platform/lib/src/http/server.dart
thosakwe 9683e97603 72!
2017-04-02 15:14:10 -04:00

629 lines
20 KiB
Dart

library angel_framework.http.server;
import 'dart:async';
import 'dart:io';
import 'dart:mirrors';
import 'package:angel_route/angel_route.dart';
export 'package:container/container.dart';
import 'package:flatten/flatten.dart';
import 'package:json_god/json_god.dart' as god;
import 'angel_base.dart';
import 'angel_http_exception.dart';
import 'controller.dart';
import 'fatal_error.dart';
import 'request_context.dart';
import 'response_context.dart';
import 'routable.dart';
import 'service.dart';
final RegExp _straySlashes = new RegExp(r'(^/+)|(/+$)');
/// A function that binds an [Angel] server to an Internet address and port.
typedef Future<HttpServer> ServerGenerator(InternetAddress address, int port);
/// Handles an [AngelHttpException].
typedef Future AngelErrorHandler(
AngelHttpException err, RequestContext req, ResponseContext res);
/// A function that configures an [Angel] server in some way.
typedef Future AngelConfigurer(Angel app);
/// A powerful real-time/REST/MVC server class.
class Angel extends AngelBase {
StreamController<HttpRequest> _afterProcessed =
new StreamController<HttpRequest>.broadcast();
StreamController<HttpRequest> _beforeProcessed =
new StreamController<HttpRequest>.broadcast();
StreamController<AngelFatalError> _fatalErrorStream =
new StreamController<AngelFatalError>.broadcast();
StreamController<Controller> _onController =
new StreamController<Controller>.broadcast();
final List<Angel> _children = [];
Router _flattened;
bool _isProduction;
Angel _parent;
ServerGenerator _serverGenerator = HttpServer.bind;
final Map _injections = {};
final Map<dynamic, InjectionRequest> _preContained = {};
ResponseSerializer _serializer;
/// Determines whether to allow HTTP request method overrides.
bool allowMethodOverrides = true;
/// Fired after a request is processed. Always runs.
Stream<HttpRequest> get afterProcessed => _afterProcessed.stream;
/// Fired before a request is processed. Always runs.
Stream<HttpRequest> get beforeProcessed => _beforeProcessed.stream;
/// All child application mounted on this instance.
List<Angel> get children => new List<Angel>.unmodifiable(_children);
/// Fired on fatal errors.
Stream<AngelFatalError> get fatalErrorStream => _fatalErrorStream.stream;
/// Indicates whether the application is running in a production environment.
///
/// The criteria for this is the `ANGEL_ENV` environment variable being set to
/// `'production'`.
///
/// This value is memoized the first time you call it, so do not change environment
/// configuration at runtime!
bool get isProduction {
if (_isProduction != null)
return _isProduction;
else
return _isProduction = Platform.environment['ANGEL_ENV'] == 'production';
}
/// The function used to bind this instance to an HTTP server.
ServerGenerator get serverGenerator => _serverGenerator;
/// Fired whenever a controller is added to this instance.
///
/// **NOTE**: This is a broadcast stream.
Stream<Controller> get onController => _onController.stream;
/// Returns the parent instance of this application, if any.
Angel get parent => _parent;
/// Plug-ins to be called right before server startup.
///
/// If the server is never started, they will never be called.
final List<AngelConfigurer> justBeforeStart = [];
/// Always run before responses are sent.
///
/// These will only not run if an [AngelFatalError] occurs,
/// or if a response's `willCloseItself` is set to `true`.
final List<RequestHandler> responseFinalizers = [];
/// The handler currently configured to run on [AngelHttpException]s.
AngelErrorHandler errorHandler =
(AngelHttpException e, req, ResponseContext res) {
res.headers[HttpHeaders.CONTENT_TYPE] = ContentType.HTML.toString();
res.statusCode = e.statusCode;
res.write("<!DOCTYPE html><html><head><title>${e.message}</title>");
res.write("</head><body><h1>${e.message}</h1><ul>");
for (String error in e.errors) {
res.write("<li>$error</li>");
}
res.write("</ul></body></html>");
res.end();
};
/// [RequestMiddleware] to be run before all requests.
final List before = [];
/// [RequestMiddleware] to be run after all requests.
final List after = [];
/// The native HttpServer running this instancce.
HttpServer httpServer;
/// Handles a server error.
_onError(e, [StackTrace st]) {
_fatalErrorStream.add(new AngelFatalError(error: e, stack: st));
}
void _printDebug(x) {
if (debug) print(x);
}
/// Starts the server.
