public static void RunSample()
{
Console.WriteLine("**Utf8JsonReader Sample***");
var jsonBytes = File.ReadAllBytes("sample.json");
var jsonSpan = jsonBytes.AsSpan();
var json = new System.Text.Json.Utf8JsonReader(jsonSpan);
while (json.Read())
{
Console.WriteLine(GetTokenDesc(json));
}
}
public override int Read(ref System.Text.Json.Utf8JsonReader reader, System.Type typeToConvert, System.Text.Json.JsonSerializerOptions options)
{
if (reader.TokenType == JsonTokenType.String)
{
ReadOnlySpan <byte> span = reader.HasValueSequence ? reader.ValueSequence.ToArray() : reader.ValueSpan;
if (Utf8Parser.TryParse(span, out int number, out int bytesConsumed) && span.Length == bytesConsumed)
{
return(number);
}
if (int.TryParse(reader.GetString(), out number))
{
return(number);
}
}
return(reader.GetInt32());
}
public override ElmTestRsReportJsonEntryFailureReasonData Read(
ref System.Text.Json.Utf8JsonReader reader,
System.Type typeToConvert,
System.Text.Json.JsonSerializerOptions options)
{
try
{
var equalityReader = reader;
var asEquality = new ElmTestRsReportJsonEntryFailureReasonData(
Equality: System.Text.Json.JsonSerializer.Deserialize <ElmTestRsReportJsonEntryFailureReasonDataEquality>(ref equalityReader));
reader = equalityReader;
return(asEquality);
}
catch { }
return(new ElmTestRsReportJsonEntryFailureReasonData(
String: System.Text.Json.JsonSerializer.Deserialize <string>(ref reader)));
}
private static string GetResourceString(ref Utf8JsonReader json, ExceptionResource resource, byte nextByte, string characters)
{
string character = IsPrintable(nextByte) ? ((char)nextByte).ToString() : $"0x{nextByte:X2}";
string message = "";
switch (resource)
{
case ExceptionResource.ArrayDepthTooLarge:
message = SR.Format(SR.ArrayDepthTooLarge, json.CurrentState.Options.MaxDepth);
break;
case ExceptionResource.MismatchedObjectArray:
message = SR.Format(SR.MismatchedObjectArray, character);
break;
case ExceptionResource.EndOfStringNotFound:
message = SR.EndOfStringNotFound;
break;
case ExceptionResource.RequiredDigitNotFoundAfterSign:
message = SR.Format(SR.RequiredDigitNotFoundAfterSign, character);
break;
case ExceptionResource.RequiredDigitNotFoundAfterDecimal:
message = SR.Format(SR.RequiredDigitNotFoundAfterDecimal, character);
break;
case ExceptionResource.RequiredDigitNotFoundEndOfData:
message = SR.RequiredDigitNotFoundEndOfData;
break;
case ExceptionResource.ExpectedEndAfterSingleJson:
message = SR.Format(SR.ExpectedEndAfterSingleJson, character);
break;
case ExceptionResource.ExpectedEndOfDigitNotFound:
message = SR.Format(SR.ExpectedEndOfDigitNotFound, character);
break;
case ExceptionResource.ExpectedNextDigitEValueNotFound:
message = SR.Format(SR.ExpectedNextDigitEValueNotFound, character);
break;
case ExceptionResource.ExpectedSeparatorAfterPropertyNameNotFound:
message = SR.Format(SR.ExpectedSeparatorAfterPropertyNameNotFound, character);
break;
case ExceptionResource.ExpectedStartOfPropertyNotFound:
message = SR.Format(SR.ExpectedStartOfPropertyNotFound, character);
break;
case ExceptionResource.ExpectedStartOfPropertyOrValueNotFound:
message = SR.ExpectedStartOfPropertyOrValueNotFound;
break;
case ExceptionResource.ExpectedStartOfValueNotFound:
message = SR.Format(SR.ExpectedStartOfValueNotFound, character);
break;
case ExceptionResource.ExpectedValueAfterPropertyNameNotFound:
message = SR.ExpectedValueAfterPropertyNameNotFound;
break;
case ExceptionResource.FoundInvalidCharacter:
message = SR.Format(SR.FoundInvalidCharacter, character);
break;
case ExceptionResource.InvalidEndOfJsonNonPrimitive:
message = SR.Format(SR.InvalidEndOfJsonNonPrimitive, json.TokenType);
break;
case ExceptionResource.ObjectDepthTooLarge:
message = SR.Format(SR.ObjectDepthTooLarge, json.CurrentState.Options.MaxDepth);
break;
case ExceptionResource.ExpectedFalse:
message = SR.Format(SR.ExpectedFalse, characters);
break;
case ExceptionResource.ExpectedNull:
