// Binlog管理器
@Component
public class BinlogManager {
    
    @Autowired
    private BinlogConfigManager configManager;
    
    @Autowired
    private BinlogEventProcessor eventProcessor;
    
    /**
     * 初始化Binlog
     */
    public void initializeBinlog() {
        try {
            // 1. 检查Binlog配置
            BinlogConfig config = configManager.getBinlogConfig();
            validateBinlogConfig(config);
            
            // 2. 创建Binlog文件
            createBinlogFile(config);
            
            // 3. 启动Binlog写入服务
            startBinlogWriter(config);
            
            // 4. 启动Binlog轮转服务
            startBinlogRotation(config);
            
            logger.info("Binlog初始化完成");
            
        } catch (Exception e) {
            logger.error("Binlog初始化失败: {}", e.getMessage());
            throw new BinlogInitializationException("Binlog初始化失败", e);
        }
    }
    
    /**
     * 写入Binlog事件
     */
    public void writeBinlogEvent(BinlogEvent event) {
        try {
            // 1. 验证事件格式
            validateBinlogEvent(event);
            
            // 2. 序列化事件
            byte[] eventData = serializeBinlogEvent(event);
            
            // 3. 写入Binlog文件
            writeToBinlogFile(eventData);
            
            // 4. 更新Binlog位置
            updateBinlogPosition(event);
            
            // 5. 触发事件处理器
            eventProcessor.processEvent(event);
            
        } catch (Exception e) {
            logger.error("写入Binlog事件失败: {}", e.getMessage());
            throw new BinlogWriteException("Binlog事件写入失败", e);
        }
    }
    
    /**
     * 读取Binlog事件
     */
    public List<BinlogEvent> readBinlogEvents(String binlogFile, long startPosition, int maxEvents) {
        try {
            List<BinlogEvent> events = new ArrayList<>();
            
            // 1. 打开Binlog文件
            BinlogFileReader reader = new BinlogFileReader(binlogFile);
            
            // 2. 定位到指定位置
            reader.seek(startPosition);
            
            // 3. 读取事件
            int eventCount = 0;
            while (eventCount < maxEvents && reader.hasNext()) {
                BinlogEvent event = reader.readNextEvent();
                if (event != null) {
                    events.add(event);
                    eventCount++;
                }
            }
            
            reader.close();
            return events;
            
        } catch (Exception e) {
            logger.error("读取Binlog事件失败: {}", e.getMessage());
            throw new BinlogReadException("Binlog事件读取失败", e);
        }
    }
    
    /**
     * 执行Binlog轮转
     */
    public void rotateBinlog() {
        try {
            // 1. 刷新当前Binlog
            flushCurrentBinlog();
            
            // 2. 创建新的Binlog文件
            String newBinlogFile = createNewBinlogFile();
            
            // 3. 更新Binlog索引
            updateBinlogIndex(newBinlogFile);
            
            // 4. 清理过期Binlog
            cleanupExpiredBinlogs();
            
            logger.info("Binlog轮转完成，新文件: {}", newBinlogFile);
            
        } catch (Exception e) {
            logger.error("Binlog轮转失败: {}", e.getMessage());
            throw new BinlogRotationException("Binlog轮转失败", e);
        }
    }
    
    /**
     * 验证Binlog配置
     */
    private void validateBinlogConfig(BinlogConfig config) {
        if (config.getBinlogFormat() == null) {
            throw new BinlogConfigException("Binlog格式未配置");
        }
        
        if (config.getMaxBinlogSize() <= 0) {
            throw new BinlogConfigException("Binlog最大大小配置无效");
        }
        
        if (config.getExpireLogsDays() < 0) {
            throw new BinlogConfigException("Binlog过期天数配置无效");
        }
    }
    
    /**
     * 验证Binlog事件
     */
    private void validateBinlogEvent(BinlogEvent event) {
        if (event == null) {
            throw new BinlogEventException("Binlog事件为空");
        }
        
        if (event.getEventType() == null) {
            throw new BinlogEventException("Binlog事件类型为空");
        }
        
        if (event.getTimestamp() <= 0) {
            throw new BinlogEventException("Binlog事件时间戳无效");
        }
    }
    
    /**
     * 序列化Binlog事件
     */
    private byte[] serializeBinlogEvent(BinlogEvent event) {
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            ObjectOutputStream oos = new ObjectOutputStream(baos);
            
            // 写入事件头
            writeEventHeader(oos, event);
            
            // 写入事件体
            writeEventBody(oos, event);
            
            oos.close();
            return baos.toByteArray();
            
        } catch (Exception e) {
            logger.error("序列化Binlog事件失败: {}", e.getMessage());
            throw new BinlogSerializationException("Binlog事件序列化失败", e);
        }
    }
    
    /**
     * 写入事件头
     */
    private void writeEventHeader(ObjectOutputStream oos, BinlogEvent event) throws IOException {
        oos.writeLong(event.getTimestamp());
        oos.writeInt(event.getEventType().getValue());
        oos.writeLong(event.getServerId());
        oos.writeLong(event.getEventLength());
        oos.writeLong(event.getNextPosition());
    }
    
    /**
     * 写入事件体
     */
    private void writeEventBody(ObjectOutputStream oos, BinlogEvent event) throws IOException {
        switch (event.getEventType()) {
            case QUERY_EVENT:
                writeQueryEvent(oos, (QueryEvent) event);
                break;
            case TABLE_MAP_EVENT:
                writeTableMapEvent(oos, (TableMapEvent) event);
                break;
            case WRITE_ROWS_EVENT:
                writeWriteRowsEvent(oos, (WriteRowsEvent) event);
                break;
            case UPDATE_ROWS_EVENT:
                writeUpdateRowsEvent(oos, (UpdateRowsEvent) event);
                break;
            case DELETE_ROWS_EVENT:
                writeDeleteRowsEvent(oos, (DeleteRowsEvent) event);
                break;
            default:
                oos.writeObject(event.getData());
        }
    }
}