///
/// Returns false on failure; otherwise, returns the HttpServer.
Future<HttpServer> startServer([InternetAddress address, int port]) async {
var host = address ?? InternetAddress.LOOPBACK_IP_V4;
this.httpServer = await _serverGenerator(host, port ?? 0);
for (var configurer in justBeforeStart) {
await configure(configurer);
}
optimizeForProduction();
return httpServer..listen(handleRequest);
}
@override
Route addRoute(String method, String path, Object handler,
{List middleware: const []}) {
if (_flattened != null) {
print(
'WARNING: You added a route ($method $path) to the router, after it had been optimized.');
print('This route will be ignored, and no requests will ever reach it.');
}
return super.addRoute(method, path, handler, middleware: middleware ?? []);
}
@override
mount(Pattern path, Router router, {bool hooked: true, String namespace}) {
if (_flattened != null) {
print(
'WARNING: You added mounted a child router ($path) on the router, after it had been optimized.');
print('This route will be ignored, and no requests will ever reach it.');
}
return super
.mount(path, router, hooked: hooked != false, namespace: namespace);
}
/// Loads some base dependencies into the service container.
void bootstrapContainer() {
if (runtimeType != Angel) container.singleton(this, as: Angel);
container.singleton(this, as: AngelBase);
container.singleton(this, as: Routable);
container.singleton(this, as: Router);
container.singleton(this);
}
@override
void dumpTree(
{callback(String tree),
String header: 'Dumping route tree:',
String tab: ' ',
bool showMatchers: false}) {
if (isProduction) {
if (_flattened == null) _flattened = flatten(this);
_flattened.dumpTree(
callback: callback,
header: header?.isNotEmpty == true
? header
: (isProduction
? 'Dumping flattened route tree:'
: 'Dumping route tree:'),
tab: tab ?? ' ',
showMatchers: showMatchers == true);
} else {
super.dumpTree(
callback: callback,
header: header?.isNotEmpty == true
? header
: (isProduction
? 'Dumping flattened route tree:'
: 'Dumping route tree:'),
tab: tab ?? ' ',
showMatchers: showMatchers == true);
}
}
/// Shortcut for adding a middleware to inject a key/value pair on every request.
void inject(key, value) {
_injections[key] = value;
}
/// Shortcut for adding a middleware to inject a serialize on every request.
void injectSerializer(ResponseSerializer serializer) {
_serializer = serializer;
}
/// Runs some [handler]. Returns `true` if request execution should continue.
Future<bool> executeHandler(
handler, RequestContext req, ResponseContext res) async {
if (handler is RequestMiddleware) {
var result = await handler(req, res);
if (result is bool)
return result == true;
else if (result is RequestHandler)
return await executeHandler(result, req, res);
else if (result != null) {
res.serialize(result,
contentType: res.headers[HttpHeaders.CONTENT_TYPE] ??
ContentType.JSON.mimeType);
return false;
} else
return res.isOpen;
}
if (handler is RequestHandler) {
var result = await handler(req, res);
if (result is RequestHandler)
return await executeHandler(result, req, res);
return res.isOpen;
}
if (handler is Future) {
var result = await handler;
if (result is bool)
return result == true;
else if (result is RequestHandler)
return await executeHandler(result, req, res);
else if (result != null) {
res.serialize(result,
contentType: res.headers[HttpHeaders.CONTENT_TYPE] ??
ContentType.JSON.mimeType);
return false;
} else
return true;
}
if (handler is Function) {
var result = await runContained(handler, req, res);
if (result is bool)
return result == true;
else if (result is RequestHandler)
return await executeHandler(result, req, res);
else if (result != null) {
res.serialize(result,
contentType: res.headers[HttpHeaders.CONTENT_TYPE] ??
ContentType.JSON.mimeType);
return false;
} else
return true;
}
if (requestMiddleware.containsKey(handler)) {
return await executeHandler(requestMiddleware[handler], req, res);
}
res.serialize(handler,
contentType:
res.headers[HttpHeaders.CONTENT_TYPE] ?? ContentType.JSON.mimeType);
return false;
}
Future<RequestContext> createRequestContext(HttpRequest request) {
_beforeProcessed.add(request);
return RequestContext.from(request, this).then((req) {
return req..injections.addAll(_injections ?? {});
});
}
Future<ResponseContext> createResponseContext(HttpResponse response) async =>
new ResponseContext(response, this)
..serializer = (_serializer ?? god.serialize);
/// Handles a single request.
