Micro optimizations for serialization

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Value/Int16Converter.cs

@@ -14,7 +14,8 @@ public override short Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSe
 
         public override void Write(Utf8JsonWriter writer, short value, JsonSerializerOptions options)
         {
-            writer.WriteNumberValue(value);
+            // For performance, lift up the writer implementation.
+            writer.WriteNumberValue((long)value);
         }
 
         internal override short ReadWithQuotes(ref Utf8JsonReader reader)

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Value/Int32Converter.cs

@@ -12,7 +12,8 @@ public override int Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSeri
 
         public override void Write(Utf8JsonWriter writer, int value, JsonSerializerOptions options)
         {
-            writer.WriteNumberValue(value);
+            // For performance, lift up the writer implementation.
+            writer.WriteNumberValue((long)value);
         }
 
         internal override int ReadWithQuotes(ref Utf8JsonReader reader)

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Value/StringConverter.cs

@@ -14,7 +14,15 @@ internal sealed class StringConverter : JsonConverter<string>
 
         public override void Write(Utf8JsonWriter writer, string? value, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(value);
+            // For performance, lift up the writer implementation.
+            if (value == null)
+            {
+                writer.WriteNullValue();
+            }
+            else
+            {
+                writer.WriteStringValue(value.AsSpan());
+            }
         }
 
         internal override string ReadWithQuotes(ref Utf8JsonReader reader)

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Value/UInt16Converter.cs

@@ -12,7 +12,8 @@ public override ushort Read(ref Utf8JsonReader reader, Type typeToConvert, JsonS
 
         public override void Write(Utf8JsonWriter writer, ushort value, JsonSerializerOptions options)
         {
-            writer.WriteNumberValue(value);
+            // For performance, lift up the writer implementation.
+            writer.WriteNumberValue((long)value);
         }
 
         internal override ushort ReadWithQuotes(ref Utf8JsonReader reader)

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Value/UInt32Converter.cs

@@ -12,7 +12,8 @@ public override uint Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSer
 
         public override void Write(Utf8JsonWriter writer, uint value, JsonSerializerOptions options)
         {
-            writer.WriteNumberValue(value);
+            // For performance, lift up the writer implementation.
+            writer.WriteNumberValue((ulong)value);
         }
 
         internal override uint ReadWithQuotes(ref Utf8JsonReader reader)

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteProperties.Bytes.cs

@@ -18,10 +18,8 @@ public sealed partial class Utf8JsonWriter
         /// Thrown if this would result in invalid JSON being written (while validation is enabled).
         /// </exception>
         public void WriteBase64String(JsonEncodedText propertyName, ReadOnlySpan<byte> bytes)
-            => WriteBase64StringHelper(propertyName.EncodedUtf8Bytes, bytes);
-
-        private void WriteBase64StringHelper(ReadOnlySpan<byte> utf8PropertyName, ReadOnlySpan<byte> bytes)
         {
+            ReadOnlySpan<byte> utf8PropertyName = propertyName.EncodedUtf8Bytes;
             Debug.Assert(utf8PropertyName.Length <= JsonConstants.MaxUnescapedTokenSize);
 
             JsonWriterHelper.ValidateBytes(bytes);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteProperties.DateTime.cs

@@ -22,10 +22,8 @@ public sealed partial class Utf8JsonWriter
         /// The property name should already be escaped when the instance of <see cref="JsonEncodedText"/> was created.
         /// </remarks>
         public void WriteString(JsonEncodedText propertyName, DateTime value)
-            => WriteStringHelper(propertyName.EncodedUtf8Bytes, value);
-
-        private void WriteStringHelper(ReadOnlySpan<byte> utf8PropertyName, DateTime value)
         {
+            ReadOnlySpan<byte> utf8PropertyName = propertyName.EncodedUtf8Bytes;
             Debug.Assert(utf8PropertyName.Length <= JsonConstants.MaxUnescapedTokenSize);
 
             WriteStringByOptions(utf8PropertyName, value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteProperties.DateTimeOffset.cs