message = SR.Format(SR.ExpectedNull, characters);
break;
case ExceptionResource.ExpectedTrue:
message = SR.Format(SR.ExpectedTrue, characters);
break;
case ExceptionResource.InvalidCharacterWithinString:
message = SR.Format(SR.InvalidCharacterWithinString, character);
break;
case ExceptionResource.InvalidCharacterAfterEscapeWithinString:
message = SR.Format(SR.InvalidCharacterAfterEscapeWithinString, character);
break;
case ExceptionResource.InvalidHexCharacterWithinString:
message = SR.Format(SR.InvalidHexCharacterWithinString, character);
break;
case ExceptionResource.EndOfCommentNotFound:
message = SR.EndOfCommentNotFound;
break;
case ExceptionResource.ZeroDepthAtEnd:
message = SR.Format(SR.ZeroDepthAtEnd);
break;
case ExceptionResource.ExpectedJsonTokens:
message = SR.ExpectedJsonTokens;
break;
default:
Debug.Fail($"The ExceptionResource enum value: {resource} is not part of the switch. Add the appropriate case and exception message.");
break;
}
return(message);
}
public static void ThrowJsonReaderException(ref Utf8JsonReader json, ExceptionResource resource, byte nextByte = default, ReadOnlySpan <byte> bytes = default)
{
throw GetJsonReaderException(ref json, resource, nextByte, bytes);
}
private void VerifyRead(JsonTokenType tokenType, int depth, long bytesConsumed, ref ReadStack state, ref Utf8JsonReader reader)
{
switch (tokenType)
{
case JsonTokenType.StartArray:
if (reader.TokenType != JsonTokenType.EndArray)
{
ThrowHelper.ThrowJsonException_SerializationConverterRead(reader, state.JsonPath, ConverterBase.ToString());
}
else if (depth != reader.CurrentDepth)
{
ThrowHelper.ThrowJsonException_SerializationConverterRead(reader, state.JsonPath, ConverterBase.ToString());
}
// Should not be possible to have not read anything.
Debug.Assert(bytesConsumed < reader.BytesConsumed);
break;
case JsonTokenType.StartObject:
if (reader.TokenType != JsonTokenType.EndObject)
{
ThrowHelper.ThrowJsonException_SerializationConverterRead(reader, state.JsonPath, ConverterBase.ToString());
}
else if (depth != reader.CurrentDepth)
{
ThrowHelper.ThrowJsonException_SerializationConverterRead(reader, state.JsonPath, ConverterBase.ToString());
}
// Should not be possible to have not read anything.
Debug.Assert(bytesConsumed < reader.BytesConsumed);
break;
default:
// Reading a single property value.
if (reader.BytesConsumed != bytesConsumed)
{
ThrowHelper.ThrowJsonException_SerializationConverterRead(reader, state.JsonPath, ConverterBase.ToString());
}
// Should not be possible to change token type.
Debug.Assert(reader.TokenType == tokenType);
break;
}
}
protected abstract void OnReadEnumerable(JsonTokenType tokenType, ref ReadStack state, ref Utf8JsonReader reader);
// If this method is changed, also change JsonPropertyInfoNullable.ReadEnumerable and JsonSerializer.ApplyObjectToEnumerable
public override void ReadEnumerable(JsonTokenType tokenType, ref ReadStack state, ref Utf8JsonReader reader)
{
Debug.Assert(ShouldDeserialize);
if (state.Current.KeyName == null && (state.Current.IsProcessingDictionary || state.Current.IsProcessingIDictionaryConstructibleOrKeyValuePair))
{
ThrowHelper.ThrowJsonException_DeserializeUnableToConvertValue(RuntimePropertyType, reader, state.JsonPath);
return;
}
// We need an initialized array in order to store the values.
if (state.Current.IsProcessingEnumerable && state.Current.TempEnumerableValues == null && state.Current.ReturnValue == null)
{
ThrowHelper.ThrowJsonException_DeserializeUnableToConvertValue(RuntimePropertyType, reader, state.JsonPath);
return;
}
if (ValueConverter == null || !ValueConverter.TryRead(RuntimePropertyType, ref reader, out TRuntimeProperty value))
{
if (state.Current.IsProcessingKeyValuePair && state.Current.KeyName == "Key")
{
// Handle the special case where the input KeyValuePair is of form {"Key": "MyKey", "Value": 1}
// (as opposed to form {"MyKey": 1}) and the value type is not string.
