private static void HandleStartObject(JsonSerializerOptions options, ref Utf8JsonReader reader, ref ReadStack state)
{
if (state.Current.Skip())
{
state.Push();
state.Current.Drain = true;
return;
}
if (state.Current.IsProcessingEnumerable)
{
Type objType = state.Current.GetElementType();
state.Push();
state.Current.Initialize(objType, options);
}
else if (state.Current.JsonPropertyInfo != null)
{
if (state.Current.IsDictionary)
{
// Verify that the Dictionary can be deserialized by having <string> as first generic argument.
Type[] args = state.Current.JsonClassInfo.Type.GetGenericArguments();
if (args.Length == 0 || args[0].UnderlyingSystemType != typeof(string))
{
ThrowHelper.ThrowJsonException_DeserializeUnableToConvertValue(state.Current.JsonClassInfo.Type, reader, state.PropertyPath);
}
if (state.Current.ReturnValue == null)
{
// The Dictionary created below will be returned to corresponding Parse() etc method.
// Ensure any nested array creates a new frame.
state.Current.EnumerableCreated = true;
}
else
{
ClassType classType = state.Current.JsonClassInfo.ElementClassInfo.ClassType;
// Verify that the second parameter is not a value.
if (state.Current.JsonClassInfo.ElementClassInfo.ClassType == ClassType.Value)
{
ThrowHelper.ThrowJsonException_DeserializeUnableToConvertValue(state.Current.JsonClassInfo.Type, reader, state.PropertyPath);
}
// A nested object, dictionary or enumerable.
JsonClassInfo classInfoTemp = state.Current.JsonClassInfo;
state.Push();
state.Current.JsonClassInfo = classInfoTemp.ElementClassInfo;
state.Current.InitializeJsonPropertyInfo();
}
}
else
{
// Nested object.
Type objType = state.Current.JsonPropertyInfo.RuntimePropertyType;
state.Push();
state.Current.Initialize(objType, options);
}
}
JsonClassInfo classInfo = state.Current.JsonClassInfo;
state.Current.ReturnValue = classInfo.CreateObject();
}
internal static bool SingleValueReadWithReadAhead(ClassType classType, ref Utf8JsonReader reader, ref ReadStack state)
{
bool readAhead = (state.ReadAhead && (classType & (ClassType.Value | ClassType.NewValue)) != 0);
if (!readAhead)
{
return(reader.Read());
}
return(DoSingleValueReadWithReadAhead(ref reader, ref state));
}
private static void HandleStartArray(
JsonSerializerOptions options,
ref Utf8JsonReader reader,
ref ReadStack state)
{
JsonPropertyInfo jsonPropertyInfo = state.Current.JsonPropertyInfo;
bool skip = jsonPropertyInfo != null && !jsonPropertyInfo.ShouldDeserialize;
if (skip || state.Current.Skip())
{
// The array is not being applied to the object.
state.Push();
state.Current.Drain = true;
return;
}
if (jsonPropertyInfo == null || state.Current.JsonClassInfo.ClassType == ClassType.Unknown)
{
jsonPropertyInfo = state.Current.JsonClassInfo.CreatePolymorphicProperty(jsonPropertyInfo, typeof(object), options);
}
Type arrayType = jsonPropertyInfo.RuntimePropertyType;
if (!typeof(IEnumerable).IsAssignableFrom(arrayType) || (arrayType.IsArray && arrayType.GetArrayRank() > 1))
{
ThrowHelper.ThrowJsonReaderException_DeserializeUnableToConvertValue(arrayType, reader, state);
}
Debug.Assert(state.Current.IsPropertyEnumerable());
if (state.Current.IsPropertyEnumerable())
{
if (state.Current.EnumerableCreated)
{
// A nested json array so push a new stack frame.
Type elementType = state.Current.JsonClassInfo.ElementClassInfo.GetPolicyProperty().RuntimePropertyType;
state.Push();
state.Current.Initialize(elementType, options);
state.Current.PopStackOnEndArray = true;
}
else
{
state.Current.EnumerableCreated = true;
}
jsonPropertyInfo = state.Current.JsonPropertyInfo;
// If current property is already set (from a constructor, for example) leave as-is
if (jsonPropertyInfo.GetValueAsObject(state.Current.ReturnValue, options) == null)
{
// Create the enumerable.
object value = ReadStackFrame.CreateEnumerableValue(ref reader, ref state, options);
if (value != null)
{
if (state.Current.ReturnValue != null)
{
state.Current.JsonPropertyInfo.SetValueAsObject(state.Current.ReturnValue, value, options);
}
else
{
// Primitive arrays being returned without object
state.Current.SetReturnValue(value, options);
}
}
}
}
}
/// <summary>
/// Creates the instance and assigns it to state.Current.ReturnValue.
