From 03ae4dfbb2d86fc421e16a0095b84c7192efbd20 Mon Sep 17 00:00:00 2001
From: Denis Kuzmenchuk <denis@alphaflightguru.com>
Date: Tue, 14 Dec 2021 18:50:54 +0300
Subject: [PATCH 1/2] [8.x] Fix possible out of memory error when deleting
 values by reference key from cache in Redis driver

---
 src/Illuminate/Cache/RedisTaggedCache.php | 21 +++++++++++++++++----
 tests/Cache/CacheTaggedCacheTest.php      |  8 ++++----
 2 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/src/Illuminate/Cache/RedisTaggedCache.php b/src/Illuminate/Cache/RedisTaggedCache.php
index 6a683c10c36..21f367df17d 100644
--- a/src/Illuminate/Cache/RedisTaggedCache.php
+++ b/src/Illuminate/Cache/RedisTaggedCache.php
@@ -178,13 +178,26 @@ protected function deleteKeysByReference($reference)
      */
     protected function deleteValues($referenceKey)
     {
-        $values = array_unique($this->store->connection()->smembers($referenceKey));
+        $cursor = $defaultCursorValue = '0';
+
+        do {
+            [$cursor, $valuesChunk] = $this->store->connection()->sscan(
+                $referenceKey, $cursor, ['match' => '*', 'count' => 1000]
+            );
+
+            // PhpRedis client returns false if set does not exist or empty. Destruction on false stores null
+            // in each variable. If valuesChunk is null, it means that there is no results from sscan command.
+            // Iteration over set could be finished.
+            if ($valuesChunk === null) {
+                break;
+            }
+
+            $valuesChunk = array_unique($valuesChunk);
 
-        if (count($values) > 0) {
-            foreach (array_chunk($values, 1000) as $valuesChunk) {
+            if (count($valuesChunk) > 0) {
                 $this->store->connection()->del(...$valuesChunk);
             }
-        }
+        } while (((string) $cursor) !== $defaultCursorValue);
     }
 
     /**
diff --git a/tests/Cache/CacheTaggedCacheTest.php b/tests/Cache/CacheTaggedCacheTest.php
index 05baebd209a..b2493694d13 100644
--- a/tests/Cache/CacheTaggedCacheTest.php
+++ b/tests/Cache/CacheTaggedCacheTest.php
@@ -267,16 +267,16 @@ public function testRedisCacheTagsCanBeFlushed()
         $store->shouldReceive('connection')->andReturn($conn = m::mock(stdClass::class));
 
         // Forever tag keys
-        $conn->shouldReceive('smembers')->once()->with('prefix:foo:forever_ref')->andReturn(['key1', 'key2']);
-        $conn->shouldReceive('smembers')->once()->with('prefix:bar:forever_ref')->andReturn(['key3']);
+        $conn->shouldReceive('sscan')->once()->with('prefix:foo:forever_ref', '0', ['match' => '*', 'count' => 1000])->andReturn(['0', ['key1', 'key2']]);
+        $conn->shouldReceive('sscan')->once()->with('prefix:bar:forever_ref', '0', ['match' => '*', 'count' => 1000])->andReturn(['0', ['key3']]);
         $conn->shouldReceive('del')->once()->with('key1', 'key2');
         $conn->shouldReceive('del')->once()->with('key3');
         $conn->shouldReceive('del')->once()->with('prefix:foo:forever_ref');
         $conn->shouldReceive('del')->once()->with('prefix:bar:forever_ref');
 
         // Standard tag keys
-        $conn->shouldReceive('smembers')->once()->with('prefix:foo:standard_ref')->andReturn(['key4', 'key5']);
-        $conn->shouldReceive('smembers')->once()->with('prefix:bar:standard_ref')->andReturn(['key6']);
+        $conn->shouldReceive('sscan')->once()->with('prefix:foo:standard_ref', '0', ['match' => '*', 'count' => 1000])->andReturn(['0', ['key4', 'key5']]);
+        $conn->shouldReceive('sscan')->once()->with('prefix:bar:standard_ref', '0', ['match' => '*', 'count' => 1000])->andReturn(['0', ['key6']]);
         $conn->shouldReceive('del')->once()->with('key4', 'key5');
         $conn->shouldReceive('del')->once()->with('key6');
         $conn->shouldReceive('del')->once()->with('prefix:foo:standard_ref');

From 14401a511a3c70b42ad648eeaed8e183399323c2 Mon Sep 17 00:00:00 2001
From: Taylor Otwell <taylor@laravel.com>
Date: Wed, 15 Dec 2021 08:12:52 -0600
Subject: [PATCH 2/2] formatting

---
 src/Illuminate/Cache/RedisTaggedCache.php | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/Illuminate/Cache/RedisTaggedCache.php b/src/Illuminate/Cache/RedisTaggedCache.php
index 21f367df17d..7863dbc0a60 100644
--- a/src/Illuminate/Cache/RedisTaggedCache.php
+++ b/src/Illuminate/Cache/RedisTaggedCache.php
@@ -185,10 +185,10 @@ protected function deleteValues($referenceKey)
                 $referenceKey, $cursor, ['match' => '*', 'count' => 1000]
             );
 
-            // PhpRedis client returns false if set does not exist or empty. Destruction on false stores null
-            // in each variable. If valuesChunk is null, it means that there is no results from sscan command.
-            // Iteration over set could be finished.
-            if ($valuesChunk === null) {
+            // PhpRedis client returns false if set does not exist or empty. Array destruction
+            // on false stores null in each variable. If valuesChunk is null, it means that
+            // there were not results from the previously executed "sscan" Redis command.
+            if (is_null($valuesChunk)) {
                 break;
             }