InterfaceImplTableReader.cs

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using System.Reflection.Internal;
 
namespace System.Reflection.Metadata.Ecma335;
 
internal readonly struct InterfaceImplTableReader
{
    internal readonly int NumberOfRows;
 
    private readonly bool _IsTypeDefTableRowRefSizeSmall;
 
    private readonly bool _IsTypeDefOrRefRefSizeSmall;
 
    private readonly int _ClassOffset;
 
    private readonly int _InterfaceOffset;
 
    internal readonly int RowSize;
 
    internal readonly MemoryBlock Block;
 
    internal InterfaceImplTableReader(int numberOfRows, bool declaredSorted, int typeDefTableRowRefSize, int typeDefOrRefRefSize, MemoryBlock containingBlock, int containingBlockOffset)
    {
        NumberOfRows = numberOfRows;
        _IsTypeDefTableRowRefSizeSmall = typeDefTableRowRefSize == 2;
        _IsTypeDefOrRefRefSizeSmall = typeDefOrRefRefSize == 2;
        _ClassOffset = 0;
        _InterfaceOffset = _ClassOffset + typeDefTableRowRefSize;
        RowSize = _InterfaceOffset + typeDefOrRefRefSize;
        Block = containingBlock.GetMemoryBlockAt(containingBlockOffset, RowSize * numberOfRows);
        if (!declaredSorted && !CheckSorted())
        {
            Throw.TableNotSorted(TableIndex.InterfaceImpl);
        }
    }
 
    private bool CheckSorted()
    {
        return Block.IsOrderedByReferenceAscending(RowSize, _ClassOffset, _IsTypeDefTableRowRefSizeSmall);
    }
 
    internal void GetInterfaceImplRange(TypeDefinitionHandle typeDef, out int firstImplRowId, out int lastImplRowId)
    {
        int rowId = typeDef.RowId;
        Block.BinarySearchReferenceRange(NumberOfRows, RowSize, _ClassOffset, (uint)rowId, _IsTypeDefTableRowRefSizeSmall, out var startRowNumber, out var endRowNumber);
        if (startRowNumber == -1)
        {
            firstImplRowId = 1;
            lastImplRowId = 0;
        }
        else
        {
            firstImplRowId = startRowNumber + 1;
            lastImplRowId = endRowNumber + 1;
        }
    }
 
    internal EntityHandle GetInterface(int rowId)
    {
        int num = (rowId - 1) * RowSize;
        return TypeDefOrRefTag.ConvertToHandle(Block.PeekTaggedReference(num + _InterfaceOffset, _IsTypeDefOrRefRefSizeSmall));
    }
}