Prove native transactional table capabilities

inc/native/class-wp-markdown-native-query-contracts.php

@@ -571,8 +571,19 @@ interface WP_Markdown_Query_Runtime {
 	public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result;
 }
 
+/** Optional proof surface for callers that require atomic canonical table writes. */
+interface WP_Markdown_Native_Transactional_Table_Support {
+	/** @param string[] $tables */
+	public function supports_transactional_tables( array $tables ): bool;
+}
+
 /** Providers supply validated rows without exposing storage to the executor. */
 interface WP_Markdown_Native_Table_Provider {
 	/** @return iterable<int,array<string,mixed>>|WP_Markdown_Query_Result */
 	public function read( WP_Markdown_Native_Table_Access $access ): iterable|WP_Markdown_Query_Result;
 }
+
+/** A canonical provider exposes the factory-validated root it reads and writes. */
+interface WP_Markdown_Native_Canonical_Table_Provider extends WP_Markdown_Native_Table_Provider {
+	public function canonical_root(): string;
+}

inc/native/class-wp-markdown-native-query-executor.php

@@ -30,7 +30,7 @@ public function read( WP_Markdown_Native_Table_Access $access ): iterable|WP_Mar
 	}
 }
 
-final class WP_Markdown_Native_Query_Runtime implements WP_Markdown_Query_Runtime {
+final class WP_Markdown_Native_Query_Runtime implements WP_Markdown_Query_Runtime, WP_Markdown_Native_Transactional_Table_Support {
 	private const MAX_JOIN_CANDIDATE_PAIRS = 100000;
 	private const MAX_CORRELATED_SUBQUERY_EVALUATIONS = 10000;
 	/** The largest SQL request accepted by the native request boundary. */
@@ -90,6 +90,40 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		}
 	}
 
+	/**
+	 * Confirm that every exact table has a recognized canonical provider, its
+	 * matching configured mutation runtime, and a factory-admitted journal root.
+	 * This is an atomic-write guarantee, not an InnoDB or mysqli-session claim.
+	 *
+	 * @param string[] $tables
+	 */
+	public function supports_transactional_tables( array $tables ): bool {
+		if ( null === $this->transactions || array() === $tables ) {
+			return false;
+		}
+
+		foreach ( $tables as $table_name ) {
+			if ( ! is_string( $table_name ) || 1 !== preg_match( '/^[A-Za-z_][A-Za-z0-9_]*$/D', $table_name ) || $this->registry->is_shadowed( $table_name ) ) {
+				return false;
+			}
+			$table = $this->registry->table( $table_name );
+			if ( null === $table || ! $this->supports_transactional_provider( $table['provider'] ) ) {
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	private function supports_transactional_provider( WP_Markdown_Native_Table_Provider $provider ): bool {
+		if ( ! $provider instanceof WP_Markdown_Native_Canonical_Table_Provider || ! $this->transactions->covers_root( $provider->canonical_root() ) ) {
+			return false;
+		}
+		return ( $provider instanceof WP_Markdown_Native_Post_Provider && null !== $this->post_mutations )
+			|| ( $provider instanceof WP_Markdown_Native_Option_Provider && null !== $this->option_mutations )
+			|| ( $provider instanceof WP_Markdown_Native_JSON_Snapshot_Provider && null !== $this->table_mutations );
+	}
+
 	private function execute_request( WP_Markdown_Query_Request $request ): WP_Markdown_Query_Result {
 		self::trace_runtime_phase( 'executor', $request->sql() );
 		if ( strlen( $request->sql() ) > self::MAX_SQL_BYTES ) {
@@ -108,17 +142,26 @@ private function execute_request( WP_Markdown_Query_Request $request ): WP_Markd
 		if ( null !== $transaction_control ) {
 			return $this->execute_transaction_control( $transaction_control );
 		}
-		$write_admitted = null !== $this->transactions && null !== WP_Markdown_SQL_Classifier::mutation( $request->sql() );
-		if ( $write_admitted ) {
+		// Advisory locks have their own root-scoped lock files. Holding the
+		// transaction lock while waiting for one would invert their release order.
+		$mutation = null !== WP_Markdown_SQL_Classifier::mutation( $request->sql() );
+		$canonical_admitted = null !== $this->transactions && ! $this->is_advisory_lock_statement( $request->sql() );
+		if ( $canonical_admitted ) {
+			$transactional_view = $this->transactions->is_in_transaction();
 			$locked = $this->transactions->begin_write();
 			if ( true !== $locked ) {
-				return $this->failure( 'transaction_write_lock_failed', $locked );
+				return $this->failure( $mutation ? 'transaction_write_lock_failed' : 'transaction_read_lock_failed', $locked );
+			}
+			if ( ! $transactional_view || $this->transactions->waited_for_write_lock() ) {
+				// Autocommit requests start a fresh canonical view. A transaction that
+				// waited also cannot retain snapshots from before the prior commit.
+				$this->registry->forget_snapshots();
 			}
 		}
 		try {
 			return $this->execute_unlocked_request( $request );
 		} finally {
-			if ( $write_admitted ) {
+			if ( $canonical_admitted ) {
 				$this->transactions->finish_write();
 			}
 		}
@@ -354,6 +397,10 @@ private function advisory_lock_query( string $sql ): ?WP_Markdown_Query_Result {
 		);
 	}
 
