sdk/lib/_internal/pub/lib/src/barback/server.dart - sdk.git - Git at Google

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 library pub.barback.server;

 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';

 import 'package:barback/barback.dart';
 import 'package:path/path.dart' as path;
 import 'package:stack_trace/stack_trace.dart';

 import '../barback.dart';
 import '../log.dart' as log;
 import '../utils.dart';

 /// A server that serves assets transformed by barback.
 class BarbackServer {
   /// The underlying HTTP server.
   final HttpServer _server;

   /// The name of the root package, from whose `web` directory root assets will
   /// be served.
   final String _rootPackage;

   /// The barback instance from which this serves assets.
   final Barback barback;

   /// The server's port.
   final int port;

   /// The server's address.
   final InternetAddress address;

   /// The results of requests handled by the server.
   ///
   /// These can be used to provide visual feedback for the server's processing.
   /// This stream is also used to emit any programmatic errors that occur in the
   /// server.
   Stream<BarbackServerResult> get results => _resultsController.stream;
   final _resultsController =
       new StreamController<BarbackServerResult>.broadcast();

   /// Creates a new server and binds it to [port] of [host].
   ///
   /// This server will serve assets from [barback], and use [rootPackage] as the
   /// root package.
   static Future<BarbackServer> bind(String host, int port, Barback barback,
       String rootPackage) {
     return HttpServer.bind(host, port)
         .then((server) => new BarbackServer._(server, barback, rootPackage));
   }

   BarbackServer._(HttpServer server, this.barback, this._rootPackage)
       : _server = server,
         port = server.port,
         address = server.address {
     _server.listen(_handleRequest, onError: (error, stackTrace) {
       _resultsController.addError(error, stackTrace);
       close();
     });
   }

   /// Closes this server.
   Future close() {
     _server.close();
     _resultsController.close();
   }

   /// Handles an HTTP request.
   void _handleRequest(HttpRequest request) {
     if (WebSocketTransformer.isUpgradeRequest(request)) {
       _handleWebSocket(request);
       return;
     }

     if (request.method != "GET" && request.method != "HEAD") {
       _methodNotAllowed(request);
       return;
     }

     var id;
     try {
       id = _urlToId(request.uri);
     } on FormatException catch (ex) {
       // If we got here, we had a path like "/packages" which is a special
       // directory, but not a valid path since it lacks a following package name.
       _notFound(request, ex.message);
       return;
     }

     _logRequest(request, "Loading $id");
     barback.getAssetById(id).then((asset) {
       return validateStream(asset.read()).then((stream) {
         _resultsController.add(
             new BarbackServerResult._success(request.uri, id));
         // TODO(rnystrom): Set content-type based on asset type.
         return request.response.addStream(stream).then((_) {
           // Log successful requests both so we can provide debugging
           // information and so scheduled_test knows we haven't timed out while
           // loading transformers.
           _logRequest(request, "Served $id");
           request.response.close();
         });
       }).catchError((error) {
         _resultsController.add(
             new BarbackServerResult._failure(request.uri, id, error));

         // If we couldn't read the asset, handle the error gracefully.
         if (error is FileSystemException) {
           // Assume this means the asset was a file-backed source asset
           // and we couldn't read it, so treat it like a missing asset.
           _notFound(request, error);
           return;
         }

         var trace = new Trace.from(getAttachedStackTrace(error));
         _logRequest(request, "$error\n$trace");

         // Otherwise, it's some internal error.
         request.response.statusCode = 500;
         request.response.reasonPhrase = "Internal Error";
         request.response.write(error);
         request.response.close();
       });
     }).catchError((error) {
       if (error is! AssetNotFoundException) {
         var trace = new Trace.from(getAttachedStackTrace(error));
         _logRequest(request, "$error\n$trace");

         _resultsController.addError(error);
         close();
         return;
       }

       _resultsController.add(
           new BarbackServerResult._failure(request.uri, id, error));
       _notFound(request, error);
     });
   }

