update Codec and RDataCodecs

TBD54566975 · Apr 17, 2024 · 8e8d59e · 8e8d59e
1 parent fc9436b
commit 8e8d59e
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Showing 8 changed files with 402 additions and 415 deletions.
diff --git a/packages/web5/lib/src/dids/did_dht/dns/answer.dart b/packages/web5/lib/src/dids/did_dht/dns/answer.dart
@@ -65,13 +65,13 @@ class Answer<T extends RData> {
 
   Answer._();
 
-  static Codec<Answer> codec = Codec<Answer>(_encode, _decode);
+  static final codec = _AnswerCodec();
 
   /// Decodes a [Answer] from a byte buffer [buf] starting at the given [offset].
   ///
   /// Throws [FormatException] if the buffer data cannot be decoded into a valid DNS answer.
   factory Answer.decode(Uint8List buf, int offset) =>
-      codec.decode(buf, offset: offset).value;
+      codec.decode(buf, offset: offset).value as Answer<T>;
 
   Uint8List encode({Uint8List? buf, int offset = 0}) =>
       codec.encode(this, input: buf, offset: offset).value;
@@ -81,96 +81,100 @@ class Answer<T extends RData> {
   }
 }
 
-Encode<Answer> _encode = (
-  Answer answer, {
-  Uint8List? input,
-  int offset = 0,
-}) {
-  final buf = input ?? Uint8List(answer.encodingLength());
-  final oldOffset = offset;
-
-  final n = RecordName.codec.encode(answer.name, input: buf, offset: offset);
-  offset += n.offset;
-
-  ByteData.view(buf.buffer).setUint16(offset, answer.type.value, Endian.big);
-
-  if (answer.type == RecordType.OPT) {
-    if (answer.name.value != '.') {
-      throw Exception('OPT name must be root.');
+class _AnswerCodec implements Codec<Answer> {
+  @override
+  EncodeResult encode(
+    Answer answer, {
+    Uint8List? input,
+    int offset = 0,
+  }) {
+    final buf = input ?? Uint8List(answer.encodingLength());
+    final oldOffset = offset;
+
+    final n = RecordName.codec.encode(answer.name, input: buf, offset: offset);
+    offset += n.offset;
+
+    ByteData.view(buf.buffer).setUint16(offset, answer.type.value, Endian.big);
+
+    if (answer.type == RecordType.OPT) {
+      if (answer.name.value != '.') {
+        throw Exception('OPT name must be root.');
+      }
+      ByteData.view(buf.buffer)
+          .setUint16(offset, answer.udpPayloadSize!, Endian.big);
+
+      buf[offset + 4] = answer.extendedRcode!;
+      buf[offset + 5] = answer.ednsVersion!;
+
+      ByteData.view(buf.buffer)
+          .setUint16(offset + 6, answer.flags ?? 0, Endian.big);
+
+      offset += 8;
+      // TODO: need OptDataCodec here
+      offset += answer.options.encode(buf, offset) as int;
+    } else {
+      final klassValue = answer.flush ? FLUSH_MASK : answer.klass.value;
+      ByteData.view(buf.buffer).setUint16(offset + 2, klassValue, Endian.big);
+
+      ByteData.view(buf.buffer).setUint32(offset + 4, answer.ttl, Endian.big);
+
+      offset += 8;
+
+      final result = RDataCodecs.encode(
+        answer.type,
+        answer.data,
+        input: buf,
+        offset: offset,
+      );
+      offset += result.offset;
     }
-    ByteData.view(buf.buffer)
-        .setUint16(offset, answer.udpPayloadSize!, Endian.big);
-
-    buf[offset + 4] = answer.extendedRcode!;
-    buf[offset + 5] = answer.ednsVersion!;
-
-    ByteData.view(buf.buffer)
-        .setUint16(offset + 6, answer.flags ?? 0, Endian.big);
-
-    offset += 8;
-    // TODO: need OptDataCodec here
-    offset += answer.options.encode(buf, offset) as int;
-  } else {
-    final klassValue = answer.flush ? FLUSH_MASK : answer.klass.value;
-    ByteData.view(buf.buffer).setUint16(offset + 2, klassValue, Endian.big);
-
-    ByteData.view(buf.buffer).setUint32(offset + 4, answer.ttl, Endian.big);
 
-    offset += 8;
-
-    final result = RdataCodecs.encode(
-      answer.type,
-      answer.data,
-      input: buf,
-      offset: offset,
-    );
-    offset += result.offset;
+    return EncodeResult(buf, offset - oldOffset);
   }
 
-  return EncodeResult(buf, offset - oldOffset);
-};
+  @override
+  DecodeResult<Answer> decode(Uint8List buf, {int offset = 0}) {
+    final originalOffset = offset;
 
-Decode _decode = (Uint8List buf, {int offset = 0}) {
-  final originalOffset = offset;
+    final nameResult = RecordName.codec.decode(buf, offset: offset);
+    offset += nameResult.offset;
 
-  final nameResult = RecordName.codec.decode(buf, offset: offset);
-  offset += nameResult.offset;
+    final byteData = ByteData.sublistView(buf);
 
