,
   PasswordException,
@@ -1057,9 +922,6 @@ export {
   UnexpectedResponseException,
   UnknownErrorException,
   Util,
-  toRomanNumerals,
-  XRefEntryException,
-  XRefParseException,
   FormatError,
   arrayByteLength,
   arraysToBytes,
@@ -1068,8 +930,6 @@ export {
   createPromiseCapability,
   createObjectURL,
   deprecated,
-  getInheritableProperty,
-  getLookupTableFactory,
   getVerbosityLevel,
   info,
   isArrayBuffer,