   /// Creates a web socket for [request] which should be an upgrade request.
   void _handleWebSocket(HttpRequest request) {
     WebSocketTransformer.upgrade(request).then((socket) {
       socket.listen((data) {
         var command;
         try {
           command = JSON.decode(data);
         } on FormatException catch (ex) {
           _webSocketError(socket, '"$data" is not valid JSON: ${ex.message}');
           return;
         }

         if (command is! Map) {
           _webSocketError(socket, "Command must be a JSON map. Got: $data.");
           return;
         }

         if (!command.containsKey("command")) {
           _webSocketError(socket, "Missing command name. Got: $data.");
           return;
         }

         switch (command["command"]) {
           case "urlToAsset":
             var urlPath = command["path"];
             if (urlPath is! String) {
               _webSocketError(socket, '"path" must be a string. Got: '
                   '${JSON.encode(urlPath)}.');
               return;
             }

             var url = new Uri(path: urlPath);
             var id = _urlToId(url);
             socket.add(JSON.encode({
               "package": id.package,
               "path": id.path
             }));
             break;

           case "assetToUrl":
             var packageName = command["package"];
             if (packageName is! String) {
               _webSocketError(socket, '"package" must be a string. Got: '
                   '${JSON.encode(packageName)}.');
               return;
             }

             var packagePath = command["path"];
             if (packagePath is! String) {
               _webSocketError(socket, '"path" must be a string. Got: '
                   '${JSON.encode(packagePath)}.');
               return;
             }

             var id = new AssetId(packageName, packagePath);
             try {
               var urlPath = idtoUrlPath(_rootPackage, id);
               socket.add(JSON.encode({"path": urlPath}));
             } on FormatException catch (ex) {
               _webSocketError(socket, ex.message);
             }
             break;

           default:
             _webSocketError(socket, 'Unknown command "${command["command"]}".');
             break;
         }
       }, onError: (error) {
         _resultsController.addError(error);
       }, cancelOnError: true);
     }).catchError((error) {
       _resultsController.addError(error);
     });
   }

   /// Converts a [url] served by pub serve into an [AssetId] that can be
   /// requested from barback.
   AssetId _urlToId(Uri url) {
     var id = specialUrlToId(url);
     if (id != null) return id;

     // Otherwise, it's a path in current package's web directory.
     var parts = path.url.split(url.path);

     // Strip the leading "/" from the URL.
     if (parts.isNotEmpty && parts.first == "/") parts = parts.skip(1);

     var relativePath = path.url.join("web", path.url.joinAll(parts));
     return new AssetId(_rootPackage, relativePath);
   }

   /// Responds to [request] with a 405 response and closes it.
   void _methodNotAllowed(HttpRequest request) {
     _logRequest(request, "405 Method Not Allowed");
     request.response.statusCode = 405;
     request.response.reasonPhrase = "Method Not Allowed";
     request.response.headers.add('Allow', 'GET, HEAD');
     request.response.write(
         "The ${request.method} method is not allowed for ${request.uri}.");
     request.response.close();
   }

   /// Responds to [request] with a 404 response and closes it.
   void _notFound(HttpRequest request, message) {
     _logRequest(request, "404 Not Found");
     request.response.statusCode = 404;
     request.response.reasonPhrase = "Not Found";
     request.response.write(message);
     request.response.close();
   }

   /// Log [message] at [log.Level.FINE] with metadata about [request].
   void _logRequest(HttpRequest request, String message) =>
     log.fine("BarbackServer ${request.method} ${request.uri}\n$message");

   void _webSocketError(WebSocket socket, String message) {
     socket.add(JSON.encode({"error": message}));
   }
 }

 /// The result of the server handling a URL.
 ///
 /// Only requests for which an asset was requested from barback will emit a
 /// result. Malformed requests will be handled internally.
 class BarbackServerResult {
   /// The requested url.
   final Uri url;

   /// The id that [url] identifies.
   final AssetId id;

   /// The error thrown by barback.
   ///
   /// If the request was served successfully, this will be null.
   final error;

   /// Whether the request was served successfully.
   bool get isSuccess => error == null;

   /// Whether the request was served unsuccessfully.
   bool get isFailure => !isSuccess;

   BarbackServerResult._success(this.url, this.id)
       : error = null;

