C++ QSystemError函数代码示例

//static
bool QFileSystemEngine::renameFile(const QFileSystemEntry &source, const QFileSystemEntry &target, QSystemError &error)
{
    if (::rename(source.nativeFilePath().constData(), target.nativeFilePath().constData()) == 0)
        return true;
    error = QSystemError(errno, QSystemError::StandardLibraryError);
    return false;
}

//static
bool QFileSystemEngine::setPermissions(const QFileSystemEntry &entry, QFile::Permissions permissions, QSystemError &error, QFileSystemMetaData *data)
{
    mode_t mode = 0;
    if (permissions & (QFile::ReadOwner | QFile::ReadUser))
        mode |= S_IRUSR;
    if (permissions & (QFile::WriteOwner | QFile::WriteUser))
        mode |= S_IWUSR;
    if (permissions & (QFile::ExeOwner | QFile::ExeUser))
        mode |= S_IXUSR;
    if (permissions & QFile::ReadGroup)
        mode |= S_IRGRP;
    if (permissions & QFile::WriteGroup)
        mode |= S_IWGRP;
    if (permissions & QFile::ExeGroup)
        mode |= S_IXGRP;
    if (permissions & QFile::ReadOther)
        mode |= S_IROTH;
    if (permissions & QFile::WriteOther)
        mode |= S_IWOTH;
    if (permissions & QFile::ExeOther)
        mode |= S_IXOTH;

    bool success = ::chmod(entry.nativeFilePath().constData(), mode) == 0;
    if (success && data) {
        data->entryFlags &= ~QFileSystemMetaData::Permissions;
        data->entryFlags |= QFileSystemMetaData::MetaDataFlag(uint(permissions));
        data->knownFlagsMask |= QFileSystemMetaData::Permissions;
    }
    if (!success)
        error = QSystemError(errno, QSystemError::StandardLibraryError);
    return success;
}

//static
bool QFileSystemEngine::copyFile(const QFileSystemEntry &source, const QFileSystemEntry &target, QSystemError &error)
{
    Q_UNUSED(source);
    Q_UNUSED(target);
    error = QSystemError(ENOSYS, QSystemError::StandardLibraryError); //Function not implemented
    return false;
}

bool QFSFileEnginePrivate::unmap(uchar *ptr)
{
#if !defined(Q_OS_INTEGRITY)
    Q_Q(QFSFileEngine);
    if (!maps.contains(ptr)) {
        q->setError(QFile::PermissionsError, qt_error_string(EACCES));
        return false;
    }

#ifdef QT_SYMBIAN_USE_NATIVE_FILEMAP
    RFileMap mapping = maps.value(ptr);
    TInt err = mapping.Flush();
    mapping.Close();
    maps.remove(ptr);
    if (err) {
        q->setError(QFile::WriteError, QSystemError(err, QSystemError::NativeError).toString());
        return false;
    }
    return true;
#else
    uchar *start = ptr - maps[ptr].first;
    size_t len = maps[ptr].second;
    if (-1 == munmap(start, len)) {
        q->setError(QFile::UnspecifiedError, qt_error_string(errno));
        return false;
    }
    maps.remove(ptr);
    return true;
#endif
#else
    return false;
#endif
}

//static
bool QFileSystemEngine::createLink(const QFileSystemEntry &source, const QFileSystemEntry &target, QSystemError &error)
{
    Q_UNUSED(source)
    Q_UNUSED(target)
    error = QSystemError(KErrNotSupported, QSystemError::NativeError);
    return false;
}

/*!
    Opens the file descriptor specified by \a file in the mode given by
    \a openMode. Returns true on success; otherwise returns false.

