public void StartParsing(ref DdbReadStack state)
{
if (GlobalDynamoDbConfig.InternAttributeNames)
{
state.KeysCache = new KeysCache(DdbReadStack.DefaultKeysCacheSize, DdbReadStack.MaxKeysCacheSize);
}
}
private static void HandleNumberValue(ref Utf8JsonReader reader, ref DdbReadStack state, IParsingOptions callbacks)
{
if (state.IsLastFrame && callbacks.HasNumberCallback)
{
callbacks.OnNumber(ref reader, ref state);
}
ref var current = ref state.GetCurrent();
private static void HandleEndObject(ref DdbReadStack state)
{
if (state.IsLastFrame)
{
return;
}
var document = state.GetCurrent().CreateDocumentFromBuffer();
state.PopObject();
if (document == null)
{
return;
}
ref var current = ref state.GetCurrent();
private static void HandleEndArray(ref DdbReadStack state)
{
ref var initialCurrent = ref state.GetCurrent();
private static void HandleStartArray(ref DdbReadStack state)
{
state.PushArray();
ref var current = ref state.GetCurrent();
public void OnNumber(ref Utf8JsonReader reader, ref DdbReadStack state)
{
}
public void StartParsing(ref DdbReadStack state)
{
}
private static void HandleNullValue(ref DdbReadStack state)
{
ref var current = ref state.GetCurrent();
public static async ValueTask <ReadResult <Document> > ReadAsync(Stream utf8Json, IParsingOptions options, bool returnCrc, CancellationToken cancellationToken = default)
{
var readerState = new JsonReaderState();
var readStack = new DdbReadStack(DdbReadStack.DefaultStackLength, options.Metadata);
try
{
options.StartParsing(ref readStack);
var buffer = ArrayPool <byte> .Shared.Rent(DefaultBufferSize);
var clearMax = 0;
try
{
var bytesInBuffer = 0;
uint crc = 0;
while (true)
{
var isFinalBlock = false;
while (true)
{
var bytesRead = await utf8Json.ReadAsync(new Memory <byte>(buffer, bytesInBuffer, buffer.Length - bytesInBuffer), cancellationToken).ConfigureAwait(false);
if (bytesRead == 0)
{
isFinalBlock = true;
break;
}
if (returnCrc)
{
crc = Crc32Algorithm.Append(crc, buffer, bytesInBuffer, bytesRead);
}
bytesInBuffer += bytesRead;
if (bytesInBuffer == buffer.Length)
{
break;
}
}
if (bytesInBuffer > clearMax)
{
clearMax = bytesInBuffer;
}
ReadCore(ref readerState, isFinalBlock, new ReadOnlySpan <byte>(buffer, 0, bytesInBuffer), ref readStack, options);
var bytesConsumed = (int)readStack.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);
}
}
return(new ReadResult <Document>(readStack.GetCurrent().CreateDocumentFromBuffer(), crc));
}
finally
{
new Span <byte>(buffer, 0, clearMax).Clear();
ArrayPool <byte> .Shared.Return(buffer);
}
}
finally
{
readStack.Dispose();
}
}
public void OnNumber(ref Utf8JsonReader reader, ref DdbReadStack state)
{
ref var current = ref state.GetCurrent();
private static void HandlePropertyName(ref Utf8JsonReader reader, ref DdbReadStack state)
{
ref var current = ref state.GetCurrent();
private static void ReadCore(ref JsonReaderState readerState, bool isFinalBlock, ReadOnlySpan <byte> buffer, ref DdbReadStack readStack, IParsingOptions options)
{
var reader = new Utf8JsonReader(buffer, isFinalBlock, readerState);
readStack.BytesConsumed = 0;
ReadCore(ref reader, ref readStack, options);
readerState = reader.CurrentState;
}
private static void ReadCore(ref Utf8JsonReader reader, ref DdbReadStack state, IParsingOptions options)
{
while (reader.Read())
{
switch (reader.TokenType)
{
case JsonTokenType.String:
{
HandleStringValue(ref reader, ref state);
break;
}
case JsonTokenType.PropertyName:
{
HandlePropertyName(ref reader, ref state);
break;
}
case JsonTokenType.StartObject:
{
if (!state.IsLastFrame || state.GetCurrent().IsProcessingValue())
{
// Parse inner object start
HandleNestedStartObject(ref state);
}
break;
}
case JsonTokenType.EndObject:
{
HandleEndObject(ref state);
break;
}
case JsonTokenType.True:
{
HandleBoolValue(ref state, true);
break;
}
case JsonTokenType.False:
{
HandleBoolValue(ref state, false);
break;
}
case JsonTokenType.StartArray:
{
HandleStartArray(ref state);
break;
}
case JsonTokenType.EndArray:
{
HandleEndArray(ref state);
break;
}
case JsonTokenType.Number:
{
HandleNumberValue(ref reader, ref state, options);
break;
}
case JsonTokenType.Null:
{
HandleNullValue(ref state);
break;
}
}
}
state.BytesConsumed += reader.BytesConsumed;
}
private static void HandleBoolValue(ref DdbReadStack state, bool value)
{
ref var current = ref state.GetCurrent();
private static void HandleStringValue(ref Utf8JsonReader reader, ref DdbReadStack state)
{
ref var current = ref state.GetCurrent();
private static void HandleNestedStartObject(ref DdbReadStack state)
{
state.PushObject();
}