-  final byteData = ByteData.sublistView(buf);
+    final rawType = byteData.getUint16(offset, Endian.big);
+    final type = RecordType.fromValue(rawType);
+    offset += 2;
 
-  final rawType = byteData.getUint16(offset, Endian.big);
-  final type = RecordType.fromValue(rawType);
-  offset += 2;
+    final answer = Answer._();
+    answer.name = nameResult.value;
+    answer.type = type;
 
-  final answer = Answer._();
-  answer.name = nameResult.value;
-  answer.type = type;
+    if (type == RecordType.OPT) {
+      answer.udpPayloadSize = byteData.getUint16(offset + 2, Endian.big);
+      answer.extendedRcode = byteData.getUint8(offset + 4);
+      answer.ednsVersion = byteData.getUint8(offset + 5);
 
-  if (type == RecordType.OPT) {
-    answer.udpPayloadSize = byteData.getUint16(offset + 2, Endian.big);
-    answer.extendedRcode = byteData.getUint8(offset + 4);
-    answer.ednsVersion = byteData.getUint8(offset + 5);
+      answer.flags = byteData.getUint16(offset + 6, Endian.big);
+      answer.flagDo = (answer.flags! >> 15) & 0x1 == 1;
 
-    answer.flags = byteData.getUint16(offset + 6, Endian.big);
-    answer.flagDo = (answer.flags! >> 15) & 0x1 == 1;
+      answer.options = OptionData.decode(buf, offset + 8);
 
-    answer.options = OptionData.decode(buf, offset + 8);
+      offset += (8 + answer.options.numBytes).toInt();
+    } else {
+      final rawDnsClass = byteData.getUint16(offset, Endian.big);
+      answer.klass = RecordClass.fromValue(rawDnsClass & NOT_FLUSH_MASK);
 
-    offset += (8 + answer.options.numBytes).toInt();
-  } else {
-    final rawDnsClass = byteData.getUint16(offset, Endian.big);
-    answer.klass = RecordClass.fromValue(rawDnsClass & NOT_FLUSH_MASK);
+      answer.flush = (rawDnsClass & FLUSH_MASK) != 0;
+      offset += 2;
 
-    answer.flush = (rawDnsClass & FLUSH_MASK) != 0;
-    offset += 2;
+      answer.ttl = byteData.getUint32(offset, Endian.big);
+      offset += 4;
 
-    answer.ttl = byteData.getUint32(offset, Endian.big);
-    offset += 4;
+      final result = RDataCodecs.decode(type, buf, offset: offset);
+      answer.data = result.value;
+      offset += result.offset;
+    }
 
-    final result = RdataCodecs.decode(type, buf);
-    answer.data = result.value;
-    offset += result.offset;
+    return DecodeResult(answer, offset - originalOffset);
   }
-
-  return DecodeResult(answer, offset - originalOffset);
-};
+}
diff --git a/packages/web5/lib/src/dids/did_dht/dns/codec.dart b/packages/web5/lib/src/dids/did_dht/dns/codec.dart
@@ -1,6 +1,9 @@
 import 'dart:typed_data';
 
-import 'package:web5/src/dids/did_dht/dns/record_type.dart';
+abstract interface class Codec<T> {
+  EncodeResult encode(T value, {Uint8List? input, int offset});
+  DecodeResult<T> decode(Uint8List buf, {int offset});
+}
 
 class EncodeResult {
   final Uint8List value;
@@ -15,18 +18,3 @@ class DecodeResult<T> {
 
   DecodeResult(this.value, this.offset);
 }
-
-typedef Decode = DecodeResult<dynamic> Function(Uint8List buf, {int offset});
-typedef Encode<T> = EncodeResult Function(
-  T value, {
-  Uint8List? input,
-  int offset,
-});
-
-class Codec<T> {
-  Encode<T> encode;
-  Decode decode;
-  RecordType? type;
-
-  Codec(this.encode, this.decode, {this.type});
-}
diff --git a/packages/web5/lib/src/dids/did_dht/dns/header.dart b/packages/web5/lib/src/dids/did_dht/dns/header.dart
@@ -75,7 +75,7 @@ class Header {
     required this.arcount,
   });
 
-  static Codec<Header> codec = Codec<Header>(_encode, _decode);
+  static final codec = _HeaderCodec();
 
   factory Header.decode(Uint8List buf, {int offset = 0}) =>
       codec.decode(buf, offset: offset).value;
@@ -86,65 +86,65 @@ class Header {
   int encodingLength() => numBytes;
 }
 
