private static NbtDocument Parse(
ReadOnlyMemory <byte> data,
NbtOptions options,
byte[]?extraRentedBytes,
out int bytesConsumed)
{
ReadOnlySpan <byte> dataSpan = data.Span;
var database = new MetadataDb(data.Length);
var stack = new ByteStack <ContainerFrame>(NbtOptions.DefaultMaxDepth, clearOnReturn: false);
var readerState = new NbtReaderState(options);
var reader = new NbtReader(dataSpan, isFinalBlock: true, readerState);
try
{
Parse(ref reader, ref database, ref stack);
bytesConsumed = (int)reader.BytesConsumed;
}
catch
{
database.Dispose();
throw;
}
finally
{
readerState.Dispose();
stack.Dispose();
}
return(new NbtDocument(data, options, database, extraRentedBytes, isDisposable: true));
}
//public static NbtDocument ParseValue(ref NbtReader reader)
//{
//
//}
//
//public static bool TryParseValue(ref NbtReader reader, out NbtDocument document)
//{
//}
private static void Parse(
ref NbtReader reader,
ref MetadataDb database,
ref ByteStack <ContainerFrame> stack)
{
int rowCount = 0;
MetadataDb.Accessor accessor = new(ref database);
NbtReadStatus status;
while ((status = reader.TryRead()) == NbtReadStatus.Done)
{
int location = reader.TagLocation;
NbtType type = reader.TagType;
NbtFlags flags = reader.TagFlags;
PeekStack:
ref ContainerFrame frame = ref stack.TryPeek();
if (!Unsafe.IsNullRef(ref frame))
{
if (frame.ListEntriesRemaining == 0)
{
stack.TryPop();
int totalRowCount = rowCount - frame.InitialRowCount;
accessor.GetRow(frame.ContainerRow).RowCount = totalRowCount;
goto PeekStack;
}
else if (frame.ListEntriesRemaining != -1)
{
frame.ListEntriesRemaining--;
}
else
{
frame.CompoundEntryCounter++;
}
}
switch (type)
{
case NbtType.End:
{
// Documents with a single End tag (no Compound root) are valid.
if (stack.TryPop(out ContainerFrame compoundFrame))
{
int totalRowCount = rowCount - compoundFrame.InitialRowCount;
int compoundLength = compoundFrame.CompoundEntryCounter - 1; // -1 to exclude End
ref DbRow row = ref accessor.GetRow(compoundFrame.ContainerRow);
row.RowCount = totalRowCount;
row.CollectionLength = compoundLength;
}
continue; // Continue to not increment row count
}
//public static NbtDocument ParseValue(ref NbtReader reader)
//{
//
//}
//
//public static bool TryParseValue(ref NbtReader reader, out NbtDocument document)
//{
//}
private static void Parse(
ref NbtReader reader,
ref MetadataDb database,
ref ByteStack <ContainerFrame> stack)
{
int rowCount = 0;
while (reader.Read())
{
int location = reader.TagLocation;
NbtType type = reader.TagType;
NbtFlags flags = reader.TagFlags;
PeekStack:
ref ContainerFrame frame = ref stack.TryPeek();
if (!Unsafe.IsNullRef(ref frame))
{
if (frame.ListEntriesRemaining == 0)
{
stack.TryPop();
int totalRowCount = rowCount - frame.InitialRowCount;
database.SetRowCount(frame.ContainerRow, totalRowCount);
goto PeekStack;
}
else if (frame.ListEntriesRemaining != -1)
{
frame.ListEntriesRemaining--;
}
else
{
frame.CompoundEntryCounter++;
}
}
switch (type)
{
case NbtType.End:
{
// Documents with a single End tag (no Compound root) are valid.
if (stack.TryPop(out var compoundFrame))
{
int totalRowCount = rowCount - compoundFrame.InitialRowCount;
int compoundLength = compoundFrame.CompoundEntryCounter - 1; // -1 to exclude End
database.SetRowCount(compoundFrame.ContainerRow, totalRowCount);
database.SetLength(compoundFrame.ContainerRow, compoundLength);
}
continue; // Continue to not increment row count
}
case NbtType.Compound:
{
int containerRow = database.Append(
location, collectionLength: 0, rowCount: 1, type, flags);
stack.Push(new ContainerFrame(containerRow, rowCount)
{
ListEntriesRemaining = -1
});
break;
}
case NbtType.List:
{
int listLength = reader.TagCollectionLength;
int containerRow = database.Append(
location, listLength, rowCount: 1, type, flags);
stack.Push(new ContainerFrame(containerRow, rowCount)
{
ListEntriesRemaining = listLength
});
break;
}
default:
database.Append(location, reader.TagCollectionLength, rowCount: 1, type, flags);
break;
}
rowCount++;
}
database.TrimExcess();
}