+	private function is_advisory_lock_statement( string $sql ): bool {
+		return 1 === preg_match( '/^\s*SELECT\s+(?:GET_LOCK|RELEASE_LOCK)\s*\(/i', $sql );
+	}
+
 	private function execute_query_plan( WP_Markdown_Native_Query_Plan $plan, bool $allow_union = true ): WP_Markdown_Query_Result {
 		$hint_error = $this->validate_index_hints( $plan );
 		if ( null !== $hint_error ) {
@@ -2583,6 +2630,9 @@ private function execute_transaction_control( array $control ): WP_Markdown_Quer
 		if ( true !== $outcome ) {
 			return $this->failure( 'transaction_control_failed', $outcome );
 		}
+		if ( $this->transactions->waited_for_write_lock() || in_array( $control['action'], array( 'begin', 'autocommit_0' ), true ) ) {
+			$this->registry->forget_snapshots();
+		}
 		if ( 'commit_chain' === $control['action'] || 'rollback_chain' === $control['action'] ) {
 			$chained = $this->transactions->begin();
 			if ( true !== $chained ) {

inc/native/class-wp-markdown-native-query-runtime.php

@@ -618,7 +618,7 @@ private static function all_ascii_strings( array $values ): bool {
 	}
 }
 
-final class WP_Markdown_Native_Option_Query_Runtime implements WP_Markdown_Query_Runtime {
+final class WP_Markdown_Native_Option_Query_Runtime implements WP_Markdown_Query_Runtime, WP_Markdown_Native_Transactional_Table_Support {
 
 	private WP_Markdown_Native_Query_Runtime $runtime;
 
@@ -641,10 +641,14 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		}
 		return $this->runtime->execute( $request );
 	}
+
+	public function supports_transactional_tables( array $tables ): bool {
+		return $this->runtime->supports_transactional_tables( $tables );
+	}
 }
 
 /** Lazily construct a single-root runtime for the prefix selected by wpdb. */
-final class WP_Markdown_Native_Prefix_Query_Runtime implements WP_Markdown_Query_Runtime {
+final class WP_Markdown_Native_Prefix_Query_Runtime implements WP_Markdown_Query_Runtime, WP_Markdown_Native_Transactional_Table_Support {
 
 	/** @var array<string,WP_Markdown_Native_Query_Runtime> */
 	private array $runtimes = array();
@@ -674,14 +678,30 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		return $this->runtimes[ $prefix ]->execute( $request );
 	}
 