/// </summary>
internal virtual void CreateInstanceForReferenceResolver(ref Utf8JsonReader reader, ref ReadStack state, JsonSerializerOptions options)
{
}
public abstract void ApplyNullValue(JsonSerializerOptions options, ref ReadStack state);
internal override sealed bool TryReadAsObject(ref Utf8JsonReader reader, JsonSerializerOptions options, ref ReadStack state, out object?value)
{
bool success = TryRead(ref reader, TypeToConvert, options, ref state, out T typedValue);
value = typedValue;
return(success);
}
public abstract void ReadEnumerable(JsonTokenType tokenType, ref ReadStack state, ref Utf8JsonReader reader);
private static bool HandleEndArray(
JsonSerializerOptions options,
ref ReadStack state,
ref Utf8JsonReader reader)
{
bool lastFrame = state.IsLastFrame;
if (state.Current.Drain)
{
// The array is not being applied to the object.
state.Pop();
return(lastFrame);
}
IEnumerable value = ReadStackFrame.GetEnumerableValue(state.Current);
bool setPropertyDirectly;
bool popStackOnEnd = state.Current.PopStackOnEnd;
if (state.Current.TempEnumerableValues != null)
{
JsonEnumerableConverter converter = state.Current.JsonPropertyInfo.EnumerableConverter;
Debug.Assert(converter != null);
value = converter.CreateFromList(ref state, (IList)value, options);
setPropertyDirectly = true;
}
else if (!popStackOnEnd)
{
Debug.Assert(state.Current.IsPropertyEnumerable);
// We added the items to the list property already.
state.Current.ResetProperty();
return(false);
}
else
{
setPropertyDirectly = false;
}
if (popStackOnEnd)
{
state.Pop();
}
if (lastFrame)
{
if (state.Current.ReturnValue == null)
{
// Returning a converted list or object.
state.Current.Reset();
state.Current.ReturnValue = value;
return(true);
}
else if (state.Current.IsEnumerable || state.Current.IsDictionary)
{
// Returning a non-converted list.
return(true);
}
// else there must be an outer object, so we'll return false here.
}
ApplyObjectToEnumerable(value, options, ref state, ref reader, setPropertyDirectly: setPropertyDirectly);
if (!popStackOnEnd)
{
Debug.Assert(state.Current.IsPropertyEnumerable);
state.Current.ResetProperty();
}
return(false);
}
internal override void ReadEnumerable(JsonTokenType tokenType, JsonSerializerOptions options, ref ReadStack state, ref Utf8JsonReader reader)
{
if (ValueConverter != null)
{
if (ValueConverter.TryRead(s_underlyingType, ref reader, out TProperty value))
{
ReadStackFrame.SetReturnValue(value, options, ref state.Current);
return;
}
}
ThrowHelper.ThrowJsonReaderException_DeserializeUnableToConvertValue(RuntimePropertyType, reader, state);
}
public override void ReadEnumerable(JsonTokenType tokenType, JsonSerializerOptions options, ref ReadStack state, ref Utf8JsonReader reader)
{
if (ValueConverter == null || !ValueConverter.TryRead(typeof(TProperty), ref reader, out TProperty value))
{
ThrowHelper.ThrowJsonReaderException_DeserializeUnableToConvertValue(RuntimePropertyType, reader, state);
return;
}
// Converting to TProperty? here lets us share a common ApplyValue() with ApplyNullValue().
TProperty?nullableValue = new TProperty?(value);
JsonSerializer.ApplyValueToEnumerable(ref nullableValue, options, ref state.Current);
}
public override void ApplyNullValue(JsonSerializerOptions options, ref ReadStack state)
{
TProperty?nullableValue = null;
JsonSerializer.ApplyValueToEnumerable(ref nullableValue, options, ref state.Current);
}
/// <summary>
/// Initializes the state for polymorphic cases and returns the appropriate derived converter.