   BarbackServerResult._failure(this.url, this.id, this.error);
 }
	// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	library pub.barback.server;

	import 'dart:async';
	import 'dart:convert';
	import 'dart:io';

	import 'package:barback/barback.dart';
	import 'package:path/path.dart' as path;
	import 'package:stack_trace/stack_trace.dart';

	import '../barback.dart';
	import '../log.dart' as log;
	import '../utils.dart';

	/// A server that serves assets transformed by barback.
	class BarbackServer {
	/// The underlying HTTP server.
	final HttpServer _server;

	/// The name of the root package, from whose `web` directory root assets will
	/// be served.
	final String _rootPackage;

	/// The barback instance from which this serves assets.
	final Barback barback;

	/// The server's port.
	final int port;

	/// The server's address.
	final InternetAddress address;

	/// The results of requests handled by the server.
	///
	/// These can be used to provide visual feedback for the server's processing.
	/// This stream is also used to emit any programmatic errors that occur in the
	/// server.
	Stream<BarbackServerResult> get results => _resultsController.stream;
	final _resultsController =
	new StreamController<BarbackServerResult>.broadcast();

	/// Creates a new server and binds it to [port] of [host].
	///
	/// This server will serve assets from [barback], and use [rootPackage] as the
	/// root package.
	static Future<BarbackServer> bind(String host, int port, Barback barback,
	String rootPackage) {
	return HttpServer.bind(host, port)
	.then((server) => new BarbackServer._(server, barback, rootPackage));
	}

	BarbackServer._(HttpServer server, this.barback, this._rootPackage)
	: _server = server,
	port = server.port,
	address = server.address {
	_server.listen(_handleRequest, onError: (error, stackTrace) {
	_resultsController.addError(error, stackTrace);
	close();
	});
	}

	/// Closes this server.
	Future close() {
	_server.close();
	_resultsController.close();
	}

	/// Handles an HTTP request.
	void _handleRequest(HttpRequest request) {
	if (WebSocketTransformer.isUpgradeRequest(request)) {
	_handleWebSocket(request);
	return;
	}

	if (request.method != "GET" && request.method != "HEAD") {
	_methodNotAllowed(request);
	return;
	}

	var id;
	try {
	id = _urlToId(request.uri);
	} on FormatException catch (ex) {
	// If we got here, we had a path like "/packages" which is a special
	// directory, but not a valid path since it lacks a following package name.
	_notFound(request, ex.message);
	return;
	}

	_logRequest(request, "Loading $id");
	barback.getAssetById(id).then((asset) {
	return validateStream(asset.read()).then((stream) {
	_resultsController.add(
	new BarbackServerResult._success(request.uri, id));
	// TODO(rnystrom): Set content-type based on asset type.
	return request.response.addStream(stream).then((_) {
	// Log successful requests both so we can provide debugging
	// information and so scheduled_test knows we haven't timed out while
	// loading transformers.
	_logRequest(request, "Served $id");
	request.response.close();
	});
	}).catchError((error) {
	_resultsController.add(
	new BarbackServerResult._failure(request.uri, id, error));

	// If we couldn't read the asset, handle the error gracefully.
	if (error is FileSystemException) {
	// Assume this means the asset was a file-backed source asset
	// and we couldn't read it, so treat it like a missing asset.
	_notFound(request, error);
	return;
	}

	var trace = new Trace.from(getAttachedStackTrace(error));
	_logRequest(request, "$error\n$trace");

	// Otherwise, it's some internal error.
	request.response.statusCode = 500;
	request.response.reasonPhrase = "Internal Error";
	request.response.write(error);
	request.response.close();
	});
	}).catchError((error) {
	if (error is! AssetNotFoundException) {
	var trace = new Trace.from(getAttachedStackTrace(error));
	_logRequest(request, "$error\n$trace");

	_resultsController.addError(error);
	close();
	return;
	}

	_resultsController.add(
	new BarbackServerResult._failure(request.uri, id, error));
	_notFound(request, error);
	});
	}

