Simpler API surface, better names, small fixes

CHANGELOG.md

@@ -2,10 +2,12 @@
 
 ## 3.4.0
 
-- Allowing custom type codecs to be registered when creating the `TypeRegistry`.
-- `TypeCodec` interface is used for encoding/decoding value by OIDs.
-  Gets a reference to `TypeCodecContext` which contains `encoding` and runtime parameters.
-- `TypeEncoderFn` value converter for generic Dart -> Postgres object encoders (where type is not specified as parameter).
+**Allowing custom type codecs**:
+
+- `Codec` interface is used for encoding/decoding value by type OIDs or Dart values.
+- `Codec.encode` and `Codec.decode` gets a reference to `CodecContext` which provides
+   access to `encoding`, observed runtime parameters and the `TypeRegistry`.
+- `EncoderFn` value converter for generic Dart object -> Postgres-encoded bytes (for values where type is not specified).
 - `RelationTracker` tracks information about relations (currently limited to `RelationMessage` caching).
 - `RuntimeParameters` to access server-provided parameter status values.
 

lib/postgres.dart

@@ -17,12 +17,18 @@ export 'src/exceptions.dart';
 export 'src/pool/pool_api.dart';
 export 'src/replication.dart';
 export 'src/types.dart';
+export 'src/types/codec.dart'
+    show
+        Codec,
+        CodecContext,
+        EncodedValue,
+        EncoderFn,
+        EncodingFormat,
+        RuntimeParameters;
 export 'src/types/geo_types.dart';
 export 'src/types/range_types.dart';
 export 'src/types/text_search.dart'
     show TsVector, TsWord, TsWordPos, TsWeight, TsQuery;
-export 'src/types/type_codec.dart'
-    show RuntimeParameters, TypeCodec, TypeCodecContext, TypeEncoderFn;
 export 'src/types/type_registry.dart' show TypeRegistry;
 
 /// A description of a SQL query as interpreted by this package.

lib/src/buffer.dart

@@ -1,7 +1,7 @@
 import 'dart:convert';
 
 import 'package:buffer/buffer.dart';
-import 'package:postgres/src/types/type_codec.dart';
+import 'package:postgres/src/types/codec.dart';
 
 /// This class doesn't add much over using `List<int>` instead, however,
 /// it creates a nice explicit type difference from both `String` and `List<int>`,
@@ -43,19 +43,19 @@ class PgByteDataWriter extends ByteDataWriter {
 const _emptyString = '';
 
 class PgByteDataReader extends ByteDataReader {
-  final TypeCodecContext typeCodecContext;
+  final CodecContext codecContext;
 
   PgByteDataReader({
-    required this.typeCodecContext,
+    required this.codecContext,
   });
 
-  Encoding get encoding => typeCodecContext.encoding;
+  Encoding get encoding => codecContext.encoding;
 
   String readNullTerminatedString() {
     final bytes = readUntilTerminatingByte(0);
     if (bytes.isEmpty) {
       return _emptyString;
     }
-    return typeCodecContext.encoding.decode(bytes);
+    return codecContext.encoding.decode(bytes);
   }
 }

lib/src/message_window.dart

@@ -3,7 +3,7 @@ import 'dart:typed_data';
 
 import 'package:buffer/buffer.dart';
 import 'package:charcode/ascii.dart';
-import 'package:postgres/src/types/type_codec.dart';
+import 'package:postgres/src/types/codec.dart';
 
 import 'buffer.dart';
 import 'messages/server_messages.dart';
@@ -35,11 +35,11 @@ Map<int, _ServerMessageFn> _messageTypeMap = {
 };
 
 class MessageFramer {
-  final TypeCodecContext _typeCodecContext;
-  late final _reader = PgByteDataReader(typeCodecContext: _typeCodecContext);
+  final CodecContext _codecContext;
+  late final _reader = PgByteDataReader(codecContext: _codecContext);
   final messageQueue = Queue<ServerMessage>();
 
