自学教程：C++ HasError函数代码示例

voidDecoder::CompleteDecode(){  // Implementation-specific finalization  BeforeFinishInternal();  if (!HasError()) {    FinishInternal();  } else {    FinishWithErrorInternal();  }  // If the implementation left us mid-frame, finish that up.  if (mInFrame && !HasError()) {    PostFrameStop();  }  // If PostDecodeDone() has not been called, and this decoder wasn't aborted  // early because of low-memory conditions or losing a race with another  // decoder, we need to send teardown notifications (and report an error to the  // console later).  if (!IsMetadataDecode() && !mDecodeDone && !WasAborted()) {    mShouldReportError = true;    // If we only have a data error, we're usable if we have at least one    // complete frame.    if (!HasDecoderError() && GetCompleteFrameCount() > 0) {      // We're usable, so do exactly what we should have when the decoder      // completed.      // Not writing to the entire frame may have left us transparent.      PostHasTransparency();      if (mInFrame) {        PostFrameStop();      }      PostDecodeDone();    } else {      // We're not usable. Record some final progress indicating the error.      if (!IsMetadataDecode()) {        mProgress |= FLAG_DECODE_COMPLETE;      }      mProgress |= FLAG_HAS_ERROR;    }  }  if (mDecodeDone && !IsMetadataDecode()) {    MOZ_ASSERT(HasError() || mCurrentFrame, "Should have an error or a frame");    // If this image wasn't animated and isn't a transient image, mark its frame    // as optimizable. We don't support optimizing animated images and    // optimizing transient images isn't worth it.    if (!HasAnimation() &&        !(mDecoderFlags & DecoderFlags::IMAGE_IS_TRANSIENT) &&        mCurrentFrame) {      mCurrentFrame->SetOptimizable();    }  }}

voidDecoder::FinishSharedDecoder(){  if (!HasError()) {    FinishInternal();  }}

bool CSrFile::Read (void* pBuffer, const int Size) {  size_t Result;  size_t uSize = (size_t) Size;	/* Check valid input and state */  if (!IsOpen()) return AddSrUserError(SRERR_USER_NOTOPEN);  if (Size == 0) return (true);  if (pBuffer == NULL) {    return AddSrUserError(SRERR_USER_NULL, "File input buffer cannot be NULL!");  }  if (Size < 0) return AddSrUserError(SRERR_USER_BADINPUT, "File input buffer size must be positive!");	/* Check for overflows */  if ((int)uSize != Size) return AddSrUserError(SRERR_USER_OVERFLOW, "Requested file input was too large!");	/* Attempt to input buffer */  Result = fread(pBuffer, 1, uSize, m_pFile);  if (Result != uSize) {    if (HasError())      return AddSrSystemError("Failed to read data from file! Only %u of %d bytes input.", Result, Size);    else       return AddSrUserError(SRERR_USER_EOF);   }  return (true); }

voidFileSystemTaskBase::Start(){  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");  if (HasError()) {    HandlerCallback();    return;  }  if (FileSystemUtils::IsParentProcess()) {    // Run in parent process.    // Start worker thread.    nsCOMPtr<nsIEventTarget> target      = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);    NS_ASSERTION(target, "Must have stream transport service.");    target->Dispatch(this, NS_DISPATCH_NORMAL);    return;  }  // Run in child process.  nsRefPtr<FileSystemBase> filesystem = do_QueryReferent(mFileSystem);  if (!filesystem) {    return;  }  // Retain a reference so the task object isn't deleted without IPDL's  // knowledge. The reference will be released by  // mozilla::dom::ContentChild::DeallocPFileSystemRequestChild.  NS_ADDREF_THIS();  ContentChild::GetSingleton()->SendPFileSystemRequestConstructor(this,    GetRequestParams(filesystem->ToString()));}

  bool FileScanner::Read(bool& boolean)  {    if (HasError()) {      return false;    }#if defined(HAVE_MMAP) || defined(__WIN32__) || defined(WIN32)    if (buffer!=NULL) {      if (offset>=size) {        log.Error() << "Cannot read bool beyond end of file'"  << filename << "'";        hasError=true;        return false;      }      boolean=buffer[offset]!=0;      offset++;      return true;    }#endif    char value;    hasError=fread(&value,1,1,file)!=1;    if (hasError) {      log.Error() << "Cannot read bool beyond end of file'"  << filename << "'";      return false;    }    boolean=value!=0;    return true;  }

