[Data Liberation] First topological sorter draft

packages/playground/data-liberation/bin/import/blueprint-import-wxr.json

@@ -11,8 +11,8 @@
 			"pluginPath": "data-liberation/plugin.php"
 		},
 		{
-			"step": "runPHP",
-			"code": "<?php require_once 'wordpress/wp-load.php';\n$upload_dir = wp_upload_dir();\nforeach ( wp_visit_file_tree( $upload_dir['basedir'] . '/import-wxr' ) as $event ) {\nforeach ( $event->files as $file ) {\nif ( $file->isFile() && pathinfo( $file->getPathname(), PATHINFO_EXTENSION ) === 'xml' ) {\ndata_liberation_import( $file->getPathname() );\n}\n}\n};"
+			"step": "wp-cli",
+			"command": "wp data-liberation import /wordpress/wp-content/uploads/import-wxr"
 		}
 	]
 }

packages/playground/data-liberation/bootstrap.php

@@ -58,6 +58,8 @@
 require_once __DIR__ . '/src/import/WP_Markdown_Importer.php';
 require_once __DIR__ . '/src/import/WP_Entity_Iterator_Chain.php';
 require_once __DIR__ . '/src/import/WP_Retry_Frontloading_Iterator.php';
+require_once __DIR__ . '/src/import/WP_Logger.php';
+require_once __DIR__ . '/src/import/WP_Topological_Sorter.php';
 
 require_once __DIR__ . '/src/utf8_decoder.php';
 

packages/playground/data-liberation/phpunit.xml

@@ -11,6 +11,7 @@
       <file>tests/WPXMLProcessorTests.php</file>
       <file>tests/UrldecodeNTests.php</file>
       <file>tests/WPStreamImporterTests.php</file>
+      <!--<file>tests/WPTopologicalSorterTests.php</file>-->
     </testsuite>
   </testsuites>
 </phpunit>

packages/playground/data-liberation/plugin.php

@@ -39,40 +39,54 @@ function () {
 	}
 );
 
-add_action(
-	'init',
-	function () {
-		if ( defined( 'WP_CLI' ) && WP_CLI ) {
-			/**
-			 * Import a WXR file.
-			 *
-			 * <file>
-			 * : The WXR file to import.
-			 */
-			$command = function ( $args, $assoc_args ) {
-				$file = $args[0];
-				data_liberation_import( $file );
-			};
-
-			// Register the WP-CLI import command.
-			// Example usage: wp data-liberation /path/to/file.xml
-			WP_CLI::add_command( 'data-liberation', $command );
-		}
+function data_liberation_init() {
+	if ( defined( 'WP_CLI' ) && WP_CLI ) {
+		require_once __DIR__ . '/src/cli/WP_Import_Command.php';
 
-		register_post_status(
-			'error',
-			array(
-				'label' => _x( 'Error', 'post' ), // Label name
-				'public' => false,
-				'exclude_from_search' => false,
-				'show_in_admin_all_list' => false,
-				'show_in_admin_status_list' => false,
-				// translators: %s is the number of errors
-				'label_count' => _n_noop( 'Error <span class="count">(%s)</span>', 'Error <span class="count">(%s)</span>' ),
-			)
-		);
+		// Register the WP-CLI import command.
+		WP_CLI::add_command( 'data-liberation', WP_Import_Command::class );
 	}
-);
+
+	register_post_status(
+		'error',
+		array(
+			'label' => _x( 'Error', 'post' ), // Label name
+			'public' => false,
+			'exclude_from_search' => false,
+			'show_in_admin_all_list' => false,
+			'show_in_admin_status_list' => false,
+			// translators: %s is the number of errors
+			'label_count' => _n_noop( 'Error <span class="count">(%s)</span>', 'Error <span class="count">(%s)</span>' ),
+		)
+	);
+}
+
+add_action( 'init', 'data_liberation_init' );
+
+function data_liberation_activate() {
+	// Activate the topological sorter. Create tables and options.
+	WP_Topological_Sorter::activate();
+}
+
+// Run when the plugin is activated.
+register_activation_hook( __FILE__, 'data_liberation_activate' );
+
+function data_liberation_deactivate() {
+	// Deactivate the topological sorter. Flush away all data.
+	WP_Topological_Sorter::deactivate();
+
+	// @TODO: Cancel any active import sessions and cleanup other data.
+}
+
+// Run when the plugin is deactivated.
+register_deactivation_hook( __FILE__, 'data_liberation_deactivate' );
+
+function data_liberation_load() {
+	WP_Topological_Sorter::load();
+}
+
+// Run when the plugin is loaded.
+add_action( 'plugins_loaded', 'data_liberation_load' );
 
