qsettings.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

    if (readOnly) {
        QFileInfo fileInfo(confFile->name);
        if (confFile->size == fileInfo.size() && confFile->timeStamp == fileInfo.lastModified())
            return;
    }

    /*
        Open the configuration file and try to use it using a named
        semaphore on Windows and an advisory lock on Unix-based
        systems. This protect us against other QSettings instances
        trying to access the same file from other threads or
        processes.

        As it stands now, the locking mechanism doesn't work for
        .plist files.
    */
    QFile file(confFile->name);
    bool createFile = !file.exists();
    if (!readOnly)
        file.open(QFile::ReadWrite);
    if (!file.isOpen())
        file.open(QFile::ReadOnly);

#ifdef Q_OS_WIN
    HANDLE semaphore = 0;
    static const int FileLockSemMax = 50;
    int numLocks = readOnly ? 1 : FileLockSemMax;

    if (file.isOpen()) {
        QString semName = QLatin1String("QSettings semaphore ");
        semName.append(file.fileName());

        QT_WA( {
            semaphore = CreateSemaphoreW(0, FileLockSemMax, FileLockSemMax, reinterpret_cast<const wchar_t *>(semName.utf16()));
        } , {
            semaphore = CreateSemaphoreA(0, FileLockSemMax, FileLockSemMax, semName.toLocal8Bit());
        } );

        if (semaphore) {
            for (int i = 0; i < numLocks; ++i)
                WaitForSingleObject(semaphore, INFINITE);
        } else {
            setStatus(QSettings::AccessError);
            return;
        }
    }
#else
    if (file.isOpen())
        unixLock(file.handle(), readOnly ? F_RDLCK : F_WRLCK);
#endif

    // If we have created the file, apply the file perms
    if (file.isOpen()) {
        if (createFile) {
            QFile::Permissions perms = QFile::ReadOwner|QFile::WriteOwner;
            if (!confFile->userPerms)
                perms |= QFile::ReadGroup|QFile::ReadOther;
            file.setPermissions(perms);
        }
    }

    /*
        We hold the lock. Let's reread the file if it has changed
        since last time we read it.
    */
    QFileInfo fileInfo(confFile->name);
    bool mustReadFile = true;

    if (!readOnly) {
        mustReadFile = (confFile->size != fileInfo.size()
                        || (confFile->size != 0 && confFile->timeStamp != fileInfo.lastModified()));
    }

    if (mustReadFile) {
        InternalSettingsMap newKeys;

        /*
            Files that we can't read (because of permissions or
            because they don't exist) are treated as empty files.
        */
        if (file.isReadable() && fileInfo.size() != 0) {
#ifdef Q_OS_MAC
            if (format == QSettings::NativeFormat) {
                ok = readPlistFile(confFile->name, &newKeys);
            } else
#endif
            {
                if (format <= QSettings::IniFormat) {
                    ok = readIniFile(file, &newKeys);
                } else {
                    if (readFunc) {
                        QSettings::SettingsMap tempNewKeys;
                        ok = readFunc(file, tempNewKeys);

                        if (ok) {
                            QSettings::SettingsMap::const_iterator i = tempNewKeys.constBegin();
                            while (i != tempNewKeys.constEnd()) {
                                newKeys.insert(QSettingsKey(i.key(), caseSensitivity), i.value());
                                ++i;
                            }
                        }
                    } else {
                        ok = false;
                    }
                }
            }

            if (!ok)
                setStatus(QSettings::FormatError);
        }

        confFile->originalKeys = newKeys;
        confFile->size = fileInfo.size();
        confFile->timeStamp = fileInfo.lastModified();
    }

    /*
        We also need to save the file. We still hold the file lock,
        so everything is under control.
    */
    if (!readOnly) {
        InternalSettingsMap mergedKeys = confFile->mergedKeyMap();

        if (file.isWritable()) {
#ifdef Q_OS_MAC
            if (format == QSettings::NativeFormat) {
                ok = writePlistFile(confFile->name, mergedKeys);
            } else
#endif
            {
                file.seek(0); // shouldn't be necessary
                file.resize(0);

                if (format <= QSettings::IniFormat) {
                    ok = writeIniFile(file, mergedKeys);
                } else {
                    if (writeFunc) {
                        QSettings::SettingsMap tempOriginalKeys;