Result<ExitCode> SelfTest::Run(const Settings& settings) const{		auto statisticResult = GetStatistic(settings);	if (statisticResult.HasError())	{		return statisticResult.GetError();	}	auto statistic = statisticResult.GetResultValue();	if (statistic.IsService())	{			if (!statistic.HasAdministrativePrivileges())		{			return EXIT_CODE_NO_ADMIN;		}		if (!statistic.HasSeAssignPrimaryTokenPrivilege())		{			return EXIT_CODE_NO_ASSIGN_PRIMARY_TOKEN_PRIV;		}		if (!statistic.HasSeTcbPrivilegePrivilege())		{			return EXIT_CODE_NO_TCB_PRIV;		}	}		return Is64OS() ? EXIT_CODE_READY_FOR_64 : EXIT_CODE_READY_FOR_32;}

  bool FileScanner::SetPos(FileOffset pos)  {    if (HasError()) {      return false;    }#if defined(HAVE_MMAP) || defined(__WIN32__) || defined(WIN32)    if (buffer!=NULL) {      if (pos>=size) {        return false;      }      offset=pos;      return true;    }#endif    clearerr(file);#if defined(HAVE_FSEEKO)    hasError=fseeko(file,(off_t)pos,SEEK_SET)!=0;#else    hasError=fseek(file,pos,SEEK_SET)!=0;#endif    if (hasError) {      log.Error() << "Cannot set file pos for file '" << filename << "':" << strerror(errno);    }    return !hasError;  }

/*=========================================================================== * * Class CSrFile Method - bool ReadLine (Buffer); * * Inputs a line of text from a text file. * *=========================================================================*/bool CSrFile::ReadLine (CSString& Buffer) {  byte    Value;  size_t  Result;  //SSCHAR  TempBuffer[256];  //SSCHAR* pResult;	/* Set some initial string size */  Buffer.SetSizeEmpty(64);  //Buffer.Empty();  while (!IsEOF()) {      		/* Attempt to input buffer */    Result = fread(&Value, 1, 1, m_pFile);    if (Result != 1) {      if (HasError()) return AddSrSystemError("Failed to read byte from file!");      return (true);    }    if (Value == '/n') {      ++m_LineCount;      return (true);     }    else {      Buffer += Value;     }   }  return (true);}

  bool FileScanner::ReadNumber(int16_t& number)  {    if (HasError()) {      return false;    }    number=0;#if defined(HAVE_MMAP) || defined(__WIN32__) || defined(WIN32)    if (buffer!=NULL) {      if (offset>=size) {        log.Error() << "Cannot read compressed int16_t beyond end of file'"  << filename << "'";        hasError=true;        return false;      }      unsigned int bytes=DecodeNumber(&buffer[offset],number);      offset+=bytes;      return true;    }#endif    char buffer;    if (fread(&buffer,1,1,file)!=1) {      log.Error() << "Cannot read compressed int16_t beyond end of file'"  << filename << "'";      hasError=true;      return false;    }    typedef int16_t num_t;    unsigned int shift=0;    unsigned int nextShift=0;    // negative form    if ((buffer & 0x01)!=0) {      char val=(buffer & 0x7e) >> 1;      number=-1;      nextShift=6;      while ((buffer & 0x80)!=0) {        if (fread(&buffer,1,1,file)!=1) {          log.Error() << "Cannot read compressed int16_t beyond end of file'"  << filename << "'";          hasError=true;          return false;        }        number^=(val << shift);        val=buffer & 0x7f;        shift=nextShift;        nextShift+=7;      }      number^=static_cast<num_t>(val) << shift;    }

void NetworkConnection::HandleRecv(const boost::system::error_code & error, int32_t actual_bytes){	if (error || HasError() || m_service->HasStopped())	{        if (m_socket.is_open())        {            if (error == boost::asio::error::eof) //we got disconnected on the client side            {                OnError(error);                //Disconnect();            }            else                StartError(error);        }	}	else	{		m_recv_buffer.resize(actual_bytes);		OnRecv(m_recv_buffer);		m_pending_recvs.pop_front();		if (!m_pending_recvs.empty())		{			StartRecv(m_pending_recvs.front());		}	}}

voidGetFileOrDirectoryTask::HandlerCallback(){  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");  if (mFileSystem->IsShutdown()) {    mPromise = nullptr;    return;  }  if (HasError()) {    nsRefPtr<DOMError> domError = new DOMError(mFileSystem->GetWindow(),      mErrorValue);    mPromise->MaybeRejectBrokenly(domError);    mPromise = nullptr;    return;  }  if (mIsDirectory) {    nsRefPtr<Directory> dir = new Directory(mFileSystem, mTargetRealPath);    mPromise->MaybeResolve(dir);    mPromise = nullptr;    return;  }  nsRefPtr<File> file = new File(mFileSystem->GetWindow(), mTargetFileImpl);  mPromise->MaybeResolve(file);  mPromise = nullptr;}

