platform/lib/src/core/driver.dart
2018-11-07 23:11:10 -05:00

357 lines
12 KiB
Dart

import 'dart:async';
import 'dart:convert';
import 'dart:io' show stderr, Cookie;
import 'package:angel_http_exception/angel_http_exception.dart';
import 'package:angel_route/angel_route.dart';
import 'package:combinator/combinator.dart';
import 'package:stack_trace/stack_trace.dart';
import 'package:tuple/tuple.dart';
import 'core.dart';
/// Base driver class for Angel implementations.
///
/// Powers both AngelHttp and AngelHttp2.
abstract class Driver<
Request,
Response,
Server extends Stream<Request>,
RequestContextType extends RequestContext,
ResponseContextType extends ResponseContext> {
final Angel app;
final bool useZone;
bool _closed = false;
Server _server;
StreamSubscription<Request> _sub;
/// The function used to bind this instance to a server..
final Future<Server> Function(dynamic, int) serverGenerator;
Driver(this.app, this.serverGenerator, {this.useZone: true});
/// The path at which this server is listening for requests.
Uri get uri;
/// The native server running this instance.
Server get server => _server;
/// Starts, and returns the server.
Future<Server> startServer([address, int port]) {
var host = address ?? '127.0.0.1';
return serverGenerator(host, port ?? 0).then((server) {
_server = server;
return Future.wait(app.startupHooks.map(app.configure)).then((_) {
app.optimizeForProduction();
_sub = server.listen((request) =>
handleRawRequest(request, createResponseFromRawRequest(request)));
return _server;
});
});
}
/// Shuts down the underlying server.
Future<Server> close() {
if (_closed) return new Future.value(_server);
_closed = true;
_sub?.cancel();
return app.close().then((_) =>
Future.wait(app.shutdownHooks.map(app.configure)).then((_) => _server));
}
Future<RequestContextType> createRequestContext(
Request request, Response response);
Future<ResponseContextType> createResponseContext(
Request request, Response response,
[RequestContextType correspondingRequest]);
void setHeader(Response response, String key, String value);
void setContentLength(Response response, int length);
void setChunkedEncoding(Response response, bool value);
void setStatusCode(Response response, int value);
void addCookies(Response response, Iterable<Cookie> cookies);
void writeStringToResponse(Response response, String value);
void writeToResponse(Response response, List<int> data);
Uri getUriFromRequest(Request request);
Future closeResponse(Response response);
Response createResponseFromRawRequest(Request request);
/// Handles a single request.
Future handleRawRequest(Request request, Response response) {
return createRequestContext(request, response).then((req) {
return createResponseContext(request, response, req).then((res) {
handle() {
var path = req.path;
if (path == '/') path = '';
Tuple3<List, Map<String, dynamic>, ParseResult<Map<String, dynamic>>>
resolveTuple() {
Router r = app.optimizedRouter;
var resolved =
r.resolveAbsolute(path, method: req.method, strip: false);
return new Tuple3(
new MiddlewarePipeline(resolved).handlers,
resolved.fold<Map<String, dynamic>>(
<String, dynamic>{}, (out, r) => out..addAll(r.allParams)),
resolved.isEmpty ? null : resolved.first.parseResult,
);
}
var cacheKey = req.method + path;
var tuple = app.isProduction
? app.handlerCache.putIfAbsent(cacheKey, resolveTuple)
: resolveTuple();
req.params.addAll(tuple.item2);
req.container.registerSingleton<ParseResult<Map<String, dynamic>>>(
tuple.item3);
req.container.registerSingleton<ParseResult>(tuple.item3);
if (!app.isProduction && app.logger != null) {
req.container
.registerSingleton<Stopwatch>(new Stopwatch()..start());
}
var pipeline = tuple.item1;
Future Function() runPipeline;
for (var handler in pipeline) {
if (handler == null) break;
if (runPipeline == null)
runPipeline = () =>
Future.sync(() => app.executeHandler(handler, req, res));
else {
var current = runPipeline;
runPipeline = () => current().then((result) => !res.isOpen
? new Future.value(result)
: app.executeHandler(handler, req, res));
}
}
return runPipeline == null
? sendResponse(request, response, req, res)
: runPipeline()
.then((_) => sendResponse(request, response, req, res));
}
if (useZone == false) {
Future f;
try {
f = handle();
} catch (e, st) {
f = Future.error(e, st);
}
return f.catchError((e, StackTrace st) {
if (e is FormatException)
throw new AngelHttpException.badRequest(message: e.message)
..stackTrace = st;
throw new AngelHttpException(e,
stackTrace: st,
statusCode: 500,
message: e?.toString() ?? '500 Internal Server Error');
}, test: (e) => e is! AngelHttpException).catchError(
(ee, StackTrace st) {
var e = ee as AngelHttpException;
if (app.logger != null) {
var error = e.error ?? e;
var trace =
new Trace.from(e.stackTrace ?? StackTrace.current).terse;
app.logger.severe(e.message ?? e.toString(), error, trace);
}
return handleAngelHttpException(
e, e.stackTrace ?? st, req, res, request, response);
});
} else {
var zoneSpec = new ZoneSpecification(
print: (self, parent, zone, line) {
if (app.logger != null)
app.logger.info(line);
else
parent.print(zone, line);
},
handleUncaughtError: (self, parent, zone, error, stackTrace) {
var trace =
new Trace.from(stackTrace ?? StackTrace.current).terse;
return new Future(() {
AngelHttpException e;
if (error is FormatException) {
e = new AngelHttpException.badRequest(message: error.message);
} else if (error is AngelHttpException) {
e = error;
} else {
e = new AngelHttpException(error,
stackTrace: stackTrace,
message:
error?.toString() ?? '500 Internal Server Error');
}
if (app.logger != null) {
app.logger.severe(e.message ?? e.toString(), error, trace);
}
return handleAngelHttpException(
e, trace, req, res, request, response);
}).catchError((e, StackTrace st) {
var trace = new Trace.from(st ?? StackTrace.current).terse;
var uri = getUriFromRequest(request);
closeResponse(response);
// Ideally, we won't be in a position where an absolutely fatal error occurs,
// but if so, we'll need to log it.