    The \a handleFlags argument specifies whether the file handle will be
    closed by Qt. See the QFile::FileHandleFlags documentation for more
    information.
*/
bool QFSFileEngine::open(QIODevice::OpenMode openMode, const RFile &file, QFile::FileHandleFlags handleFlags)
{
    Q_D(QFSFileEngine);

    // Append implies WriteOnly.
    if (openMode & QFile::Append)
        openMode |= QFile::WriteOnly;

    // WriteOnly implies Truncate if neither ReadOnly nor Append are sent.
    if ((openMode & QFile::WriteOnly) && !(openMode & (QFile::ReadOnly | QFile::Append)))
        openMode |= QFile::Truncate;

    d->openMode = openMode;
    d->lastFlushFailed = false;
    d->closeFileHandle = (handleFlags & QFile::AutoCloseHandle);
    d->fileEntry.clear();
    d->fh = 0;
    d->fd = -1;
    d->tried_stat = 0;

#ifdef SYMBIAN_ENABLE_64_BIT_FILE_SERVER_API
    //RFile64 adds only functions to RFile, no data members
    d->symbianFile = static_cast<const RFile64&>(file);
#else
    d->symbianFile = file;
#endif
    TInt ret;
    d->symbianFilePos = 0;
    if (openMode & QFile::Append) {
        // Seek to the end when in Append mode.
        ret = d->symbianFile.Size(d->symbianFilePos);
    } else {
        // Seek to current otherwise
        ret = d->symbianFile.Seek(ESeekCurrent, d->symbianFilePos);
    }

    if (ret != KErrNone) {
        setError(QFile::OpenError, QSystemError(ret, QSystemError::NativeError).toString());

        d->openMode = QIODevice::NotOpen;
#ifdef SYMBIAN_ENABLE_64_BIT_FILE_SERVER_API
        d->symbianFile = RFile64();
#else
        d->symbianFile = RFile();
#endif
        return false;
    }

    // Extract filename (best effort)
    TFileName fn;
    TInt err = d->symbianFile.FullName(fn);
    if (err == KErrNone)
        d->fileEntry = QFileSystemEntry(qt_TDesC2QString(fn), QFileSystemEntry::FromNativePath());
    else
        d->fileEntry.clear();

    return true;
}

//static
bool QFileSystemEngine::removeFile(const QFileSystemEntry &entry, QSystemError &error)
{
    QString targetpath = absoluteName(entry).nativeFilePath();
    RFs& fs(qt_s60GetRFs());
    TInt err = fs.Delete(qt_QString2TPtrC(targetpath));
    if (err == KErrNone)
        return true;
    error = QSystemError(err, QSystemError::NativeError);
    return false;
}

//static
bool QFileSystemEngine::copyFile(const QFileSystemEntry &source, const QFileSystemEntry &target, QSystemError &error)
{
    //CFileMan is allocated each time because it is not thread-safe
    CFileMan *fm = 0;
    TRAPD(err, fm = CFileMan::NewL(qt_s60GetRFs()));
    if (err == KErrNone) {
        err = fm->Copy(qt_QString2TPtrC(absoluteName(source).nativeFilePath()), qt_QString2TPtrC(absoluteName(target).nativeFilePath()), 0);
        delete fm;
    }
    if (err == KErrNone)
        return true;
    error = QSystemError(err, QSystemError::NativeError);
    return false;
}

void QSymbianHostResolver::run()
{
    switch (iState) {
    case EGetByName:
        processNameResult();
        break;
    case EGetByAddress:
        processAddressResult();
        break;
    case ECompleteFromCache:
    case EError:
        returnResults();
        break;
    default:
        qWarning("QSymbianHostResolver internal error, bad state in run()");
        iResults.setError(QHostInfo::UnknownError);
        iResults.setErrorString(QSystemError(KErrCorrupt,QSystemError::NativeError).toString());
        returnResults();
    }
}

QT_BEGIN_NAMESPACE

static void setError_helper(QHostInfo &info, TInt symbianError)
{
    switch (symbianError) {
    case KErrDndNameNotFound:
    case KErrDndAddrNotFound:
    case KErrNotFound:
    case KErrEof:
        // various "no more results" error codes
        info.setError(QHostInfo::HostNotFound);
        info.setErrorString(QObject::tr("Host not found"));
        break;
    default:
        // Unknown error
        info.setError(QHostInfo::UnknownError);
        info.setErrorString(QSystemError(symbianError, QSystemError::NativeError).toString());
        break;
    }
}