 // Register admin menu
 add_action(

packages/playground/data-liberation/src/cli/WP_Import_Command.php

@@ -0,0 +1,246 @@
+<?php
+
+require_once __DIR__ . '/WP_Import_Logger.php';
+
+/**
+ * Implements the `wp data-liberation` command.
+ *
+ * ## EXAMPLES
+ *
+ *     # Import a WXR file.
+ *     wp data-liberation import /path/to/file.xml
+ *
+ *     # Import all files inside a folder.
+ *     wp data-liberation import /path/to/folder
+ *
+ *     # Import a WXR file from a URL.
+ *     wp data-liberation import http://example.com/file.xml
+ *
+ *     Success: Imported data.
+ */
+class WP_Import_Command {
+	/**
+	 * @var bool $dry_run Whether to perform a dry run.
+	 */
+	private $dry_run = false;
+
+	/**
+	 * @var WP_Stream_Importer $importer The importer instance.
+	 */
+	private $importer = null;
+
+	/**
+	 * @var string $wxr_path The path to the WXR file.
+	 */
+	private $wxr_path = '';
+
+	/**
+	 * @var int $count The number of items to import in one go.
+	 */
+	private $count;
+
+	/**
+	 * @var WP_Import_Session $import_session The import session.
+	 */
+	private $import_session;
+
+	/**
+	 * Import a WXR file.
+	 *
+	 * ## OPTIONS
+	 *
+	 * <path>
+	 * : The path to the WXR file. Either a file, a directory or a URL.
+	 *
+	 * [--count=<count>]
+	 * : The number of items to import in one go. Default is 10,000.
+	 *
+	 * [--dry-run]
+	 * : Perform a dry run if set.
+	 *
+	 * ## EXAMPLES
+	 *
+	 *     wp data-liberation import /path/to/file.xml
+	 *
+	 * @param array $args
+	 * @param array $assoc_args
+	 * @return void
+	 */
+	public function import( $args, $assoc_args ) {
+		$path          = $args[0];
+		$this->dry_run = WP_CLI\Utils\get_flag_value( $assoc_args, 'dry-run', false );
+		$this->count   = isset( $assoc_args['count'] ) ? (int) $assoc_args['count'] : 10000;
+		$options       = array(
+			'logger' => new WP_Import_logger(),
+		);
+
+		if ( extension_loaded( 'pcntl' ) ) {
+			// Set the signal handler.
+			$this->register_handlers();
+		}
+
+		// Be sure Data Liberation is activated.
+		data_liberation_activate();
+
+		if ( filter_var( $path, FILTER_VALIDATE_URL ) ) {
+			// Import URL.
+			$this->import_wxr_url( $path, $options );
+		} elseif ( is_dir( $path ) ) {
+			$count = 0;
+			// Get all the WXR files in the directory.
+			foreach ( wp_visit_file_tree( $path ) as $event ) {
+				foreach ( $event->files as $file ) {
+					if ( $file->isFile() && 'xml' === pathinfo( $file->getPathname(), PATHINFO_EXTENSION ) ) {
+						++$count;
+
+						// Import the WXR file.
+						$this->import_wxr_file( $file->getPathname(), $options );
+					}
+				}
+			}
+
+			if ( ! $count ) {
+				WP_CLI::error( WP_CLI::colorize( "No WXR files found in the %R{$path}%n directory" ) );
+			}
+		} else {
+			if ( ! is_file( $path ) ) {
+				WP_CLI::error( WP_CLI::colorize( "File not found: %R{$path}%n" ) );
+			}
+
+			// Import the WXR file.
+			$this->import_wxr_file( $path, $options );
+		}
+	}
+
+	private function start_session( $args ) {
+		if ( $this->dry_run ) {
+			WP_CLI::line( 'Dry run enabled. No session created.' );
+
+			return;
+		}
+
