From 11cc2265516911c6cd2912254d0b0d9d2d42a398 Mon Sep 17 00:00:00 2001
From: Philipp Uhl <git@ph-uhl.com>
Date: Fri, 27 Jan 2023 13:04:31 +0100
Subject: [PATCH 1/2] Fixes slow rehashing on image instance

Fixes #171
---
 img.js | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/img.js b/img.js
index 30ac266..5947f2b 100644
--- a/img.js
+++ b/img.js
@@ -292,6 +292,10 @@ class Image {
   }
 
   getHash() {
+    if (this.computedHash) {
+      return this.computedHash;
+    }
+
     let hash = createHash("sha256");
 
     if(fs.existsSync(this.src)) {
@@ -342,7 +346,9 @@ class Image {
     // replace with hash.digest('base64url')
     let base64hash = hash.digest('base64').replace(/=/g, "").replace(/\+/g, "-").replace(/\//g, "_");
 
-    return base64hash.slice(0, this.options.hashLength);
+    const resultHash = base64hash.substring(0, this.options.hashLength);
+    this.computedHash = resultHash;
+    return resultHash;
   }
 
   getStat(outputFormat, width, height) {

From 4db05da567d3509f434020a84a00ca0503e4a128 Mon Sep 17 00:00:00 2001
From: Zach Leatherman <zachleatherman@gmail.com>
Date: Mon, 30 Jan 2023 16:07:35 -0600
Subject: [PATCH 2/2] A bit more useful debug logging here to analyze this one!

---
 img.js          | 12 ++++++++++--
 memory-cache.js | 10 ++++------
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/img.js b/img.js
index 5947f2b..c0ec9b9 100644
--- a/img.js
+++ b/img.js
@@ -172,6 +172,7 @@ class Image {
 
     // TODO @zachleat add a smarter cache here (not too aggressive! must handle input file changes)
     if(!this._contents) {
+      debug("Reading from file system: %o", this.src);
       this._contents = fs.readFileSync(this.src);
     }
 
@@ -293,6 +294,7 @@ class Image {
 
   getHash() {
     if (this.computedHash) {
+      debug("Re-using computed hash for %o: %o", this.src, this.computedHash);
       return this.computedHash;
     }
 
@@ -347,7 +349,9 @@ class Image {
     let base64hash = hash.digest('base64').replace(/=/g, "").replace(/\+/g, "-").replace(/\//g, "_");
 
     const resultHash = base64hash.substring(0, this.options.hashLength);
+
     this.computedHash = resultHash;
+
     return resultHash;
   }
 
@@ -530,7 +534,10 @@ class Image {
             }));
           }
         }
-        debug( "Wrote %o", stat.outputPath );
+
+        if(stat.outputPath) {
+          debug( "Wrote %o", stat.outputPath );
+        }
       }
     }
 
@@ -620,11 +627,12 @@ function queueImage(src, opts) {
     key = img.getInMemoryCacheKey();
     let cached = memCache.get(key);
     if(cached) {
-      debug("Found cached, returning %o", cached);
       return cached;
     }
   }
 
+  debug("In-memory cache miss for %o, options: %o", src, opts);
+
   let promise = processingQueue.add(async () => {
     if(typeof src === "string" && opts && opts.statsOnly) {
       if(Util.isRemoteUrl(src)) {
diff --git a/memory-cache.js b/memory-cache.js
index c237afe..f88e50e 100644
--- a/memory-cache.js
+++ b/memory-cache.js
@@ -3,23 +3,21 @@ const debug = require("debug")("EleventyImg");
 class MemoryCache {
   constructor() {
     this.cache = {};
-    debug("New cache.");
   }
 
   add(key, results) {
-    debug("Before add cache size %o", Object.keys(this.cache).length);
-    debug("Added %o to cache: %o", key, results);
-
     this.cache[key] = {
       results
     };
+
+    debug("Added %o to cache (size: %o)", key, Object.keys(this.cache).length);
   }
 
   get(key) {
     if(this.cache[key]) {
       // may return promise
-      debug("Cache size %o", Object.keys(this.cache).length);
-      debug("Found cached for %o %o", key, this.cache[key].results);
+      // debug("Cache size %o", Object.keys(this.cache).length);
+      // debug("Found cached for %o", key);
       return this.cache[key].results;
     }