From 7f3273dfe707b6bd837f2c44b7839533f4aec40c Mon Sep 17 00:00:00 2001
From: wingman-jr-addon <wingman.jr.addon@gmail.com>
Date: Thu, 23 Dec 2021 09:03:44 -0600
Subject: [PATCH 1/2] Trying out a limiter on GIF frame parsing to improve
 responsiveness on pages with lots of GIFs

---
 background_gif.js | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/background_gif.js b/background_gif.js
index 5ddadd4..161ef9a 100644
--- a/background_gif.js
+++ b/background_gif.js
@@ -125,12 +125,13 @@ function gifTryGetExtLength(parsedGif, si) {
     return (i + subBlockSize) - si;
 }
 
-function parseGifFrames(nextBuffer, parsedGif) {
+function parseGifFrames(nextBuffer, parsedGif, maxFramesToParse) {
     if(!parsedGif) {
         parsedGif = {
             header: null, //actually header plus global color table
             screenWidth: -1,
             screenHeight: -1,
+            lidCount: 0,
             unscannedFrames: [],
             newParsedData: new Uint8Array(),
             parsedIndex: 0, //index of last fully parsed image
@@ -184,8 +185,9 @@ function parseGifFrames(nextBuffer, parsedGif) {
 
         let wasParseFailure = false;
         let isComplete = false;
+        let framesParsedThisTime = 0;
 
-        while(!wasParseFailure && !isComplete && i < b.byteLength) {
+        while(!wasParseFailure && !isComplete && i < b.byteLength && (maxFramesToParse == -1 || framesParsedThisTime < maxFramesToParse)) {
             let peekByte = b[i]; i+=1;
             switch(peekByte) {
                 // Local Image Descriptor + Data Blocks
@@ -208,6 +210,8 @@ function parseGifFrames(nextBuffer, parsedGif) {
                         i += lidLength;
                         parsedGif.parsedIndex = i;
                         WJR_DEBUG && console.debug(`DEFG: Parsed LID - results now ${parsedGif.unscannedFrames.length} and parsed index ${parsedGif.parsedIndex}`);
+                        framesParsedThisTime++;
+                        parsedGif.lidCount++;
                     } else {
                         WJR_DEBUG && console.debug(`DEFG: Could not fully parse LID - results now ${parsedGif.unscannedFrames.length}`);
                         wasParseFailure = true;
@@ -227,6 +231,7 @@ function parseGifFrames(nextBuffer, parsedGif) {
                     break;
                 case PEEK_TRAILER:
                     WJR_DEBUG && console.debug('DEFG: Found Trailer!');
+                    console.warn(`DEFG: GIF had a total of ${parsedGif.lidCount} frames`);
                     parsedGif.parsedIndex = i;
                     isComplete = true;
                     break;
@@ -238,6 +243,10 @@ function parseGifFrames(nextBuffer, parsedGif) {
             }
         }
 
+        if(framesParsedThisTime >= maxFramesToParse && maxFramesToParse != -1) {
+            console.warn(`DEFG: GIF parsing capped at ${framesParsedThisTime}`);
+        }
+
         parsedGif.newParsedData = parsedGif.data.slice(parsedGif.lastParsedIndex, parsedGif.parsedIndex);
     } catch(e) {
         console.error('DEFG: Error parsing gif '+e);
@@ -326,7 +335,7 @@ async function gifListener(details) {
         {
             //Ensure this top section remains synchronous
             WJR_DEBUG && console.debug(`DEFG: Data for ${details.requestId} of size ${newData.byteLength}`);
-            parsedGif = parseGifFrames(newData, parsedGif);
+            parsedGif = parseGifFrames(newData, parsedGif, isComplete ? -1 : 5);
             let capturedParsedIndex = parsedGif.parsedIndex;
             let capturedLastParsedIndex = parsedGif.lastParsedIndex;
             let unscannedFrames = parsedGif.unscannedFrames;

From 71a97e9bc5335ce7035f927a95973f1b8d06187a Mon Sep 17 00:00:00 2001
From: wingman-jr-addon <wingman.jr.addon@gmail.com>
Date: Sat, 25 Dec 2021 20:46:05 -0600
Subject: [PATCH 2/2] Tweaking logging a bit

---
 background_gif.js | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/background_gif.js b/background_gif.js
index 161ef9a..4d2b036 100644
--- a/background_gif.js
+++ b/background_gif.js
@@ -230,8 +230,7 @@ function parseGifFrames(nextBuffer, parsedGif, maxFramesToParse) {
                     }
                     break;
                 case PEEK_TRAILER:
-                    WJR_DEBUG && console.debug('DEFG: Found Trailer!');
-                    console.warn(`DEFG: GIF had a total of ${parsedGif.lidCount} frames`);
+                    WJR_DEBUG && console.info(`DEFG: Found Trailer - GIF had a total of ${parsedGif.lidCount} frames`);
                     parsedGif.parsedIndex = i;
                     isComplete = true;
                     break;
@@ -244,7 +243,7 @@ function parseGifFrames(nextBuffer, parsedGif, maxFramesToParse) {
         }
 
         if(framesParsedThisTime >= maxFramesToParse && maxFramesToParse != -1) {
-            console.warn(`DEFG: GIF parsing capped at ${framesParsedThisTime}`);
+            WJR_DEBUG && console.warn(`DEFG: GIF parsing capped at ${framesParsedThisTime}`);
         }
 
         parsedGif.newParsedData = parsedGif.data.slice(parsedGif.lastParsedIndex, parsedGif.parsedIndex);