@@ -21,10 +21,8 @@ public sealed partial class Utf8JsonWriter
         /// Writes the <see cref="DateTimeOffset"/> using the round-trippable ('O') <see cref="StandardFormat"/> , for example: 2017-06-12T05:30:45.7680000-07:00.
         /// </remarks>
         public void WriteString(JsonEncodedText propertyName, DateTimeOffset value)
-            => WriteStringHelper(propertyName.EncodedUtf8Bytes, value);
-
-        private void WriteStringHelper(ReadOnlySpan<byte> utf8PropertyName, DateTimeOffset value)
         {
+            ReadOnlySpan<byte> utf8PropertyName = propertyName.EncodedUtf8Bytes;
             Debug.Assert(utf8PropertyName.Length <= JsonConstants.MaxUnescapedTokenSize);
 
             WriteStringByOptions(utf8PropertyName, value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteProperties.Decimal.cs

@@ -21,10 +21,8 @@ public sealed partial class Utf8JsonWriter
         /// Writes the <see cref="decimal"/> using the default <see cref="StandardFormat"/> (that is, 'G').
         /// </remarks>
         public void WriteNumber(JsonEncodedText propertyName, decimal value)
-            => WriteNumberHelper(propertyName.EncodedUtf8Bytes, value);
-
-        private void WriteNumberHelper(ReadOnlySpan<byte> utf8PropertyName, decimal value)
         {
+            ReadOnlySpan<byte> utf8PropertyName = propertyName.EncodedUtf8Bytes;
             Debug.Assert(utf8PropertyName.Length <= JsonConstants.MaxUnescapedTokenSize);
 
             WriteNumberByOptions(utf8PropertyName, value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteProperties.Double.cs

@@ -21,10 +21,8 @@ public sealed partial class Utf8JsonWriter
         /// Writes the <see cref="double"/> using the default <see cref="StandardFormat"/> (that is, 'G').
         /// </remarks>
         public void WriteNumber(JsonEncodedText propertyName, double value)
-            => WriteNumberHelper(propertyName.EncodedUtf8Bytes, value);
-
-        private void WriteNumberHelper(ReadOnlySpan<byte> utf8PropertyName, double value)
         {
+            ReadOnlySpan<byte> utf8PropertyName = propertyName.EncodedUtf8Bytes;
             Debug.Assert(utf8PropertyName.Length <= JsonConstants.MaxUnescapedTokenSize);
 
             JsonWriterHelper.ValidateDouble(value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteProperties.Float.cs

@@ -21,10 +21,8 @@ public sealed partial class Utf8JsonWriter
         /// Writes the <see cref="float"/> using the default <see cref="StandardFormat"/> (that is, 'G').
         /// </remarks>
         public void WriteNumber(JsonEncodedText propertyName, float value)
-            => WriteNumberHelper(propertyName.EncodedUtf8Bytes, value);
-
-        private void WriteNumberHelper(ReadOnlySpan<byte> utf8PropertyName, float value)
         {
+            ReadOnlySpan<byte> utf8PropertyName = propertyName.EncodedUtf8Bytes;
             Debug.Assert(utf8PropertyName.Length <= JsonConstants.MaxUnescapedTokenSize);
 
             JsonWriterHelper.ValidateSingle(value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteProperties.Guid.cs

@@ -21,10 +21,8 @@ public sealed partial class Utf8JsonWriter
         /// Writes the <see cref="Guid"/> using the default <see cref="StandardFormat"/> (that is, 'D'), as the form: nnnnnnnn-nnnn-nnnn-nnnn-nnnnnnnnnnnn.
         /// </remarks>
         public void WriteString(JsonEncodedText propertyName, Guid value)
-            => WriteStringHelper(propertyName.EncodedUtf8Bytes, value);
-
-        private void WriteStringHelper(ReadOnlySpan<byte> utf8PropertyName, Guid value)
         {
+            ReadOnlySpan<byte> utf8PropertyName = propertyName.EncodedUtf8Bytes;
             Debug.Assert(utf8PropertyName.Length <= JsonConstants.MaxUnescapedTokenSize);
 
             WriteStringByOptions(utf8PropertyName, value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteProperties.SignedNumber.cs

