Hostname syntax parser

CHANGELOG.md

@@ -1,5 +1,6 @@
 # 2.0.5
-* Add `allowHttp1` to `AngelHttp2` constructors.
+* Add `allowHttp1` to `AngelHttp2` constructors. https://github.com/angel-dart/angel/issues/108
+* 
 
 # 2.0.4
 * Prepare for Dart SDK change to `Stream<List<int>>` that are now

lib/src/core/hostname_parser.dart

@@ -0,0 +1,64 @@
+import 'dart:collection';
+import 'package:string_scanner/string_scanner.dart';
+
+/// Parses a string into a [RegExp] that is matched against hostnames.
+class HostnameSyntaxParser {
+  final SpanScanner _scanner;
+  var _safe = RegExp(r"[0-9a-zA-Z-_]+");
+
+  HostnameSyntaxParser(String hostname) : _scanner = SpanScanner(hostname);
+
+  RegExp parse() {
+    var b = StringBuffer();
+    var parts = Queue<String>();
+
+    while (!_scanner.isDone) {
+      if (_scanner.scan('|')) {
+        if (parts.isEmpty) {
+          throw FormatException(
+              '${_scanner.emptySpan.end.toolString}: No hostname parts found before "|".');
+        } else {
+          var next = _parseHostnamePart();
+          if (next == null) {
+            throw FormatException(
+                '${_scanner.emptySpan.end.toolString}: No hostname parts found after "|".');
+          } else {
+            var prev = parts.removeLast();
+            parts.addLast('(($prev)|($next))');
+          }
+        }
+      } else {
+        var part = _parseHostnamePart();
+        if (part != null) {
+          parts.add(part);
+        }
+      }
+    }
+
+    while (parts.isNotEmpty) {
+      b.write(parts.removeFirst());
+    }
+
+    if (b.isEmpty) {
+      throw FormatException('Invalid or empty hostname.');
+    } else {
+      return RegExp(b.toString(), caseSensitive: false);
+    }
+  }
+
+  String _parseHostnamePart() {
+    if (_scanner.scan('*.')) {
+      return r'([^$]+\.)?';
+    } else if (_scanner.scan('*')) {
+      return r'[^$]*';
+    } else if (_scanner.scan(_safe)) {
+      return _scanner.lastMatch[0];
+    } else if (!_scanner.isDone) {
+      var s = String.fromCharCode(_scanner.peekChar());
+      throw FormatException(
+          '${_scanner.emptySpan.end.toolString}: Unexpected character "$s".');
+    } else {
+      return null;
+    }
+  }
+}

lib/src/core/hostname_router.dart

@@ -0,0 +1,5 @@
+import 'dart:async';
+import 'package:string_scanner/string_scanner.dart';
+import 'request_context.dart';
+import 'response_context.dart';
+import 'server.dart';