MethodImplTableReader.cs

Go to the documentation of this file.

using System.Reflection.Internal;
 
namespace System.Reflection.Metadata.Ecma335;
 
internal readonly struct MethodImplTableReader
{
    internal readonly int NumberOfRows;
 
    private readonly bool _IsTypeDefTableRowRefSizeSmall;
 
    private readonly bool _IsMethodDefOrRefRefSizeSmall;
 
    private readonly int _ClassOffset;
 
    private readonly int _MethodBodyOffset;
 
    private readonly int _MethodDeclarationOffset;
 
    internal readonly int RowSize;
 
    internal readonly MemoryBlock Block;
 
    internal MethodImplTableReader(int numberOfRows, bool declaredSorted, int typeDefTableRowRefSize, int methodDefOrRefRefSize, MemoryBlock containingBlock, int containingBlockOffset)
    {
        NumberOfRows = numberOfRows;
        _IsTypeDefTableRowRefSizeSmall = typeDefTableRowRefSize == 2;
        _IsMethodDefOrRefRefSizeSmall = methodDefOrRefRefSize == 2;
        _ClassOffset = 0;
        _MethodBodyOffset = _ClassOffset + typeDefTableRowRefSize;
        _MethodDeclarationOffset = _MethodBodyOffset + methodDefOrRefRefSize;
        RowSize = _MethodDeclarationOffset + methodDefOrRefRefSize;
        Block = containingBlock.GetMemoryBlockAt(containingBlockOffset, RowSize * numberOfRows);
        if (!declaredSorted && !CheckSorted())
        {
            Throw.TableNotSorted(TableIndex.MethodImpl);
        }
    }
 
    internal TypeDefinitionHandle GetClass(MethodImplementationHandle handle)
    {
        int num = (handle.RowId - 1) * RowSize;
        return TypeDefinitionHandle.FromRowId(Block.PeekReference(num + _ClassOffset, _IsTypeDefTableRowRefSizeSmall));
    }
 
    internal EntityHandle GetMethodBody(MethodImplementationHandle handle)
    {
        int num = (handle.RowId - 1) * RowSize;
        return MethodDefOrRefTag.ConvertToHandle(Block.PeekTaggedReference(num + _MethodBodyOffset, _IsMethodDefOrRefRefSizeSmall));
    }
 
    internal EntityHandle GetMethodDeclaration(MethodImplementationHandle handle)
    {
        int num = (handle.RowId - 1) * RowSize;
        return MethodDefOrRefTag.ConvertToHandle(Block.PeekTaggedReference(num + _MethodDeclarationOffset, _IsMethodDefOrRefRefSizeSmall));
    }
 
    internal void GetMethodImplRange(TypeDefinitionHandle typeDef, out int firstImplRowId, out int lastImplRowId)
    {
        Block.BinarySearchReferenceRange(NumberOfRows, RowSize, _ClassOffset, (uint)typeDef.RowId, _IsTypeDefTableRowRefSizeSmall, out var startRowNumber, out var endRowNumber);
        if (startRowNumber == -1)
        {
            firstImplRowId = 1;
            lastImplRowId = 0;
        }
        else
        {
            firstImplRowId = startRowNumber + 1;
            lastImplRowId = endRowNumber + 1;
        }
    }
 
    private bool CheckSorted()
    {
        return Block.IsOrderedByReferenceAscending(RowSize, _ClassOffset, _IsTypeDefTableRowRefSizeSmall);
    }
}