[4.x] Allow a custom static caching url store to be specified

config/static_caching.php

@@ -36,6 +36,7 @@
         'full' => [
             'driver' => 'file',
             'path' => public_path('static'),
+            'cache_path' => null,
             'lock_hold_length' => 0,
         ],
 

src/StaticCaching/Cachers/FileCacher.php

@@ -4,6 +4,7 @@
 
 use Illuminate\Contracts\Cache\Repository;
 use Illuminate\Http\Request;
+use Illuminate\Support\Facades\File as LaravelFile;
 use Illuminate\Support\Facades\Log;
 use Statamic\Events\UrlInvalidated;
 use Statamic\Facades\File;
@@ -103,6 +104,10 @@ public function flush()
             $this->writer->flush($path);
         }
 
+        if ($path = config('statamic.static_caching.strategies.full.cache_path')) {
+            LaravelFile::deleteDirectory($path);
+        }
+
         $this->flushUrls();
     }
 

src/StaticCaching/StaticCacheManager.php

@@ -4,6 +4,7 @@
 
 use Illuminate\Cache\Repository;
 use Illuminate\Support\Facades\Cache;
+use Statamic\Extensions\FileStore;
 use Statamic\Facades\Site;
 use Statamic\StaticCaching\Cachers\ApplicationCacher;
 use Statamic\StaticCaching\Cachers\FileCacher;
@@ -30,7 +31,15 @@ public function createNullDriver()
 
     public function createFileDriver(array $config)
     {
-        return new FileCacher(new Writer, $this->app[Repository::class], $config);
+        $customCacheStore = null;
+
+        if ($path = config('statamic.static_caching.strategies.full.cache_path')) {
+            $customCacheStore = app('cache')->repository(
+                (new FileStore($this->app['files'], $path))
+            );
+        }
+
+        return new FileCacher(new Writer, $customCacheStore ?? $this->app[Repository::class], $config);
     }
 
     public function createApplicationDriver(array $config)