From 1dc4713a0baa73c2d395713fc955ac7a053dc2a3 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Tue, 5 Apr 2022 16:01:01 +0200
Subject: [PATCH 1/2] Re-factor the `isLittleEndian`/`isEvalSupported` caching

This functionality is very old, hence we should be able to improve the caching a little bit with modern JavaScript features.
---
 src/core/function.js       |  4 ++--
 src/display/canvas.js      |  4 ++--
 src/display/font_loader.js |  4 ++--
 src/shared/util.js         | 23 +++++++++++------------
 4 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/src/core/function.js b/src/core/function.js
index 37710610f..3d1285f41 100644
--- a/src/core/function.js
+++ b/src/core/function.js
@@ -15,9 +15,9 @@
 
 import { Dict, Ref } from "./primitives.js";
 import {
+  FeatureTest,
   FormatError,
   info,
-  IsEvalSupportedCached,
   shadow,
   unreachable,
 } from "../shared/util.js";
@@ -438,7 +438,7 @@ class PDFFunction {
     const parser = new PostScriptParser(lexer);
     const code = parser.parse();
 
-    if (isEvalSupported && IsEvalSupportedCached.value) {
+    if (isEvalSupported && FeatureTest.isEvalSupported) {
       const compiled = new PostScriptCompiler().compile(code, domain, range);
       if (compiled) {
         // Compiled function consists of simple expressions such as addition,
diff --git a/src/display/canvas.js b/src/display/canvas.js
index 6ca01a1c7..3dc0ad1de 100644
--- a/src/display/canvas.js
+++ b/src/display/canvas.js
@@ -14,11 +14,11 @@
  */
 
 import {
+  FeatureTest,
   FONT_IDENTITY_MATRIX,
   IDENTITY_MATRIX,
   ImageKind,
   info,
-  IsLittleEndianCached,
   OPS,
   shadow,
   TextRenderingMode,
@@ -702,7 +702,7 @@ function putBinaryImageData(ctx, imgData, transferMaps = null) {
     const dest32DataLength = dest32.length;
     const fullSrcDiff = (width + 7) >> 3;
     let white = 0xffffffff;
-    let black = IsLittleEndianCached.value ? 0xff000000 : 0x000000ff;
+    let black = FeatureTest.isLittleEndian ? 0xff000000 : 0x000000ff;
 
     if (transferMapGray) {
       if (transferMapGray[0] === 0xff && transferMapGray[0xff] === 0) {
diff --git a/src/display/font_loader.js b/src/display/font_loader.js
index 0b6aedc45..a80a7de6e 100644
--- a/src/display/font_loader.js
+++ b/src/display/font_loader.js
@@ -16,7 +16,7 @@
 import {
   assert,
   bytesToString,
-  IsEvalSupportedCached,
+  FeatureTest,
   shadow,
   string32,
   unreachable,
@@ -455,7 +455,7 @@ class FontFaceObject {
     }
 
     // If we can, compile cmds into JS for MAXIMUM SPEED...
-    if (this.isEvalSupported && IsEvalSupportedCached.value) {
+    if (this.isEvalSupported && FeatureTest.isEvalSupported) {
       const jsBuf = [];
       for (const current of cmds) {
         const args = current.args !== undefined ? current.args.join(",") : "";
diff --git a/src/shared/util.js b/src/shared/util.js
index e51f61735..ee0a7eceb 100644
--- a/src/shared/util.js
+++ b/src/shared/util.js
@@ -682,11 +682,6 @@ function isLittleEndian() {
   const view32 = new Uint32Array(buffer8.buffer, 0, 1);
   return view32[0] === 1;
 }
-const IsLittleEndianCached = {
-  get value() {
-    return shadow(this, "value", isLittleEndian());
-  },
-};
 
 // Checks if it's possible to eval JS expressions.
 function isEvalSupported() {
@@ -697,11 +692,16 @@ function isEvalSupported() {
     return false;
   }
 }
-const IsEvalSupportedCached = {
-  get value() {
-    return shadow(this, "value", isEvalSupported());
-  },
-};
+
+class FeatureTest {
+  static get isLittleEndian() {
+    return shadow(this, "isLittleEndian", isLittleEndian());
+  }
+
+  static get isEvalSupported() {
+    return shadow(this, "isEvalSupported", isEvalSupported());
+  }
+}
 
 const hexNumbers = [...Array(256).keys()].map(n =>
   n.toString(16).padStart(2, "0")
@@ -1103,6 +1103,7 @@ export {
   createValidAbsoluteUrl,
   DocumentActionEventType,
   escapeString,
+  FeatureTest,
   FONT_IDENTITY_MATRIX,
   FontType,
   FormatError,
@@ -1115,8 +1116,6 @@ export {
   isArrayBuffer,
   isArrayEqual,
   isAscii,
-  IsEvalSupportedCached,
-  IsLittleEndianCached,
   MissingPDFException,
   objectFromMap,
   objectSize,

From a919959d8388602d0789a1b56e093a67678cd1fd Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Tue, 5 Apr 2022 16:04:09 +0200
Subject: [PATCH 2/2] Slightly simplify the `Catalog._readMarkInfo` method

We don't need to first check if the Dictionary contains the key, since trying to get a non-existent key simply returns `undefined` and we're already ensuring that the value is a boolean.
Furthermore, we shouldn't need to worry about the `Object.prototype` containing enumerable properties since the checks (in `src/core/worker.js`) done for `Array.prototype` *indirectly* also cover `Object`s. (Keep in mind that an `Array` is just a special kind of `Object` in JavaScript.)
---
 src/core/catalog.js | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/core/catalog.js b/src/core/catalog.js
index 13f54f75d..dcc509c91 100644
--- a/src/core/catalog.js
+++ b/src/core/catalog.js
@@ -209,20 +209,16 @@ class Catalog {
       return null;
     }
 
-    const markInfo = Object.assign(Object.create(null), {
+    const markInfo = {
       Marked: false,
       UserProperties: false,
       Suspects: false,
-    });
+    };
     for (const key in markInfo) {
-      if (!obj.has(key)) {
-        continue;
-      }
       const value = obj.get(key);
-      if (typeof value !== "boolean") {
-        continue;
+      if (typeof value === "boolean") {
+        markInfo[key] = value;
       }
-      markInfo[key] = value;
     }
 
     return markInfo;