+	public function supports_transactional_tables( array $tables ): bool {
+		$prefix = isset( $GLOBALS['wpdb']->prefix ) && is_string( $GLOBALS['wpdb']->prefix ) ? $GLOBALS['wpdb']->prefix : 'wp_';
+		if ( ! isset( $this->runtimes[ $prefix ] ) ) {
+			$this->runtimes[ $prefix ] = WP_Markdown_Native_Runtime_Factory::runtime(
+				$this->state_root,
+				$prefix,
+				$prefix,
+				false,
+				$this->content_root,
+				advisory_locks: $this->advisory_locks,
+				session: $this->session
+			);
+		}
+		return $this->runtimes[ $prefix ]->supports_transactional_tables( $tables );
+	}
+
 	public function close(): void {
 		$this->advisory_locks->close();
 		$this->session->reset();
 	}
 }
 
 /** Defer WordPress topology detection because db.php precedes multisite bootstrap. */
-final class WP_Markdown_Native_WordPress_Query_Runtime implements WP_Markdown_Query_Runtime {
+final class WP_Markdown_Native_WordPress_Query_Runtime implements WP_Markdown_Query_Runtime, WP_Markdown_Native_Transactional_Table_Support {
 
 	private WP_Markdown_Native_Prefix_Query_Runtime $prefix_runtime;
 	/** @var array<string,WP_Markdown_Native_Multisite_Query_Runtime> */
@@ -718,10 +738,22 @@ public function close(): void {
 			$runtime->close();
 		}
 	}
+
+	public function supports_transactional_tables( array $tables ): bool {
+		$multisite = ( defined( 'WP_INSTALLING_NETWORK' ) && WP_INSTALLING_NETWORK ) || ( defined( 'MULTISITE' ) && MULTISITE ) || ( function_exists( 'is_multisite' ) && is_multisite() );
+		if ( ! $multisite ) {
+			return $this->prefix_runtime->supports_transactional_tables( $tables );
+		}
+		$base_prefix = isset( $GLOBALS['wpdb']->base_prefix ) && is_string( $GLOBALS['wpdb']->base_prefix ) ? $GLOBALS['wpdb']->base_prefix : $this->base_prefix;
+		if ( ! isset( $this->multisite_runtimes[ $base_prefix ] ) ) {
+			$this->multisite_runtimes[ $base_prefix ] = new WP_Markdown_Native_Multisite_Query_Runtime( $this->state_root, $base_prefix, $this->content_root, $this->session );
+		}
+		return $this->multisite_runtimes[ $base_prefix ]->supports_transactional_tables( $tables );
+	}
 }
 
 /** Lazily compose a native runtime for each WordPress multisite table scope. */
-final class WP_Markdown_Native_Multisite_Query_Runtime implements WP_Markdown_Query_Runtime {
+final class WP_Markdown_Native_Multisite_Query_Runtime implements WP_Markdown_Query_Runtime, WP_Markdown_Native_Transactional_Table_Support {
 
 	/** @var array<string,WP_Markdown_Native_Query_Runtime> */
 	private array $runtimes = array();
@@ -791,6 +823,27 @@ public function execute( WP_Markdown_Query_Request $request ): WP_Markdown_Query
 		return $this->runtimes[ $prefix ]->execute( $request );
 	}
 
+	public function supports_transactional_tables( array $tables ): bool {
+		$prefix = isset( $GLOBALS['wpdb']->prefix ) && is_string( $GLOBALS['wpdb']->prefix ) ? $GLOBALS['wpdb']->prefix : $this->base_prefix;
+		if ( ! $this->is_scope_prefix( $prefix ) ) {
+			return false;
+		}
+		if ( ! isset( $this->runtimes[ $prefix ] ) ) {
+			$roots = $this->roots( $prefix );
+			if ( null === $roots ) {
+				return false;
+			}
+			try {
+				$this->runtimes[ $prefix ] = WP_Markdown_Native_Runtime_Factory::runtime(
+					$roots['state'], $prefix, $this->base_prefix, true, $roots['content'], $this->state_root, $this->content_root, $this->advisory_locks, $this->state_root, $this->session
+				);
+			} catch ( Throwable ) {
+				return false;
+			}
+		}
+		return $this->runtimes[ $prefix ]->supports_transactional_tables( $tables );
+	}
+
 	public function close(): void {
 		$this->advisory_locks->close();
 		$this->session->reset();

