Limit sync on term updates depending on posts number

includes/classes/IndexHelper.php

@@ -465,15 +465,7 @@ protected function get_objects_to_index() {
 		 */
 		do_action( "ep_pre_{$this->args['method']}_index", $this->index_meta, ( $this->index_meta['start'] ? 'start' : false ), $indexable );
 
-		/**
-		 * Filter number of items to index per cycle in the dashboard
-		 *
-		 * @since  2.1
-		 * @hook ep_index_default_per_page
-		 * @param  {int} Entries per cycle
-		 * @return  {int} New number of entries
-		 */
-		$per_page = apply_filters( 'ep_index_default_per_page', Utils\get_option( 'ep_bulk_setting', 350 ) );
+		$per_page = $this->get_index_default_per_page();
 
 		if ( ! empty( $this->args['per_page'] ) ) {
 			$per_page = $this->args['per_page'];
@@ -1219,6 +1211,24 @@ protected function on_error_update_and_clean( $error ) {
 		);
 	}
 
+	/**
+	 * Return the default number of documents to be sent to Elasticsearch on each batch.
+	 *
+	 * @since 4.4.0
+	 * @return integer
+	 */
+	public function get_index_default_per_page() : int {
+		/**
+		 * Filter number of items to index per cycle in the dashboard
+		 *
+		 * @since  2.1
+		 * @hook ep_index_default_per_page
+		 * @param  {int} Entries per cycle
+		 * @return  {int} New number of entries
+		 */
+		return (int) apply_filters( 'ep_index_default_per_page', Utils\get_option( 'ep_bulk_setting', 350 ) );
+	}
+
 	/**
 	 * Return singleton instance of class.
 	 *

includes/classes/Indexable/Post/SyncManager.php

@@ -11,6 +11,8 @@
 use ElasticPress\Elasticsearch as Elasticsearch;
 use ElasticPress\Indexables as Indexables;
 use ElasticPress\SyncManager as SyncManagerAbstract;
+use ElasticPress\Utils;
+use ElasticPress\IndexHelper;
 
 if ( ! defined( 'ABSPATH' ) ) {
 	// @codeCoverageIgnoreStart
@@ -61,13 +63,17 @@ public function setup() {
 		// Called just because we need to know somehow if $delete_all is set before action_queue_meta_sync() runs.
 		add_filter( 'delete_post_metadata', array( $this, 'maybe_delete_meta_for_all' ), 10, 5 );
 		add_action( 'deleted_post_meta', array( $this, 'action_queue_meta_sync' ), 10, 4 );
-		add_action( 'set_object_terms', array( $this, 'action_set_object_terms' ), 10, 6 );
-		add_action( 'edited_term', array( $this, 'action_edited_term' ), 10, 3 );
-		add_action( 'deleted_term_relationships', array( $this, 'action_deleted_term_relationships' ), 10, 3 );
 		add_action( 'wp_initialize_site', array( $this, 'action_create_blog_index' ) );
 
 		add_filter( 'ep_sync_insert_permissions_bypass', array( $this, 'filter_bypass_permission_checks_for_machines' ) );
 		add_filter( 'ep_sync_delete_permissions_bypass', array( $this, 'filter_bypass_permission_checks_for_machines' ) );
+
+		// Conditionally update posts associated with terms
+		add_action( 'ep_admin_notices', [ $this, 'maybe_display_notice_edit_single_term' ] );
+		add_action( 'ep_admin_notices', [ $this, 'maybe_display_notice_term_list_screen' ] );
+		add_action( 'set_object_terms', array( $this, 'action_set_object_terms' ), 10, 6 );
+		add_action( 'edited_term', array( $this, 'action_edited_term' ), 10, 3 );
+		add_action( 'deleted_term_relationships', array( $this, 'action_deleted_term_relationships' ), 10, 3 );
 	}
 