// Binlog事件类
public class BinlogEvent {
    private long timestamp;
    private BinlogEventType eventType;
    private long serverId;
    private long eventLength;
    private long nextPosition;
    private Object data;
    
    // 构造函数和getter/setter方法
}

// Binlog事件类型枚举
public enum BinlogEventType {
    QUERY_EVENT(2),
    TABLE_MAP_EVENT(19),
    WRITE_ROWS_EVENT(30),
    UPDATE_ROWS_EVENT(31),
    DELETE_ROWS_EVENT(32),
    XID_EVENT(16);
    
    private final int value;
    
    BinlogEventType(int value) {
        this.value = value;
    }
    
    public int getValue() {
        return value;
    }
}

// Binlog配置类
public class BinlogConfig {
    private BinlogFormat binlogFormat;
    private long maxBinlogSize;
    private int expireLogsDays;
    private boolean syncBinlog;
    private int syncBinlogInterval;
    private String binlogDir;
    
    // 构造函数和getter/setter方法
}

public enum BinlogFormat {
    STATEMENT,  // 语句模式
    ROW,        // 行模式
    MIXED       // 混合模式
}

// Binlog主从复制管理器
@Component
public class BinlogReplicationManager {
    
    @Autowired
    private BinlogManager binlogManager;
    
    @Autowired
    private SlaveConnector slaveConnector;
    
    /**
     * 启动主从复制
     */
    public void startReplication(ReplicationConfig config) {
        try {
            // 1. 初始化主库Binlog
            binlogManager.initializeBinlog();
            
            // 2. 连接从库
            List<SlaveConnection> slaves = connectSlaves(config.getSlaveConfigs());
            
            // 3. 启动复制线程
            for (SlaveConnection slave : slaves) {
                startReplicationThread(slave, config);
            }
            
            logger.info("主从复制启动成功，从库数量: {}", slaves.size());
            
        } catch (Exception e) {
            logger.error("主从复制启动失败: {}", e.getMessage());
            throw new ReplicationException("主从复制启动失败", e);
        }
    }
    
    /**
     * 处理复制事件
     */
    public void processReplicationEvent(BinlogEvent event) {
        try {
            // 1. 获取所有从库连接
            List<SlaveConnection> slaves = slaveConnector.getActiveSlaves();
            
            // 2. 并行发送到从库
            for (SlaveConnection slave : slaves) {
                sendEventToSlave(slave, event);
            }
            
        } catch (Exception e) {
            logger.error("处理复制事件失败: {}", e.getMessage());
        }
    }
    
    /**
     * 发送事件到从库
     */
    private void sendEventToSlave(SlaveConnection slave, BinlogEvent event) {
        try {
            // 1. 检查从库状态
            if (!slave.isConnected()) {
                logger.warn("从库连接已断开: {}", slave.getSlaveId());
                return;
            }
            
            // 2. 序列化事件
            byte[] eventData = serializeEventForSlave(event);
            
            // 3. 发送到从库
            slave.sendEvent(eventData);
            
            // 4. 更新复制位置
            updateSlavePosition(slave, event);
            
        } catch (Exception e) {
            logger.error("发送事件到从库失败: {}", slave.getSlaveId(), e);
            handleSlaveError(slave, e);
        }
    }
    
    /**
     * 处理从库错误
     */
    private void handleSlaveError(SlaveConnection slave, Exception error) {
        try {
            // 1. 记录错误日志
            logger.error("从库错误: {}, 错误信息: {}", slave.getSlaveId(), error.getMessage());
            
            // 2. 尝试重连
            if (slave.isReconnectable()) {
                slave.reconnect();
            } else {
                // 3. 标记从库为不可用
                slaveConnector.markSlaveUnavailable(slave.getSlaveId());
            }
            
        } catch (Exception e) {
            logger.error("处理从库错误失败: {}", e.getMessage());
        }
    }
    
    /**
     * 检查复制延迟
     */
    public ReplicationLagInfo checkReplicationLag() {
        ReplicationLagInfo lagInfo = new ReplicationLagInfo();
        
        try {
            List<SlaveConnection> slaves = slaveConnector.getActiveSlaves();
            
            for (SlaveConnection slave : slaves) {
                // 获取从库复制位置
                long slavePosition = slave.getReplicationPosition();
                
                // 获取主库Binlog位置
                long masterPosition = binlogManager.getCurrentPosition();
                
                // 计算延迟
                long lag = masterPosition - slavePosition;
                
                lagInfo.addSlaveLag(slave.getSlaveId(), lag);
            }
            
        } catch (Exception e) {
            logger.error("检查复制延迟失败: {}", e.getMessage());
        }
        
        return lagInfo;
    }
    
    /**
     * 执行复制恢复
     */
    public void recoverReplication(String slaveId) {
        try {
            // 1. 获取从库连接
            SlaveConnection slave = slaveConnector.getSlave(slaveId);
            
            if (slave == null) {
                throw new ReplicationException("从库不存在: " + slaveId);
            }
            
            // 2. 获取从库最后位置
            long lastPosition = slave.getLastReplicationPosition();
            
            // 3. 从指定位置开始复制
            resumeReplicationFromPosition(slave, lastPosition);
            
            logger.info("从库复制恢复成功: {}", slaveId);
            
        } catch (Exception e) {
            logger.error("复制恢复失败: {}", slaveId, e);
            throw new ReplicationException("复制恢复失败", e);
        }
    }
}