bool QFSFileEngine::renameOverwrite(const QString &newName)
{
    Q_D(QFSFileEngine);
#if defined(Q_OS_WINCE)
    // Windows Embedded Compact 7 does not have MoveFileEx, simulate it with  the following sequence:
    //   1. DeleteAndRenameFile  (Should work on RAM FS when both files exist)
    //   2. DeleteFile/MoveFile  (Should work on all file systems)
    //
    // DeleteFile/MoveFile fallback implementation violates atomicity, but it is more acceptable than
    // alternative CopyFile/DeleteFile sequence for the following reasons:
    //
    //  1. DeleteFile/MoveFile is way faster than CopyFile/DeleteFile and thus more atomic.
    //  2. Given the intended use case of this function in QSaveFile, DeleteFile/MoveFile sequence will
    //     delete the old content, but leave a file "filename.ext.XXXXXX" in the same directory if MoveFile fails.
    //     With CopyFile/DeleteFile sequence, it can happen that new data is partially copied to target file
    //     (because CopyFile is not atomic either), thus leaving *some* content to target file.
    //     This makes the need for application level recovery harder to detect than in DeleteFile/MoveFile
    //     sequence where target file simply does not exist.
    //
    bool ret = ::DeleteAndRenameFile((wchar_t*)QFileSystemEntry(newName).nativeFilePath().utf16(),
                                     (wchar_t*)d->fileEntry.nativeFilePath().utf16()) != 0;
    if (!ret) {
        ret = ::DeleteFile((wchar_t*)QFileSystemEntry(newName).nativeFilePath().utf16()) != 0;
        if (ret || ::GetLastError() == ERROR_FILE_NOT_FOUND)
            ret = ::MoveFile((wchar_t*)d->fileEntry.nativeFilePath().utf16(),
                             (wchar_t*)QFileSystemEntry(newName).nativeFilePath().utf16()) != 0;
    }
#else
    bool ret = ::MoveFileEx((wchar_t*)d->fileEntry.nativeFilePath().utf16(),
                            (wchar_t*)QFileSystemEntry(newName).nativeFilePath().utf16(),
                            MOVEFILE_REPLACE_EXISTING) != 0;
#endif
    if (!ret)
        setError(QFile::RenameError, QSystemError(::GetLastError(), QSystemError::NativeError).toString());
    return ret;
}

QT_BEGIN_NAMESPACE

void QDnsLookupRunnable::query(const int requestType, const QByteArray &requestName, QDnsLookupReply *reply)
{
    // Perform DNS query.
    PDNS_RECORD dns_records = 0;
    const QString requestNameUtf16 = QString::fromUtf8(requestName.data(), requestName.size());
    const DNS_STATUS status = DnsQuery_W(reinterpret_cast<const wchar_t*>(requestNameUtf16.utf16()), requestType, DNS_QUERY_STANDARD, NULL, &dns_records, NULL);
    switch (status) {
    case ERROR_SUCCESS:
        break;
    case DNS_ERROR_RCODE_FORMAT_ERROR:
        reply->error = QDnsLookup::InvalidRequestError;
        reply->errorString = tr("Server could not process query");
        return;
    case DNS_ERROR_RCODE_SERVER_FAILURE:
        reply->error = QDnsLookup::ServerFailureError;
        reply->errorString = tr("Server failure");
        return;
    case DNS_ERROR_RCODE_NAME_ERROR:
        reply->error = QDnsLookup::NotFoundError;
        reply->errorString = tr("Non existent domain");
        return;
    case DNS_ERROR_RCODE_REFUSED:
        reply->error = QDnsLookup::ServerRefusedError;
        reply->errorString = tr("Server refused to answer");
        return;
    default:
        reply->error = QDnsLookup::InvalidReplyError;
        reply->errorString = QSystemError(status, QSystemError::NativeError).toString();
        return;
    }

    // Extract results.
    for (PDNS_RECORD ptr = dns_records; ptr != NULL; ptr = ptr->pNext) {
        const QString name = QUrl::fromAce( QString::fromWCharArray( ptr->pName ).toLatin1() );
        if (ptr->wType == QDnsLookup::A) {
            QDnsHostAddressRecord record;
            record.d->name = name;
            record.d->timeToLive = ptr->dwTtl;
            record.d->value = QHostAddress(ntohl(ptr->Data.A.IpAddress));
            reply->hostAddressRecords.append(record);
        } else if (ptr->wType == QDnsLookup::AAAA) {
            Q_IPV6ADDR addr;
            memcpy(&addr, &ptr->Data.AAAA.Ip6Address, sizeof(Q_IPV6ADDR));