voidDecoder::FinishSharedDecoder(){  MOZ_ASSERT(NS_IsMainThread());  if (!HasError()) {    FinishInternal();  }}

nsresultDecoder::Decode(IResumable* aOnResume){  MOZ_ASSERT(mInitialized, "Should be initialized here");  MOZ_ASSERT(mIterator, "Should have a SourceBufferIterator");  // If no IResumable was provided, default to |this|.  IResumable* onResume = aOnResume ? aOnResume : this;  // We keep decoding chunks until the decode completes or there are no more  // chunks available.  while (!GetDecodeDone() && !HasError()) {    auto newState = mIterator->AdvanceOrScheduleResume(onResume);    if (newState == SourceBufferIterator::WAITING) {      // We can't continue because the rest of the data hasn't arrived from the      // network yet. We don't have to do anything special; the      // SourceBufferIterator will ensure that Decode() gets called again on a      // DecodePool thread when more data is available.      return NS_OK;    }    if (newState == SourceBufferIterator::COMPLETE) {      mDataDone = true;      nsresult finalStatus = mIterator->CompletionStatus();      if (NS_FAILED(finalStatus)) {        PostDataError();      }      CompleteDecode();      return finalStatus;    }    MOZ_ASSERT(newState == SourceBufferIterator::READY);    Write(mIterator->Data(), mIterator->Length());  }  CompleteDecode();  return HasError() ? NS_ERROR_FAILURE : NS_OK;}

void Acceptor::HandleTimer( const boost::system::error_code & error ){	if( error || HasError() || m_hive->HasStopped() )	{		StartError( error );	}	else	{		OnTimer( boost::posix_time::microsec_clock::local_time() - m_last_time );		StartTimer();	}}

Result<Environment> ProcessAsUser::GetEnvironment(const Settings& settings, Handle& userToken, const InheritanceMode inheritanceMode, Trace& trace){	auto callingProcessEnvironmentResult = Environment::CreateForCurrentProcess(trace);	if(callingProcessEnvironmentResult.HasError())	{		return callingProcessEnvironmentResult;	}	if (inheritanceMode == INHERITANCE_MODE_ON)	{		return GetEnvironmentWithSpecifiedByCaller(			settings, 			callingProcessEnvironmentResult.GetResultValue(), 			trace);	}	// Get target user's environment	auto targetUserEnvironmentResult = Environment::CreateForUser(userToken, false, trace);	if (targetUserEnvironmentResult.HasError())	{		return targetUserEnvironmentResult;	}	if (inheritanceMode == INHERITANCE_MODE_OFF)	{		return GetEnvironmentWithSpecifiedByCaller(			settings, 			targetUserEnvironmentResult.GetResultValue(), 			trace);	}		return GetEnvironmentWithSpecifiedByCaller(		settings, 		Environment::Override(			callingProcessEnvironmentResult.GetResultValue(), 			targetUserEnvironmentResult.GetResultValue(), 			trace),		trace);}

void Connection::HandleSend( const boost::system::error_code &  error, std::list< std::vector< uint8_t > >::iterator itr ){	if( error || HasError() || m_hive->HasStopped() )	{		StartError( error );	}	else	{		OnSend( *itr );		m_pending_sends.erase( itr );		StartSend();	}}

voidDecoder::Finish(){  // Implementation-specific finalization  if (!HasError())    FinishInternal();  // If the implementation left us mid-frame, finish that up.  if (mInFrame && !HasDecoderError())    PostFrameStop();  // If PostDecodeDone() has not been called, we need to sent teardown  // notifications.  if (!IsSizeDecode() && !mDecodeDone) {    // Log data errors to the error console    nsCOMPtr<nsIConsoleService> consoleService =      do_GetService(NS_CONSOLESERVICE_CONTRACTID);    nsCOMPtr<nsIScriptError2> errorObject =      do_CreateInstance(NS_SCRIPTERROR_CONTRACTID);    if (consoleService && errorObject && !HasDecoderError()) {      nsAutoString msg(NS_LITERAL_STRING("Image corrupt or truncated: ") +                       NS_ConvertASCIItoUTF16(mImage->GetURIString()));      errorObject->InitWithWindowID        (msg.get(),         NS_ConvertUTF8toUTF16(mImage->GetURIString()).get(),         nsnull,         0, 0, nsIScriptError::errorFlag,         "Image", mImage->InnerWindowID()         );        nsCOMPtr<nsIScriptError> error = do_QueryInterface(errorObject);      consoleService->LogMessage(error);    }    // If we only have a data error, see if things are worth salvaging    bool salvage = !HasDecoderError() && mImage->GetNumFrames();    // If we're salvaging, say we finished decoding    if (salvage)      mImage->DecodingComplete();    // Fire teardown notifications    if (mObserver) {      mObserver->OnStopContainer(nsnull, mImage);      mObserver->OnStopDecode(nsnull, salvage ? NS_OK : NS_ERROR_FAILURE, nsnull);    }  }}