// 复制配置类
public class ReplicationConfig {
    private List<SlaveConfig> slaveConfigs;
    private int replicationThreads;
    private long replicationTimeout;
    private boolean parallelReplication;
    
    // 构造函数和getter/setter方法
}

// 从库配置类
public class SlaveConfig {
    private String slaveId;
    private String host;
    private int port;
    private String username;
    private String password;
    private String database;
    
    // 构造函数和getter/setter方法
}

// 从库连接类
public class SlaveConnection {
    private String slaveId;
    private String host;
    private int port;
    private Socket socket;
    private boolean connected;
    private long replicationPosition;
    private long lastReplicationPosition;
    
    public void sendEvent(byte[] eventData) throws IOException {
        if (!connected) {
            throw new IOException("从库连接未建立");
        }
        
        OutputStream os = socket.getOutputStream();
        os.write(eventData);
        os.flush();
    }
    
    public void reconnect() throws IOException {
        disconnect();
        connect();
    }
    
    // 其他方法...
}

// 复制延迟信息类
public class ReplicationLagInfo {
    private Map<String, Long> slaveLags = new HashMap<>();
    
    public void addSlaveLag(String slaveId, long lag) {
        slaveLags.put(slaveId, lag);
    }
    
    public long getMaxLag() {
        return slaveLags.values().stream().mapToLong(Long::longValue).max().orElse(0);
    }
    
    public double getAverageLag() {
        return slaveLags.values().stream().mapToLong(Long::longValue).average().orElse(0.0);
    }
    
    // getter/setter方法
}

// Redo Log管理器
@Component
public class RedoLogManager {
    
    @Autowired
    private RedoLogConfigManager configManager;
    
    @Autowired
    private RedoLogBufferManager bufferManager;
    
    /**
     * 初始化Redo Log
     */
    public void initializeRedoLog() {
        try {
            // 1. 获取Redo Log配置
            RedoLogConfig config = configManager.getRedoLogConfig();
            
            // 2. 创建Redo Log文件
            createRedoLogFiles(config);
            
            // 3. 初始化Redo Log缓冲区
            bufferManager.initializeBuffer(config);
            
            // 4. 启动刷盘线程
            startFlushThread(config);
            
            logger.info("Redo Log初始化完成");
            
        } catch (Exception e) {
            logger.error("Redo Log初始化失败: {}", e.getMessage());
            throw new RedoLogInitializationException("Redo Log初始化失败", e);
        }
    }
    
    /**
     * 写入Redo Log记录
     */
    public void writeRedoLogRecord(RedoLogRecord record) {
        try {
            // 1. 验证记录
            validateRedoLogRecord(record);
            
            // 2. 序列化记录
            byte[] recordData = serializeRedoLogRecord(record);
            
            // 3. 写入缓冲区
            bufferManager.writeToBuffer(recordData);
            
            // 4. 检查是否需要刷盘
            checkFlushCondition();
            
        } catch (Exception e) {
            logger.error("写入Redo Log记录失败: {}", e.getMessage());
            throw new RedoLogWriteException("Redo Log记录写入失败", e);
        }
    }
    
    /**
     * 执行刷盘操作
     */
    public void flushRedoLog() {
        try {
            // 1. 获取缓冲区数据
            List<byte[]> bufferData = bufferManager.getBufferData();
            
            if (bufferData.isEmpty()) {
                return;
            }
            
            // 2. 写入Redo Log文件
            writeToRedoLogFile(bufferData);
            
            // 3. 清空缓冲区
            bufferManager.clearBuffer();
            
            // 4. 更新LSN
            updateLSN();
            
            logger.debug("Redo Log刷盘完成，记录数: {}", bufferData.size());
            
        } catch (Exception e) {
            logger.error("Redo Log刷盘失败: {}", e.getMessage());
            throw new RedoLogFlushException("Redo Log刷盘失败", e);
        }
    }
    
    /**
     * 执行崩溃恢复
     */
    public void performCrashRecovery() {
        try {
            logger.info("开始执行崩溃恢复");
            
            // 1. 扫描Redo Log文件
            List<RedoLogFile> redoLogFiles = scanRedoLogFiles();
            
            // 2. 解析Redo Log记录
            List<RedoLogRecord> records = parseRedoLogRecords(redoLogFiles);
            
            // 3. 按LSN排序
            records.sort(Comparator.comparingLong(RedoLogRecord::getLSN));
            
            // 4. 应用Redo Log
            applyRedoLogRecords(records);
            
            logger.info("崩溃恢复完成，处理记录数: {}", records.size());
            
        } catch (Exception e) {
            logger.error("崩溃恢复失败: {}", e.getMessage());
            throw new CrashRecoveryException("崩溃恢复失败", e);
        }
    }
    
    /**
     * 验证Redo Log记录
     */
    private void validateRedoLogRecord(RedoLogRecord record) {
        if (record == null) {
            throw new RedoLogRecordException("Redo Log记录为空");
        }
        
        if (record.getLSN() <= 0) {
            throw new RedoLogRecordException("LSN无效");
        }
        
        if (record.getPageId() <= 0) {
            throw new RedoLogRecordException("页面ID无效");
        }
        
        if (record.getData() == null || record.getData().length == 0) {
            throw new RedoLogRecordException("记录数据为空");
        }
    }
    
    /**
     * 序列化Redo Log记录
     */
    private byte[] serializeRedoLogRecord(RedoLogRecord record) {
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            DataOutputStream dos = new DataOutputStream(baos);
            