                        InternalSettingsMap::const_iterator i = mergedKeys.constBegin();
                        while (i != mergedKeys.constEnd()) {
                            tempOriginalKeys.insert(i.key(), i.value());
                            ++i;
                        }
                        ok = writeFunc(file, tempOriginalKeys);
                    } else {
                        ok = false;
                    }
                }
            }
        } else {
            ok = false;
        }

        if (ok) {
            confFile->originalKeys = mergedKeys;
            confFile->addedKeys.clear();
            confFile->removedKeys.clear();

            QFileInfo fileInfo(confFile->name);
            confFile->size = fileInfo.size();
            confFile->timeStamp = fileInfo.lastModified();
        } else {
            setStatus(QSettings::AccessError);
        }
    }

    /*
        Release the file lock.
    */
#ifdef Q_OS_WIN
    if (semaphore != 0) {
        ReleaseSemaphore(semaphore, numLocks, 0);
        CloseHandle(semaphore);
    }
#endif
}

bool QConfFileSettingsPrivate::readIniLine(QIODevice &device, QByteArray &line, int &len,
                                           int &equalsCharPos)
{
#define MAYBE_GROW() \
    if (pos + 4 > line.size()) { \
        line.resize(pos << 1); \
        data = line.data(); \
    }

    char *data = line.data();
    char ch, ch2;
    int pos = 0;

    equalsCharPos = -1;

    while (device.getChar(&ch)) {
    process_ch:
        MAYBE_GROW();

        switch (ch) {
        case '"':
            data[pos++] = '"';
            while (device.getChar(&ch) && ch != '"') {
                MAYBE_GROW();

                if (static_cast<signed char>(ch) == -1)
                    goto end;

                if (ch == '\\') {
                    data[pos++] = '\\';
                    if (!device.getChar(&ch))
                        goto end;
                }
                data[pos++] = ch;
            }
            data[pos++] = '"';
            break;
        case ' ':
        case '\t':
            if (pos > 0)
                data[pos++] = ch;
            break;
        case '\n':
        case '\r':
        process_newline:
            /*
                According to the specs, a line ends with CF, LF,
                CR+LF, or LF+CR. In practice, this is irrelevant and
                the ungetch() call is expensive, so let's not do it.
            */
#if 0
            if (!device.getChar(&ch2))
                goto end;
            if ((ch2 != '\n' && ch2 != '\r') || ch == ch2)
                device.ungetChar(ch2);
#endif
            if (pos > 0)
                goto end;
            break;
        case '\\':
            if (!device.getChar(&ch))
                goto end;

            if (ch == '\n' || ch == '\r') {
                if (device.getChar(&ch2)) {
                    if ((ch2 != '\n' && ch2 != '\r') || ch == ch2) {
                        ch = ch2;
                        goto process_ch;
                    }
                }
            } else {
                data[pos++] = '\\';
                data[pos++] = ch;
            }
            break;
        case ';':
            while (device.getChar(&ch)) {
                if (ch == '\n' || ch == '\r')
                    goto process_newline;
            }
            break;
        case '=':
            if (equalsCharPos == -1) {
                while (pos > 0 && (ch = data[pos - 1]) == ' ' || ch == '\t')
                    --pos;
                equalsCharPos = pos;
            }
            data[pos++] = '=';
            break;
        default:
            data[pos++] = ch;
        }
    }

end:
    data[pos] = '\0';
    len = pos;
    return pos > 0;
}

/*
    Returns false on parse error. However, as many keys are read as
    possible, so if the user doesn't check the status he will get the
    most out of the file anyway.
*/
bool QConfFileSettingsPrivate::readIniFile(QIODevice &device, InternalSettingsMap *map)
{
    QString currentSection;
    bool currentSectionIsLowercase = true;
    QByteArray line;
    line.resize(512);
    int equalsCharPos;
    int len;