 	/**
@@ -359,6 +365,74 @@ public function action_sync_on_update( $post_id ) {
 		}
 	}
 
+	/**
+	 * Depending on the number of posts associated with the term display an admin notice
+	 *
+	 * @since 4.4.0
+	 * @param array $notices Current ElasticPress admin notices
+	 * @return array
+	 */
+	public function maybe_display_notice_edit_single_term( $notices ) {
+		global $pagenow, $tag;
+
+		/**
+		 * Make sure we're on a term-related page in the admin dashboard.
+		 */
+		if ( ! is_admin() || 'term.php' !== $pagenow || ! $tag instanceof \WP_Term ) {
+			return $notices;
+		}
+
+		if ( IndexHelper::factory()->get_index_default_per_page() >= $tag->count ) {
+			return $notices;
+		}
+
+		$notices['edited_single_term'] = [
+			'html'    => sprintf(
+				/* translators: Sync Page URL */
+				__( 'Due to the number of posts associated with this term, you will need to <a href="%s">resync</a> after editing or deleting it.', 'elasticpress' ),
+				Utils\get_sync_url()
+			),
+			'type'    => 'warning',
+			'dismiss' => true,
+		];
+
+		return $notices;
+	}
+
+	/**
+	 * Depending on the number of posts display an admin notice in the Dashboard Terms List Screen
+	 *
+	 * @since 4.4.0
+	 * @param array $notices Current ElasticPress admin notices
+	 * @return array
+	 */
+	public function maybe_display_notice_term_list_screen( $notices ) {
+		global $pagenow, $tax;
+
+		/**
+		 * Make sure we're on a term-related page in the admin dashboard.
+		 */
+		if ( ! is_admin() || 'edit-tags.php' !== $pagenow || ! $tax instanceof \WP_Taxonomy ) {
+			return $notices;
+		}
+
+		if ( ! $this->is_tax_max_count_bigger_than_items_per_cycle( $tax ) ) {
+			return $notices;
+		}
+
+		$notices['too_many_posts_on_term'] = [
+			'html'    => sprintf(
+				/* translators: Sync Page URL */
+				__( 'Depending on the number of posts associated with a term, you may need to <a href="%s">resync</a> after editing or deleting it.', 'elasticpress' ),
+				Utils\get_sync_url()
+			),
+			'type'    => 'warning',
+			'dismiss' => true,
+		];
+
+		return $notices;
+	}
+
 	/**
 	 * When a post's terms are changed, re-index.
 	 *
@@ -473,6 +547,9 @@ public function action_edited_term( $term_id, $tt_id, $taxonomy ) {
 			return;
 		}
 
+		// If we have more items to update than the number set as Content Items per Index Cycle, skip it.
+		$should_skip = count( $object_ids ) > IndexHelper::factory()->get_index_default_per_page();
+
 		/**
 		 * Filter to allow skipping this action in case of custom handling
 		 *
@@ -484,12 +561,10 @@ public function action_edited_term( $term_id, $tt_id, $taxonomy ) {
 		 * @param {array}  $object_ids IDs of the objects attached to the term id.
 		 * @return {bool}  New value of whether to skip running action_edited_term or not
 		 */
-		if ( apply_filters( 'ep_skip_action_edited_term', false, $term_id, $tt_id, $taxonomy, $object_ids ) ) {
+		if ( apply_filters( 'ep_skip_action_edited_term', $should_skip, $term_id, $tt_id, $taxonomy, $object_ids ) ) {
 			return;
 		}
 
-		$indexable = Indexables::factory()->get( $this->indexable_slug );
-
 		// Add all of them to the queue
 		foreach ( $object_ids as $post_id ) {
 			if ( ! $this->should_reindex_post( $post_id, $taxonomy ) ) {
@@ -652,6 +727,54 @@ protected function should_reindex_post( $post_id, $taxonomy ) {
 			return false;
 		}
 