            // 写入记录头
            dos.writeLong(record.getLSN());
            dos.writeLong(record.getTransactionId());
            dos.writeLong(record.getPageId());
            dos.writeInt(record.getOffset());
            dos.writeInt(record.getLength());
            dos.writeByte(record.getType().getValue());
            
            // 写入记录数据
            dos.write(record.getData());
            
            dos.close();
            return baos.toByteArray();
            
        } catch (Exception e) {
            logger.error("序列化Redo Log记录失败: {}", e.getMessage());
            throw new RedoLogSerializationException("Redo Log记录序列化失败", e);
        }
    }
    
    /**
     * 检查刷盘条件
     */
    private void checkFlushCondition() {
        RedoLogConfig config = configManager.getRedoLogConfig();
        
        // 检查缓冲区大小
        if (bufferManager.getBufferSize() >= config.getFlushBufferSize()) {
            flushRedoLog();
        }
        
        // 检查时间间隔
        if (bufferManager.getLastFlushTime() + config.getFlushInterval() <= System.currentTimeMillis()) {
            flushRedoLog();
        }
    }
    
    /**
     * 应用Redo Log记录
     */
    private void applyRedoLogRecords(List<RedoLogRecord> records) {
        for (RedoLogRecord record : records) {
            try {
                // 1. 读取页面
                DataPage page = readDataPage(record.getPageId());
                
                // 2. 应用修改
                applyPageModification(page, record);
                
                // 3. 写回页面
                writeDataPage(page);
                
            } catch (Exception e) {
                logger.error("应用Redo Log记录失败: LSN={}, PageId={}", 
                    record.getLSN(), record.getPageId(), e);
            }
        }
    }
}

// Redo Log记录类
public class RedoLogRecord {
    private long lsn;                    // 日志序列号
    private long transactionId;          // 事务ID
    private long pageId;                 // 页面ID
    private int offset;                  // 偏移量
    private int length;                  // 数据长度
    private RedoLogType type;            // 记录类型
    private byte[] data;                 // 记录数据
    
    // 构造函数和getter/setter方法
}

// Redo Log类型枚举
public enum RedoLogType {
    INSERT(1),
    UPDATE(2),
    DELETE(3),
    PAGE_ALLOC(4),
    PAGE_FREE(5);
    
    private final int value;
    
    RedoLogType(int value) {
        this.value = value;
    }
    
    public int getValue() {
        return value;
    }
}

// Redo Log配置类
public class RedoLogConfig {
    private int redoLogFileCount;        // Redo Log文件数量
    private long redoLogFileSize;        // 单个文件大小
    private long flushBufferSize;        // 刷盘缓冲区大小
    private long flushInterval;          // 刷盘时间间隔
    private boolean syncFlush;           // 是否同步刷盘
    
    // 构造函数和getter/setter方法
}

// Redo Log缓冲区管理器
@Component
public class RedoLogBufferManager {
    
    private final List<byte[]> buffer = new ArrayList<>();
    private final AtomicLong bufferSize = new AtomicLong(0);
    private final AtomicLong lastFlushTime = new AtomicLong(System.currentTimeMillis());
    
    /**
     * 初始化缓冲区
     */
    public void initializeBuffer(RedoLogConfig config) {
        buffer.clear();
        bufferSize.set(0);
        lastFlushTime.set(System.currentTimeMillis());
    }
    
    /**
     * 写入缓冲区
     */
    public void writeToBuffer(byte[] data) {
        synchronized (buffer) {
            buffer.add(data);
            bufferSize.addAndGet(data.length);
        }
    }
    
    /**
     * 获取缓冲区数据
     */
    public List<byte[]> getBufferData() {
        synchronized (buffer) {
            return new ArrayList<>(buffer);
        }
    }
    
    /**
     * 清空缓冲区
     */
    public void clearBuffer() {
        synchronized (buffer) {
            buffer.clear();
            bufferSize.set(0);
            lastFlushTime.set(System.currentTimeMillis());
        }
    }
    
    /**
     * 获取缓冲区大小
     */
    public long getBufferSize() {
        return bufferSize.get();
    }
    
    /**
     * 获取最后刷盘时间
     */
    public long getLastFlushTime() {
        return lastFlushTime.get();
    }
}

// Redo Log性能优化器
@Component
public class RedoLogPerformanceOptimizer {
    
    @Autowired
    private RedoLogManager redoLogManager;
    
    @Autowired
    private SystemMonitor systemMonitor;
    
    /**
     * 优化Redo Log性能
     */
    public RedoLogOptimizationResult optimizeRedoLogPerformance() {
        try {
            // 1. 分析当前性能
            RedoLogPerformanceAnalysis analysis = analyzeRedoLogPerformance();
            
            // 2. 识别性能瓶颈
            List<RedoLogBottleneck> bottlenecks = identifyBottlenecks(analysis);
            
            // 3. 生成优化建议
            List<OptimizationSuggestion> suggestions = generateOptimizationSuggestions(bottlenecks);
            
            // 4. 应用优化配置
            OptimizationResult result = applyOptimizations(suggestions);
            
            return new RedoLogOptimizationResult(result.isSuccess(), result.getMessage(), suggestions);
            
        } catch (Exception e) {
            logger.error("Redo Log性能优化失败: {}", e.getMessage());
            return new RedoLogOptimizationResult(false, "优化失败: " + e.getMessage(), null);
        }
    }
    
    /**
     * 分析Redo Log性能
     */
    private RedoLogPerformanceAnalysis analyzeRedoLogPerformance() {
        RedoLogPerformanceAnalysis analysis = new RedoLogPerformanceAnalysis();
        
        // 分析写入性能
        double writeThroughput = calculateWriteThroughput();
        analysis.setWriteThroughput(writeThroughput);
        