/// </summary>
internal JsonConverter?ResolvePolymorphicConverter(JsonTypeInfo jsonTypeInfo, JsonSerializerOptions options, ref ReadStack state)
{
Debug.Assert(!IsValueType);
Debug.Assert(CanHaveMetadata);
Debug.Assert(state.Current.MetadataPropertyNames.HasFlag(MetadataPropertyName.Type));
Debug.Assert(state.Current.PolymorphicSerializationState != PolymorphicSerializationState.PolymorphicReEntryStarted);
Debug.Assert(jsonTypeInfo.PolymorphicTypeResolver?.UsesTypeDiscriminators == true);
JsonConverter?polymorphicConverter = null;
switch (state.Current.PolymorphicSerializationState)
{
case PolymorphicSerializationState.None:
Debug.Assert(!state.IsContinuation);
Debug.Assert(state.PolymorphicTypeDiscriminator != null);
PolymorphicTypeResolver resolver = jsonTypeInfo.PolymorphicTypeResolver;
if (resolver.TryGetDerivedJsonTypeInfo(state.PolymorphicTypeDiscriminator, out JsonTypeInfo? resolvedType))
{
Debug.Assert(TypeToConvert.IsAssignableFrom(resolvedType.Type));
polymorphicConverter = state.InitializePolymorphicReEntry(resolvedType);
if (!polymorphicConverter.CanHaveMetadata)
{
ThrowHelper.ThrowNotSupportedException_DerivedConverterDoesNotSupportMetadata(resolvedType.Type);
}
}
else
{
state.Current.PolymorphicSerializationState = PolymorphicSerializationState.PolymorphicReEntryNotFound;
}
state.PolymorphicTypeDiscriminator = null;
break;
case PolymorphicSerializationState.PolymorphicReEntrySuspended:
polymorphicConverter = state.ResumePolymorphicReEntry();
Debug.Assert(TypeToConvert.IsAssignableFrom(polymorphicConverter.TypeToConvert));
break;
case PolymorphicSerializationState.PolymorphicReEntryNotFound:
Debug.Assert(state.Current.PolymorphicJsonTypeInfo is null);
break;
default:
Debug.Fail("Unexpected PolymorphicSerializationState.");
break;
}
return(polymorphicConverter);
}
// todo: for readability, refactor this method to split by ClassType(Enumerable, Object, or Value) like Write()
private static void ReadCore(
JsonSerializerOptions options,
ref Utf8JsonReader reader,
ref ReadStack state)
{
while (reader.Read())
{
JsonTokenType tokenType = reader.TokenType;
if (JsonHelpers.IsInRangeInclusive(tokenType, JsonTokenType.String, JsonTokenType.False))
{
Debug.Assert(tokenType == JsonTokenType.String || tokenType == JsonTokenType.Number || tokenType == JsonTokenType.True || tokenType == JsonTokenType.False);
if (HandleValue(tokenType, options, ref reader, ref state))
{
return;
}
}
else if (tokenType == JsonTokenType.PropertyName)
{
if (!state.Current.Drain)
{
Debug.Assert(state.Current.ReturnValue != default);
Debug.Assert(state.Current.JsonClassInfo != default);
ReadOnlySpan <byte> propertyName = reader.HasValueSequence ? reader.ValueSequence.ToArray() : reader.ValueSpan;
state.Current.JsonPropertyInfo = state.Current.JsonClassInfo.GetProperty(propertyName, state.Current.PropertyIndex);
if (state.Current.JsonPropertyInfo == null)
{
state.Current.JsonPropertyInfo = s_missingProperty;
}
state.Current.PropertyIndex++;
}
}
else if (tokenType == JsonTokenType.StartObject)
{
HandleStartObject(options, ref state);
}
else if (tokenType == JsonTokenType.EndObject)
{
if (HandleEndObject(options, ref state))
{
return;
}
}
else if (tokenType == JsonTokenType.StartArray)
{
HandleStartArray(options, ref reader, ref state);
}
else if (tokenType == JsonTokenType.EndArray)
{
if (HandleEndArray(options, ref state))
{
return;
}
}
else if (tokenType == JsonTokenType.Null)
{
if (HandleNull(ref reader, ref state, options))
{
return;
}
}
}
return;
}
internal static bool SingleValueReadWithReadAhead(bool requiresReadAhead, ref Utf8JsonReader reader, ref ReadStack state)
{
bool readAhead = requiresReadAhead && state.ReadAhead;
if (!readAhead)
{
return(reader.Read());
}
return(DoSingleValueReadWithReadAhead(ref reader, ref state));
}
private static void HandleEndDictionary(JsonSerializerOptions options, ref Utf8JsonReader reader, ref ReadStack state)
{
if (state.Current.IsDictionaryProperty)
{
// We added the items to the dictionary already.