inc/native/class-wp-markdown-native-table-insert-parser.php

@@ -75,7 +75,7 @@ public function parse_rows( WP_Markdown_Query_Request $request ): array|WP_Markd
 				if ( $replace || $ignore_duplicate || null !== $unless_exists ) {
 					throw new WP_Markdown_Native_SQL_Parse_Error( 'unsupported_grammar', $this->current()->sql_offset(), 'mdi-native cannot combine INSERT IGNORE or INSERT SELECT FROM DUAL with ON DUPLICATE KEY UPDATE.' );
 				}
-				$upsert_assignments = $this->upsert_assignments();
+				$upsert_assignments = $this->upsert_assignments( $table );
 			}
 			$this->type( WP_Markdown_Native_SQL_Token::END );
 			$inserts = array();
@@ -351,8 +351,8 @@ private function identifier_list(): array {
 		return array_values( $columns );
 	}
 
-	/** @return array<int,array{target:string,kind:string,source:?string,value:int|string|null}> */
-	private function upsert_assignments(): array {
+	/** @return array<int,array{target:string,kind:string,source:?string,value:int|string|null|WP_Markdown_Native_Query_Scalar_Expression}> */
+	private function upsert_assignments( string $table ): array {
 		$this->word( 'ON' );
 		$this->word( 'DUPLICATE' );
 		$this->word( 'KEY' );
@@ -369,12 +369,19 @@ private function upsert_assignments(): array {
 				$source = $this->identifier();
 				$this->type( WP_Markdown_Native_SQL_Token::RIGHT_PAREN );
 				$kind = 'inserted';
-			} elseif ( in_array( $this->current()->type(), array( WP_Markdown_Native_SQL_Token::WORD, WP_Markdown_Native_SQL_Token::QUOTED_IDENTIFIER ), true ) ) {
-				$source = $this->identifier();
-				$kind = 'column';
 			} else {
-				$value = $this->literal();
-				$kind = 'literal';
+				$parser = new WP_Markdown_Native_Select_AST_Parser( $this->tokens, $this->position );
+				$expression = $parser->scalar_value();
+				$this->position = $parser->position();
+				foreach ( $expression->columns() as $column ) {
+					if ( null !== $column->qualifier() && 0 !== strcasecmp( $table, $column->qualifier() ) ) {
+						throw new WP_Markdown_Native_SQL_Parse_Error( 'unsupported_mutation_column', $column->sql_offset(), 'A duplicate-key expression must reference its target table.' );
+					}
+				}
+				$value = 'literal' === $expression->kind()
+					? $expression->literal()
+					: ( new WP_Markdown_Native_Query_Parser() )->lower_scalar_expression( $expression, null, $table );
+				$kind = $value instanceof WP_Markdown_Native_Query_Scalar_Expression ? 'expression' : 'literal';
 			}
 			$assignments[] = array( 'target' => $target, 'kind' => $kind, 'source' => $source, 'value' => $value );
 			if ( WP_Markdown_Native_SQL_Token::COMMA !== $this->current()->type() ) {