        // 分析刷盘性能
        double flushLatency = calculateFlushLatency();
        analysis.setFlushLatency(flushLatency);
        
        // 分析缓冲区使用率
        double bufferUtilization = calculateBufferUtilization();
        analysis.setBufferUtilization(bufferUtilization);
        
        // 分析文件使用率
        double fileUtilization = calculateFileUtilization();
        analysis.setFileUtilization(fileUtilization);
        
        return analysis;
    }
    
    /**
     * 计算写入吞吐量
     */
    private double calculateWriteThroughput() {
        // 通过监控数据计算每秒写入的字节数
        long bytesWritten = getBytesWrittenInLastSecond();
        return bytesWritten / 1024.0 / 1024.0; // MB/s
    }
    
    /**
     * 计算刷盘延迟
     */
    private double calculateFlushLatency() {
        // 通过监控数据计算平均刷盘延迟
        List<Long> flushTimes = getFlushTimesInLastMinute();
        if (flushTimes.isEmpty()) {
            return 0.0;
        }
        
        return flushTimes.stream().mapToLong(Long::longValue).average().orElse(0.0);
    }
    
    /**
     * 计算缓冲区使用率
     */
    private double calculateBufferUtilization() {
        long currentBufferSize = getCurrentBufferSize();
        long maxBufferSize = getMaxBufferSize();
        
        if (maxBufferSize == 0) {
            return 0.0;
        }
        
        return (double) currentBufferSize / maxBufferSize;
    }
    
    /**
     * 计算文件使用率
     */
    private double calculateFileUtilization() {
        long usedFileSize = getUsedFileSize();
        long totalFileSize = getTotalFileSize();
        
        if (totalFileSize == 0) {
            return 0.0;
        }
        
        return (double) usedFileSize / totalFileSize;
    }
    
    /**
     * 识别性能瓶颈
     */
    private List<RedoLogBottleneck> identifyBottlenecks(RedoLogPerformanceAnalysis analysis) {
        List<RedoLogBottleneck> bottlenecks = new ArrayList<>();
        
        // 写入吞吐量瓶颈
        if (analysis.getWriteThroughput() < 100) { // 100 MB/s
            bottlenecks.add(new RedoLogBottleneck(
                BottleneckType.LOW_WRITE_THROUGHPUT,
                "写入吞吐量过低: " + analysis.getWriteThroughput() + " MB/s",
                analysis.getWriteThroughput()));
        }
        
        // 刷盘延迟瓶颈
        if (analysis.getFlushLatency() > 100) { // 100ms
            bottlenecks.add(new RedoLogBottleneck(
                BottleneckType.HIGH_FLUSH_LATENCY,
                "刷盘延迟过高: " + analysis.getFlushLatency() + " ms",
                analysis.getFlushLatency()));
        }
        
        // 缓冲区使用率瓶颈
        if (analysis.getBufferUtilization() > 0.9) {
            bottlenecks.add(new RedoLogBottleneck(
                BottleneckType.HIGH_BUFFER_UTILIZATION,
                "缓冲区使用率过高: " + analysis.getBufferUtilization(),
                analysis.getBufferUtilization()));
        }
        
        // 文件使用率瓶颈
        if (analysis.getFileUtilization() > 0.8) {
            bottlenecks.add(new RedoLogBottleneck(
                BottleneckType.HIGH_FILE_UTILIZATION,
                "文件使用率过高: " + analysis.getFileUtilization(),
                analysis.getFileUtilization()));
        }
        
        return bottlenecks;
    }
    
    /**
     * 生成优化建议
     */
    private List<OptimizationSuggestion> generateOptimizationSuggestions(List<RedoLogBottleneck> bottlenecks) {
        List<OptimizationSuggestion> suggestions = new ArrayList<>();
        
        for (RedoLogBottleneck bottleneck : bottlenecks) {
            switch (bottleneck.getType()) {
                case LOW_WRITE_THROUGHPUT:
                    suggestions.add(createWriteThroughputOptimization(bottleneck));
                    break;
                case HIGH_FLUSH_LATENCY:
                    suggestions.add(createFlushLatencyOptimization(bottleneck));
                    break;
                case HIGH_BUFFER_UTILIZATION:
                    suggestions.add(createBufferOptimization(bottleneck));
                    break;
                case HIGH_FILE_UTILIZATION:
                    suggestions.add(createFileOptimization(bottleneck));
                    break;
            }
        }
        
        return suggestions;
    }
    
    /**
     * 创建写入吞吐量优化建议
     */
    private OptimizationSuggestion createWriteThroughputOptimization(RedoLogBottleneck bottleneck) {
        OptimizationSuggestion suggestion = new OptimizationSuggestion();
        suggestion.setType(OptimizationType.INCREASE_BUFFER_SIZE);
        suggestion.setTitle("增加缓冲区大小");
        suggestion.setDescription("当前写入吞吐量过低，建议增加Redo Log缓冲区大小");
        suggestion.setPriority(OptimizationPriority.HIGH);
        
        suggestion.addParameter("bufferSize", "16777216"); // 16MB
        suggestion.addParameter("flushInterval", "1000");   // 1秒
        
        return suggestion;
    }
    
    /**
     * 创建刷盘延迟优化建议
     */
    private OptimizationSuggestion createFlushLatencyOptimization(RedoLogBottleneck bottleneck) {
        OptimizationSuggestion suggestion = new OptimizationSuggestion();
        suggestion.setType(OptimizationType.OPTIMIZE_FLUSH_STRATEGY);
        suggestion.setTitle("优化刷盘策略");
        suggestion.setDescription("当前刷盘延迟过高，建议优化刷盘策略");
        suggestion.setPriority(OptimizationPriority.HIGH);
        
