Fix duplicate spec evaluation in `evaluate_specs()` (#51166)

* feat: Add memoization to EvaluateSuggestion class

This commit adds memoization to the `EvaluateSuggestion` class in order to improve performance by caching the results of the `evaluate_specs` method. The memoization is implemented using an associative array called `$memo`, which stores the results of previous evaluations based on the input specifications and logger arguments. The memoization logic checks if the results for a given set of specifications and logger arguments already exist in the `$memo` array, and if so, returns the cached results instead of re-evaluating the specs. This helps to avoid redundant computations and improves the overall efficiency of the `evaluate_specs` method.

* Add changelog

* Only use specs as key

* Move shipping test to correct folder

* Fix tests

* Fix tests

* Fix lint

* Address PR feedback

plugins/woocommerce/changelog/fix-duplicate-spec-evaluation

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fix
+
+Fix duplicate spec evaluation in evaluate_specs()

plugins/woocommerce/src/Admin/Features/PaymentGatewaySuggestions/EvaluateSuggestion.php

@@ -13,6 +13,13 @@ use Automattic\WooCommerce\Admin\RemoteSpecs\RuleProcessors\RuleEvaluator;
  * Evaluates the spec and returns the evaluated suggestion.
  */
 class EvaluateSuggestion {
+	/**
+	 * Stores memoized results of evaluate_specs.
+	 *
+	 * @var array
+	 */
+	protected static $memo = array();
+
 	/**
 	 * Evaluates the spec and returns the suggestion.
 	 *
@@ -58,6 +65,12 @@ class EvaluateSuggestion {
 	 * @return array The visible suggestions and errors.
 	 */
 	public static function evaluate_specs( $specs, $logger_args = array() ) {
+		$specs_key = self::get_memo_key( $specs );
+
+		if ( isset( self::$memo[ $specs_key ] ) ) {
+			return self::$memo[ $specs_key ];
+		}
+
 		$suggestions = array();
 		$errors      = array();
 
@@ -72,9 +85,43 @@ class EvaluateSuggestion {
 			}
 		}
 
-		return array(
+		$result = array(
 			'suggestions' => $suggestions,
 			'errors'      => $errors,
 		);
+
+		// Memoize results, with a fail safe to prevent unbounded memory growth.
+		// This limit is unlikely to be reached under normal circumstances.
+		if ( count( self::$memo ) > 50 ) {
+			self::reset_memo();
+		}
+		self::$memo[ $specs_key ] = $result;
+
+		return $result;
+	}
+
+	/**
+	 * Resets the memoized results. Useful for testing.
+	 */
+	public static function reset_memo() {
+		self::$memo = array();
+	}
+
+	/**
+	 * Returns a memoization key for the given specs.
+	 *
+	 * @param array $specs The specs to generate a key for.
+	 *
+	 * @return string The memoization key.
+	 */
+	private static function get_memo_key( $specs ) {
+		$data = wp_json_encode( $specs );
+
+		if ( function_exists( 'hash' ) && in_array( 'xxh3', hash_algos(), true ) ) {
+			// Use xxHash (xxh3) if available.
+			return hash( 'xxh3', $data );
+		}
+		// Fall back to CRC32.
+		return (string) crc32( $data );
 	}
 }

plugins/woocommerce/tests/legacy/unit-tests/woocommerce-admin/features/payment-gateway-suggestions/evaluate-suggestion.php

@@ -323,6 +323,31 @@ class WC_Admin_Tests_PaymentGatewaySuggestions_EvaluateSuggestion extends WC_Uni
 		remove_filter( 'woocommerce_admin_remote_specs_evaluator_should_log', '__return_true' );
 	}
 
