source: trunk/src/shell32/memorystream.c

/*
 *      this class implements a pure IStream object
 *      and can be used for many purposes
 *
 *      the main reason for implementing this was
 *      a cleaner implementation of IShellLink which
 *      needs to be able to load lnk's from a IStream
 *      interface so it was obvious to capsule the file
 *      access in a IStream to.
 */

#include <string.h>

#include "winbase.h"
#include "winerror.h"
#include "shlobj.h"
#include "debugtools.h"
#include "heap.h"
#include "shell32_main.h"

DEFAULT_DEBUG_CHANNEL(shell);

static HRESULT WINAPI IStream_fnQueryInterface(IStream *iface, REFIID riid, LPVOID *ppvObj);
static ULONG WINAPI IStream_fnAddRef(IStream *iface);
static ULONG WINAPI IStream_fnRelease(IStream *iface);
static HRESULT WINAPI IStream_fnRead (IStream * iface, void* pv, ULONG cb, ULONG* pcbRead);
static HRESULT WINAPI IStream_fnWrite (IStream * iface, const void* pv, ULONG cb, ULONG* pcbWritten);
static HRESULT WINAPI IStream_fnSeek (IStream * iface, LARGE_INTEGER dlibMove, DWORD dwOrigin, ULARGE_INTEGER* plibNewPosition);
static HRESULT WINAPI IStream_fnSetSize (IStream * iface, ULARGE_INTEGER libNewSize);
static HRESULT WINAPI IStream_fnCopyTo (IStream * iface, IStream* pstm, ULARGE_INTEGER cb, ULARGE_INTEGER* pcbRead, ULARGE_INTEGER* pcbWritten);
static HRESULT WINAPI IStream_fnCommit (IStream * iface, DWORD grfCommitFlags);
static HRESULT WINAPI IStream_fnRevert (IStream * iface);
static HRESULT WINAPI IStream_fnLockRegion (IStream * iface, ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType);
static HRESULT WINAPI IStream_fnUnlockRegion (IStream * iface, ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType);
static HRESULT WINAPI IStream_fnStat (IStream * iface, STATSTG*   pstatstg, DWORD grfStatFlag);
static HRESULT WINAPI IStream_fnClone (IStream * iface, IStream** ppstm);

static ICOM_VTABLE(IStream) stvt = 
{       
        ICOM_MSVTABLE_COMPAT_DummyRTTIVALUE
        IStream_fnQueryInterface,
        IStream_fnAddRef,
        IStream_fnRelease,
        IStream_fnRead,
        IStream_fnWrite,
        IStream_fnSeek,
        IStream_fnSetSize,
        IStream_fnCopyTo,
        IStream_fnCommit,
        IStream_fnRevert,
        IStream_fnLockRegion,
        IStream_fnUnlockRegion,
        IStream_fnStat,
        IStream_fnClone
        
};

typedef struct 
{       ICOM_VTABLE(IStream)    *lpvtst;
        DWORD           ref;
        LPBYTE          pImage;
        HANDLE          hMapping;
        DWORD           dwLength;
        DWORD           dwPos;
} ISHFileStream;

/**************************************************************************
 *   CreateStreamOnFile()
 *
 *   similar to CreateStreamOnHGlobal
 */
HRESULT CreateStreamOnFile (LPCSTR pszFilename, IStream ** ppstm)
{
        ISHFileStream*  fstr;
        OFSTRUCT        ofs;
        HFILE           hFile = OpenFile( pszFilename, &ofs, OF_READ );
        HRESULT         ret = E_FAIL;
        
        fstr = (ISHFileStream*)HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,sizeof(ISHFileStream));
        fstr->lpvtst=&stvt;
        fstr->ref = 1;
        fstr->dwLength = GetFileSize (hFile, NULL);

        shell32_ObjCount++;

        if (!(fstr->hMapping = CreateFileMappingA(hFile,NULL,PAGE_READONLY|SEC_COMMIT,0,0,NULL)))
        {
          WARN("failed to create filemap.\n");
          goto end_2;
        }

        if (!(fstr->pImage = MapViewOfFile(fstr->hMapping,FILE_MAP_READ,0,0,0)))
        {
          WARN("failed to mmap filemap.\n");
          goto end_3;
        }

        ret = S_OK;
        goto end_1;
        
end_3:  CloseHandle(fstr->hMapping);
end_2:  HeapFree(GetProcessHeap(), 0, fstr);
        fstr = NULL;

end_1:  _lclose(hFile);
        (*ppstm) = (IStream*)fstr;
        return ret;
}

/**************************************************************************
*  IStream_fnQueryInterface
*/
static HRESULT WINAPI IStream_fnQueryInterface(IStream *iface, REFIID riid, LPVOID *ppvObj)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)->(\n\tIID:\t%s,%p)\n",This,debugstr_guid(riid),ppvObj);