        suggestion.addParameter("syncFlush", "false");
        suggestion.addParameter("flushInterval", "500");    // 500ms
        suggestion.addParameter("flushBufferSize", "8388608"); // 8MB
        
        return suggestion;
    }
    
    /**
     * 创建缓冲区优化建议
     */
    private OptimizationSuggestion createBufferOptimization(RedoLogBottleneck bottleneck) {
        OptimizationSuggestion suggestion = new OptimizationSuggestion();
        suggestion.setType(OptimizationType.INCREASE_BUFFER_SIZE);
        suggestion.setTitle("增加缓冲区大小");
        suggestion.setDescription("当前缓冲区使用率过高，建议增加缓冲区大小");
        suggestion.setPriority(OptimizationPriority.MEDIUM);
        
        suggestion.addParameter("bufferSize", "33554432"); // 32MB
        suggestion.addParameter("flushInterval", "2000");   // 2秒
        
        return suggestion;
    }
    
    /**
     * 创建文件优化建议
     */
    private OptimizationSuggestion createFileOptimization(RedoLogBottleneck bottleneck) {
        OptimizationSuggestion suggestion = new OptimizationSuggestion();
        suggestion.setType(OptimizationType.INCREASE_FILE_COUNT);
        suggestion.setTitle("增加文件数量");
        suggestion.setDescription("当前文件使用率过高，建议增加Redo Log文件数量");
        suggestion.setPriority(OptimizationPriority.MEDIUM);
        
        suggestion.addParameter("fileCount", "4");
        suggestion.addParameter("fileSize", "1073741824"); // 1GB
        
        return suggestion;
    }
    
    /**
     * 应用优化配置
     */
    private OptimizationResult applyOptimizations(List<OptimizationSuggestion> suggestions) {
        try {
            for (OptimizationSuggestion suggestion : suggestions) {
                applyOptimizationSuggestion(suggestion);
            }
            
            return new OptimizationResult(true, "优化配置应用成功");
            
        } catch (Exception e) {
            logger.error("应用优化配置失败: {}", e.getMessage());
            return new OptimizationResult(false, "应用优化配置失败: " + e.getMessage());
        }
    }
    
    /**
     * 应用单个优化建议
     */
    private void applyOptimizationSuggestion(OptimizationSuggestion suggestion) {
        switch (suggestion.getType()) {
            case INCREASE_BUFFER_SIZE:
                applyBufferSizeIncrease(suggestion);
                break;
            case OPTIMIZE_FLUSH_STRATEGY:
                applyFlushStrategyOptimization(suggestion);
                break;
            case INCREASE_FILE_COUNT:
                applyFileCountIncrease(suggestion);
                break;
        }
    }
    
    /**
     * 应用缓冲区大小增加
     */
    private void applyBufferSizeIncrease(OptimizationSuggestion suggestion) {
        String bufferSizeStr = suggestion.getParameter("bufferSize");
        String flushIntervalStr = suggestion.getParameter("flushInterval");
        
        if (bufferSizeStr != null) {
            long bufferSize = Long.parseLong(bufferSizeStr);
            updateBufferSize(bufferSize);
            logger.info("缓冲区大小已更新为: {} bytes", bufferSize);
        }
        
        if (flushIntervalStr != null) {
            long flushInterval = Long.parseLong(flushIntervalStr);
            updateFlushInterval(flushInterval);
            logger.info("刷盘间隔已更新为: {} ms", flushInterval);
        }
    }
    
    /**
     * 应用刷盘策略优化
     */
    private void applyFlushStrategyOptimization(OptimizationSuggestion suggestion) {
        String syncFlushStr = suggestion.getParameter("syncFlush");
        String flushIntervalStr = suggestion.getParameter("flushInterval");
        String flushBufferSizeStr = suggestion.getParameter("flushBufferSize");
        
        if (syncFlushStr != null) {
            boolean syncFlush = Boolean.parseBoolean(syncFlushStr);
            updateSyncFlush(syncFlush);
            logger.info("同步刷盘已更新为: {}", syncFlush);
        }
        
        if (flushIntervalStr != null) {
            long flushInterval = Long.parseLong(flushIntervalStr);
            updateFlushInterval(flushInterval);
            logger.info("刷盘间隔已更新为: {} ms", flushInterval);
        }
        
        if (flushBufferSizeStr != null) {
            long flushBufferSize = Long.parseLong(flushBufferSizeStr);
            updateFlushBufferSize(flushBufferSize);
            logger.info("刷盘缓冲区大小已更新为: {} bytes", flushBufferSize);
        }
    }
    
    /**
     * 应用文件数量增加
     */
    private void applyFileCountIncrease(OptimizationSuggestion suggestion) {
        String fileCountStr = suggestion.getParameter("fileCount");
        String fileSizeStr = suggestion.getParameter("fileSize");
        
        if (fileCountStr != null) {
            int fileCount = Integer.parseInt(fileCountStr);
            updateFileCount(fileCount);
            logger.info("文件数量已更新为: {}", fileCount);
        }
        
        if (fileSizeStr != null) {
            long fileSize = Long.parseLong(fileSizeStr);
            updateFileSize(fileSize);
            logger.info("文件大小已更新为: {} bytes", fileSize);
        }
    }
    
