Refactor ParameterValue's buffer handling. (#134)

isoos · Sep 24, 2023 · ae390ab · ae390ab
1 parent e0c0346
commit ae390ab
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Showing 3 changed files with 45 additions and 59 deletions.
diff --git a/lib/src/client_messages.dart b/lib/src/client_messages.dart
@@ -180,42 +180,33 @@ class BindMessage extends ClientMessage {
   final List<ParameterValue> _parameters;
   final String _portalName;
   final String _statementName;
-  final int _typeSpecCount;
 
   BindMessage(this._parameters,
       {String portalName = '', String statementName = ''})
-      : _typeSpecCount = _parameters.where((p) => p.isBinary).length,
-        _portalName = portalName,
+      : _portalName = portalName,
         _statementName = statementName;
 
-  int _length(EncodedString statementName, EncodedString portalName) {
-    var length = 0;
+  @override
+  void applyToBuffer(PgByteDataWriter buffer) {
+    buffer.writeUint8(ClientMessage.BindIdentifier);
+    final portalName = buffer.prepareString(_portalName);
+    final statementName = buffer.prepareString(_statementName);
+
+    final parameterBytes = _parameters.map((p) => p.encodeAsBytes()).toList();
+    final typeSpecCount = _parameters.where((p) => p.hasKnownType).length;
     var inputParameterElementCount = _parameters.length;
-    if (_typeSpecCount == _parameters.length || _typeSpecCount == 0) {
+    if (typeSpecCount == _parameters.length || typeSpecCount == 0) {
       inputParameterElementCount = 1;
     }
 
-    length = 15;
+    var length = 14;
     length += statementName.bytesLength;
     length += portalName.bytesLength;
     length += inputParameterElementCount * 2;
-    length += _parameters.fold<int>(0, (len, ParameterValue paramValue) {
-      if (paramValue.bytes == null) {
-        return len + 4;
-      } else {
-        return len + 4 + paramValue.length;
-      }
-    });
-    return length;
-  }
-
-  @override
-  void applyToBuffer(PgByteDataWriter buffer) {
-    buffer.writeUint8(ClientMessage.BindIdentifier);
-    final portalName = buffer.prepareString(_portalName);
-    final statementName = buffer.prepareString(_statementName);
+    length += parameterBytes.fold<int>(
+        0, (len, bytes) => len + 4 + (bytes?.length ?? 0));
 
-    buffer.writeUint32(_length(statementName, portalName) - 1);
+    buffer.writeUint32(length);
 
     // Name of portal.
     buffer.writeEncodedString(portalName);
@@ -224,31 +215,32 @@ class BindMessage extends ClientMessage {
 
     // OK, if we have no specified types at all, we can use 0. If we have all specified types, we can use 1. If we have a mix, we have to individually
     // call out each type.
-    if (_typeSpecCount == _parameters.length) {
+    if (typeSpecCount == _parameters.length) {
       buffer.writeUint16(1);
       // Apply following format code for all parameters by indicating 1
       buffer.writeUint16(ClientMessage.FormatBinary);
-    } else if (_typeSpecCount == 0) {
+    } else if (typeSpecCount == 0) {
       buffer.writeUint16(1);
       // Apply following format code for all parameters by indicating 1
       buffer.writeUint16(ClientMessage.FormatText);
     } else {
       // Well, we have some text and some binary, so we have to be explicit about each one
       buffer.writeUint16(_parameters.length);
       for (final p in _parameters) {
-        buffer.writeUint16(
-            p.isBinary ? ClientMessage.FormatBinary : ClientMessage.FormatText);
+        buffer.writeUint16(p.hasKnownType
+            ? ClientMessage.FormatBinary
+            : ClientMessage.FormatText);
       }
     }
 
     // This must be the number of $n's in the query.
     buffer.writeUint16(_parameters.length);
-    for (final p in _parameters) {
-      if (p.bytes == null) {
+    for (final bytes in parameterBytes) {
+      if (bytes == null) {
         buffer.writeInt32(-1);
       } else {
-        buffer.writeInt32(p.length);
-        buffer.write(p.bytes!);
+        buffer.writeInt32(bytes.length);
+        buffer.write(bytes);
       }
     }
 

diff --git a/lib/src/query.dart b/lib/src/query.dart
@@ -4,6 +4,7 @@ import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:buffer/buffer.dart';
+import 'package:postgres/src/v3/types.dart';
 
 import 'binary_codec.dart';
 import 'client_messages.dart';
@@ -83,7 +84,7 @@ class Query<T> {
         formatIdentifiers.map((i) => i.type).toList();
 
     final parameterList = formatIdentifiers
-        .map((id) => ParameterValue(id, substitutionValues))
+        .map((id) => ParameterValue.resolve(id, substitutionValues))
         .toList();
 
     final messages = [
@@ -105,7 +106,8 @@ class Query<T> {
       Map<String, dynamic>? substitutionValues) {
     final statementName = cacheQuery.preparedStatementName;
     final parameterList = cacheQuery.orderedParameters!
-        .map((identifier) => ParameterValue(identifier, substitutionValues))
+        .map((identifier) =>
+            ParameterValue.resolve(identifier, substitutionValues))
         .toList();
 
     final bytes = ClientMessage.aggregateBytes([
@@ -217,38 +219,30 @@ class CachedQuery {
 }
 
 class ParameterValue {
-  factory ParameterValue(PostgreSQLFormatIdentifier identifier,
-      Map<String, dynamic>? substitutionValues) {
-    if (identifier.type == null) {
-      return ParameterValue.text(substitutionValues?[identifier.name]);
-    }
+  final PgDataType<Object>? _type;
+  final Object? _value;
+  ParameterValue(this._type, this._value);
 
-    return ParameterValue.binary(
-        substitutionValues?[identifier.name], identifier.type!);
+  factory ParameterValue.resolve(PostgreSQLFormatIdentifier identifier,
+      Map<String, dynamic>? substitutionValues) {
+    final value = substitutionValues?[identifier.name];
+    final type = identifier.type;
+    return ParameterValue(type, value);
   }
 
-  factory ParameterValue.binary(
-      dynamic value, PostgreSQLDataType postgresType) {
-    final bytes = postgresType.binaryCodec.encoder.convert(value);
-    return ParameterValue._(true, bytes, bytes?.length ?? 0);
-  }
+  bool get hasKnownType => _type != null;
 
-  factory ParameterValue.text(dynamic value) {
-    Uint8List? bytes;
-    if (value != null) {
+  Uint8List? encodeAsBytes() {
+    if (_type != null) {
+      return _type!.binaryCodec.encoder.convert(_value);
+    }
+    if (_value != null) {
       const converter = PostgresTextEncoder();
-      bytes = castBytes(
-          utf8.encode(converter.convert(value, escapeStrings: false)));
+      return castBytes(
+          utf8.encode(converter.convert(_value, escapeStrings: false)));
     }
-    final length = bytes?.length ?? 0;
-    return ParameterValue._(false, bytes, length);
+    return null;
   }
-
-  ParameterValue._(this.isBinary, this.bytes, this.length);
-
-  final bool isBinary;
-  final Uint8List? bytes;
-  final int length;
 }
 
 class FieldDescription implements ColumnDescription {

diff --git a/lib/src/v3/connection.dart b/lib/src/v3/connection.dart
@@ -478,7 +478,7 @@ class _PgResultStreamSubscription
         BindMessage(
           [
             for (final parameter in statement.parameters)
-              ParameterValue.binary(parameter.value, parameter.type)
+              ParameterValue(parameter.type, parameter.value)
           ],
           portalName: _portalName,
           statementName: statement.statement._name,