	/// Creates a web socket for [request] which should be an upgrade request.
	void _handleWebSocket(HttpRequest request) {
	WebSocketTransformer.upgrade(request).then((socket) {
	socket.listen((data) {
	var command;
	try {
	command = JSON.decode(data);
	} on FormatException catch (ex) {
	_webSocketError(socket, '"$data" is not valid JSON: ${ex.message}');
	return;
	}

	if (command is! Map) {
	_webSocketError(socket, "Command must be a JSON map. Got: $data.");
	return;
	}

	if (!command.containsKey("command")) {
	_webSocketError(socket, "Missing command name. Got: $data.");
	return;
	}

	switch (command["command"]) {
	case "urlToAsset":
	var urlPath = command["path"];
	if (urlPath is! String) {
	_webSocketError(socket, '"path" must be a string. Got: '
	'${JSON.encode(urlPath)}.');
	return;
	}

	var url = new Uri(path: urlPath);
	var id = _urlToId(url);
	socket.add(JSON.encode({
	"package": id.package,
	"path": id.path
	}));
	break;

	case "assetToUrl":
	var packageName = command["package"];
	if (packageName is! String) {
	_webSocketError(socket, '"package" must be a string. Got: '
	'${JSON.encode(packageName)}.');
	return;
	}

	var packagePath = command["path"];
	if (packagePath is! String) {
	_webSocketError(socket, '"path" must be a string. Got: '
	'${JSON.encode(packagePath)}.');
	return;
	}

	var id = new AssetId(packageName, packagePath);
	try {
	var urlPath = idtoUrlPath(_rootPackage, id);
	socket.add(JSON.encode({"path": urlPath}));
	} on FormatException catch (ex) {
	_webSocketError(socket, ex.message);
	}
	break;

	default:
	_webSocketError(socket, 'Unknown command "${command["command"]}".');
	break;
	}
	}, onError: (error) {
	_resultsController.addError(error);
	}, cancelOnError: true);
	}).catchError((error) {
	_resultsController.addError(error);
	});
	}

	/// Converts a [url] served by pub serve into an [AssetId] that can be
	/// requested from barback.
	AssetId _urlToId(Uri url) {
	var id = specialUrlToId(url);
	if (id != null) return id;

	// Otherwise, it's a path in current package's web directory.
	var parts = path.url.split(url.path);

	// Strip the leading "/" from the URL.
	if (parts.isNotEmpty && parts.first == "/") parts = parts.skip(1);

	var relativePath = path.url.join("web", path.url.joinAll(parts));
	return new AssetId(_rootPackage, relativePath);
	}

	/// Responds to [request] with a 405 response and closes it.
	void _methodNotAllowed(HttpRequest request) {
	_logRequest(request, "405 Method Not Allowed");
	request.response.statusCode = 405;
	request.response.reasonPhrase = "Method Not Allowed";
	request.response.headers.add('Allow', 'GET, HEAD');
	request.response.write(
	"The ${request.method} method is not allowed for ${request.uri}.");
	request.response.close();
	}

	/// Responds to [request] with a 404 response and closes it.
	void _notFound(HttpRequest request, message) {
	_logRequest(request, "404 Not Found");
	request.response.statusCode = 404;
	request.response.reasonPhrase = "Not Found";
	request.response.write(message);
	request.response.close();
	}

	/// Log [message] at [log.Level.FINE] with metadata about [request].
	void _logRequest(HttpRequest request, String message) =>
	log.fine("BarbackServer ${request.method} ${request.uri}\n$message");

	void _webSocketError(WebSocket socket, String message) {
	socket.add(JSON.encode({"error": message}));
	}
	}

	/// The result of the server handling a URL.
	///
	/// Only requests for which an asset was requested from barback will emit a
	/// result. Malformed requests will be handled internally.
	class BarbackServerResult {
	/// The requested url.
	final Uri url;

	/// The id that [url] identifies.
	final AssetId id;

	/// The error thrown by barback.
	///
	/// If the request was served successfully, this will be null.
	final error;

	/// Whether the request was served successfully.
	bool get isSuccess => error == null;

	/// Whether the request was served unsuccessfully.
	bool get isFailure => !isSuccess;

	BarbackServerResult._success(this.url, this.id)
	: error = null;

	BarbackServerResult._failure(this.url, this.id, this.error);
	}