// If we have one, the ValueConverter failed to read the current token because it should be of type string
// (we only support string keys) but we initially tried to read it as type TRuntimeProperty.
// We have TRuntimeProperty not string because for deserialization, we parse the KeyValuePair as a
// dictionary before creating a KeyValuePair instance in a converter-like manner with the parsed values.
// Because it's dictionary-like parsing, we set the element type of the dictionary earlier on to the KeyValuePair's value
// type, which led us here.
// If there's no ValueConverter, the runtime type of the KeyValuePair's value is probably an object, dictionary or enumerable.
JsonValueConverter <string> stringConverter = DefaultConverters <string> .s_converter;
if (!stringConverter.TryRead(typeof(string), ref reader, out string strValue))
{
ThrowHelper.ThrowJsonException_DeserializeUnableToConvertValue(typeof(string), reader, state.JsonPath);
}
object objValue = strValue;
JsonSerializer.ApplyValueToEnumerable(ref objValue, ref state, ref reader);
return;
}
ThrowHelper.ThrowJsonException_DeserializeUnableToConvertValue(RuntimePropertyType, reader, state.JsonPath);
return;
}
if (state.Current.IsProcessingKeyValuePair)
{
// The value is being applied to a Dictionary<string, object>, so we need to cast to object here.
object objValue = value;
JsonSerializer.ApplyValueToEnumerable(ref objValue, ref state, ref reader);
return;
}
JsonSerializer.ApplyValueToEnumerable(ref value, ref state, ref reader);
}
/// <summary>
/// Reads one JSON value (including objects or arrays) from the provided reader into a <typeparamref name="TValue"/>.
/// </summary>
/// <returns>A <typeparamref name="TValue"/> representation of the JSON value.</returns>
/// <param name="reader">The reader to read.</param>
/// <param name="options">Options to control the serializer behavior during reading.</param>
/// <exception cref="JsonException">
/// Thrown when the JSON is invalid,
/// <typeparamref name="TValue"/> is not compatible with the JSON,
/// or a value could not be read from the reader.
/// </exception>
/// <exception cref="ArgumentException">
/// <paramref name="reader"/> is using unsupported options.
/// </exception>
/// <remarks>
/// <para>
/// If the <see cref="Utf8JsonReader.TokenType"/> property of <paramref name="reader"/>
/// is <see cref="JsonTokenType.PropertyName"/> or <see cref="JsonTokenType.None"/>, the
/// reader will be advanced by one call to <see cref="Utf8JsonReader.Read"/> to determine
/// the start of the value.
/// </para>
///
/// <para>
/// Upon completion of this method <paramref name="reader"/> will be positioned at the
/// final token in the JSON value. If an exception is thrown the reader is reset to
/// the state it was in when the method was called.
/// </para>
///
/// <para>
/// This method makes a copy of the data the reader acted on, so there is no caller
/// requirement to maintain data integrity beyond the return of this method.
/// </para>
///
/// <para>
/// The <see cref="JsonReaderOptions"/> used to create the instance of the <see cref="Utf8JsonReader"/> take precedence over the <see cref="JsonSerializerOptions"/> when they conflict.
/// Hence, <see cref="JsonReaderOptions.AllowTrailingCommas"/>, <see cref="JsonReaderOptions.MaxDepth"/>, <see cref="JsonReaderOptions.CommentHandling"/> are used while reading.
/// </para>
/// </remarks>
public static TValue Deserialize <TValue>(ref Utf8JsonReader reader, JsonSerializerOptions options = null)
{
return((TValue)ReadValueCore(ref reader, typeof(TValue), options));
}
private static void ReadValueCore(JsonSerializerOptions options, ref Utf8JsonReader reader, ref ReadStack readStack)
{
JsonReaderState state = reader.CurrentState;
CheckSupportedOptions(state.Options, nameof(reader));
// Value copy to overwrite the ref on an exception and undo the destructive reads.