state.Current.ResetProperty();
}
else if (state.Current.IsImmutableDictionaryProperty)
{
Debug.Assert(state.Current.TempDictionaryValues != null);
state.Current.JsonPropertyInfo.SetValueAsObject(state.Current.ReturnValue, CreateImmutableDictionaryFromTempValues(ref state, options));
state.Current.ResetProperty();
}
else
{
object value;
if (state.Current.TempDictionaryValues != null)
{
value = CreateImmutableDictionaryFromTempValues(ref state, options);
}
else
{
value = state.Current.ReturnValue;
}
if (state.IsLastFrame)
{
// Set the return value directly since this will be returned to the user.
state.Current.Reset();
state.Current.ReturnValue = value;
}
else
{
state.Pop();
ApplyObjectToEnumerable(value, ref state, ref reader);
}
}
}
internal override void Read(JsonTokenType tokenType, JsonSerializerOptions options, ref ReadStack state, ref Utf8JsonReader reader)
{
if (ElementClassInfo != null)
{
// Forward the setter to the value-based JsonPropertyInfo.
JsonPropertyInfo propertyInfo = ElementClassInfo.GetPolicyProperty();
propertyInfo.ReadEnumerable(tokenType, options, ref state, ref reader);
}
else if (ShouldDeserialize)
{
if (ValueConverter != null)
{
if (ValueConverter.TryRead(RuntimePropertyType, ref reader, out TRuntimeProperty value))
{
if (state.Current.ReturnValue == null)
{
state.Current.ReturnValue = value;
}
else
{
// Null values were already handled.
Debug.Assert(value != null);
Set((TClass)state.Current.ReturnValue, value);
}
return;
}
}
ThrowHelper.ThrowJsonReaderException_DeserializeUnableToConvertValue(RuntimePropertyType, reader, state);
}
}
internal bool TryRead(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options, ref ReadStack state, [MaybeNull] out T value)
{
if (ClassType == ClassType.Value)
{
// A value converter should never be within a continuation.
Debug.Assert(!state.IsContinuation);
// For perf and converter simplicity, handle null here instead of forwarding to the converter.
if (reader.TokenType == JsonTokenType.Null && !HandleNull)
{
if (!CanBeNull)
{
ThrowHelper.ThrowJsonException_DeserializeUnableToConvertValue(TypeToConvert);
}
value = default;
return(true);
}
#if !DEBUG
// For performance, only perform validation on internal converters on debug builds.
if (IsInternalConverter)
{
value = Read(ref reader, typeToConvert, options);
}
else
#endif
{
JsonTokenType originalPropertyTokenType = reader.TokenType;
int originalPropertyDepth = reader.CurrentDepth;
long originalPropertyBytesConsumed = reader.BytesConsumed;
value = Read(ref reader, typeToConvert, options);
VerifyRead(
originalPropertyTokenType,
originalPropertyDepth,
originalPropertyBytesConsumed,
isValueConverter: true,
ref reader);
}
if (CanBePolymorphic && options.ReferenceHandler != null)
{
// Edge case where we want to lookup for a reference when parsing into typeof(object)
// instead of return `value` as a JsonElement.