-		return true;
+		// If we have more items to update than the number set as Content Items per Index Cycle, skip it to avoid a timeout.
+		$single_ids_queued   = array_unique( array_keys( $this->sync_queue ) );
+		$has_too_many_queued = count( $single_ids_queued ) > IndexHelper::factory()->get_index_default_per_page();
+
+		return ! $has_too_many_queued;
+	}
+
+	/**
+	 * Given a taxonomy, check if the term with most posts is under or above the number set as Content Items per Index Cycle.
+	 *
+	 * The result will be cached in a transient. Its TTL will depend on the result:
+	 * If it is determined we have a term with more posts, cache it for more time.
+	 *
+	 * @since 4.4.0
+	 * @param \WP_Taxonomy $tax The taxonomy object
+	 * @return boolean
+	 */
+	protected function is_tax_max_count_bigger_than_items_per_cycle( \WP_Taxonomy $tax ) : bool {
+		$transient_name   = "ep_term_max_count_{$tax->name}";
+		$cached_max_count = get_transient( $transient_name );
+
+		if ( is_integer( $cached_max_count ) ) {
+			return $cached_max_count > IndexHelper::factory()->get_index_default_per_page();
+		}
+
+		$max_count = get_terms(
+			[
+				'taxonomy' => $tax->name,
+				'orderby'  => 'count',
+				'order'    => 'DESC',
+				'number'   => 1,
+				'count'    => true,
+			]
+		);
+
+		if ( ! is_array( $max_count ) || ! $max_count[0] instanceof \WP_Term || ! is_integer( $max_count[0]->count ) ) {
+			set_transient( $transient_name, 0, HOUR_IN_SECONDS );
+			return false;
+		}
+
+		$is_max_count_bigger = $max_count[0]->count > IndexHelper::factory()->get_index_default_per_page();
+
+		set_transient(
+			$transient_name,
+			$max_count[0]->count,
+			$is_max_count_bigger ? DAY_IN_SECONDS : HOUR_IN_SECONDS
+		);
+
+		return $is_max_count_bigger;
 	}
 }

includes/utils.php

@@ -671,3 +671,20 @@ function get_asset_info( $slug, $attribute = null ) {
 
 	return $asset;
 }
+
+/**
+ * Return the Sync Page URL.
+ *
+ * @since 4.4.0
+ * @param boolean $do_sync Whether the link should or should not start a resync.
+ * @return string
+ */
+function get_sync_url( bool $do_sync = false ) : string {
+	$page = 'admin.php?page=elasticpress-sync';
+	if ( $do_sync ) {
+		$page .= '&do_sync';
+	}
+	return ( defined( 'EP_IS_NETWORK' ) && EP_IS_NETWORK ) ?
+		network_admin_url( $page ) :
+		admin_url( $page );
+}

tests/cypress/integration/dashboard-sync.cy.js

@@ -1,11 +1,6 @@
 /* global indexNames */
 
 describe('Dashboard Sync', () => {
-	function setPerIndexCycle(number = null) {
-		const newValue = number || 350;
-		cy.wpCli(`option set ep_bulk_setting ${newValue}`);
-	}
-
 	function canSeeIndexesNames() {
 		cy.visitAdminPage('admin.php?page=elasticpress-health');
 		cy.get('.metabox-holder')
@@ -145,7 +140,7 @@ describe('Dashboard Sync', () => {
 	});
 
 	it('Can pause the dashboard sync, can not activate a feature during sync nor perform a sync via WP-CLI', () => {
-		setPerIndexCycle(20);
+		cy.setPerIndexCycle(20);
 
 		cy.visitAdminPage('admin.php?page=elasticpress-sync');
 
@@ -176,6 +171,6 @@ describe('Dashboard Sync', () => {
 		cy.visitAdminPage('admin.php?page=elasticpress');
 		cy.get('.error-overlay').should('not.have.class', 'syncing');
 