            QDnsHostAddressRecord record;
            record.d->name = name;
            record.d->timeToLive = ptr->dwTtl;
            record.d->value = QHostAddress(addr);
            reply->hostAddressRecords.append(record);
        } else if (ptr->wType == QDnsLookup::CNAME) {
            QDnsDomainNameRecord record;
            record.d->name = name;
            record.d->timeToLive = ptr->dwTtl;
            record.d->value = QUrl::fromAce(QString::fromWCharArray(ptr->Data.Cname.pNameHost).toLatin1());
            reply->canonicalNameRecords.append(record);
        } else if (ptr->wType == QDnsLookup::MX) {
            QDnsMailExchangeRecord record;
            record.d->name = name;
            record.d->exchange = QUrl::fromAce(QString::fromWCharArray(ptr->Data.Mx.pNameExchange).toLatin1());
            record.d->preference = ptr->Data.Mx.wPreference;
            record.d->timeToLive = ptr->dwTtl;
            reply->mailExchangeRecords.append(record);
        } else if (ptr->wType == QDnsLookup::NS) {
            QDnsDomainNameRecord record;
            record.d->name = name;
            record.d->timeToLive = ptr->dwTtl;
            record.d->value = QUrl::fromAce(QString::fromWCharArray(ptr->Data.Ns.pNameHost).toLatin1());
            reply->nameServerRecords.append(record);
        } else if (ptr->wType == QDnsLookup::PTR) {
            QDnsDomainNameRecord record;
            record.d->name = name;
            record.d->timeToLive = ptr->dwTtl;
            record.d->value = QUrl::fromAce(QString::fromWCharArray(ptr->Data.Ptr.pNameHost).toLatin1());
            reply->pointerRecords.append(record);
        } else if (ptr->wType == QDnsLookup::SRV) {
            QDnsServiceRecord record;
            record.d->name = name;
            record.d->target = QUrl::fromAce(QString::fromWCharArray(ptr->Data.Srv.pNameTarget).toLatin1());
            record.d->port = ptr->Data.Srv.wPort;
            record.d->priority = ptr->Data.Srv.wPriority;
            record.d->timeToLive = ptr->dwTtl;
            record.d->weight = ptr->Data.Srv.wWeight;
            reply->serviceRecords.append(record);
        } else if (ptr->wType == QDnsLookup::TXT) {
            QDnsTextRecord record;
            record.d->name = name;
            record.d->timeToLive = ptr->dwTtl;
            for (unsigned int i = 0; i < ptr->Data.Txt.dwStringCount; ++i) {
                record.d->values << QString::fromWCharArray((ptr->Data.Txt.pStringArray[i])).toLatin1();;
            }
            reply->textRecords.append(record);
        }
    }

    DnsRecordListFree(dns_records, DnsFreeRecordList);
}

/*!
    \internal

    Generates a unique file path and returns a native handle to the open file.
    \a path is used as a template when generating unique paths, \a pos
    identifies the position of the first character that will be replaced in the
    template and \a length the number of characters that may be substituted.

    Returns an open handle to the newly created file if successful, an invalid
    handle otherwise. In both cases, the string in \a path will be changed and
    contain the generated path name.
*/
static bool createFileFromTemplate(NativeFileHandle &file,
        QFileSystemEntry::NativePath &path, size_t pos, size_t length,
        QSystemError &error)
{
    Q_ASSERT(length != 0);
    Q_ASSERT(pos < size_t(path.length()));
    Q_ASSERT(length <= size_t(path.length()) - pos);

    Char *const placeholderStart = (Char *)path.data() + pos;
    Char *const placeholderEnd = placeholderStart + length;

    // Initialize placeholder with random chars + PID.
    {
        Char *rIter = placeholderEnd;