Debug.Assert(TypeToConvert == typeof(object));
Debug.Assert(value is JsonElement);
if (JsonSerializer.TryGetReferenceFromJsonElement(ref state, (JsonElement)(object)value, out object?referenceValue))
{
value = (T)referenceValue;
}
}
return(true);
}
bool success;
// Remember if we were a continuation here since Push() may affect IsContinuation.
bool wasContinuation = state.IsContinuation;
state.Push();
#if !DEBUG
// For performance, only perform validation on internal converters on debug builds.
if (IsInternalConverter)
{
if (reader.TokenType == JsonTokenType.Null && !HandleNull && !wasContinuation)
{
if (!CanBeNull)
{
ThrowHelper.ThrowJsonException_DeserializeUnableToConvertValue(TypeToConvert);
}
// For perf and converter simplicity, handle null here instead of forwarding to the converter.
value = default;
success = true;
}
else
{
success = OnTryRead(ref reader, typeToConvert, options, ref state, out value);
}
}
else
#endif
{
if (!wasContinuation)
{
// For perf and converter simplicity, handle null here instead of forwarding to the converter.
if (reader.TokenType == JsonTokenType.Null && !HandleNull)
{
if (!CanBeNull)
{
ThrowHelper.ThrowJsonException_DeserializeUnableToConvertValue(TypeToConvert);
}
value = default;
state.Pop(true);
return(true);
}
Debug.Assert(state.Current.OriginalTokenType == JsonTokenType.None);
state.Current.OriginalTokenType = reader.TokenType;
Debug.Assert(state.Current.OriginalDepth == 0);
state.Current.OriginalDepth = reader.CurrentDepth;
}
success = OnTryRead(ref reader, typeToConvert, options, ref state, out value);
if (success)
{
if (state.IsContinuation)
{
// The resumable converter did not forward to the next converter that previously returned false.
ThrowHelper.ThrowJsonException_SerializationConverterRead(this);
}
VerifyRead(
state.Current.OriginalTokenType,
state.Current.OriginalDepth,
bytesConsumed: 0,
isValueConverter: false,
ref reader);
// No need to clear state.Current.* since a stack pop will occur.
}
}
state.Pop(success);
return(success);
}
// If this method is changed, also change JsonPropertyInfoNullable.ReadEnumerable and JsonSerializer.ApplyObjectToEnumerable
internal override void ReadEnumerable(JsonTokenType tokenType, JsonSerializerOptions options, ref ReadStack state, ref Utf8JsonReader reader)
{
if (ValueConverter == null || !ValueConverter.TryRead(RuntimePropertyType, ref reader, out TRuntimeProperty value))
{
ThrowHelper.ThrowJsonReaderException_DeserializeUnableToConvertValue(RuntimePropertyType, reader, state);
return;
}
JsonSerializer.ApplyValueToEnumerable(ref value, options, ref state.Current);
}
// Provide a default implementation for value converters.
internal virtual bool OnTryRead(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options, ref ReadStack state, [MaybeNull] out T value)
{
value = Read(ref reader, typeToConvert, options);
return(true);
}
internal override void ApplyNullValue(JsonSerializerOptions options, ref ReadStack state)
{
Debug.Assert(state.Current.JsonPropertyInfo != null);
state.Current.JsonPropertyInfo.SetValueAsObject(state.Current.ReturnValue, null, options);
}
internal abstract bool TryReadAsObject(ref Utf8JsonReader reader, JsonSerializerOptions options, ref ReadStack state, out object?value);
private static void ReadCore(
JsonSerializerOptions options,
ref Utf8JsonReader reader,
ref ReadStack state)
{
try
{
while (reader.Read())
{
JsonTokenType tokenType = reader.TokenType;
if (JsonHelpers.IsInRangeInclusive(tokenType, JsonTokenType.String, JsonTokenType.False))
{
Debug.Assert(tokenType == JsonTokenType.String || tokenType == JsonTokenType.Number || tokenType == JsonTokenType.True || tokenType == JsonTokenType.False);
if (HandleValue(tokenType, options, ref reader, ref state))
{
continue;
}
}
else if (tokenType == JsonTokenType.PropertyName)
{
HandlePropertyName(options, ref reader, ref state);
}
else if (tokenType == JsonTokenType.StartObject)
{
if (state.Current.SkipProperty)
{
state.Push();
state.Current.Drain = true;
}
else if (state.Current.IsProcessingValue)
{
if (HandleValue(tokenType, options, ref reader, ref state))
{
continue;
}
}
else if (state.Current.IsProcessingDictionary)
{
HandleStartDictionary(options, ref reader, ref state);
}
else
{
HandleStartObject(options, ref reader, ref state);
}
}
else if (tokenType == JsonTokenType.EndObject)
{
if (state.Current.Drain)
{
state.Pop();
}
else if (state.Current.IsProcessingDictionary)
{
HandleEndDictionary(options, ref reader, ref state);
}
else
{
HandleEndObject(options, ref reader, ref state);
}
}
else if (tokenType == JsonTokenType.StartArray)
{
if (!state.Current.IsProcessingValue)
{
HandleStartArray(options, ref reader, ref state);
}
else if (HandleValue(tokenType, options, ref reader, ref state))
{
continue;
}
}
else if (tokenType == JsonTokenType.EndArray)
{
if (HandleEndArray(options, ref reader, ref state))
{
continue;
}
}
else if (tokenType == JsonTokenType.Null)
{
if (HandleNull(ref reader, ref state, options))
{
continue;
}
}
}
}
catch (JsonReaderException e)
{
// Re-throw with Path information.