    bool ok = true;

    while (readIniLine(device, line, len, equalsCharPos)) {
        if (line.at(0) == '[') {
            // this is a section
            QByteArray iniSection;
            int idx = line.indexOf(']');
            if (idx == -1) {
                ok = false;
                iniSection = line.mid(1);
            } else {
                iniSection = line.mid(1, idx - 1);
            }

            iniSection = iniSection.trimmed();

            if (qstricmp(iniSection, "general") == 0) {
                currentSection.clear();
            } else if (qstricmp(iniSection, "%general") == 0) {
                currentSection = QLatin1String("general");
                currentSection += QLatin1Char('/');
            } else {
                currentSection.clear();
                currentSectionIsLowercase = iniUnescapedKey(iniSection, 0, iniSection.size(),
                                                            currentSection);
                currentSection += QLatin1Char('/');
            }
        } else {
            if (equalsCharPos < 1) {
                ok = false;
                continue;
            }

            QString key = currentSection;
            bool keyIsLowercase = (iniUnescapedKey(line, 0, equalsCharPos, key)
                                   && currentSectionIsLowercase);

            QString strValue;
            strValue.reserve(len - equalsCharPos);
            QStringList *strListValue = iniUnescapedStringList(line, equalsCharPos + 1, len,
                                                               strValue);
            QVariant variant;
            if (strListValue) {
                variant = stringListToVariantList(*strListValue);
                delete strListValue;
            } else {
                variant = stringToVariant(strValue);
            }

            /*
                We try to avoid the expensive toLower() call in
                QSettingsKey by passing Qt::CaseSensitive when the
                key is already in lowercase.
            */
            map->insert(QSettingsKey(key, keyIsLowercase ? Qt::CaseSensitive : Qt::CaseInsensitive),
                        variant);
        }
    }

    return ok;
}

bool QConfFileSettingsPrivate::writeIniFile(QIODevice &device, const InternalSettingsMap &map)
{
    typedef QMap<QString, QVariantMap> IniMap;
    IniMap iniMap;
    IniMap::const_iterator i;

#ifdef Q_OS_WIN
    const char * const eol = "\r\n";
#else
    const char eol = '\n';
#endif

    for (InternalSettingsMap::const_iterator j = map.constBegin(); j != map.constEnd(); ++j) {
        QString section;
        QString key = j.key().realKey();
        int slashPos;

        if ((slashPos = key.indexOf(QLatin1Char('/'))) != -1) {
            section = key.left(slashPos);
            key.remove(0, slashPos + 1);
        }
        iniMap[section][key] = j.value();
    }

    bool writeError = false;
    for (i = iniMap.constBegin(); !writeError && i != iniMap.constEnd(); ++i) {
        QByteArray realSection;

        iniEscapedKey(i.key(), realSection);

        if (realSection.isEmpty()) {
            realSection = "[General]";
        } else if (qstricmp(realSection, "general") == 0) {
            realSection = "[%General]";
        } else {
            realSection.prepend('[');
            realSection.append(']');
        }

        if (i != iniMap.constBegin())
            realSection.prepend(eol);
        realSection += eol;

        device.write(realSection);

        const QVariantMap &ents = i.value();
        for (QVariantMap::const_iterator j = ents.constBegin(); j != ents.constEnd(); ++j) {
            QByteArray block;
            iniEscapedKey(j.key(), block);
            block += '=';

            const QVariant &value = j.value();

            /*
                The size() != 1 trick is necessary because
                QVariant(QString("foo")).toList() returns an empty
                list, not a list containing "foo".
            */
            if (value.type() == QVariant::StringList
                    || (value.type() == QVariant::List && value.toList().size() != 1)) {
                iniEscapedStringList(variantListToStringList(value.toList()), block);
            } else {