-		setPerIndexCycle();
+		cy.setPerIndexCycle();
 	});
 });

tests/cypress/integration/features/comments.cy.js

@@ -107,11 +107,7 @@ describe('Comments Feature', () => {
 		cy.get('#submit').click();
 
 		// Check if the new comment was indexed
-		cy.wpCliEval(
-			`
-			$comments_index = \\ElasticPress\\Indexables::factory()->get( "comment" )->get_index_name();
-			WP_CLI::runcommand("elasticpress request {$comments_index}/_refresh --method=POST");`,
-		).then(() => {
+		cy.refreshIndex('comment').then(() => {
 			cy.wpCli('wp elasticpress stats')
 				.its('stdout')
 				.should('contain', `Documents:  ${defaultApprovedComments + 1}`);

tests/cypress/integration/indexables/post.cy.js

@@ -0,0 +1,53 @@
+describe('Post Indexable', () => {
+	it('Can conditionally update posts when a term is edited', () => {
+		/**
+		 * At this point, using the default content:
+		 * - the `Classic` (ID 29) term has 36 posts
+		 * - the `Block` (ID 54) term has 7 posts
+		 * Important: There is no post with both categories, as that would skew results.
+		 */
+		cy.setPerIndexCycle();
+		cy.visitAdminPage('edit-tags.php?taxonomy=category');
+		cy.get('div[data-ep-notice="too_many_posts_on_term"]').should('not.exist');
+
+		cy.setPerIndexCycle(35);
+		cy.visitAdminPage('edit-tags.php?taxonomy=category&orderby=count&order=desc');
+		cy.get('div[data-ep-notice="too_many_posts_on_term"]').should('exist');
+
+		// Change the `Classic` term, should not index
+		cy.visitAdminPage('term.php?taxonomy=category&tag_ID=29');
+		cy.get('div[data-ep-notice="edited_single_term"]').should('exist');
+		cy.get('#name').clearThenType('totallydifferenttermname');
+		cy.get('input.button-primary').click();
+
+		// Change the `Block` term, should index
+		cy.visitAdminPage('term.php?taxonomy=category&tag_ID=20');
+		cy.get('div[data-ep-notice="edited_single_term"]').should('not.exist');
+		cy.get('#name').clearThenType('b10ck');
+		cy.get('input.button-primary').click();
+
+		// Make sure the changes are processed by ES
+		cy.refreshIndex('post');
+
+		cy.visit('/?s=totallydifferenttermname');
+		cy.get('.hentry').should('not.exist');
+
+		cy.visit('/?s=b10ck');
+		cy.get('.hentry').should('exist');
+		cy.get('#debug-menu-target-EP_Debug_Bar_ElasticPress .ep-query-debug').should(
+			'contain.text',
+			'"name": "b10ck",',
+		);
+
+		// Restore
+		cy.visitAdminPage('term.php?taxonomy=category&tag_ID=29');
+		cy.get('#name').clearThenType('Classic');
+		cy.get('input.button-primary').click();
+
+		cy.visitAdminPage('term.php?taxonomy=category&tag_ID=20');
+		cy.get('#name').clearThenType('Block');
+		cy.get('input.button-primary').click();
+
+		cy.setPerIndexCycle();
+	});
+});

tests/cypress/support/commands.js

@@ -444,3 +444,15 @@ Cypress.Commands.add('createUser', (userData) => {
 		cy.get('#user_pass').clear().type(`${newUserDate.password}{enter}`);
 	}
 });
+
+Cypress.Commands.add('setPerIndexCycle', (number = 350) => {
+	cy.wpCli(`option set ep_bulk_setting ${number}`);
+});
+
+Cypress.Commands.add('refreshIndex', (indexable) => {
+	cy.wpCliEval(
+		`
+		$index = \\ElasticPress\\Indexables::factory()->get( "${indexable}" )->get_index_name();
+		WP_CLI::runcommand("elasticpress request {$index}/_refresh --method=POST");`,
+	);
+});