聊聊puma的ClientPositionService

序

本文主要研究一下puma的ClientPositionService

ClientPositionService

puma/puma/src/main/java/com/dianping/puma/biz/service/ClientPositionService.java

public interface ClientPositionService {

    List<ClientPositionEntity> findAll();

    ClientPositionEntity find(String clientName);

    void update(ClientPositionEntity clientPositionEntity, boolean flush);

    void flush();

    void cleanUpTestClients();
}

• ClientPositionService定義了findAll、find、update、flush、cleanUpTestClients方法

ClientPositionServiceImpl

puma/puma/src/main/java/com/dianping/puma/biz/service/impl/ClientPositionServiceImpl.java

@Service
public class ClientPositionServiceImpl implements ClientPositionService {

    private final static Logger logger = LoggerFactory.getLogger(ClientPositionServiceImpl.class);

    @Autowired
    private ClientPositionDao clientPositionDao;

    private Map<String, ClientPositionEntity> positionEntityMap = new ConcurrentHashMap<String, ClientPositionEntity>();

    @Override
    public List<ClientPositionEntity> findAll() {
        return clientPositionDao.findAll();
    }

    @Override
    public ClientPositionEntity find(String clientName) {
        return clientPositionDao.findByClientName(clientName);
    }

    @Override
    public void update(ClientPositionEntity clientPositionEntity, boolean flush) {
        if (flush) {
            positionEntityMap.remove(clientPositionEntity.getClientName());
            insertOrUpdate(clientPositionEntity);
        } else {
            positionEntityMap.put(clientPositionEntity.getClientName(), clientPositionEntity);
        }
    }

    @Scheduled(fixedDelay = 5000)
    public void flush() {
        Set<String> keys = positionEntityMap.keySet();
        for (String key : keys) {
            ClientPositionEntity entity = positionEntityMap.remove(key);
            if (entity == null) {
                continue;
            }
            insertOrUpdate(entity);
        }
    }

    private void insertOrUpdate(ClientPositionEntity entity) {
        try {
            entity.setUpdateTime(new Date());
            int updateRow = clientPositionDao.update(entity);
            if (updateRow == 0) {
                clientPositionDao.insert(entity);
            }
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
        }
    }

    public void cleanUpTestClients() {
        List<ClientPositionEntity> clients = clientPositionDao.findOldTestClient();
        for (ClientPositionEntity entity : clients) {
            clientPositionDao.delete(entity.getId());
        }
    }
}

• ClientPositionServiceImpl實現了ClientPositionService接口，其findAll方法執行clientPositionDao.findAll()；其find方法執行clientPositionDao.findByClientName(clientName)；其update方法在flush爲true時執行positionEntityMap.remove及insertOrUpdate，在flush爲false時執行positionEntityMap.put；其flush方法遍歷positionEntityMap，挨個移除，而後執行insertOrUpdate(entity)

ClientPositionDao

puma/biz/src/main/java/com/dianping/puma/biz/dao/ClientPositionDao.java

public interface ClientPositionDao {

    List<ClientPositionEntity> findAll();

    ClientPositionEntity findByClientName(String clientName);

    int update(ClientPositionEntity entity);

    int insert(ClientPositionEntity entity);

    int delete(int id);

    List<ClientPositionEntity> findOldTestClient();
}

• ClientPositionDao定義了findAll、findByClientName、update、insert、delete、findOldTestClient方法

ClientPositionEntity

puma/biz/src/main/java/com/dianping/puma/biz/entity/ClientPositionEntity.java

public class ClientPositionEntity extends BaseEntity {

    private String clientName;

    private String binlogFile;

    private long binlogPosition;

    private long serverId;

    private int eventIndex;

    private long timestamp;

    //......

}

• ClientPositionEntity繼承了BaseEntity，定義了clientName、binlogFile、binlogPosition、serverId、eventIndex、timestamp屬性

ClientPositionMapper

puma/biz/src/main/resources/sqlmap/ClientPositionMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.dianping.puma.biz.dao.ClientPositionDao">

    <select id="findAll" resultType="ClientPositionEntity">
        SELECT * FROM ClientPosition
    </select>

    <select id="findByClientName" resultType="ClientPositionEntity">
        SELECT * FROM ClientPosition where ClientName = #{clientName}
    </select>

    <update id="update" parameterType="ClientPositionEntity">
        update ClientPosition
        set
        BinlogFile = #{binlogFile},
        BinlogPosition = #{binlogPosition},
        ServerId = #{serverId},
        EventIndex = #{eventIndex},
        Timestamp = #{timestamp},
        UpdateTime = #{updateTime}
        where
        ClientName = #{clientName}
    </update>

    <insert id="insert" parameterType="ClientPositionEntity" useGeneratedKeys="true" keyProperty="id">
        insert into ClientPosition
        (
        ClientName,
        BinlogFile,
        BinlogPosition,
        ServerId,
        EventIndex,
        Timestamp,
        UpdateTime
        )
        values
        (
        #{clientName},
        #{binlogFile},
        #{binlogPosition},
        #{serverId},
        #{eventIndex},
        #{timestamp},
        #{updateTime}
        )
    </insert>

    <select id="findOldTestClient" resultType="ClientPositionEntity">
        select * from ClientPosition
        where UpdateTime &lt; NOW() - INTERVAL 10 DAY
        and ClientName like '%test'
    </select>

    <delete id="delete" parameterType="int">
        delete from ClientPosition where id = #{id}
    </delete>

</mapper>

• ClientPositionMapper實現了ClientPositionDao定義的方法

小結

ClientPositionService定義了findAll、find、update、flush、cleanUpTestClients方法；ClientPositionServiceImpl實現了ClientPositionService接口，其findAll方法執行clientPositionDao.findAll()；其find方法執行clientPositionDao.findByClientName(clientName)；其update方法在flush爲true時執行positionEntityMap.remove及insertOrUpdate，在flush爲false時執行positionEntityMap.put；其flush方法遍歷positionEntityMap，挨個移除，而後執行insertOrUpdate(entity)

doc

• ClientPositionService