    // 更新配置的方法
    private void updateBufferSize(long bufferSize) {
        // 通过配置管理器更新缓冲区大小
        logger.info("更新缓冲区大小为: {}", bufferSize);
    }
    
    private void updateFlushInterval(long flushInterval) {
        logger.info("更新刷盘间隔为: {}", flushInterval);
    }
    
    private void updateSyncFlush(boolean syncFlush) {
        logger.info("更新同步刷盘为: {}", syncFlush);
    }
    
    private void updateFlushBufferSize(long flushBufferSize) {
        logger.info("更新刷盘缓冲区大小为: {}", flushBufferSize);
    }
    
    private void updateFileCount(int fileCount) {
        logger.info("更新文件数量为: {}", fileCount);
    }
    
    private void updateFileSize(long fileSize) {
        logger.info("更新文件大小为: {}", fileSize);
    }
    
    // 获取监控数据的方法
    private long getBytesWrittenInLastSecond() {
        // 通过监控系统获取
        return 1024 * 1024; // 1MB
    }
    
    private List<Long> getFlushTimesInLastMinute() {
        // 通过监控系统获取
        return Arrays.asList(50L, 60L, 70L, 80L, 90L);
    }
    
    private long getCurrentBufferSize() {
        // 通过缓冲区管理器获取
        return 8 * 1024 * 1024; // 8MB
    }
    
    private long getMaxBufferSize() {
        // 通过配置获取
        return 16 * 1024 * 1024; // 16MB
    }
    
    private long getUsedFileSize() {
        // 通过文件系统获取
        return 2 * 1024 * 1024 * 1024; // 2GB
    }
    
    private long getTotalFileSize() {
        // 通过配置获取
        return 3 * 1024 * 1024 * 1024; // 3GB
    }
}

// Redo Log性能分析类
public class RedoLogPerformanceAnalysis {
    private double writeThroughput;
    private double flushLatency;
    private double bufferUtilization;
    private double fileUtilization;
    
    // getter/setter方法
}

// Redo Log瓶颈类
public class RedoLogBottleneck {
    private BottleneckType type;
    private String description;
    private double severity;
    
    // 构造函数和getter/setter方法
}

public enum BottleneckType {
    LOW_WRITE_THROUGHPUT,
    HIGH_FLUSH_LATENCY,
    HIGH_BUFFER_UTILIZATION,
    HIGH_FILE_UTILIZATION
}

// Redo Log优化结果类
public class RedoLogOptimizationResult {
    private boolean success;
    private String message;
    private List<OptimizationSuggestion> suggestions;
    
    // 构造函数和getter/setter方法
}

// Undo Log管理器
@Component
public class UndoLogManager {
    
    @Autowired
    private UndoLogConfigManager configManager;
    
    @Autowired
    private UndoLogStorageManager storageManager;
    
    /**
     * 初始化Undo Log
     */
    public void initializeUndoLog() {
        try {
            // 1. 获取Undo Log配置
            UndoLogConfig config = configManager.getUndoLogConfig();
            
            // 2. 创建Undo Log表空间
            createUndoTablespace(config);
            
            // 3. 初始化Undo Log段
            initializeUndoSegments(config);
            
            // 4. 启动清理线程
            startPurgeThread(config);
            
            logger.info("Undo Log初始化完成");
            
        } catch (Exception e) {
            logger.error("Undo Log初始化失败: {}", e.getMessage());
            throw new UndoLogInitializationException("Undo Log初始化失败", e);
        }
    }
    
    /**
     * 写入Undo Log记录
     */
    public void writeUndoLogRecord(UndoLogRecord record) {
        try {
            // 1. 验证记录
            validateUndoLogRecord(record);
            
            // 2. 分配Undo Log页
            UndoLogPage page = allocateUndoLogPage(record.getTransactionId());
            
            // 3. 写入记录
            writeRecordToPage(page, record);
            
            // 4. 更新事务信息
            updateTransactionInfo(record.getTransactionId(), page);
            
        } catch (Exception e) {
            logger.error("写入Undo Log记录失败: {}", e.getMessage());
            throw new UndoLogWriteException("Undo Log记录写入失败", e);
        }
    }
    
    /**
     * 执行事务回滚
     */
    public void rollbackTransaction(long transactionId) {
        try {
            logger.info("开始回滚事务: {}", transactionId);
            
            // 1. 获取事务的Undo Log记录
            List<UndoLogRecord> records = getTransactionUndoRecords(transactionId);
            
            // 2. 按相反顺序应用回滚
            Collections.reverse(records);
            
            for (UndoLogRecord record : records) {
                applyUndoRecord(record);
            }
            
            // 3. 清理Undo Log记录
            cleanupTransactionUndoRecords(transactionId);
            
            logger.info("事务回滚完成: {}", transactionId);
            
        } catch (Exception e) {
            logger.error("事务回滚失败: {}", transactionId, e);
            throw new TransactionRollbackException("事务回滚失败", e);
        }
    }
    
    /**
     * 执行MVCC读
     */
    public Object readWithMVCC(long transactionId, long pageId, int offset) {
        try {
            // 1. 获取当前数据
            Object currentData = readCurrentData(pageId, offset);
            
            // 2. 检查可见性
            if (isDataVisible(transactionId, currentData)) {
                return currentData;
            }
            
            // 3. 查找历史版本
            Object historicalData = findHistoricalData(transactionId, pageId, offset);
            
            return historicalData;
            
        } catch (Exception e) {
            logger.error("MVCC读失败: transactionId={}, pageId={}, offset={}", 
                transactionId, pageId, offset, e);
            throw new MVCCReadException("MVCC读失败", e);
        }
    }
    
    /**
     * 执行Undo Log清理
     */
    public void purgeUndoLog() {
        try {
            // 1. 获取可清理的Undo Log记录
            List<UndoLogRecord> purgeableRecords = getPurgeableRecords();
            
            // 2. 清理记录
            for (UndoLogRecord record : purgeableRecords) {
                purgeUndoRecord(record);
            }
            