+		$active_session = WP_Import_Session::get_active();
+
+		if ( $active_session ) {
+			$this->import_session = $active_session;
+
+			$id = $this->import_session->get_id();
+			WP_CLI::line( WP_CLI::colorize( "Current session: %g{$id}%n" ) );
+		} else {
+			$this->import_session = WP_Import_Session::create( $args );
+
+			$id = $this->import_session->get_id();
+			WP_CLI::line( WP_CLI::colorize( "New session: %g{$id}%n" ) );
+		}
+	}
+
+	/**
+	 * Import a WXR file.
+	 *
+	 * @param string $file_path The path to the WXR file.
+	 * @return void
+	 */
+	private function import_wxr_file( $file_path, $options = array() ) {
+		$this->wxr_path = $file_path;
+
+		$this->start_session(
+			array(
+				'data_source' => 'wxr_file',
+				'file_name'   => $file_path,
+			)
+		);
+
+		// Pass the session ID.
+		$options['session_id'] = $this->import_session->get_id();
+
+		$this->importer = WP_Stream_Importer::create_for_wxr_file( $file_path, $options );
+		$this->import_wxr();
+	}
+
+	/**
+	 * Import a WXR file from a URL.
+	 *
+	 * @param string $url The URL to the WXR file.
+	 * @return void
+	 */
+	private function import_wxr_url( $url, $options = array() ) {
+		$this->wxr_path = $url;
+
+		$this->start_session(
+			array(
+				'data_source' => 'wxr_url',
+				'file_name'   => $url,
+			)
+		);
+
+		// Pass the session ID.
+		$options['session_id'] = $this->import_session->get_id();
+
+		$this->importer = WP_Stream_Importer::create_for_wxr_url( $url, $options );
+		$this->import_wxr();
+	}
+
+	/**
+	 * Import the WXR file.
+	 */
+	private function import_wxr() {
+		if ( ! $this->importer ) {
+			WP_CLI::error( 'Could not create importer' );
+		}
+
+		if ( ! $this->import_session ) {
+			WP_CLI::error( 'Could not create session' );
+		}
+
+		WP_CLI::line( "Importing {$this->wxr_path}" );
+
+		if ( $this->dry_run ) {
+			// @TODO: do something with the dry run.
+			WP_CLI::line( 'Dry run enabled.' );
+		} else {
+			do {
+				$current_stage = $this->importer->get_stage();
+				WP_CLI::line( WP_CLI::colorize( "Stage %g{$current_stage}%n" ) );
+				$step_count = 0;
+
+				while ( $this->importer->next_step( $this->count ) ) {
+					++$step_count;
+					WP_CLI::line( WP_CLI::colorize( "Step %g{$step_count}%n" ) );
+				}
+			} while ( $this->importer->advance_to_next_stage() );
+		}
+
+		WP_CLI::success( 'Import finished' );
+	}
+
+	/**
+	 * Callback function registered to `pcntl_signal` to handle signals.
+	 *
+	 * @param int $signal The signal number.
+	 * @return void
+	 */
+	protected function signal_handler( $signal ) {
+		switch ( $signal ) {
+			case SIGINT:
+				WP_CLI::line( 'Received SIGINT signal' );
+				exit( 0 );
+
+			case SIGTERM:
+				WP_CLI::line( 'Received SIGTERM signal' );
+				exit( 0 );
+		}
+	}
+
+	/**
+	 * Register signal handlers for the command.
+	 *
+	 * @return void
+	 */
+	private function register_handlers() {
+		// Handle the Ctrl + C signal to terminate the program.
+		pcntl_signal( SIGINT, array( $this, 'signal_handler' ) );
+
+		// Handle the `kill` command to terminate the program.
+		pcntl_signal( SIGTERM, array( $this, 'signal_handler' ) );
+	}
+}