Implementing a TextReader to extract various files contents using IFilter

using System;
using System.Runtime.InteropServices;
using System.Runtime.InteropServices.ComTypes;
using System.Security;
using FILETIME = System.Runtime.InteropServices.ComTypes.FILETIME;
using STATSTG = System.Runtime.InteropServices.ComTypes.STATSTG;

namespace Eclipse.IndexingService.COMTypeDef
{
    [ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), SuppressUnmanagedCodeSecurity, Guid("0000000B-0000-0000-C000-000000000046")]
    public interface IStorage
    {
        [return: MarshalAs(UnmanagedType.Interface)]
        IStream CreateStream([In, MarshalAs(UnmanagedType.BStr)] string pwcsName, [In, MarshalAs(UnmanagedType.U4)] int grfMode, [In, MarshalAs(UnmanagedType.U4)] int reserved1, [In, MarshalAs(UnmanagedType.U4)] int reserved2);
        [return: MarshalAs(UnmanagedType.Interface)]
        IStream OpenStream([In, MarshalAs(UnmanagedType.BStr)] string pwcsName, IntPtr reserved1, [In, MarshalAs(UnmanagedType.U4)] int grfMode, [In, MarshalAs(UnmanagedType.U4)] int reserved2);
        [return: MarshalAs(UnmanagedType.Interface)]
        IStorage CreateStorage([In, MarshalAs(UnmanagedType.BStr)] string pwcsName, [In, MarshalAs(UnmanagedType.U4)] int grfMode, [In, MarshalAs(UnmanagedType.U4)] int reserved1, [In, MarshalAs(UnmanagedType.U4)] int reserved2);
        [return: MarshalAs(UnmanagedType.Interface)]
        IStorage OpenStorage([In, MarshalAs(UnmanagedType.BStr)] string pwcsName, IntPtr pstgPriority, [In, MarshalAs(UnmanagedType.U4)] int grfMode, IntPtr snbExclude, [In, MarshalAs(UnmanagedType.U4)] int reserved);
        void CopyTo(int ciidExclude, [In, MarshalAs(UnmanagedType.LPArray)] Guid[] pIIDExclude, IntPtr snbExclude, [In, MarshalAs(UnmanagedType.Interface)] IStorage stgDest);
        void MoveElementTo([In, MarshalAs(UnmanagedType.BStr)] string pwcsName, [In, MarshalAs(UnmanagedType.Interface)] IStorage stgDest, [In, MarshalAs(UnmanagedType.BStr)] string pwcsNewName, [In, MarshalAs(UnmanagedType.U4)] int grfFlags);
        void Commit(int grfCommitFlags);
        void Revert();
        void EnumElements([In, MarshalAs(UnmanagedType.U4)] int reserved1, IntPtr reserved2, [In, MarshalAs(UnmanagedType.U4)] int reserved3, [MarshalAs(UnmanagedType.Interface)] out IEnumSTATSTG ppVal);
        void DestroyElement([In, MarshalAs(UnmanagedType.BStr)] string pwcsName);
        void RenameElement([In, MarshalAs(UnmanagedType.BStr)] string pwcsOldName, [In, MarshalAs(UnmanagedType.BStr)] string pwcsNewName);
        void SetElementTimes([In, MarshalAs(UnmanagedType.BStr)] string pwcsName, [In] FILETIME pctime, [In] FILETIME patime, [In] FILETIME pmtime);
        void SetClass([In] ref Guid clsid);
        void SetStateBits(int grfStateBits, int grfMask);
        void Stat([Out] STATSTG pStatStg, int grfStatFlag);
    }

}