#if defined(QT_BUILD_CORE_LIB)
        quint64 pid = quint64(QCoreApplication::applicationPid());
        do {
            *--rIter = Latin1Char((pid % 10) + '0');
            pid /= 10;
        } while (rIter != placeholderStart && pid != 0);
#endif

        while (rIter != placeholderStart) {
            char ch = char((qrand() & 0xffff) % (26 + 26));
            if (ch < 26)
                *--rIter = Latin1Char(ch + 'A');
            else
                *--rIter = Latin1Char(ch - 26 + 'a');
        }
    }

    for (;;) {
        // Atomically create file and obtain handle
#if defined(Q_OS_WIN)
#  ifndef Q_OS_WINRT
        file = CreateFile((const wchar_t *)path.constData(),
                GENERIC_READ | GENERIC_WRITE,
                FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, CREATE_NEW,
                FILE_ATTRIBUTE_NORMAL, NULL);
#  else // !Q_OS_WINRT
        file = CreateFile2((const wchar_t *)path.constData(),
                GENERIC_READ | GENERIC_WRITE,
                FILE_SHARE_READ | FILE_SHARE_WRITE, CREATE_NEW,
                NULL);
#  endif // Q_OS_WINRT

        if (file != INVALID_HANDLE_VALUE)
            return true;

        DWORD err = GetLastError();
        if (err == ERROR_ACCESS_DENIED) {
            WIN32_FILE_ATTRIBUTE_DATA attributes;
            if (!GetFileAttributesEx((const wchar_t *)path.constData(),
                                     GetFileExInfoStandard, &attributes)
                    || attributes.dwFileAttributes == INVALID_FILE_ATTRIBUTES) {
                // Potential write error (read-only parent directory, etc.).
                error = QSystemError(err, QSystemError::NativeError);
                return false;
            } // else file already exists as a directory.
        } else if (err != ERROR_FILE_EXISTS) {
            error = QSystemError(err, QSystemError::NativeError);
            return false;
        }
#else // POSIX
        file = QT_OPEN(path.constData(),
                QT_OPEN_CREAT | O_EXCL | QT_OPEN_RDWR | QT_OPEN_LARGEFILE,
                0600);

        if (file != -1)
            return true;

        int err = errno;
        if (err != EEXIST) {
            error = QSystemError(err, QSystemError::NativeError);
            return false;
        }
#endif

        /* tricky little algorwwithm for backward compatibility */
        for (Char *iter = placeholderStart;;) {
            // Character progression: [0-9] => 'a' ... 'z' => 'A' .. 'Z'
            // String progression: "ZZaiC" => "aabiC"
            switch (char(*iter)) {
                case 'Z':
                    // Rollover, advance next character
                    *iter = Latin1Char('a');
                    if (++iter == placeholderEnd) {
//.........这里部分代码省略.........

QT_BEGIN_NAMESPACE

void QDnsLookupRunnable::query(const int requestType, const QByteArray &requestName, const QHostAddress &nameserver, QDnsLookupReply *reply)
{
    // Perform DNS query.
    PDNS_RECORD dns_records = 0;
    const QString requestNameUtf16 = QString::fromUtf8(requestName.data(), requestName.size());
    IP4_ARRAY srvList;
    memset(&srvList, 0, sizeof(IP4_ARRAY));
    if (!nameserver.isNull()) {
        if (nameserver.protocol() == QAbstractSocket::IPv4Protocol) {
            // The below code is referenced from: http://support.microsoft.com/kb/831226
            srvList.AddrCount = 1;
            srvList.AddrArray[0] = htonl(nameserver.toIPv4Address());
        } else if (nameserver.protocol() == QAbstractSocket::IPv6Protocol) {
            // For supoprting IPv6 nameserver addresses, we'll need to switch
            // from DnsQuey() to DnsQueryEx() as it supports passing an IPv6
            // address in the nameserver list
            qWarning() << Q_FUNC_INFO << "IPv6 addresses for nameservers is currently not supported";
            reply->error = QDnsLookup::ResolverError;
            reply->errorString = tr("IPv6 addresses for nameservers is currently not supported");
            return;
        }
    }
    const DNS_STATUS status = DnsQuery_W(reinterpret_cast<const wchar_t*>(requestNameUtf16.utf16()), requestType, DNS_QUERY_STANDARD, &srvList, &dns_records, NULL);
    switch (status) {
    case ERROR_SUCCESS:
        break;
    case DNS_ERROR_RCODE_FORMAT_ERROR:
        reply->error = QDnsLookup::InvalidRequestError;
        reply->errorString = tr("Server could not process query");
        return;
    case DNS_ERROR_RCODE_SERVER_FAILURE:
        reply->error = QDnsLookup::ServerFailureError;
        reply->errorString = tr("Server failure");
        return;
    case DNS_ERROR_RCODE_NAME_ERROR:
        reply->error = QDnsLookup::NotFoundError;
        reply->errorString = tr("Non existent domain");
        return;
    case DNS_ERROR_RCODE_REFUSED:
        reply->error = QDnsLookup::ServerRefusedError;
        reply->errorString = tr("Server refused to answer");
        return;
    default:
        reply->error = QDnsLookup::InvalidReplyError;
        reply->errorString = QSystemError(status, QSystemError::NativeError).toString();
        return;
    }

