hide hash post meta, minor movement of variables

src/css-optimize.php

@@ -117,9 +117,6 @@ public function generate_optimied_css_for_post( $post_id, $post, $update ) {
 				return;
 			}
 
-			// Get the hashed CSS from post meta.
-			$hashed_css = get_post_meta( $post_id, 'stackable_css_hash', true );
-
 			// Convert content to blocks.
 			$blocks = parse_blocks( $post->post_content );
 
@@ -135,11 +132,12 @@ public function generate_optimied_css_for_post( $post_id, $post, $update ) {
 				}
 			}
 
-			$serialized_css = json_encode( $styles_only );
-			$css_to_hash = hash( 'sha256', $serialized_css );
+			// Get the hashed CSS from post meta.
+			$hashed_css = get_post_meta( $post_id, 'stackable_css_hash', true );
+			$new_hashed_css = hash( 'sha256', json_encode( $styles_only ) );
 
 			// if the hash is the same, don't update
-			if ( hash_equals( $hashed_css, $css_to_hash ) ) {
+			if ( hash_equals( $hashed_css, $new_hashed_css ) ) {
 				return;
 			}
 
@@ -149,7 +147,7 @@ public function generate_optimied_css_for_post( $post_id, $post, $update ) {
 			update_post_meta( $post_id, 'stackable_optimized_css', $optimized_css );
 			update_post_meta( $post_id, 'stackable_optimized_css_raw', $styles );
 			// Update the hash of the styles.
-			update_post_meta( $post_id, 'stackable_css_hash', $css_to_hash );
+			update_post_meta( $post_id, 'stackable_css_hash', $new_hashed_css );
 		}
 
 		/**
@@ -486,7 +484,9 @@ public static function generate_css( $styles ) {
 		 * @return boolean
 		 */
 		public function protect_optimized_css_meta( $protected, $meta_key ) {
-			if ( $meta_key === 'stackable_optimized_css' || $meta_key === 'stackable_optimized_css_raw' ) {
+			if ( $meta_key === 'stackable_optimized_css' ||
+			     $meta_key === 'stackable_optimized_css_raw' ||
+			     $meta_key === 'stackable_css_hash' ) {
 				return true;
 			}
 			return $protected;