feature#9151 [HttpKernel] made the cache key generation configurable for the default HttpCache store (fabpot)

This PR was merged into the master branch.

Discussion
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[HttpKernel] made the cache key generation configurable for the default HttpCache store

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #9088
| License       | MIT
| Doc PR        | n/a

Commits
-------

780b77a [HttpKernel] made the cache key generation configurable for the default HttpCache store

src/Symfony/Component/HttpKernel/HttpCache/Store.php

@@ -364,6 +364,25 @@ class Store implements StoreInterface
         return $this->root.DIRECTORY_SEPARATOR.substr($key, 0, 2).DIRECTORY_SEPARATOR.substr($key, 2, 2).DIRECTORY_SEPARATOR.substr($key, 4, 2).DIRECTORY_SEPARATOR.substr($key, 6);
     }
 
+    /**
+     * Generates a cache key for the given Request.
+     *
+     * This method should return a key that must only depend on a
+     * normalized version of the request URI.
+     *
+     * If the same URI can have more than one representation, based on some
+     * headers, use a Vary header to indicate them, and each representation will
+     * be stored independently under the same cache key.
+     *
+     * @param Request $request A Request instance
+     *
+     * @return string A key for the given Request
+     */
+    protected function generateCacheKey(Request $request)
+    {
+        return 'md'.hash('sha256', $request->getUri());
+    }
+
     /**
      * Returns a cache key for the given Request.
      *
@@ -377,7 +396,7 @@ class Store implements StoreInterface
             return $this->keyCache[$request];
         }
 
-        return $this->keyCache[$request] = 'md'.hash('sha256', $request->getUri());
+        return $this->keyCache[$request] = $this->generateCacheKey($request);
     }
 
     /**