FieldPtrTableReader.cs

Go to the documentation of this file.

using System.Reflection.Internal;
 
namespace System.Reflection.Metadata.Ecma335;
 
internal readonly struct FieldPtrTableReader
{
    internal readonly int NumberOfRows;
 
    private readonly bool _IsFieldTableRowRefSizeSmall;
 
    private readonly int _FieldOffset;
 
    internal readonly int RowSize;
 
    internal readonly MemoryBlock Block;
 
    internal FieldPtrTableReader(int numberOfRows, int fieldTableRowRefSize, MemoryBlock containingBlock, int containingBlockOffset)
    {
        NumberOfRows = numberOfRows;
        _IsFieldTableRowRefSizeSmall = fieldTableRowRefSize == 2;
        _FieldOffset = 0;
        RowSize = _FieldOffset + fieldTableRowRefSize;
        Block = containingBlock.GetMemoryBlockAt(containingBlockOffset, RowSize * numberOfRows);
    }
 
    internal FieldDefinitionHandle GetFieldFor(int rowId)
    {
        int num = (rowId - 1) * RowSize;
        return FieldDefinitionHandle.FromRowId(Block.PeekReference(num + _FieldOffset, _IsFieldTableRowRefSizeSmall));
    }
 
    internal int GetRowIdForFieldDefRow(int fieldDefRowId)
    {
        return Block.LinearSearchReference(RowSize, _FieldOffset, (uint)fieldDefRowId, _IsFieldTableRowRefSizeSmall) + 1;
    }
}