Blocks: Remove extra get_theme_file_path() calls in register_block_style_handle().

The `register_block_style_handle()` function runs ~200 times on each page load. Each time it runs, we call `get_theme_file_path()` and then run it through `wp_normalize_path()`.

`get_theme_file_path()` calls a few other functions: `get_stylesheet_directory()`, `get_stylesheet()`, `get_option()`, and there's a bunch of filters that run on each iteration of that, without ever changing.

By caching the value in a static variable, we can avoid ~200 calls on many functions and filters, improving performance.

Follow-up to [53091], [54290], [54291], [54309].

Props aristath, mukesh27.
Fixes #56666.

git-svn-id: https://develop.svn.wordpress.org/trunk@54327 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-includes/blocks.php

@@ -127,12 +127,14 @@ function register_block_script_handle( $metadata, $field_name, $index = 0 ) {
 		);
 		return false;
 	}
+
 	// Path needs to be normalized to work in Windows env.
 	$wpinc_path_norm  = wp_normalize_path( realpath( ABSPATH . WPINC ) );
 	$theme_path_norm  = wp_normalize_path( get_theme_file_path() );
 	$script_path_norm = wp_normalize_path( realpath( dirname( $metadata['file'] ) . '/' . $script_path ) );
-	$is_core_block    = isset( $metadata['file'] ) && 0 === strpos( $metadata['file'], $wpinc_path_norm );
-	$is_theme_block   = 0 === strpos( $script_path_norm, $theme_path_norm );
+
+	$is_core_block  = isset( $metadata['file'] ) && 0 === strpos( $metadata['file'], $wpinc_path_norm );
+	$is_theme_block = 0 === strpos( $script_path_norm, $theme_path_norm );
 
 	$script_uri = plugins_url( $script_path, $metadata['file'] );
 	if ( $is_core_block ) {
@@ -181,8 +183,8 @@ function register_block_style_handle( $metadata, $field_name, $index = 0 ) {
 	}
 
 	$wpinc_path_norm = wp_normalize_path( realpath( ABSPATH . WPINC ) );
-	$theme_path_norm = wp_normalize_path( get_theme_file_path() );
-	$is_core_block   = isset( $metadata['file'] ) && 0 === strpos( $metadata['file'], $wpinc_path_norm );
+
+	$is_core_block = isset( $metadata['file'] ) && 0 === strpos( $metadata['file'], $wpinc_path_norm );
 	// Skip registering individual styles for each core block when a bundled version provided.
 	if ( $is_core_block && ! wp_should_load_separate_core_block_assets() ) {
 		return false;
@@ -212,15 +214,25 @@ function register_block_style_handle( $metadata, $field_name, $index = 0 ) {
 	if ( $is_core_block ) {
 		$style_path = "style$suffix.css";
 	}
+
 	$style_path_norm = wp_normalize_path( realpath( dirname( $metadata['file'] ) . '/' . $style_path ) );
 	$has_style_file  = '' !== $style_path_norm;
+
 	if ( $has_style_file ) {
-		$style_uri      = plugins_url( $style_path, $metadata['file'] );
+		$style_uri = plugins_url( $style_path, $metadata['file'] );
+
+		// Cache $theme_path_norm to avoid calling get_theme_file_path() multiple times.
+		static $theme_path_norm = '';
+		if ( ! $theme_path_norm ) {
+			$theme_path_norm = wp_normalize_path( get_theme_file_path() );
+		}
+
 		$is_theme_block = str_starts_with( $style_path_norm, $theme_path_norm );
+
 		if ( $is_theme_block ) {
 			$style_uri = get_theme_file_uri( str_replace( $theme_path_norm, '', $style_path_norm ) );
 		} elseif ( $is_core_block ) {
-			$style_uri  = includes_url( 'blocks/' . str_replace( 'core/', '', $metadata['name'] ) . "/style$suffix.css" );
+			$style_uri = includes_url( 'blocks/' . str_replace( 'core/', '', $metadata['name'] ) . "/style$suffix.css" );
 		}
 	} else {
 		$style_uri = false;