+	/**
+	 * Test that the memo is set correctly.
+	 */
+	public function test_memo_set_correctly() {
+		$specs = array(
+			array(
+				'id'         => 'test-gateway-1',
+				'is_visible' => true,
+			),
+			array(
+				'id'         => 'test-gateway-2',
+				'is_visible' => false,
+			),
+		);
+
+		$result = TestableEvaluateSuggestion::evaluate_specs( $specs );
+		$memo   = TestableEvaluateSuggestion::get_memo_for_tests();
+
+		$this->assertCount( 1, $memo );
+		$memo_key = array_keys( $memo )[0];
+		$this->assertEquals( $result, $memo[ $memo_key ] );
+		$this->assertCount( 1, $result['suggestions'] );
+		$this->assertEquals( 'test-gateway-1', $result['suggestions'][0]->id );
+	}
+
 	/**
 	 * Overrides the WC logger.
 	 *
@@ -359,3 +384,19 @@ class WC_Admin_Tests_PaymentGatewaySuggestions_EvaluateSuggestion extends WC_Uni
 			);
 	}
 }
+
+//phpcs:disable Generic.Files.OneObjectStructurePerFile.MultipleFound, Squiz.Classes.ClassFileName.NoMatch, Suin.Classes.PSR4.IncorrectClassName
+/**
+ * TestableEvaluateSuggestion class.
+ */
+class TestableEvaluateSuggestion extends EvaluateSuggestion {
+	/**
+	 * Get the memo for testing.
+	 *
+	 * @return array
+	 */
+	public static function get_memo_for_tests() {
+		return self::$memo;
+	}
+}
+//phpcs:enable Generic.Files.OneObjectStructurePerFile.MultipleFound, Squiz.Classes.ClassFileName.NoMatch, Suin.Classes.PSR4.IncorrectClassName

plugins/woocommerce/tests/legacy/unit-tests/woocommerce-admin/features/payment-gateway-suggestions/payment-gateway-suggestions.php

@@ -25,7 +25,7 @@ class WC_Admin_Tests_PaymentGatewaySuggestions_Init extends WC_Unit_Test_Case {
 		delete_option( 'woocommerce_show_marketplace_suggestions' );
 		add_filter(
 			'transient_woocommerce_admin_' . PaymentGatewaySuggestionsDataSourcePoller::ID . '_specs',
-			function( $value ) {
+			function ( $value ) {
 				if ( $value ) {
 					return $value;
 				}
@@ -37,6 +37,8 @@ class WC_Admin_Tests_PaymentGatewaySuggestions_Init extends WC_Unit_Test_Case {
 				);
 			}
 		);
+
+		EvaluateSuggestion::reset_memo();
 	}
 
 	/**
@@ -57,7 +59,7 @@ class WC_Admin_Tests_PaymentGatewaySuggestions_Init extends WC_Unit_Test_Case {
 		remove_all_filters( 'transient_woocommerce_admin_' . PaymentGatewaySuggestionsDataSourcePoller::ID . '_specs' );
 		add_filter(
 			DataSourcePoller::FILTER_NAME,
-			function() {
+			function () {
 				return array();
 			}
 		);
@@ -242,7 +244,7 @@ class WC_Admin_Tests_PaymentGatewaySuggestions_Init extends WC_Unit_Test_Case {
 
 		add_filter(
 			'locale',
-			function( $_locale ) {
+			function () {
 				return 'zh_TW';
 			}
 		);
@@ -364,5 +366,4 @@ class WC_Admin_Tests_PaymentGatewaySuggestions_Init extends WC_Unit_Test_Case {
 		// Clean up.
 		delete_option( PaymentGatewaySuggestions::RECOMMENDED_PAYMENT_PLUGINS_DISMISS_OPTION );
 	}
-
 }

plugins/woocommerce/tests/php/src/Admin/Features/ShippingPartnerSuggestions/DefaultShippingPartnersTest.php

@@ -1,7 +1,7 @@
 <?php
 declare( strict_types = 1 );
 
-namespace Automattic\WooCommerce\Tests\Admin\ShippingPartnerSuggestions;
+namespace Automattic\WooCommerce\Tests\Admin\Features\ShippingPartnerSuggestions;
 
 use Automattic\WooCommerce\Admin\Features\PaymentGatewaySuggestions\EvaluateSuggestion;
 use Automattic\WooCommerce\Admin\Features\ShippingPartnerSuggestions\DefaultShippingPartners;
@@ -31,6 +31,8 @@ class DefaultShippingPartnersTest extends WC_Unit_Test_Case {
 		update_option( 'woocommerce_store_address', 'foo' );
 
 		update_option( 'active_plugins', array( 'foo/foo.php' ) );
+
+		EvaluateSuggestion::reset_memo();
 	}
 