ThrowHelper.ReThrowWithPath(e, state.PropertyPath);
}
return;
}
/// <summary> /// Loosely-typed ReadCore() that forwards to strongly-typed ReadCore(). /// </summary> internal abstract object?ReadCoreAsObject(ref Utf8JsonReader reader, JsonSerializerOptions options, ref ReadStack state);
// todo: for readability, refactor this method to split by ClassType(Enumerable, Object, or Value) like Write()
private static void ReadCore(
JsonSerializerOptions options,
ref Utf8JsonReader reader,
ref ReadStack state)
{
while (reader.Read())
{
JsonTokenType tokenType = reader.TokenType;
if (JsonHelpers.IsInRangeInclusive(tokenType, JsonTokenType.String, JsonTokenType.False))
{
Debug.Assert(tokenType == JsonTokenType.String || tokenType == JsonTokenType.Number || tokenType == JsonTokenType.True || tokenType == JsonTokenType.False);
if (HandleValue(tokenType, options, ref reader, ref state))
{
return;
}
}
else if (tokenType == JsonTokenType.PropertyName)
{
if (!state.Current.Drain)
{
Debug.Assert(state.Current.ReturnValue != default);
Debug.Assert(state.Current.JsonClassInfo != default);
if (state.Current.IsDictionary)
{
string keyName = reader.GetString();
if (options.DictionaryKeyPolicy != null)
{
keyName = options.DictionaryKeyPolicy.ConvertName(keyName);
}
state.Current.JsonPropertyInfo = state.Current.JsonClassInfo.GetPolicyProperty();
state.Current.KeyName = keyName;
}
else
{
ReadOnlySpan <byte> propertyName = reader.HasValueSequence ? reader.ValueSequence.ToArray() : reader.ValueSpan;
if (reader._stringHasEscaping)
{
int idx = propertyName.IndexOf(JsonConstants.BackSlash);
Debug.Assert(idx != -1);
propertyName = GetUnescapedString(propertyName, idx);
}
state.Current.JsonPropertyInfo = state.Current.JsonClassInfo.GetProperty(options, propertyName, ref state.Current);
if (state.Current.JsonPropertyInfo == null)
{
state.Current.JsonPropertyInfo = s_missingProperty;
}
state.Current.PropertyIndex++;
}
}
}
else if (tokenType == JsonTokenType.StartObject)
{
HandleStartObject(options, ref reader, ref state);
}
else if (tokenType == JsonTokenType.EndObject)
{
if (HandleEndObject(options, ref state))
{
return;
}
}
else if (tokenType == JsonTokenType.StartArray)
{
HandleStartArray(options, ref reader, ref state);
}
else if (tokenType == JsonTokenType.EndArray)
{
if (HandleEndArray(options, ref state))
{
return;
}
}
else if (tokenType == JsonTokenType.Null)
{
if (HandleNull(ref reader, ref state, options))
{
return;
}
}
}
return;
}
public abstract void ReadEnumerable(JsonTokenType tokenType, JsonSerializerOptions options, ref ReadStack state, ref Utf8JsonReader reader);
private static async ValueTask <TValue> ReadAsync <TValue>(
Stream utf8Json,
Type returnType,
JsonSerializerOptions options = null,
CancellationToken cancellationToken = default)
{
if (options == null)
{
options = JsonSerializerOptions.s_defaultOptions;
}
ReadStack state = default;
state.Current.Initialize(returnType, options);
var readerState = new JsonReaderState(options.GetReaderOptions());
// todo: switch to ArrayBuffer implementation to handle and simplify the allocs?
byte[] buffer = ArrayPool <byte> .Shared.Rent(options.DefaultBufferSize);
int bytesInBuffer = 0;
long totalBytesRead = 0;
int clearMax = 0;
try
{
while (true)
{
// Read from the stream until either our buffer is filled or we hit EOF.
