System.Reflection.Emit.UnmanagedMarshal.InternalGetBytes C# (CSharp) Method

        internal byte[] InternalGetBytes()
        {
            byte[] buf;
            if (m_unmanagedType == UnmanagedType.LPArray)
			{
    
                // syntax for NativeTypeSafeArray is 
                // <SafeArray | LPArray> <base type>
                //
                int     cBuf = 2;
                buf = new byte[cBuf];
                buf[0] = (byte) (m_unmanagedType);
                buf[1] = (byte) (m_baseType);
                return buf;
            }
            else
			if (m_unmanagedType == UnmanagedType.ByValArray || 
                    m_unmanagedType == UnmanagedType.ByValTStr) 
			{
                // <ByValArray | ByValTStr> <encoded integer>
                //
                int     cBuf;
                int     iBuf = 0;
    
                if (m_numElem <= 0x7f)
                    cBuf = 1;
                else if (m_numElem <= 0x3FFF)
                    cBuf = 2;
                else
                    cBuf = 4;
    
                // the total buffer size is the one byte + encoded integer size 
                cBuf = cBuf + 1;
                buf = new byte[cBuf];
    
                
                buf[iBuf++] = (byte) (m_unmanagedType);
                if (m_numElem <= 0x7F) 
				{
                    buf[iBuf++] = (byte)(m_numElem & 0xFF);
                } else if (m_numElem <= 0x3FFF) 
				{
                    buf[iBuf++] = (byte)((m_numElem >> 8) | 0x80);
                    buf[iBuf++] = (byte)(m_numElem & 0xFF);
                } else if (m_numElem <= 0x1FFFFFFF) 
				{
                    buf[iBuf++] = (byte)((m_numElem >> 24) | 0xC0);
                    buf[iBuf++] = (byte)((m_numElem >> 16) & 0xFF);
                    buf[iBuf++] = (byte)((m_numElem >> 8)  & 0xFF);
                    buf[iBuf++] = (byte)((m_numElem)     & 0xFF);
                }            
                return buf;
            }
            buf = new byte[1];
            buf[0] = (byte) (m_unmanagedType);
            return buf;
        }
    }

 public virtual void SetMarshal(UnmanagedMarshal unmanagedMarshal)
 {
     if (unmanagedMarshal == null)
     {
         throw new ArgumentNullException("unmanagedMarshal");
     }
     byte[] array = unmanagedMarshal.InternalGetBytes();
     TypeBuilder.SetFieldMarshal(this.m_methodBuilder.GetModuleBuilder().GetNativeHandle(), this.m_pdToken.Token, array, array.Length);
 }