Future handleRequest(HttpRequest request) async {
try {
var req = await createRequestContext(request);
var res = await createResponseContext(request.response);
String requestedUrl = request.uri.path.replaceAll(_straySlashes, '');
if (requestedUrl.isEmpty) requestedUrl = '/';
Router r =
isProduction ? (_flattened ?? (_flattened = flatten(this))) : this;
var resolved =
r.resolveAll(requestedUrl, requestedUrl, method: req.method);
for (var result in resolved) req.params.addAll(result.allParams);
if (resolved.isNotEmpty) {
var route = resolved.first.route;
req.inject(Match, route.match(requestedUrl));
}
var m = new MiddlewarePipeline(resolved);
req.inject(MiddlewarePipeline, m);
var pipeline = []..addAll(before)..addAll(m.handlers)..addAll(after);
_printDebug('Handler sequence on $requestedUrl: $pipeline');
for (var handler in pipeline) {
try {
_printDebug('Executing handler: $handler');
var result = await executeHandler(handler, req, res);
_printDebug('Result: $result');
if (!result) {
_printDebug('Last executed handler: $handler');
break;
} else {
_printDebug(
'Handler completed successfully, did not terminate response: $handler');
}
} catch (e, st) {
_printDebug('Caught error in handler $handler: $e');
_printDebug(st);
if (e is AngelHttpException) {
// Special handling for AngelHttpExceptions :)
try {
res.statusCode = e.statusCode;
List<String> accept =
request.headers[HttpHeaders.ACCEPT] ?? ['*/*'];
if (accept.isEmpty ||
accept.contains('*/*') ||
accept.contains(ContentType.JSON.mimeType) ||
accept.contains("application/javascript")) {
res.serialize(e.toMap(),
contentType: res.headers[HttpHeaders.CONTENT_TYPE] ??
ContentType.JSON.mimeType);
} else {
await errorHandler(e, req, res);
}
// _finalizeResponse(request, res);
} catch (e, st) {
_fatalErrorStream.add(
new AngelFatalError(request: request, error: e, stack: st));
}
} else {
_fatalErrorStream.add(
new AngelFatalError(request: request, error: e, stack: st));
}
break;
}
}
try {
await sendResponse(request, req, res);
} catch (e, st) {
_fatalErrorStream
.add(new AngelFatalError(request: request, error: e, stack: st));
}
} catch (e, st) {
_fatalErrorStream
.add(new AngelFatalError(request: request, error: e, stack: st));
}
}
/// Runs several optimizations, *if* [isProduction] is `true`.
///
/// * Preprocesses all dependency injection, and eliminates the burden of reflecting handlers
/// at run-time.
/// * [flatten]s the route tree into a linear one.
void optimizeForProduction() {
if (isProduction == true) {
_add(v) {
if (v is Function && !_preContained.containsKey(v)) {
_preContained[v] = preInject(v);
}
}
void _walk(Router router) {
if (router is Angel) {
router..before.forEach(_add)..after.forEach(_add);
}
router.requestMiddleware.forEach((k, v) => _add(v));
router.middleware.forEach(_add);
router.routes
.where((r) => r is SymlinkRoute)
.map((SymlinkRoute r) => r.router)
.forEach(_walk);
}
if (_flattened == null) _flattened = flatten(this);
_walk(_flattened);
print('Angel is running in production mode.');
}
}
/// Run a function after injecting from service container.
/// If this function has been reflected before, then
/// the execution will be faster, as the injection requirements were stored beforehand.
Future runContained(
Function handler, RequestContext req, ResponseContext res) {
if (_preContained.containsKey(handler)) {
return handleContained(handler, _preContained[handler])(req, res);
}
return runReflected(handler, req, res);
}
/// Runs with DI, and *always* reflects. Prefer [runContained].
Future runReflected(
Function handler, RequestContext req, ResponseContext res) async {
var h =
handleContained(handler, _preContained[handler] = preInject(handler));
return await h(req, res);
// return await closureMirror.apply(args).reflectee;
}
/// Use [sendResponse] instead.
@deprecated
Future sendRequest(
HttpRequest request, RequestContext req, ResponseContext res) =>
sendResponse(request, req, res);
/// Sends a response.
Future sendResponse(
HttpRequest request, RequestContext req, ResponseContext res) async {
_afterProcessed.add(request);
if (!res.willCloseItself) {
res.reopen();
for (var finalizer in responseFinalizers) {
await finalizer(req, res);
}
if (res.isOpen) res.end();
for (var key in res.headers.keys) {
request.response.headers.add(key, res.headers[key]);
}
request.response.headers
..chunkedTransferEncoding = res.chunked ?? true
..set(HttpHeaders.CONTENT_LENGTH, res.buffer.length);
request.response
..statusCode = res.statusCode
..cookies.addAll(res.cookies)
..add(res.buffer.takeBytes());
await request.response.close();
}
}
/// Applies an [AngelConfigurer] to this instance.