// Calling ReadCore is relatively expensive, so we minimize the number of times
// we need to call it.
bool isFinalBlock = false;
while (true)
{
int bytesRead = await utf8Json.ReadAsync(
#if BUILDING_INBOX_LIBRARY
buffer.AsMemory(bytesInBuffer),
#else
buffer, bytesInBuffer, buffer.Length - bytesInBuffer,
#endif
cancellationToken).ConfigureAwait(false);
if (bytesRead == 0)
{
isFinalBlock = true;
break;
}
totalBytesRead += bytesRead;
bytesInBuffer += bytesRead;
if (bytesInBuffer == buffer.Length)
{
break;
}
}
if (bytesInBuffer > clearMax)
{
clearMax = bytesInBuffer;
}
// Process the data available
ReadCore(
ref readerState,
isFinalBlock,
new Span <byte>(buffer, 0, bytesInBuffer),
options,
ref state);
Debug.Assert(readerState.BytesConsumed <= bytesInBuffer);
int bytesConsumed = (int)readerState.BytesConsumed;
bytesInBuffer -= bytesConsumed;
if (isFinalBlock)
{
break;
}
// Check if we need to shift or expand the buffer because there wasn't enough data to complete deserialization.
if ((uint)bytesInBuffer > ((uint)buffer.Length / 2))
{
// We have less than half the buffer available, double the buffer size.
byte[] dest = ArrayPool <byte> .Shared.Rent((buffer.Length < (int.MaxValue / 2))?buffer.Length * 2 : int.MaxValue);
// Copy the unprocessed data to the new buffer while shifting the processed bytes.
Buffer.BlockCopy(buffer, bytesConsumed, dest, 0, bytesInBuffer);
new Span <byte>(buffer, 0, clearMax).Clear();
ArrayPool <byte> .Shared.Return(buffer);
clearMax = bytesInBuffer;
buffer = dest;
}
else if (bytesInBuffer != 0)
{
// Shift the processed bytes to the beginning of buffer to make more room.
Buffer.BlockCopy(buffer, bytesConsumed, buffer, 0, bytesInBuffer);
}
}
}
finally
{
// Clear only what we used and return the buffer to the pool
new Span <byte>(buffer, 0, clearMax).Clear();
ArrayPool <byte> .Shared.Return(buffer);
}
if (bytesInBuffer != 0)
{
throw new JsonReaderException(
SR.Format(SR.DeserializeDataRemaining, totalBytesRead, bytesInBuffer),
readerState);
}
return((TValue)state.Current.ReturnValue);
}
internal static bool DoSingleValueReadWithReadAhead(ref Utf8JsonReader reader, ref ReadStack state)
{
// When we're reading ahead we always have to save the state as we don't know if the next token
// is an opening object or an array brace.
JsonReaderState initialReaderState = reader.CurrentState;
long initialReaderBytesConsumed = reader.BytesConsumed;
if (!reader.Read())
{
return(false);
}
// Perform the actual read-ahead.
JsonTokenType tokenType = reader.TokenType;
if (tokenType == JsonTokenType.StartObject || tokenType == JsonTokenType.StartArray)
{
// Attempt to skip to make sure we have all the data we need.
bool complete = reader.TrySkip();
// We need to restore the state in all cases as we need to be positioned back before
// the current token to either attempt to skip again or to actually read the value.
reader = new Utf8JsonReader(reader.OriginalSpan.Slice(checked ((int)initialReaderBytesConsumed)),
isFinalBlock: reader.IsFinalBlock,
state: initialReaderState);
Debug.Assert(reader.BytesConsumed == 0);
state.BytesConsumed += initialReaderBytesConsumed;
if (!complete)
{
// Couldn't read to the end of the object, exit out to get more data in the buffer.
return(false);
}
// Success, requeue the reader to the start token.