-  MessageFramer(this._typeCodecContext);
+  MessageFramer(this._codecContext);
 
   int? _type;
   int _expectedLength = 0;
@@ -119,7 +119,7 @@ ServerMessage _parseCopyDataMessage(PgByteDataReader reader, int length) {
     return XLogDataMessage.parse(
       reader.read(length - 1),
       reader.encoding,
-      typeCodecContext: reader.typeCodecContext,
+      codecContext: reader.codecContext,
     );
   } else {
     final bb = BytesBuffer();

lib/src/messages/client_messages.dart

@@ -7,7 +7,7 @@ import '../buffer.dart';
 import '../replication.dart';
 import '../time_converters.dart';
 import '../types.dart';
-import '../types/type_codec.dart';
+import '../types/codec.dart';
 import 'shared_messages.dart';
 
 abstract class ClientMessageFormat {

lib/src/messages/server_messages.dart

@@ -2,7 +2,7 @@ import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:meta/meta.dart';
-import 'package:postgres/src/types/type_codec.dart';
+import 'package:postgres/src/types/codec.dart';
 
 import '../buffer.dart';
 import '../time_converters.dart';
@@ -374,11 +374,11 @@ class XLogDataMessage implements ReplicationMessage, ServerMessage {
   static XLogDataMessage parse(
     Uint8List bytes,
     Encoding encoding, {
-    TypeCodecContext? typeCodecContext,
+    CodecContext? codecContext,
   }) {
     final reader = PgByteDataReader(
-        typeCodecContext: typeCodecContext ??
-            TypeCodecContext.withDefaults(encoding: encoding))
+        codecContext:
+            codecContext ?? CodecContext.withDefaults(encoding: encoding))
       ..add(bytes);
     final walStart = LSN(reader.readUint64());
     final walEnd = LSN(reader.readUint64());

lib/src/types.dart

@@ -430,11 +430,14 @@ class TypedValue<T extends Object> {
   }
 
   @override
-  int get hashCode => Object.hash(type, value);
+  int get hashCode => Object.hash(type, value, isSqlNull);
 
   @override
   bool operator ==(Object other) {
-    return other is TypedValue && other.type == type && other.value == value;
+    return other is TypedValue &&
+        other.type == type &&
+        other.value == value &&
+        other.isSqlNull == isSqlNull;
   }
 
   @override

lib/src/types/binary_codec.dart

@@ -1,13 +1,14 @@
-import 'dart:convert';
+import 'dart:convert' hide Codec;
+import 'dart:convert' as convert;
 import 'dart:typed_data';
 
 import 'package:buffer/buffer.dart';
 
 import '../buffer.dart';
 import '../types.dart';
+import 'codec.dart';
 import 'geo_types.dart';
 import 'range_types.dart';
-import 'type_codec.dart';
 import 'type_registry.dart';
 
 final _bool0 = Uint8List(1)..[0] = 0;
@@ -39,7 +40,7 @@ final _trailingZerosRegExp = RegExp(r'0+$');
 // that doesn't allocate intermediate strings.
 final _jsonUtf8Codec = json.fuse(utf8);
 
-Codec<Object?, List<int>> _jsonFusedEncoding(Encoding encoding) {
+convert.Codec<Object?, List<int>> _jsonFusedEncoding(Encoding encoding) {
   if (encoding == utf8) {
     return _jsonUtf8Codec;
   } else {
@@ -754,8 +755,7 @@ class PostgresBinaryEncoder {
 }
 
 class PostgresBinaryDecoder {
-  static Object? convert(
-      TypeCodecContext context, int typeOid, Uint8List input) {
+  static Object? convert(CodecContext context, int typeOid, Uint8List input) {
     late final buffer =
         ByteData.view(input.buffer, input.offsetInBytes, input.lengthInBytes);
 
@@ -1012,7 +1012,7 @@ class PostgresBinaryDecoder {
     return result;
   }
 
-  static (T?, T?, Bounds)? _decodeRange<T>(TypeCodecContext context,
+  static (T?, T?, Bounds)? _decodeRange<T>(CodecContext context,
       ByteData buffer, Uint8List dinput, int elementTypeOid) {
     final flag = buffer.getInt8(0);
     final bounds = Bounds.fromFlag(flag);
@@ -1040,7 +1040,7 @@ class PostgresBinaryDecoder {
   }
 
   static T _decodeRangeElement<T>(
-      TypeCodecContext context, int elementTypeOid, Uint8List bytes) {
+      CodecContext context, int elementTypeOid, Uint8List bytes) {
     return convert(context, elementTypeOid, bytes) as T;
   }