 	/**

plugins/woocommerce/tests/php/src/Internal/Admin/ShippingPartnerSuggestions/ShippingPartnerSuggestionsTest.php

@@ -7,6 +7,7 @@ use Automattic\WooCommerce\Admin\Features\OnboardingTasks\Tasks\Shipping;
 use Automattic\WooCommerce\Admin\Features\ShippingPartnerSuggestions\DefaultShippingPartners;
 use Automattic\WooCommerce\Admin\Features\ShippingPartnerSuggestions\ShippingPartnerSuggestions;
 use Automattic\WooCommerce\Admin\Features\ShippingPartnerSuggestions\ShippingPartnerSuggestionsDataSourcePoller;
+use Automattic\WooCommerce\Admin\Features\PaymentGatewaySuggestions\EvaluateSuggestion;
 use WC_Unit_Test_Case;
 
 /**
@@ -37,7 +38,7 @@ class ShippingPartnerSuggestionsTest extends WC_Unit_Test_Case {
 		delete_option( 'woocommerce_show_marketplace_suggestions' );
 		add_filter(
 			'transient_woocommerce_admin_' . ShippingPartnerSuggestionsDataSourcePoller::ID . '_specs',
-			function( $value ) {
+			function ( $value ) {
 				if ( $value ) {
 					return $value;
 				}
@@ -70,6 +71,8 @@ class ShippingPartnerSuggestionsTest extends WC_Unit_Test_Case {
 		// Have a mock logger used by the suggestions rule evaluator.
 		$this->mock_logger = $this->getMockBuilder( 'WC_Logger_Interface' )->getMock();
 		add_filter( 'woocommerce_logging_class', array( $this, 'override_wc_logger' ) );
+
+		EvaluateSuggestion::reset_memo();
 	}
 
 	/**
@@ -91,7 +94,7 @@ class ShippingPartnerSuggestionsTest extends WC_Unit_Test_Case {
 		remove_all_filters( 'transient_woocommerce_admin_' . ShippingPartnerSuggestionsDataSourcePoller::ID . '_specs' );
 		add_filter(
 			DataSourcePoller::FILTER_NAME,
-			function() {
+			function () {
 				return array();
 			}
 		);

plugins/woocommerce/tests/php/src/Internal/Admin/WCPayPromotion/DefaultPromotionsTest.php

@@ -29,6 +29,8 @@ class DefaultPromotionsTest extends WC_Unit_Test_Case {
 		update_option( 'woocommerce_store_address', 'foo' );
 
 		update_option( 'active_plugins', array( 'foo/foo.php' ) );
+
+		EvaluateSuggestion::reset_memo();
 	}
 
 	/**

plugins/woocommerce/tests/php/src/Internal/Admin/WCPayPromotion/InitTest.php

@@ -26,7 +26,7 @@ class InitTest extends WC_Unit_Test_Case {
 		delete_option( 'woocommerce_show_marketplace_suggestions' );
 		add_filter(
 			'transient_woocommerce_admin_' . WCPayPromotionDataSourcePoller::ID . '_specs',
-			function( $value ) {
+			function ( $value ) {
 				if ( $value ) {
 					return $value;
 				}
@@ -38,6 +38,8 @@ class InitTest extends WC_Unit_Test_Case {
 				);
 			}
 		);
+
+		EvaluateSuggestion::reset_memo();
 	}
 
 	/**
@@ -59,7 +61,7 @@ class InitTest extends WC_Unit_Test_Case {
 		remove_all_filters( 'transient_woocommerce_admin_' . WCPayPromotionDataSourcePoller::ID . '_specs' );
 		add_filter(
 			DataSourcePoller::FILTER_NAME,
-			function() {
+			function () {
 				return array();
 			}
 		);