if (app.logger != null) {
app.logger.severe(
'Fatal error occurred when processing $uri.', e, trace);
} else {
stderr
..writeln('Fatal error occurred when processing '
'$uri:')
..writeln(e)
..writeln(trace);
}
});
},
);
var zone = Zone.current.fork(specification: zoneSpec);
req.container.registerSingleton<Zone>(zone);
req.container.registerSingleton<ZoneSpecification>(zoneSpec);
// If a synchronous error is thrown, it's not caught by `zone.run`,
// so use a try/catch, and recover when need be.
try {
return zone.run(handle);
} catch (e, st) {
zone.handleUncaughtError(e, st);
return Future.value();
}
}
});
});
}
/// Handles an [AngelHttpException].
Future handleAngelHttpException(
AngelHttpException e,
StackTrace st,
RequestContext req,
ResponseContext res,
Request request,
Response response,
{bool ignoreFinalizers: false}) {
if (req == null || res == null) {
try {
app.logger?.severe(e, st);
setStatusCode(response, 500);
writeStringToResponse(response, '500 Internal Server Error');
closeResponse(response);
} finally {
return null;
}
}
Future handleError;
if (!res.isOpen)
handleError = new Future.value();
else {
res.statusCode = e.statusCode;
handleError =
new Future.sync(() => app.errorHandler(e, req, res)).then((result) {
return app.executeHandler(result, req, res).then((_) => res.close());
});
}
return handleError.then((_) => sendResponse(request, response, req, res,
ignoreFinalizers: ignoreFinalizers == true));
}
/// Sends a response.
Future sendResponse(Request request, Response response, RequestContext req,
ResponseContext res,
{bool ignoreFinalizers: false}) {
void _cleanup(_) {
if (!app.isProduction && app.logger != null) {
var sw = req.container.make<Stopwatch>();
app.logger.info(
"${res.statusCode} ${req.method} ${req.uri} (${sw?.elapsedMilliseconds ?? 'unknown'} ms)");
}
}
if (!res.isBuffered) return res.close().then(_cleanup);
Future finalizers = ignoreFinalizers == true
? new Future.value()
: app.responseFinalizers.fold<Future>(
new Future.value(), (out, f) => out.then((_) => f(req, res)));
return finalizers.then((_) {
if (res.isOpen) res.close();
for (var key in res.headers.keys) {
setHeader(response, key, res.headers[key]);
}
setContentLength(response, res.buffer.length);
setChunkedEncoding(response, res.chunked ?? true);
List<int> outputBuffer = res.buffer.toBytes();
if (res.encoders.isNotEmpty) {
var allowedEncodings = req.headers
.value('accept-encoding')
?.split(',')
?.map((s) => s.trim())
?.where((s) => s.isNotEmpty)
?.map((str) {
// Ignore quality specifications in accept-encoding
// ex. gzip;q=0.8
if (!str.contains(';')) return str;
return str.split(';')[0];
});
if (allowedEncodings != null) {
for (var encodingName in allowedEncodings) {
Converter<List<int>, List<int>> encoder;
String key = encodingName;
if (res.encoders.containsKey(encodingName))
encoder = res.encoders[encodingName];
else if (encodingName == '*') {
encoder = res.encoders[key = res.encoders.keys.first];
}
if (encoder != null) {
setHeader(response, 'content-encoding', key);
outputBuffer = res.encoders[key].convert(outputBuffer);
setContentLength(response, outputBuffer.length);
break;
}
}
}
}
setStatusCode(response, res.statusCode);
addCookies(response, res.cookies);
writeToResponse(response, outputBuffer);
return closeResponse(response).then(_cleanup);
});
}
}