    // Extract results.
    for (PDNS_RECORD ptr = dns_records; ptr != NULL; ptr = ptr->pNext) {
        const QString name = QUrl::fromAce( QString::fromWCharArray( ptr->pName ).toLatin1() );
        if (ptr->wType == QDnsLookup::A) {
            QDnsHostAddressRecord record;
            record.d->name = name;
            record.d->timeToLive = ptr->dwTtl;
            record.d->value = QHostAddress(ntohl(ptr->Data.A.IpAddress));
            reply->hostAddressRecords.append(record);
        } else if (ptr->wType == QDnsLookup::AAAA) {
            Q_IPV6ADDR addr;
            memcpy(&addr, &ptr->Data.AAAA.Ip6Address, sizeof(Q_IPV6ADDR));

            QDnsHostAddressRecord record;
            record.d->name = name;
            record.d->timeToLive = ptr->dwTtl;
            record.d->value = QHostAddress(addr);
            reply->hostAddressRecords.append(record);
        } else if (ptr->wType == QDnsLookup::CNAME) {
            QDnsDomainNameRecord record;
            record.d->name = name;
            record.d->timeToLive = ptr->dwTtl;
            record.d->value = QUrl::fromAce(QString::fromWCharArray(ptr->Data.Cname.pNameHost).toLatin1());
            reply->canonicalNameRecords.append(record);
        } else if (ptr->wType == QDnsLookup::MX) {
            QDnsMailExchangeRecord record;
            record.d->name = name;
            record.d->exchange = QUrl::fromAce(QString::fromWCharArray(ptr->Data.Mx.pNameExchange).toLatin1());
            record.d->preference = ptr->Data.Mx.wPreference;
            record.d->timeToLive = ptr->dwTtl;
            reply->mailExchangeRecords.append(record);
        } else if (ptr->wType == QDnsLookup::NS) {
            QDnsDomainNameRecord record;
            record.d->name = name;
            record.d->timeToLive = ptr->dwTtl;
            record.d->value = QUrl::fromAce(QString::fromWCharArray(ptr->Data.Ns.pNameHost).toLatin1());
            reply->nameServerRecords.append(record);
        } else if (ptr->wType == QDnsLookup::PTR) {
            QDnsDomainNameRecord record;
            record.d->name = name;
            record.d->timeToLive = ptr->dwTtl;
            record.d->value = QUrl::fromAce(QString::fromWCharArray(ptr->Data.Ptr.pNameHost).toLatin1());
            reply->pointerRecords.append(record);
        } else if (ptr->wType == QDnsLookup::SRV) {
            QDnsServiceRecord record;
            record.d->name = name;
            record.d->target = QUrl::fromAce(QString::fromWCharArray(ptr->Data.Srv.pNameTarget).toLatin1());
            record.d->port = ptr->Data.Srv.wPort;
            record.d->priority = ptr->Data.Srv.wPriority;
            record.d->timeToLive = ptr->dwTtl;
//.........这里部分代码省略.........