From f0950d910ce42d289363c08300488557fad4742c Mon Sep 17 00:00:00 2001
From: Matt Ford <mattford@users.noreply.github.com>
Date: Thu, 17 Aug 2023 16:26:40 +0100
Subject: [PATCH 1/8] Fix memory leak on flush method

---
 src/Illuminate/Cache/TaggedCache.php | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/Illuminate/Cache/TaggedCache.php b/src/Illuminate/Cache/TaggedCache.php
index 7cd12303882c..d4bd9c603927 100644
--- a/src/Illuminate/Cache/TaggedCache.php
+++ b/src/Illuminate/Cache/TaggedCache.php
@@ -2,6 +2,8 @@
 
 namespace Illuminate\Cache;
 
+use Illuminate\Cache\Events\KeyForgotten;
+use Illuminate\Cache\Events\KeyWritten;
 use Illuminate\Contracts\Cache\Store;
 
 class TaggedCache extends Repository
@@ -17,6 +19,12 @@ class TaggedCache extends Repository
      */
     protected $tags;
 
+    /**
+     * List of keys within this namespace
+     * @var array
+     */
+    protected $itemKeys = [];
+
     /**
      * Create a new tagged cache instance.
      *
@@ -78,6 +86,8 @@ public function decrement($key, $value = 1)
      */
     public function flush()
     {
+        array_walk($this->itemKeys, [$this->store, 'forget']);
+        $this->itemKeys = [];
         $this->tags->reset();
 
         return true;
@@ -110,6 +120,14 @@ public function taggedItemKey($key)
      */
     protected function event($event)
     {
+        $itemKey = $this->itemKey($event->key);
+        if ($event instanceof KeyWritten && !in_array($itemKey, $this->itemKeys)) {
+            $this->itemKeys[] = $itemKey;
+        } elseif ($event instanceof KeyForgotten && in_array($itemKey, $this->itemKeys)) {
+            $this->itemKeys = array_values(array_filter($this->itemKeys, function ($k) use ($itemKey) {
+                return $k !== $itemKey;
+            }));
+        }
         parent::event($event->setTags($this->tags->getNames()));
     }
 

From 63632e3c9a4e518a33841f4f6bb9f6775e978e41 Mon Sep 17 00:00:00 2001
From: Matt Ford <mattford@users.noreply.github.com>
Date: Thu, 17 Aug 2023 16:40:07 +0100
Subject: [PATCH 2/8] Style fixes

---
 src/Illuminate/Cache/TaggedCache.php | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Illuminate/Cache/TaggedCache.php b/src/Illuminate/Cache/TaggedCache.php
index d4bd9c603927..971405a0d6e8 100644
--- a/src/Illuminate/Cache/TaggedCache.php
+++ b/src/Illuminate/Cache/TaggedCache.php
@@ -21,6 +21,7 @@ class TaggedCache extends Repository
 
     /**
      * List of keys within this namespace
+     *
      * @var array
      */
     protected $itemKeys = [];
@@ -121,7 +122,7 @@ public function taggedItemKey($key)
     protected function event($event)
     {
         $itemKey = $this->itemKey($event->key);
-        if ($event instanceof KeyWritten && !in_array($itemKey, $this->itemKeys)) {
+        if ($event instanceof KeyWritten && ! in_array($itemKey, $this->itemKeys)) {
             $this->itemKeys[] = $itemKey;
         } elseif ($event instanceof KeyForgotten && in_array($itemKey, $this->itemKeys)) {
             $this->itemKeys = array_values(array_filter($this->itemKeys, function ($k) use ($itemKey) {

From a1dafdbe24c5b4839d1da03e51dc32e706611a15 Mon Sep 17 00:00:00 2001
From: Matt Ford <mattford@users.noreply.github.com>
Date: Thu, 17 Aug 2023 16:40:56 +0100
Subject: [PATCH 3/8] Add full stop.

