聊聊puma的ChangedEvent

序

本文主要研究一下puma的ChangedEvent

Event

puma/core/src/main/java/com/dianping/puma/core/event/Event.java

public abstract class Event implements Serializable {

    private static final long serialVersionUID = 7986284681273254505L;

    private long seq;
    public void setSeq(long seq) {
        this.seq = seq;
    }
    public long getSeq() {
        return seq;
    }

    public abstract BinlogInfo getBinlogInfo();

    public abstract EventType getEventType();
}

• Event定义了getBinlogInfo、getEventType抽象方法

ChangedEvent

puma/core/src/main/java/com/dianping/puma/core/event/ChangedEvent.java

public abstract class ChangedEvent extends Event implements Serializable {
    private static final long    serialVersionUID    = -2358086827502066009L;
    protected long                    executeTime;
    protected String                database;
    protected String                table;
    protected long                    serverId;
    protected BinlogInfo         binlogInfo;

    //......

}

• ChangedEvent定义了executeTime、database、table、serverId、binlogInfo属性

DdlEvent

puma/core/src/main/java/com/dianping/puma/core/event/DdlEvent.java

public class DdlEvent extends ChangedEvent implements Serializable {
    private static final long serialVersionUID = -5676914333310337620L;

    private final EventType eventType = EventType.DDL;

    private String sql;

    private DDLType ddlType;

    private DdlEventType ddlEventType;

    private DdlEventSubType ddlEventSubType;

    public DdlEvent() {

    }

    public DdlEvent(long executeTime, long serverId, String binlogFile, long binlogPosition) {
        this.executeTime = executeTime;
        this.serverId = serverId;
        this.binlogInfo = new BinlogInfo(serverId, binlogFile, binlogPosition, 0, executeTime);
    }

    //......
}

• DdlEvent继承了ChangedEvent，它定义了eventType、sql、ddlType、ddlEventType、ddlEventSubType属性

RowChangedEvent

puma/core/src/main/java/com/dianping/puma/core/event/RowChangedEvent.java

public class RowChangedEvent extends ChangedEvent implements Serializable, Cloneable {

    private final EventType eventType = EventType.DML;

    private static final long serialVersionUID = -3426837914222597530L;

    private DMLType dmlType;

    private boolean isTransactionBegin = false;

    private boolean isTransactionCommit = false;

    private Map<String, ColumnInfo> columns = new HashMap<String, ColumnInfo>();

    public RowChangedEvent() {
    }

    public RowChangedEvent(long executionTime, long serverId, String binlogFile, long binlogPosition) {
        this.executeTime = executionTime;
        this.serverId = serverId;
        this.binlogInfo = new BinlogInfo(serverId, binlogFile, binlogPosition, 0, executionTime);
    }

    //......

}

• RowChangedEvent继承了ChangedEvent，它定义了eventType、dmlType、isTransactionBegin、isTransactionCommit、columns属性

ColumnInfo

puma/core/src/main/java/com/dianping/puma/core/event/RowChangedEvent.java

    public static class ColumnInfo implements Serializable {
        private static final long serialVersionUID = 8036820944314281838L;

        private boolean isKey;

        private Object oldValue;

        private Object newValue;

        /**
         *
         */
        public ColumnInfo() {
            super();
        }

        /**
         * @param isKey
         * @param oldValue
         * @param newValue
         */
        public ColumnInfo(boolean isKey, Object oldValue, Object newValue) {
            super();
            this.isKey = isKey;
            this.oldValue = oldValue;
            this.newValue = newValue;
        }

        //......

    }

• ColumnInfo定义了isKey、oldValue、newValue属性

DDLType

puma/core/src/main/java/com/dianping/puma/core/util/sql/DDLType.java

public enum DDLType {

    ALTER_DATABASE(1),
    ALTER_EVENT(2),
    ALTER_LOGFILE_GROUP(3),
    ALTER_FUNCTION(4),
    ALTER_PROCEDURE(5),
    ALTER_SERVER(6),
    ALTER_TABLE(7),
    ALTER_TABLESPACE(8),
    ALTER_VIEW(9),

    CREATE_DATABASE(11),
    CREATE_EVENT(12),
    CREATE_INDEX(13),
    CREATE_LOGFILE_GROUP(14),
    CREATE_FUNCTION(15),
    CREATE_PROCEDURE(16),
    CREATE_SERVER(17),
    CREATE_TABLE(18),
    CREATE_TABLESPACE(19),
    CREATE_TRIGGER(20),
    CREATE_VIEW(21),

    DROP_DATABASE(31),
    DROP_EVENT(32),
    DROP_INDEX(33),
    DROP_LOGFILE_GROUP(34),
    DROP_FUNCTION(35),
    DROP_PROCEDURE(36),
    DROP_SERVER(37),
    DROP_TABLE(38),
    DROP_TABLESPACE(39),
    DROP_TRIGGER(40),
    DROP_VIEW(41),

    RENAME_DATABASE(51),
    RENAME_TABLE(52),

    TRUNCATE_TABLE(61);
    
    private int type;
    
    DDLType(int type){
        this.type = type;
    }
    
    
    public int getDDLType(){
        return this.type;
    }
    
    public static DDLType getDDLType(int type){
        for(DDLType ddlType : DDLType.values()){
            if(ddlType.getDDLType() == type){
                return ddlType;
            }
        }
        
        return null;
    }
}

• DDLType定义了alter、create、drop、rename、truncate枚举值

DMLType

puma/core/src/main/java/com/dianping/puma/core/util/sql/DMLType.java

public enum DMLType {

    NULL(0), INSERT(1), DELETE(2), UPDATE(3);

    private int type;

    DMLType(int type) {
        this.type = type;
    }

    public int getDMLType() {
        return this.type;
    }

    public static DMLType getDMLType(int type) {
        for (DMLType dmlType : DMLType.values()) {
            if (dmlType.getDMLType() == type) {
                return dmlType;
            }
        }

        return null;
    }
}

• DMLType定义了NULL、INSERT、DELETE、UPDATE枚举值

小结

ChangedEvent定义了executeTime、database、table、serverId、binlogInfo属性；它有DdlEvent及RowChangedEvent两个子类

doc

• ChangedEvent