            // 3. 更新清理统计
            updatePurgeStatistics(purgeableRecords.size());
            
            logger.debug("Undo Log清理完成，清理记录数: {}", purgeableRecords.size());
            
        } catch (Exception e) {
            logger.error("Undo Log清理失败: {}", e.getMessage());
            throw new UndoLogPurgeException("Undo Log清理失败", e);
        }
    }
    
    /**
     * 验证Undo Log记录
     */
    private void validateUndoLogRecord(UndoLogRecord record) {
        if (record == null) {
            throw new UndoLogRecordException("Undo Log记录为空");
        }
        
        if (record.getTransactionId() <= 0) {
            throw new UndoLogRecordException("事务ID无效");
        }
        
        if (record.getPageId() <= 0) {
            throw new UndoLogRecordException("页面ID无效");
        }
        
        if (record.getData() == null) {
            throw new UndoLogRecordException("记录数据为空");
        }
    }
    
    /**
     * 分配Undo Log页
     */
    private UndoLogPage allocateUndoLogPage(long transactionId) {
        // 1. 检查是否有可用的Undo Log页
        UndoLogPage availablePage = findAvailableUndoPage(transactionId);
        
        if (availablePage != null) {
            return availablePage;
        }
        
        // 2. 分配新的Undo Log页
        return allocateNewUndoPage(transactionId);
    }
    
    /**
     * 应用Undo记录
     */
    private void applyUndoRecord(UndoLogRecord record) {
        try {
            // 1. 读取当前页面
            DataPage page = readDataPage(record.getPageId());
            
            // 2. 应用Undo操作
            switch (record.getOperationType()) {
                case INSERT:
                    applyInsertUndo(page, record);
                    break;
                case UPDATE:
                    applyUpdateUndo(page, record);
                    break;
                case DELETE:
                    applyDeleteUndo(page, record);
                    break;
            }
            
            // 3. 写回页面
            writeDataPage(page);
            
        } catch (Exception e) {
            logger.error("应用Undo记录失败: {}", record.getRecordId(), e);
        }
    }
    
    /**
     * 检查数据可见性
     */
    private boolean isDataVisible(long transactionId, Object data) {
        // 1. 获取数据的创建事务ID
        long createTransactionId = getCreateTransactionId(data);
        
        // 2. 检查事务状态
        TransactionStatus status = getTransactionStatus(createTransactionId);
        
        // 3. 判断可见性
        if (status == TransactionStatus.COMMITTED) {
            return createTransactionId < transactionId;
        } else if (status == TransactionStatus.ABORTED) {
            return false;
        } else {
            // 活跃事务，需要进一步检查
            return checkActiveTransactionVisibility(transactionId, createTransactionId);
        }
    }
    
    /**
     * 查找历史数据
     */
    private Object findHistoricalData(long transactionId, long pageId, int offset) {
        // 1. 获取页面的所有版本
        List<DataVersion> versions = getPageVersions(pageId, offset);
        
        // 2. 按时间戳排序
        versions.sort(Comparator.comparingLong(DataVersion::getTimestamp).reversed());
        
        // 3. 查找可见的版本
        for (DataVersion version : versions) {
            if (isVersionVisible(transactionId, version)) {
                return version.getData();
            }
        }
        
        return null;
    }
    
    /**
     * 获取可清理的记录
     */
    private List<UndoLogRecord> getPurgeableRecords() {
        List<UndoLogRecord> purgeableRecords = new ArrayList<>();
        
        // 1. 获取所有Undo Log记录
        List<UndoLogRecord> allRecords = getAllUndoRecords();
        
        // 2. 检查哪些记录可以清理
        for (UndoLogRecord record : allRecords) {
            if (isRecordPurgeable(record)) {
                purgeableRecords.add(record);
            }
        }
        
        return purgeableRecords;
    }
    
    /**
     * 检查记录是否可清理
     */
    private boolean isRecordPurgeable(UndoLogRecord record) {
        // 1. 检查事务状态
        TransactionStatus status = getTransactionStatus(record.getTransactionId());
        
        if (status != TransactionStatus.COMMITTED) {
            return false;
        }
        
        // 2. 检查是否有活跃事务需要此记录
        long oldestActiveTransactionId = getOldestActiveTransactionId();
        
        return record.getTransactionId() < oldestActiveTransactionId;
    }
}

// Undo Log记录类
public class UndoLogRecord {
    private long recordId;               // 记录ID
    private long transactionId;          // 事务ID
    private long pageId;                 // 页面ID
    private int offset;                  // 偏移量
    private UndoOperationType operationType; // 操作类型
    private byte[] data;                 // 记录数据
    private long timestamp;              // 时间戳
    
    // 构造函数和getter/setter方法
}

// Undo操作类型枚举
public enum UndoOperationType {
    INSERT(1),
    UPDATE(2),
    DELETE(3);
    
    private final int value;
    
    UndoOperationType(int value) {
        this.value = value;
    }
    
    public int getValue() {
        return value;
    }
}

// Undo Log配置类
public class UndoLogConfig {
    private int undoTableSpaceCount;     // Undo表空间数量
    private long undoTableSpaceSize;     // 单个表空间大小
    private int undoSegmentCount;        // Undo段数量
    private long purgeInterval;          // 清理间隔
    private boolean autoPurge;           // 是否自动清理
    
    // 构造函数和getter/setter方法
}

// 数据版本类
public class DataVersion {
    private long timestamp;              // 时间戳
    private long transactionId;          // 事务ID
    private Object data;                 // 数据
    
    // 构造函数和getter/setter方法
}

// 事务状态枚举
public enum TransactionStatus {
    ACTIVE,     // 活跃
    COMMITTED,  // 已提交
    ABORTED     // 已中止
}