Utf8JsonReader restore = reader;
ReadOnlySpan <byte> valueSpan = default;
ReadOnlySequence <byte> valueSequence = default;
try
{
switch (reader.TokenType)
{
// A new reader was created and has never been read,
// so we need to move to the first token.
// (or a reader has terminated and we're about to throw)
case JsonTokenType.None:
// Using a reader loop the caller has identified a property they wish to
// hydrate into a JsonDocument. Move to the value first.
case JsonTokenType.PropertyName:
{
if (!reader.Read())
{
ThrowHelper.ThrowJsonReaderException(ref reader, ExceptionResource.ExpectedOneCompleteToken);
}
break;
}
}
switch (reader.TokenType)
{
// Any of the "value start" states are acceptable.
case JsonTokenType.StartObject:
case JsonTokenType.StartArray:
{
long startingOffset = reader.TokenStartIndex;
if (!reader.TrySkip())
{
ThrowHelper.ThrowJsonReaderException(ref reader, ExceptionResource.NotEnoughData);
}
long totalLength = reader.BytesConsumed - startingOffset;
ReadOnlySequence <byte> sequence = reader.OriginalSequence;
if (sequence.IsEmpty)
{
valueSpan = reader.OriginalSpan.Slice(
checked ((int)startingOffset),
checked ((int)totalLength));
}
else
{
valueSequence = sequence.Slice(startingOffset, totalLength);
}
Debug.Assert(
reader.TokenType == JsonTokenType.EndObject ||
reader.TokenType == JsonTokenType.EndArray);
break;
}
// Single-token values
case JsonTokenType.Number:
case JsonTokenType.True:
case JsonTokenType.False:
case JsonTokenType.Null:
{
if (reader.HasValueSequence)
{
valueSequence = reader.ValueSequence;
}
else
{
valueSpan = reader.ValueSpan;
}
break;
}
// String's ValueSequence/ValueSpan omits the quotes, we need them back.
case JsonTokenType.String:
{
ReadOnlySequence <byte> sequence = reader.OriginalSequence;
if (sequence.IsEmpty)
{
// Since the quoted string fit in a ReadOnlySpan originally
// the contents length plus the two quotes can't overflow.
int payloadLength = reader.ValueSpan.Length + 2;
Debug.Assert(payloadLength > 1);
ReadOnlySpan <byte> readerSpan = reader.OriginalSpan;
Debug.Assert(
readerSpan[(int)reader.TokenStartIndex] == (byte)'"',
$"Calculated span starts with {readerSpan[(int)reader.TokenStartIndex]}");
Debug.Assert(
readerSpan[(int)reader.TokenStartIndex + payloadLength - 1] == (byte)'"',
$"Calculated span ends with {readerSpan[(int)reader.TokenStartIndex + payloadLength - 1]}");
valueSpan = readerSpan.Slice((int)reader.TokenStartIndex, payloadLength);
}
else
{
long payloadLength = 2;
if (reader.HasValueSequence)
{
payloadLength += reader.ValueSequence.Length;
}
else
{
payloadLength += reader.ValueSpan.Length;
}
valueSequence = sequence.Slice(reader.TokenStartIndex, payloadLength);
Debug.Assert(
valueSequence.First.Span[0] == (byte)'"',
$"Calculated sequence starts with {valueSequence.First.Span[0]}");
Debug.Assert(
valueSequence.ToArray()[payloadLength - 1] == (byte)'"',
$"Calculated sequence ends with {valueSequence.ToArray()[payloadLength - 1]}");
}
break;
}
default:
{
byte displayByte;
if (reader.HasValueSequence)
{
displayByte = reader.ValueSequence.First.Span[0];
}
else
{
displayByte = reader.ValueSpan[0];
}
ThrowHelper.ThrowJsonReaderException(
ref reader,
ExceptionResource.ExpectedStartOfValueNotFound,
displayByte);
break;
}
}
}
catch (JsonReaderException ex)
{
reader = restore;
// Re-throw with Path information.