void Connection::HandleConnect(const boost::system::error_code & error){	if (error || HasError() || m_hive->HasStopped()) {		StartError(error);	} 	else {		if (m_socket.is_open()) {			OnConnect(m_socket.remote_endpoint().address().to_string(), m_socket.remote_endpoint().port());		}		else {			StartError(error);		}	}}

voidGetDirectoryListingTask::HandlerCallback(){  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");  if (mFileSystem->IsShutdown()) {    mPromise = nullptr;    return;  }  if (HasError()) {    mPromise->MaybeReject(mErrorValue);    mPromise = nullptr;    return;  }  size_t count = mTargetBlobImpls.Length();  Sequence<OwningFileOrDirectory> listing;  if (!listing.SetLength(count, mozilla::fallible_t())) {    mPromise->MaybeReject(NS_ERROR_FAILURE);    mPromise = nullptr;    return;  }  for (unsigned i = 0; i < count; i++) {    if (mTargetBlobImpls[i]->IsDirectory()) {      nsAutoString name;      mTargetBlobImpls[i]->GetName(name);      nsAutoString path(mTargetRealPath);      path.AppendLiteral(FILESYSTEM_DOM_PATH_SEPARATOR);      path.Append(name);#ifdef DEBUG      if (XRE_IsParentProcess()) {        nsCOMPtr<nsIFile> file = mFileSystem->GetLocalFile(path);        bool exist;        file->Exists(&exist);        MOZ_ASSERT(exist);      }#endif      listing[i].SetAsDirectory() = new Directory(mFileSystem, path);    } else {      listing[i].SetAsFile() = File::Create(mFileSystem->GetWindow(), mTargetBlobImpls[i]);    }  }  mPromise->MaybeResolve(listing);  mPromise = nullptr;}

Defragment::~Defragment (){    if (!IsDoneYet ())    {        Stop ();        while (!IsDoneYet()  &&  !HasError())        {            SetStatusString (L"Waiting for thread to stop ...");            Sleep (150);        }    }    Volume.Close ();    return;}

void Connection::HandleRecv( const boost::system::error_code & error, int32_t actual_bytes ){	if( error || HasError() || m_hive->HasStopped() )	{		StartError( error );	}	else	{		m_recv_buffer.resize( actual_bytes );		OnRecv( m_recv_buffer );		m_pending_recvs.pop_front();		if( !m_pending_recvs.empty() )		{			StartRecv( m_pending_recvs.front() );		}	}}

  bool FileScanner::IsEOF() const  {    if (HasError()) {      return true;    }    if (size==0) {      return true;    }#if defined(HAVE_MMAP) || defined(__WIN32__) || defined(WIN32)    if (buffer!=NULL) {      return offset>=size;    }#endif    return feof(file);  }

FileSystemResponseValueFileSystemTaskParentBase::GetRequestResult() const{  AssertIsOnBackgroundThread();  mFileSystem->AssertIsOnOwningThread();  if (HasError()) {    return FileSystemErrorResponse(mErrorValue);  }  ErrorResult rv;  FileSystemResponseValue value = GetSuccessRequestResult(rv);  if (NS_WARN_IF(rv.Failed())) {    return FileSystemErrorResponse(rv.StealNSResult());  }  return value;}

Maybe<TerminalState>nsJPEGDecoder::DoDecode(SourceBufferIterator& aIterator){  MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");  MOZ_ASSERT(aIterator.Data());  MOZ_ASSERT(aIterator.Length() > 0);  return mLexer.Lex(aIterator.Data(), aIterator.Length(),                    [=](State aState, const char* aData, size_t aLength) {    switch (aState) {      case State::JPEG_DATA:        return ReadJPEGData(aData, aLength);      case State::FINISHED_JPEG_DATA:        return FinishedJPEGData();    }    MOZ_CRASH("Unknown State");  });}