@@ -21,10 +21,8 @@ public sealed partial class Utf8JsonWriter
         /// Writes the <see cref="long"/> using the default <see cref="StandardFormat"/> (that is, 'G'), for example: 32767.
         /// </remarks>
         public void WriteNumber(JsonEncodedText propertyName, long value)
-            => WriteNumberHelper(propertyName.EncodedUtf8Bytes, value);
-
-        private void WriteNumberHelper(ReadOnlySpan<byte> utf8PropertyName, long value)
         {
+            ReadOnlySpan<byte> utf8PropertyName = propertyName.EncodedUtf8Bytes;
             Debug.Assert(utf8PropertyName.Length <= JsonConstants.MaxUnescapedTokenSize);
 
             WriteNumberByOptions(utf8PropertyName, value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteProperties.UnsignedNumber.cs

@@ -22,10 +22,8 @@ public sealed partial class Utf8JsonWriter
         /// </remarks>
         [CLSCompliant(false)]
         public void WriteNumber(JsonEncodedText propertyName, ulong value)
-            => WriteNumberHelper(propertyName.EncodedUtf8Bytes, value);
-
-        private void WriteNumberHelper(ReadOnlySpan<byte> utf8PropertyName, ulong value)
         {
+            ReadOnlySpan<byte> utf8PropertyName = propertyName.EncodedUtf8Bytes;
             Debug.Assert(utf8PropertyName.Length <= JsonConstants.MaxUnescapedTokenSize);
 
             WriteNumberByOptions(utf8PropertyName, value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.Bytes.cs

@@ -33,7 +33,10 @@ public void WriteBase64StringValue(ReadOnlySpan<byte> bytes)
 
         private void WriteBase64ByOptions(ReadOnlySpan<byte> bytes)
         {
-            ValidateWritingValue();
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
 
             if (_options.Indented)
             {

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.DateTime.cs

@@ -21,7 +21,11 @@ public sealed partial class Utf8JsonWriter
         /// </remarks>
         public void WriteStringValue(DateTime value)
         {
-            ValidateWritingValue();
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
+
             if (_options.Indented)
             {
                 WriteStringValueIndented(value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.DateTimeOffset.cs

@@ -22,7 +22,11 @@ public sealed partial class Utf8JsonWriter
         /// </remarks>
         public void WriteStringValue(DateTimeOffset value)
         {
-            ValidateWritingValue();
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
+
             if (_options.Indented)
             {
                 WriteStringValueIndented(value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.Decimal.cs

@@ -21,7 +21,11 @@ public sealed partial class Utf8JsonWriter
         /// </remarks>
         public void WriteNumberValue(decimal value)
         {
-            ValidateWritingValue();
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
+
             if (_options.Indented)
             {
                 WriteNumberValueIndented(value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.Double.cs

@@ -25,7 +25,11 @@ public void WriteNumberValue(double value)
         {
             JsonWriterHelper.ValidateDouble(value);
 
-            ValidateWritingValue();
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
+
             if (_options.Indented)
             {
                 WriteNumberValueIndented(value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.Float.cs

@@ -25,7 +25,11 @@ public void WriteNumberValue(float value)
         {
             JsonWriterHelper.ValidateSingle(value);
 
-            ValidateWritingValue();
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
+
             if (_options.Indented)
             {
                 WriteNumberValueIndented(value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.FormattedNumber.cs

@@ -25,7 +25,11 @@ internal void WriteNumberValue(ReadOnlySpan<byte> utf8FormattedNumber)
         {
             JsonWriterHelper.ValidateValue(utf8FormattedNumber);
             JsonWriterHelper.ValidateNumber(utf8FormattedNumber);
-            ValidateWritingValue();
+
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
 
             if (_options.Indented)
             {

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.Guid.cs

@@ -21,7 +21,11 @@ public sealed partial class Utf8JsonWriter
         /// </remarks>
         public void WriteStringValue(Guid value)
         {
-            ValidateWritingValue();
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
+
             if (_options.Indented)
             {
                 WriteStringValueIndented(value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.Helpers.cs