---
 src/Illuminate/Cache/TaggedCache.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Illuminate/Cache/TaggedCache.php b/src/Illuminate/Cache/TaggedCache.php
index 971405a0d6e8..d487000d6073 100644
--- a/src/Illuminate/Cache/TaggedCache.php
+++ b/src/Illuminate/Cache/TaggedCache.php
@@ -20,7 +20,7 @@ class TaggedCache extends Repository
     protected $tags;
 
     /**
-     * List of keys within this namespace
+     * List of keys within this namespace.
      *
      * @var array
      */

From 1d35633068035b055ccd011e7ce0845358aae0f3 Mon Sep 17 00:00:00 2001
From: Matt Ford <mattford@users.noreply.github.com>
Date: Fri, 18 Aug 2023 09:08:13 +0100
Subject: [PATCH 4/8] Change approach + add test

---
 src/Illuminate/Cache/TaggedCache.php | 45 +++++++++++++++++++++++-----
 tests/Cache/CacheTaggedCacheTest.php | 13 ++++++++
 2 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/src/Illuminate/Cache/TaggedCache.php b/src/Illuminate/Cache/TaggedCache.php
index d487000d6073..4f4463276c69 100644
--- a/src/Illuminate/Cache/TaggedCache.php
+++ b/src/Illuminate/Cache/TaggedCache.php
@@ -87,8 +87,10 @@ public function decrement($key, $value = 1)
      */
     public function flush()
     {
-        array_walk($this->itemKeys, [$this->store, 'forget']);
-        $this->itemKeys = [];
+        foreach ($this->getItemKeys() as $key) {
+            $this->store->forget($key);
+        }
+        $this->store->forget($this->getMetadataKey());
         $this->tags->reset();
 
         return true;
@@ -122,16 +124,43 @@ public function taggedItemKey($key)
     protected function event($event)
     {
         $itemKey = $this->itemKey($event->key);
-        if ($event instanceof KeyWritten && ! in_array($itemKey, $this->itemKeys)) {
-            $this->itemKeys[] = $itemKey;
-        } elseif ($event instanceof KeyForgotten && in_array($itemKey, $this->itemKeys)) {
-            $this->itemKeys = array_values(array_filter($this->itemKeys, function ($k) use ($itemKey) {
-                return $k !== $itemKey;
-            }));
+        if ($itemKey !== $this->getMetadataKey() && ($event instanceof KeyWritten || $event instanceof KeyForgotten)) {
+            $itemKeys = $this->getItemKeys();
+            if ($event instanceof KeyWritten && !in_array($itemKey, $itemKeys)) {
+                $itemKeys[] = $itemKey;
+            } elseif ($event instanceof KeyForgotten && in_array($itemKey, $this->itemKeys)) {
+                $itemKeys = array_values(
+                    array_filter($itemKeys, function ($k) use ($itemKey) {
+                        return $k !== $itemKey;
+                    })
+                );
+            }
+            $this->putItemKeys($itemKeys);
         }
         parent::event($event->setTags($this->tags->getNames()));
     }
 
+    private function getMetadataKey(): string
+    {
+        return $this->taggedItemKey('meta:keys');
+    }
+
+    private function getItemKeys(): array
+    {
+        $metadataKey = $this->getMetadataKey();
+        $keys = $this->store->get($metadataKey);
+        if (! is_array($keys)) {
+            $keys = [];
+        }
+        return $keys;
+    }
+
+    private function putItemKeys(array $keys): void
+    {
+        $metadataKey = $this->getMetadataKey();
+        $this->store->forever($metadataKey, $keys);
+    }
+
     /**
      * Get the tag set instance.
      *
diff --git a/tests/Cache/CacheTaggedCacheTest.php b/tests/Cache/CacheTaggedCacheTest.php
index 1834bce56d4f..7ee140c718e3 100644
--- a/tests/Cache/CacheTaggedCacheTest.php
+++ b/tests/Cache/CacheTaggedCacheTest.php
@@ -203,6 +203,19 @@ public function testTagsCacheForever()
         $this->assertSame('bar', $store->tags($tags)->get('foo'));
     }
 