ThrowHelper.ReThrowWithPath(readStack, ex);
}
int length = valueSpan.IsEmpty ? checked ((int)valueSequence.Length) : valueSpan.Length;
byte[] rented = ArrayPool <byte> .Shared.Rent(length);
Span <byte> rentedSpan = rented.AsSpan(0, length);
try
{
if (valueSpan.IsEmpty)
{
valueSequence.CopyTo(rentedSpan);
}
else
{
valueSpan.CopyTo(rentedSpan);
}
JsonReaderOptions originalReaderOptions = state.Options;
var newReader = new Utf8JsonReader(rentedSpan, originalReaderOptions);
ReadCore(options, ref newReader, ref readStack);
// The reader should have thrown if we have remaining bytes.
Debug.Assert(newReader.BytesConsumed == length);
}
catch (JsonException)
{
reader = restore;
throw;
}
finally
{
rentedSpan.Clear();
ArrayPool <byte> .Shared.Return(rented);
}
}
private static void HandleValue(JsonTokenType tokenType, JsonSerializerOptions options, ref Utf8JsonReader reader, ref ReadStack state)
{
if (state.Current.SkipProperty)
{
return;
}
JsonPropertyInfo jsonPropertyInfo = state.Current.JsonPropertyInfo;
if (jsonPropertyInfo == null)
{
jsonPropertyInfo = state.Current.JsonClassInfo.CreateRootObject(options);
}
else if (state.Current.JsonClassInfo.ClassType == ClassType.Unknown)
{
jsonPropertyInfo = state.Current.JsonClassInfo.CreatePolymorphicProperty(jsonPropertyInfo, typeof(object), options);
}
jsonPropertyInfo.Read(tokenType, ref state, ref reader);
}
/// <summary>
/// Reads one JSON value (including objects or arrays) from the provided reader into a <typeparamref name="TValue"/>.
/// </summary>
/// <returns>A <typeparamref name="TValue"/> representation of the JSON value.</returns>
/// <param name="reader">The reader to read.</param>
/// <param name="options">Options to control the serializer behavior during reading.</param>
/// <exception cref="JsonException">
/// Thrown when the JSON is invalid,
/// <typeparamref name="TValue"/> is not compatible with the JSON,
/// or a value could not be read from the reader.
/// </exception>
/// <exception cref="ArgumentException">
/// <paramref name="reader"/> is using unsupported options.
/// </exception>
/// <exception cref="NotSupportedException">
/// There is no compatible <see cref="System.Text.Json.Serialization.JsonConverter"/>
/// for <typeparamref name="TValue"/> or its serializable members.
/// </exception>
/// <remarks>
/// <para>
/// If the <see cref="Utf8JsonReader.TokenType"/> property of <paramref name="reader"/>
/// is <see cref="JsonTokenType.PropertyName"/> or <see cref="JsonTokenType.None"/>, the
/// reader will be advanced by one call to <see cref="Utf8JsonReader.Read"/> to determine
/// the start of the value.
/// </para>
///
/// <para>
/// Upon completion of this method <paramref name="reader"/> will be positioned at the
/// final token in the JSON value. If an exception is thrown the reader is reset to
/// the state it was in when the method was called.
/// </para>
///
/// <para>
/// This method makes a copy of the data the reader acted on, so there is no caller
/// requirement to maintain data integrity beyond the return of this method.
/// </para>
///
/// <para>
/// The <see cref="JsonReaderOptions"/> used to create the instance of the <see cref="Utf8JsonReader"/> take precedence over the <see cref="JsonSerializerOptions"/> when they conflict.
/// Hence, <see cref="JsonReaderOptions.AllowTrailingCommas"/>, <see cref="JsonReaderOptions.MaxDepth"/>, <see cref="JsonReaderOptions.CommentHandling"/> are used while reading.
/// </para>
/// </remarks>
public static TValue?Deserialize <[DynamicallyAccessedMembers(MembersAccessedOnRead)] TValue>(ref Utf8JsonReader reader, JsonSerializerOptions?options = null)
{
if (options == null)
{
options = JsonSerializerOptions.s_defaultOptions;
}
ReadStack state = default;
state.Initialize(typeof(TValue), options, supportContinuation: false);
return(ReadValueCore <TValue>(options, ref reader, ref state));
}