        *ppvObj = NULL;

        if(IsEqualIID(riid, &IID_IUnknown) ||
           IsEqualIID(riid, &IID_IStream))
        {
          *ppvObj = This;
        }

        if(*ppvObj)
        { 
          IStream_AddRef((IStream*)*ppvObj);      
          TRACE("-- Interface: (%p)->(%p)\n",ppvObj,*ppvObj);
          return S_OK;
        }
        TRACE("-- Interface: E_NOINTERFACE\n");
        return E_NOINTERFACE;
}

/**************************************************************************
*  IStream_fnAddRef
*/
static ULONG WINAPI IStream_fnAddRef(IStream *iface)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)->(count=%lu)\n",This, This->ref);

        shell32_ObjCount++;
        return ++(This->ref);
}

/**************************************************************************
*  IStream_fnRelease
*/
static ULONG WINAPI IStream_fnRelease(IStream *iface)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)->()\n",This);

        shell32_ObjCount--;

        if (!--(This->ref)) 
        { TRACE(" destroying SHFileStream (%p)\n",This);

          UnmapViewOfFile(This->pImage);
          CloseHandle(This->hMapping);

          HeapFree(GetProcessHeap(),0,This);
          return 0;
        }
        return This->ref;
}

static HRESULT WINAPI IStream_fnRead (IStream * iface, void* pv, ULONG cb, ULONG* pcbRead)
{
        ICOM_THIS(ISHFileStream, iface);

        DWORD dwBytesToRead, dwBytesLeft;
        
        TRACE("(%p)->(%p,0x%08lx,%p)\n",This, pv, cb, pcbRead);
        
        if ( !pv )
          return STG_E_INVALIDPOINTER;

        dwBytesLeft = This->dwLength - This->dwPos;

        if ( 0 >= dwBytesLeft )                                         /* end of buffer */
          return S_FALSE;
        
        dwBytesToRead = ( cb > dwBytesLeft) ? dwBytesLeft : cb;

        memmove ( pv, (This->pImage) + (This->dwPos), dwBytesToRead);
        
        This->dwPos += dwBytesToRead;                                   /* adjust pointer */

        if (pcbRead)
          *pcbRead = dwBytesToRead;

        return S_OK;
}
static HRESULT WINAPI IStream_fnWrite (IStream * iface, const void* pv, ULONG cb, ULONG* pcbWritten)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)\n",This);

        return E_NOTIMPL;
}
static HRESULT WINAPI IStream_fnSeek (IStream * iface, LARGE_INTEGER dlibMove, DWORD dwOrigin, ULARGE_INTEGER* plibNewPosition)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)\n",This);

        return E_NOTIMPL;
}
static HRESULT WINAPI IStream_fnSetSize (IStream * iface, ULARGE_INTEGER libNewSize)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)\n",This);

        return E_NOTIMPL;
}
static HRESULT WINAPI IStream_fnCopyTo (IStream * iface, IStream* pstm, ULARGE_INTEGER cb, ULARGE_INTEGER* pcbRead, ULARGE_INTEGER* pcbWritten)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)\n",This);

        return E_NOTIMPL;
}
static HRESULT WINAPI IStream_fnCommit (IStream * iface, DWORD grfCommitFlags)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)\n",This);

        return E_NOTIMPL;
}
static HRESULT WINAPI IStream_fnRevert (IStream * iface)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)\n",This);

        return E_NOTIMPL;
}
static HRESULT WINAPI IStream_fnLockRegion (IStream * iface, ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)\n",This);

        return E_NOTIMPL;
}
static HRESULT WINAPI IStream_fnUnlockRegion (IStream * iface, ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)\n",This);

        return E_NOTIMPL;
}
static HRESULT WINAPI IStream_fnStat (IStream * iface, STATSTG*   pstatstg, DWORD grfStatFlag)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)\n",This);

        return E_NOTIMPL;
}
static HRESULT WINAPI IStream_fnClone (IStream * iface, IStream** ppstm)
{
        ICOM_THIS(ISHFileStream, iface);

        TRACE("(%p)\n",This);

        return E_NOTIMPL;
}