+    public function testFlushFunctionDoesntLeakMemory()
+    {
+        $store = new ArrayStore;
+        $tags = ['bop'];
+        $before = memory_get_usage(true);
+        for ($i = 0; $i < 100; $i++) {
+            $store->tags($tags)->forever('foo', 'bar');
+            $store->tags($tags)->flush();
+        }
+        $after = memory_get_usage(true);
+        $this->assertSame($before, $after);
+    }
+
     private function getTestCacheStoreWithTagValues(): ArrayStore
     {
         $store = new ArrayStore;

From e2cc24a6dfc9d485f7f7ba5d76bfd5126e15c6cf Mon Sep 17 00:00:00 2001
From: Matt Ford <mattford@users.noreply.github.com>
Date: Fri, 18 Aug 2023 09:30:16 +0100
Subject: [PATCH 5/8] Make the test more robust

---
 tests/Cache/CacheTaggedCacheTest.php | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tests/Cache/CacheTaggedCacheTest.php b/tests/Cache/CacheTaggedCacheTest.php
index 7ee140c718e3..3744fc8d8ce1 100644
--- a/tests/Cache/CacheTaggedCacheTest.php
+++ b/tests/Cache/CacheTaggedCacheTest.php
@@ -208,8 +208,11 @@ public function testFlushFunctionDoesntLeakMemory()
         $store = new ArrayStore;
         $tags = ['bop'];
         $before = memory_get_usage(true);
+        // Store a 5MB cache value then flush it 100 times, then verify the overall memory usage did not increase
         for ($i = 0; $i < 100; $i++) {
-            $store->tags($tags)->forever('foo', 'bar');
+            $key = str_replace('.', '', uniqid());
+            $value = bin2hex(random_bytes(1024 * 5));
+            $store->tags($tags)->forever($key, $value);
             $store->tags($tags)->flush();
         }
         $after = memory_get_usage(true);

From 83dbce167f07911232433a0bff0c6d8614049cdc Mon Sep 17 00:00:00 2001
From: Matt Ford <mattford@users.noreply.github.com>
Date: Fri, 18 Aug 2023 09:36:48 +0100
Subject: [PATCH 6/8] Style fix

---
 src/Illuminate/Cache/TaggedCache.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Illuminate/Cache/TaggedCache.php b/src/Illuminate/Cache/TaggedCache.php
index 4f4463276c69..200af8e585da 100644
--- a/src/Illuminate/Cache/TaggedCache.php
+++ b/src/Illuminate/Cache/TaggedCache.php
@@ -126,7 +126,7 @@ protected function event($event)
         $itemKey = $this->itemKey($event->key);
         if ($itemKey !== $this->getMetadataKey() && ($event instanceof KeyWritten || $event instanceof KeyForgotten)) {
             $itemKeys = $this->getItemKeys();
-            if ($event instanceof KeyWritten && !in_array($itemKey, $itemKeys)) {
+            if ($event instanceof KeyWritten && ! in_array($itemKey, $itemKeys)) {
                 $itemKeys[] = $itemKey;
             } elseif ($event instanceof KeyForgotten && in_array($itemKey, $this->itemKeys)) {
                 $itemKeys = array_values(

From 6a94fdd3e0f48176bb7ba6018f51291d93e3a346 Mon Sep 17 00:00:00 2001
From: Matt Ford <mattford@users.noreply.github.com>
Date: Fri, 18 Aug 2023 10:02:27 +0100
Subject: [PATCH 7/8] Slight refactor to take the RedisTaggedCache into account