Future configure(AngelConfigurer configurer) async {
await configurer(this);
if (configurer is Controller)
_onController.add(controllers[configurer.findExpose().path] = configurer);
}
/// Starts the server, wrapped in a [runZoned] call.
void listen({InternetAddress address, int port: 3000}) {
runZoned(() async {
await startServer(address, port);
}, onError: _onError);
}
/// Mounts the child on this router.
///
/// If the router is an [Angel] instance, all controllers
/// will be copied, as well as services and response finalizers.
///
/// [before] and [after] will be preserved.
///
/// NOTE: The above will not be properly copied if [path] is
/// a [RegExp].
@override
use(Pattern path, Routable routable,
{bool hooked: true, String namespace: null}) {
var head = path.toString().replaceAll(_straySlashes, '');
if (routable is Angel) {
_children.add(routable.._parent = this);
_preContained.addAll(routable._preContained);
if (routable.before.isNotEmpty) {
all(path, (req, res) {
return true;
}, middleware: routable.before);
}
if (routable.after.isNotEmpty) {
all(path, (req, res) {
return true;
}, middleware: routable.after);
}
if (routable.responseFinalizers.isNotEmpty) {
responseFinalizers.add((req, res) async {
if (req.path.replaceAll(_straySlashes, '').startsWith(head)) {
for (var finalizer in routable.responseFinalizers)
await finalizer(req, res);
}
return true;
});
}
routable.controllers.forEach((k, v) {
var tail = k.toString().replaceAll(_straySlashes, '');
controllers['$head/$tail'.replaceAll(_straySlashes, '')] = v;
});
routable.services.forEach((k, v) {
var tail = k.toString().replaceAll(_straySlashes, '');
services['$head/$tail'.replaceAll(_straySlashes, '')] = v;
});
}
if (routable is Service) {
routable.app = this;
}
return super.use(path, routable, hooked: hooked, namespace: namespace);
}
/// Registers a callback to run upon errors.
@deprecated
onError(AngelErrorHandler handler) {
this.errorHandler = handler;
}
/// Default constructor. ;)
Angel({bool debug: false}) : super(debug: debug == true) {
bootstrapContainer();
}
/// An instance mounted on a server started by the [serverGenerator].
factory Angel.custom(ServerGenerator serverGenerator, {bool debug: false}) =>
new Angel(debug: debug == true).._serverGenerator = serverGenerator;
factory Angel.fromSecurityContext(SecurityContext context,
{bool debug: false}) {
var app = new Angel(debug: debug == true);
app._serverGenerator = (InternetAddress address, int port) async {
return await HttpServer.bindSecure(address, port, context);
};
return app;
}
/// Creates an HTTPS server.
///
/// Provide paths to a certificate chain and server key (both .pem).
/// If no password is provided, a random one will be generated upon running
/// the server.
factory Angel.secure(String certificateChainPath, String serverKeyPath,
{bool debug: false, String password}) {
var certificateChain =
Platform.script.resolve(certificateChainPath).toFilePath();
var serverKey = Platform.script.resolve(serverKeyPath).toFilePath();
var serverContext = new SecurityContext();
serverContext.useCertificateChain(certificateChain, password: password);
serverContext.usePrivateKey(serverKey, password: password);
return new Angel.fromSecurityContext(serverContext);
}
}
/// Predetermines what needs to be injected for a handler to run.
InjectionRequest preInject(Function handler) {
var injection = new InjectionRequest();
ClosureMirror closureMirror = reflect(handler);
if (closureMirror.function.parameters.isEmpty) return injection;
// Load parameters
for (var parameter in closureMirror.function.parameters) {
var name = MirrorSystem.getName(parameter.simpleName);
var type = parameter.type.reflectedType;
if (!parameter.isNamed) {
if (parameter.isOptional) injection.optional.add(name);
if (type == RequestContext || type == ResponseContext) {
injection.required.add(type);
} else if (name == 'req') {
injection.required.add(RequestContext);
} else if (name == 'res') {
injection.required.add(ResponseContext);
} else if (type == dynamic) {
injection.required.add(name);
} else {
injection.required.add([name, type]);
}
} else {
injection.named[name] = type;
}
}
return injection;
}