@@ -12,25 +12,24 @@ public sealed partial class Utf8JsonWriter
     {
         private void ValidateWritingValue()
         {
-            if (!_options.SkipValidation)
+            Debug.Assert(!_options.SkipValidation);
+
+            if (_inObject)
             {
-                if (_inObject)
+                if (_tokenType != JsonTokenType.PropertyName)
                 {
-                    if (_tokenType != JsonTokenType.PropertyName)
-                    {
-                        Debug.Assert(_tokenType != JsonTokenType.None && _tokenType != JsonTokenType.StartArray);
-                        ThrowHelper.ThrowInvalidOperationException(ExceptionResource.CannotWriteValueWithinObject, currentDepth: default, token: default, _tokenType);
-                    }
+                    Debug.Assert(_tokenType != JsonTokenType.None && _tokenType != JsonTokenType.StartArray);
+                    ThrowHelper.ThrowInvalidOperationException(ExceptionResource.CannotWriteValueWithinObject, currentDepth: default, token: default, _tokenType);
                 }
-                else
-                {
-                    Debug.Assert(_tokenType != JsonTokenType.PropertyName);
+            }
+            else
+            {
+                Debug.Assert(_tokenType != JsonTokenType.PropertyName);
 
-                    // It is more likely for CurrentDepth to not equal 0 when writing valid JSON, so check that first to rely on short-circuiting and return quickly.
-                    if (CurrentDepth == 0 && _tokenType != JsonTokenType.None)
-                    {
-                        ThrowHelper.ThrowInvalidOperationException(ExceptionResource.CannotWriteValueAfterPrimitiveOrClose, currentDepth: default, token: default, _tokenType);
-                    }
+                // It is more likely for CurrentDepth to not equal 0 when writing valid JSON, so check that first to rely on short-circuiting and return quickly.
+                if (CurrentDepth == 0 && _tokenType != JsonTokenType.None)
+                {
+                    ThrowHelper.ThrowInvalidOperationException(ExceptionResource.CannotWriteValueAfterPrimitiveOrClose, currentDepth: default, token: default, _tokenType);
                 }
             }
         }

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.Literal.cs

@@ -46,7 +46,11 @@ public void WriteBooleanValue(bool value)
 
         private void WriteLiteralByOptions(ReadOnlySpan<byte> utf8Value)
         {
-            ValidateWritingValue();
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
+
             if (_options.Indented)
             {
                 WriteLiteralIndented(utf8Value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.SignedNumber.cs

@@ -34,7 +34,11 @@ public void WriteNumberValue(int value)
         /// </remarks>
         public void WriteNumberValue(long value)
         {
-            ValidateWritingValue();
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
+
             if (_options.Indented)
             {
                 WriteNumberValueIndented(value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.String.cs

@@ -16,10 +16,8 @@ public sealed partial class Utf8JsonWriter
         /// Thrown if this would result in invalid JSON being written (while validation is enabled).
         /// </exception>
         public void WriteStringValue(JsonEncodedText value)
-            => WriteStringValueHelper(value.EncodedUtf8Bytes);
-
-        private void WriteStringValueHelper(ReadOnlySpan<byte> utf8Value)
         {
+            ReadOnlySpan<byte> utf8Value = value.EncodedUtf8Bytes;
             Debug.Assert(utf8Value.Length <= JsonConstants.MaxUnescapedTokenSize);
 
             WriteStringByOptions(utf8Value);
@@ -99,7 +97,11 @@ private void WriteStringEscape(ReadOnlySpan<char> value)
 
         private void WriteStringByOptions(ReadOnlySpan<char> value)
         {
-            ValidateWritingValue();
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
+
             if (_options.Indented)
             {
                 WriteStringIndented(value);
@@ -242,7 +244,11 @@ private void WriteStringEscape(ReadOnlySpan<byte> utf8Value)
 
         private void WriteStringByOptions(ReadOnlySpan<byte> utf8Value)
         {
-            ValidateWritingValue();
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
+
             if (_options.Indented)
             {
                 WriteStringIndented(utf8Value);

src/libraries/System.Text.Json/src/System/Text/Json/Writer/Utf8JsonWriter.WriteValues.UnsignedNumber.cs

@@ -36,7 +36,11 @@ public void WriteNumberValue(uint value)
         [CLSCompliant(false)]
         public void WriteNumberValue(ulong value)
         {
-            ValidateWritingValue();
+            if (!_options.SkipValidation)
+            {
+                ValidateWritingValue();
+            }
+
             if (_options.Indented)
             {
                 WriteNumberValueIndented(value);