inc/native/class-wp-markdown-native-table-mutations.php

@@ -117,6 +117,16 @@ private function execute_insert( WP_Markdown_Query_Request $request, WP_Markdown
 				if ( ! $schema->has_column( $assignment['target'] ) || ( null !== $assignment['source'] && ! $schema->has_column( $assignment['source'] ) ) ) {
 					return $this->failure( 'unsupported_column', 'The duplicate-key assignment references an undeclared column.' );
 				}
+				if ( $assignment['value'] instanceof WP_Markdown_Native_Query_Scalar_Expression ) {
+					if ( ! WP_Markdown_Native_Scalar_Evaluator::supports( $assignment['value'] ) ) {
+						return $this->failure( 'unsupported_mutation_expression', 'The duplicate-key assignment uses an unsupported expression.' );
+					}
+					foreach ( $assignment['value']->columns() as $column ) {
+						if ( ! $schema->has_column( $column ) ) {
+							return $this->failure( 'unsupported_column', 'The duplicate-key assignment references an undeclared column.' );
+						}
+					}
+				}
 			}
 			if ( ! $this->supports_unique_indexes( $definition ) ) {
 				return $this->failure( 'unsupported_unique_collation', 'mdi-native cannot enforce a persisted string or prefix unique key without its exact collation.' );
@@ -213,13 +223,15 @@ private function execute_insert( WP_Markdown_Query_Request $request, WP_Markdown
 				}
 				$duplicate = $duplicates[0];
 				$updated = $rows[ $duplicate ];
+				$scalar_runtime = new WP_Markdown_Native_Query_Runtime( $this->registry, new WP_Markdown_Native_Query_Parser() );
 				foreach ( $upsert_assignments as $assignment ) {
 					// Existing-column references see earlier assignments; VALUES sees the proposed insert.
-					$updated[ $assignment['target'] ] = match ( $assignment['kind'] ) {
+					$value = match ( $assignment['kind'] ) {
 						'inserted' => $row[ $assignment['source'] ],
-						'column' => $updated[ $assignment['source'] ],
+						'expression' => $scalar_runtime->evaluate_scalar( $assignment['value'], $updated, $schema ),
 						default => $assignment['value'],
 					};
+					$updated[ $assignment['target'] ] = null === $value ? null : (string) $value;
 				}
 				if ( true !== $schema->validate_row( $updated ) ) {
 					return $this->failure( 'invalid_insert_row', 'The INSERT row is outside the persisted table schema.' );

inc/native/class-wp-markdown-native-table-providers.php

@@ -10,7 +10,7 @@
 require_once __DIR__ . '/class-wp-markdown-native-post-catalogue.php';
 require_once __DIR__ . '/class-wp-markdown-native-option-catalogue.php';
 
-abstract class WP_Markdown_Native_File_Provider implements WP_Markdown_Native_Table_Provider {
+abstract class WP_Markdown_Native_File_Provider implements WP_Markdown_Native_Canonical_Table_Provider {
 
 	protected string $state_root;
 
@@ -25,6 +25,10 @@ public function __construct(
 		$this->state_root = rtrim( $root, DIRECTORY_SEPARATOR );
 	}
 
+	public function canonical_root(): string {
+		return $this->state_root;
+	}
+
 	protected function failure( string $code, string $reason, string $message ): WP_Markdown_Query_Result {
 		return WP_Markdown_Query_Result::failure(
 			array(

inc/native/class-wp-markdown-native-table-statements.php

@@ -9,7 +9,7 @@ final class WP_Markdown_Native_Table_Insert {
 	/**
 	 * @param array<string,int|string|null> $values
 	 * @param array<int,WP_Markdown_Native_Table_Predicate>|null $unless_exists
-	 * @param array<int,array{target:string,kind:string,source:?string,value:int|string|null}>|null $upsert_assignments
+	 * @param array<int,array{target:string,kind:string,source:?string,value:int|string|null|WP_Markdown_Native_Query_Scalar_Expression}>|null $upsert_assignments
 	 */
 	public function __construct(
 		private readonly string $table,
@@ -38,7 +38,7 @@ public function ignores_duplicate(): bool {
 		return $this->ignore_duplicate;
 	}
 
-	/** @return array<int,array{target:string,kind:string,source:?string,value:int|string|null}>|null */
+	/** @return array<int,array{target:string,kind:string,source:?string,value:int|string|null|WP_Markdown_Native_Query_Scalar_Expression}>|null */
 	public function upsert_assignments(): ?array {
 		return $this->upsert_assignments;
 	}