---
 src/Illuminate/Cache/RedisTaggedCache.php | 10 +++++
 src/Illuminate/Cache/TaggedCache.php      | 47 ++++++++++++++---------
 2 files changed, 38 insertions(+), 19 deletions(-)

diff --git a/src/Illuminate/Cache/RedisTaggedCache.php b/src/Illuminate/Cache/RedisTaggedCache.php
index b8120be95c03..d691484a795b 100644
--- a/src/Illuminate/Cache/RedisTaggedCache.php
+++ b/src/Illuminate/Cache/RedisTaggedCache.php
@@ -126,4 +126,14 @@ public function flushStale()
 
         return true;
     }
+
+    protected function onKeyWritten(string $key): void
+    {
+        // No need to do anything as the Redis store manages the entry list internally.
+    }
+
+    protected function onKeyForgotten(string $key): void
+    {
+        // No need to do anything as the Redis store manages the entry list internally.
+    }
 }
diff --git a/src/Illuminate/Cache/TaggedCache.php b/src/Illuminate/Cache/TaggedCache.php
index 200af8e585da..13c9afe950f1 100644
--- a/src/Illuminate/Cache/TaggedCache.php
+++ b/src/Illuminate/Cache/TaggedCache.php
@@ -19,13 +19,6 @@ class TaggedCache extends Repository
      */
     protected $tags;
 
-    /**
-     * List of keys within this namespace.
-     *
-     * @var array
-     */
-    protected $itemKeys = [];
-
     /**
      * Create a new tagged cache instance.
      *
@@ -124,25 +117,41 @@ public function taggedItemKey($key)
     protected function event($event)
     {
         $itemKey = $this->itemKey($event->key);
-        if ($itemKey !== $this->getMetadataKey() && ($event instanceof KeyWritten || $event instanceof KeyForgotten)) {
-            $itemKeys = $this->getItemKeys();
-            if ($event instanceof KeyWritten && ! in_array($itemKey, $itemKeys)) {
-                $itemKeys[] = $itemKey;
-            } elseif ($event instanceof KeyForgotten && in_array($itemKey, $this->itemKeys)) {
-                $itemKeys = array_values(
-                    array_filter($itemKeys, function ($k) use ($itemKey) {
-                        return $k !== $itemKey;
-                    })
-                );
+        if ($itemKey !== $this->getMetadataKey()) {
+            if ($event instanceof KeyWritten) {
+                $this->onKeyWritten($itemKey);
+            } elseif ($event instanceof KeyForgotten) {
+                $this->onKeyForgotten($itemKey);
             }
-            $this->putItemKeys($itemKeys);
         }
         parent::event($event->setTags($this->tags->getNames()));
     }
 
+    protected function onKeyWritten(string $key): void
+    {
+        $itemKeys = $this->getItemKeys();
+        if (! in_array($key, $itemKeys)) {
+            $itemKeys[] = $key;
+            $this->putItemKeys($itemKeys);
+        }
+    }
+
+    protected function onKeyForgotten(string $key): void
+    {
+        $itemKeys = $this->getItemKeys();
+        if (in_array($key, $itemKeys)) {
+            $itemKeys = array_values(
+                array_filter($itemKeys, function ($k) use ($key) {
+                    return $k !== $key;
+                })
+            );
+            $this->putItemKeys($itemKeys);
+        }
+    }
+
     private function getMetadataKey(): string
     {
-        return $this->taggedItemKey('meta:keys');
+        return $this->itemKey('meta:entries');
     }
 
     private function getItemKeys(): array

From 3c49ffb2d933b9a79995dde099e8e93ede76b309 Mon Sep 17 00:00:00 2001
From: Matt Ford <mattford@users.noreply.github.com>
Date: Fri, 18 Aug 2023 10:10:09 +0100
Subject: [PATCH 8/8] Add newline as required by styleci

---
 src/Illuminate/Cache/TaggedCache.php | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/Illuminate/Cache/TaggedCache.php b/src/Illuminate/Cache/TaggedCache.php
index 13c9afe950f1..03936db3d8b8 100644
--- a/src/Illuminate/Cache/TaggedCache.php
+++ b/src/Illuminate/Cache/TaggedCache.php
@@ -161,6 +161,7 @@ private function getItemKeys(): array
         if (! is_array($keys)) {
             $keys = [];
         }
+
         return $keys;
     }