reader.ReadWithVerify();
Debug.Assert(tokenType == reader.TokenType);
}
return(true);
}
private static void HandleStartDictionary(JsonSerializerOptions options, ref Utf8JsonReader reader, ref ReadStack state)
{
Debug.Assert(!state.Current.IsProcessingEnumerable);
JsonPropertyInfo jsonPropertyInfo = state.Current.JsonPropertyInfo;
if (jsonPropertyInfo == null)
{
jsonPropertyInfo = state.Current.JsonClassInfo.CreateRootObject(options);
}
Debug.Assert(jsonPropertyInfo != null);
// A nested object or dictionary so push new frame.
if (state.Current.PropertyInitialized)
{
state.Push();
state.Current.JsonClassInfo = jsonPropertyInfo.ElementClassInfo;
state.Current.InitializeJsonPropertyInfo();
state.Current.PropertyInitialized = true;
ClassType classType = state.Current.JsonClassInfo.ClassType;
if (classType == ClassType.Value &&
jsonPropertyInfo.ElementClassInfo.Type != typeof(object) &&
jsonPropertyInfo.ElementClassInfo.Type != typeof(JsonElement))
{
ThrowHelper.ThrowJsonException_DeserializeUnableToConvertValue(state.Current.JsonClassInfo.Type, reader, state.JsonPath);
}
JsonClassInfo classInfo = state.Current.JsonClassInfo;
if (state.Current.IsProcessingImmutableDictionary)
{
state.Current.TempDictionaryValues = (IDictionary)classInfo.CreateObject();
}
else
{
state.Current.ReturnValue = classInfo.CreateObject();
}
return;
}
state.Current.PropertyInitialized = true;
if (state.Current.IsProcessingImmutableDictionary)
{
JsonClassInfo dictionaryClassInfo = options.GetOrAddClass(jsonPropertyInfo.RuntimePropertyType);
state.Current.TempDictionaryValues = (IDictionary)dictionaryClassInfo.CreateObject();
}
// Else if current property is already set (from a constructor, for example), leave as-is.
else if (jsonPropertyInfo.GetValueAsObject(state.Current.ReturnValue) == null)
{
// Create the dictionary.
JsonClassInfo dictionaryClassInfo = jsonPropertyInfo.RuntimeClassInfo;
IDictionary value = (IDictionary)dictionaryClassInfo.CreateObject();
if (value != null)
{
if (state.Current.ReturnValue != null)
{
state.Current.JsonPropertyInfo.SetValueAsObject(state.Current.ReturnValue, value);
}
else
{
// A dictionary is being returned directly, or a nested dictionary.
state.Current.SetReturnValue(value);
}
}
}
}
private static bool HandleEndArray(
JsonSerializerOptions options,
ref ReadStack state)
{
bool lastFrame = state.IsLastFrame;
if (state.Current.Drain)
{
// The array is not being applied to the object.
state.Pop();
return(lastFrame);
}
IEnumerable value = ReadStackFrame.GetEnumerableValue(state.Current);
if (value == null)
{
// We added the items to the list property already.
state.Current.ResetProperty();
return(false);
}
bool setPropertyDirectly;
if (state.Current.TempEnumerableValues != null)
{
JsonEnumerableConverter converter = state.Current.JsonPropertyInfo.EnumerableConverter;
Debug.Assert(converter != null);
Type elementType = state.Current.GetElementType();
value = converter.CreateFromList(elementType, (IList)value);
setPropertyDirectly = true;
}
else
{
setPropertyDirectly = false;
}
bool valueReturning = state.Current.PopStackOnEndArray;
if (state.Current.PopStackOnEndArray)
{
state.Pop();
}
if (lastFrame)
{
if (state.Current.ReturnValue == null)
{
// Returning a converted list or object.
state.Current.Reset();
state.Current.ReturnValue = value;
return(true);
}
else if (state.Current.IsEnumerable())
{
// Returning a non-converted list.
return(true);
}
// else there must be an outer object, so we'll return false here.
}
ReadStackFrame.SetReturnValue(value, options, ref state.Current, setPropertyDirectly: setPropertyDirectly);
if (!valueReturning)
{
state.Current.ResetProperty();
}
return(false);
}
internal abstract void Read(JsonTokenType tokenType, JsonSerializerOptions options, ref ReadStack state, ref Utf8JsonReader reader);