-Encode<Header> _encode = (
-  Header header, {
-  Uint8List? input,
-  int offset = 0,
-}) {
-  final buf = input ?? Uint8List(12);
-  final byteData = ByteData.sublistView(buf);
-
-  byteData.setUint16(offset, header.id, Endian.big);
-  offset += 2;
-
-  final flags = (header.qr ? 1 : 0) << 15 |
-      (header.opcode.value & 0xF) << 11 |
-      (header.aa ?? false ? 1 : 0) << 10 |
-      (header.tc ? 1 : 0) << 9 |
-      (header.rd ? 1 : 0) << 8 |
-      (header.ra ?? false ? 1 : 0) << 7 |
-      (header.z ? 1 : 0) << 6 |
-      (header.ad ?? false ? 1 : 0) << 5 |
-      (header.cd ?? false ? 1 : 0) << 4 |
-      (header.rcode?.value ?? 0) & 0xF;
-
-  byteData.setUint16(offset, flags, Endian.big);
-  offset += 2;
-
-  byteData.setUint16(offset, header.qdcount, Endian.big);
-  offset += 2;
-  byteData.setUint16(offset, header.ancount, Endian.big);
-  offset += 2;
-  byteData.setUint16(offset, header.nscount, Endian.big);
-  offset += 2;
-  byteData.setUint16(offset, header.arcount, Endian.big);
-
-  return EncodeResult(buf, 12);
-};
-
-Decode _decode = (Uint8List buf, {int offset = 0}) {
-  if (buf.length < 12) throw Exception('Header must be 12 bytes');
-
-  final byteData = ByteData.sublistView(buf);
-  final flags = byteData.getUint16(offset + 2, Endian.big);
-
-  final header = Header(
-    id: byteData.getUint16(offset, Endian.big),
-    qr: (flags >> 15) & 0x1 == 1,
-    opcode: OpCode.fromValue((flags >> 11) & 0xf),
-    aa: (flags >> 10) & 0x1 == 1,
-    tc: (flags >> 9) & 0x1 == 1,
-    rd: (flags >> 8) & 0x1 == 1,
-    ra: (flags >> 7) & 0x1 == 1,
-    z: (flags >> 6) & 0x1 == 1,
-    ad: (flags >> 5) & 0x1 == 1,
-    cd: (flags >> 4) & 0x1 == 1,
-    rcode: RCode.fromValue(flags & 0xf),
-    qdcount: byteData.getUint16(offset + 4, Endian.big),
-    ancount: byteData.getUint16(offset + 6, Endian.big),
-    nscount: byteData.getUint16(offset + 8, Endian.big),
-    arcount: byteData.getUint16(offset + 10, Endian.big),
-  );
-
-  return DecodeResult(header, 12);
-};
+class _HeaderCodec implements Codec<Header> {
+  @override
+  EncodeResult encode(Header header, {Uint8List? input, int offset = 0}) {
+    final buf = input ?? Uint8List(12);
+    final byteData = ByteData.sublistView(buf);
+
+    byteData.setUint16(offset, header.id, Endian.big);
+    offset += 2;
+
+    final flags = (header.qr ? 1 : 0) << 15 |
+        (header.opcode.value & 0xF) << 11 |
+        (header.aa ?? false ? 1 : 0) << 10 |
+        (header.tc ? 1 : 0) << 9 |
+        (header.rd ? 1 : 0) << 8 |
+        (header.ra ?? false ? 1 : 0) << 7 |
+        (header.z ? 1 : 0) << 6 |
+        (header.ad ?? false ? 1 : 0) << 5 |
+        (header.cd ?? false ? 1 : 0) << 4 |
+        (header.rcode?.value ?? 0) & 0xF;
+
+    byteData.setUint16(offset, flags, Endian.big);
+    offset += 2;
+
+    byteData.setUint16(offset, header.qdcount, Endian.big);
+    offset += 2;
+    byteData.setUint16(offset, header.ancount, Endian.big);
+    offset += 2;
+    byteData.setUint16(offset, header.nscount, Endian.big);
+    offset += 2;
+    byteData.setUint16(offset, header.arcount, Endian.big);
+
+    return EncodeResult(buf, 12);
+  }
+
+  @override
+  DecodeResult<Header> decode(Uint8List buf, {int offset = 0}) {
+    if (buf.length < 12) throw Exception('Header must be 12 bytes');
+
+    final byteData = ByteData.sublistView(buf);
+    final flags = byteData.getUint16(offset + 2, Endian.big);
+
+    final header = Header(
+      id: byteData.getUint16(offset, Endian.big),
+      qr: (flags >> 15) & 0x1 == 1,
+      opcode: OpCode.fromValue((flags >> 11) & 0xf),
+      aa: (flags >> 10) & 0x1 == 1,
+      tc: (flags >> 9) & 0x1 == 1,
+      rd: (flags >> 8) & 0x1 == 1,
+      ra: (flags >> 7) & 0x1 == 1,
+      z: (flags >> 6) & 0x1 == 1,
+      ad: (flags >> 5) & 0x1 == 1,
+      cd: (flags >> 4) & 0x1 == 1,
+      rcode: RCode.fromValue(flags & 0xf),
+      qdcount: byteData.getUint16(offset + 4, Endian.big),
+      ancount: byteData.getUint16(offset + 6, Endian.big),
+      nscount: byteData.getUint16(offset + 8, Endian.big),
+      arcount: byteData.getUint16(offset + 10, Endian.big),
+    );
+
+    return DecodeResult(header, 12);
+  }
+}