Add WipeKey to storage

src/Prometheus/CollectorRegistry.php

@@ -78,6 +78,19 @@ public function wipeStorage(): void
         $this->storageAdapter->wipeStorage();
     }
 
+    /**
+     * Removes a specific previously stored metric from underlying storage adapter
+     *
+     * @param string $type
+     * @param string $name
+     *
+     * @return void
+     */
+    public function wipeKey(string $type, string $name): void
+    {
+        $this->storageAdapter->wipeKey($type, $name);
+    }
+
     /**
      * @return MetricFamilySamples[]
      */

src/Prometheus/RegistryInterface.php

@@ -14,6 +14,16 @@ interface RegistryInterface
      */
     public function wipeStorage(): void;
 
+    /**
+     * Removes a specific previously stored metric from underlying storage adapter
+     *
+     * @param string $type
+     * @param string $name
+     *
+     * @return void
+     */
+    public function wipeKey(string $type, string $name): void;
+
     /**
      * @return MetricFamilySamples[]
      */

src/Prometheus/Storage/APC.php

@@ -230,6 +230,14 @@ public function wipeStorage(): void
         }
     }
 
+    /**
+     * @inheritDoc
+     */
+    public function wipeKey(string $type, string $key): void
+    {
+        // not implemented yet
+    }
+
     /**
      * @param mixed[] $data
      * @return string

src/Prometheus/Storage/APCng.php

@@ -303,6 +303,14 @@ public function wipeStorage(): void
         apcu_delete($this->metainfoCacheKey);
     }
 
+    /**
+     * @inheritDoc
+     */
+    public function wipeKey(string $type, string $key): void
+    {
+        // not implemented yet
+    }
+
     /**
      * Scans the APCu keyspace for all metainfo keys. A new metainfo cache array is built,
      * which references all metadata keys in APCu at that moment. This prevents a corner-case

src/Prometheus/Storage/Adapter.php

@@ -49,4 +49,14 @@ public function updateCounter(array $data): void;
      * @return void
      */
     public function wipeStorage(): void;
+
+    /**
+     * Removes a specific previously stored metric from underlying storage
+     *
+     * @param string $type
+     * @param string $key
+     * @throws StorageException
+     * @return void
+     */
+    public function wipeKey(string $type, string $key): void;
 }

src/Prometheus/Storage/InMemory.php

@@ -61,6 +61,14 @@ public function wipeStorage(): void
         $this->summaries = [];
     }
 
+    /**
+     * @inheritDoc
+     */
+    public function wipeKey(string $type, string $key): void
+    {
+        // not implemented yet
+    }
+
     /**
      * @return MetricFamilySamples[]
      */

src/Prometheus/Storage/Redis.php

@@ -139,6 +139,42 @@ public function wipeStorage(): void
         );
     }
 
+    /**
+     * @inheritDoc
+     */
+    public function wipeKey(string $type, string $key): void
+    {
+        $this->ensureOpenConnection();
+
+        $searchPattern = "";
+
+        $globalPrefix = $this->redis->getOption(\Redis::OPT_PREFIX);
+        // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
+        if (is_string($globalPrefix)) {
+            $searchPattern .= $globalPrefix;
+        }
+
+        $searchPattern .= self::$prefix;
+        $searchPattern .= ":" . $type . ":" . $key;
+
+        $this->redis->eval(
+            <<<LUA
+redis.replicate_commands()
+local cursor = "0"
+repeat
+    local results = redis.call('SCAN', cursor, 'MATCH', ARGV[1])
+    cursor = results[1]
+    for _, key in ipairs(results[2]) do
+        redis.call('DEL', key)
+    end
+until cursor == "0"
+LUA
+            ,
+            [$searchPattern],
+            0
+        );
+    }
+
     /**
      * @param mixed[] $data
      *

src/Prometheus/Storage/RedisNg.php

@@ -139,6 +139,43 @@ public function wipeStorage(): void
         );
     }
 
+    /**
+     * @inheritDoc
+     */
+    public function wipeKey(string $type, string $key): void
+    {
+        $this->ensureOpenConnection();
+
+        $searchPattern = "";
+
+        $globalPrefix = $this->redis->getOption(\Redis::OPT_PREFIX);
+        // @phpstan-ignore-next-line false positive, phpstan thinks getOptions returns int
+        if (is_string($globalPrefix)) {
+            $searchPattern .= $globalPrefix;
+        }
+
+        $searchPattern .= self::$prefix;
+        $searchPattern .= ":" . $type . ":" . $key;
+
+        $this->redis->eval(
+            <<<LUA
+redis.replicate_commands()
+local cursor = "0"
+repeat
+    local results = redis.call('SCAN', cursor, 'MATCH', ARGV[1])
+    cursor = results[1]
+    for _, key in ipairs(results[2]) do
+        redis.call('DEL', key)
+    end
+until cursor == "0"
+LUA
+            ,
+            [$searchPattern],
+            0
+        );
+    }
+
+
     /**
      * @param mixed[] $data
      *