fstream.cpp

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.


#include"stdafx.h"// Precompiled header key.
#include"fstream.h"

CFileStream::CFileStream()
: _cRef(1)
, _hFile(INVALID_HANDLE_VALUE)
{
}

CFileStream::~CFileStream()
{
Close();
}

HRESULT CFileStream::OpenForRead(LPCWSTR wzFilePath)
{
 HRESULT hr = S_OK;
 DWORD dwShareMode = FILE_SHARE_READ;

 dwShareMode |= FILE_SHARE_DELETE;

_ASSERTE(_hFile == INVALID_HANDLE_VALUE && wzFilePath);
if (_hFile != INVALID_HANDLE_VALUE || !wzFilePath) {
 hr = E_INVALIDARG;
goto Exit;
 }

 _hFile = WszCreateFile(wzFilePath, GENERIC_READ,
 dwShareMode, NULL,
 OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if (_hFile == INVALID_HANDLE_VALUE) {
 hr = HRESULT_FROM_WIN32(GetLastError());
goto Exit;
 }

Exit:
return hr;
}

HRESULT CFileStream::OpenForWrite(LPCWSTR wzFilePath)
{
 HRESULT hr = S_OK;

_ASSERTE(_hFile == INVALID_HANDLE_VALUE && wzFilePath);
if (_hFile != INVALID_HANDLE_VALUE || !wzFilePath) {
 hr = E_INVALIDARG;
goto Exit;
 }

 _hFile = WszCreateFile(wzFilePath, GENERIC_WRITE,
 FILE_SHARE_READ, NULL,
 CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

if (_hFile == INVALID_HANDLE_VALUE)
 {
 hr = HRESULT_FROM_WIN32(GetLastError());
goto Exit;
 }

Exit:
return hr;
}

HRESULT CFileStream::QueryInterface(REFIID riid, void **ppv)
{
 HRESULT hr = S_OK;

if (!ppv)
return E_POINTER;

 *ppv = NULL;

if (IsEqualIID(riid, IID_IUnknown) || IsEqualIID(riid, IID_IStream)) {
 *ppv = static_cast<IStream *>(this);
 }
else {
 hr = E_NOINTERFACE;
 }

if (*ppv) {
AddRef();
 }

return hr;
}

STDMETHODIMP_(ULONG) CFileStream::AddRef()
{
returnInterlockedIncrement(&_cRef);
}

STDMETHODIMP_(ULONG) CFileStream::Release()
{
 ULONG ulRef = InterlockedDecrement(&_cRef);

if (!ulRef) {
deletethis;
 }

return ulRef;
}

HRESULT CFileStream::Read(void *pv, ULONG cb, ULONG *pcbRead)
{
 HRESULT hr = S_OK;
 ULONG cbRead = 0;

if (pcbRead != NULL) {
 *pcbRead = 0;
 }

_ASSERTE(_hFile != INVALID_HANDLE_VALUE);
if (_hFile == INVALID_HANDLE_VALUE) {
 hr = E_UNEXPECTED;
goto Exit;
 }

if (!::ReadFile(_hFile, pv, cb, &cbRead, NULL)) {
 hr = HRESULT_FROM_WIN32(::GetLastError());
goto Exit;
 }

if (cbRead == 0) {
 hr = S_FALSE;
 }
else {
 hr = NOERROR;
 }

if (pcbRead != NULL) {
 *pcbRead = cbRead;
 }

Exit:
return hr;
}

HRESULT CFileStream::Write(voidconst *pv, ULONG cb, ULONG *pcbWritten)
{
 HRESULT hr = S_OK;
 ULONG cbWritten = 0;

if (pcbWritten != NULL) {
 *pcbWritten = 0;
 }

_ASSERTE(_hFile != INVALID_HANDLE_VALUE);
if (_hFile == INVALID_HANDLE_VALUE) {
 hr = E_UNEXPECTED;
goto Exit;
 }

if (!::WriteFile(_hFile, pv, cb, &cbWritten, NULL)) {
 hr = HRESULT_FROM_WIN32(::GetLastError());
goto Exit;
 }

if (cbWritten == 0) {
 hr = S_FALSE;
 }
else {
 hr = S_OK;
 }

if (pcbWritten != NULL) {
 *pcbWritten = cbWritten;
 }

Exit:
return hr;
}

HRESULT CFileStream::Seek(LARGE_INTEGER dlibMove, DWORD dwOrigin, ULARGE_INTEGER *plibNewPosition)
{
#if1// SetFilePointerEx not supported on Win9x
return E_NOTIMPL;
#else
 HRESULT hr = S_OK;
 DWORD dwFileOrigin;
 BOOL bRet;

 _ASSERTE(_hFile != INVALID_HANDLE_VALUE);
 if (_hFile == INVALID_HANDLE_VALUE) {
 hr = E_UNEXPECTED;
 goto Exit;
 }

 switch (dwOrigin) {
 case STREAM_SEEK_SET:
 dwFileOrigin = FILE_BEGIN;
 break;

 case STREAM_SEEK_CUR:
 dwFileOrigin = FILE_CURRENT;
 break;

 case STREAM_SEEK_END:
 dwFileOrigin = FILE_END;
 break;

 default:
 hr = E_UNEXPECTED;
 goto Exit;
 }

 bRet = SetFilePointerEx(_hFile, dlibMove, (LARGE_INTEGER *)plibNewPosition,
 dwFileOrigin);
 if (!bRet) {
 hr = HRESULT_FROM_WIN32(::GetLastError());
 goto Exit;
 }


Exit:
 return hr;
#endif
}

HRESULT CFileStream::SetSize(ULARGE_INTEGER libNewSize)
{
return E_NOTIMPL;
}

HRESULT CFileStream::CopyTo(IStream *pstm, ULARGE_INTEGER cb, ULARGE_INTEGER *pcbRead, ULARGE_INTEGER *pcbWritten)
{
return E_NOTIMPL;
}

HRESULT CFileStream::Commit(DWORD grfCommitFlags)
{
 HRESULT hr = S_OK;

if (grfCommitFlags != 0) {
 hr = E_INVALIDARG;
goto Exit;
 }

if (!Close()) {
 hr = HRESULT_FROM_WIN32(GetLastError());
 }

Exit:
return hr;
}

HRESULT CFileStream::Revert()
{
return E_NOTIMPL;
}

HRESULT CFileStream::LockRegion(ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType)
{
return E_NOTIMPL;
}

HRESULT CFileStream::UnlockRegion(ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType)
{
return E_NOTIMPL;
}

HRESULT CFileStream::Stat(STATSTG *pstatstg, DWORD grfStatFlag)
{
return E_NOTIMPL;
}

HRESULT CFileStream::Clone(IStream **ppIStream)
{
return E_NOTIMPL;
}


BOOL CFileStream::Close()
{
 BOOL fSuccess = FALSE;

if (_hFile != INVALID_HANDLE_VALUE) {
if (!::CloseHandle(_hFile)) {
 _hFile = INVALID_HANDLE_VALUE;
goto Exit;
 }

 _hFile = INVALID_HANDLE_VALUE;
 }

fSuccess = TRUE;

Exit:
returnfSuccess;
}