[feature](binlog) Allow BarrierLog to wrap another binlog

to make it worked in old doris version without breaking compatibility

fe/fe-core/src/main/java/org/apache/doris/persist/BarrierLog.java

@@ -20,6 +20,7 @@
 import org.apache.doris.common.io.Text;
 import org.apache.doris.common.io.Writable;
 import org.apache.doris.persist.gson.GsonUtils;
+import org.apache.doris.thrift.TBinlogType;
 
 import com.google.gson.annotations.SerializedName;
 
@@ -37,6 +38,11 @@ public class BarrierLog implements Writable {
     @SerializedName(value = "tableName")
     String tableName;
 
+    @SerializedName(value = "binlogType")
+    int binlogType;
+    @SerializedName(value = "binlog")
+    String binlog;
+
     public BarrierLog() {
     }
 
@@ -47,6 +53,28 @@ public BarrierLog(long dbId, String dbName, long tableId, String tableName) {
         this.tableName = tableName;
     }
 
+    // A trick: Wrap the binlog as part of the BarrierLog so that it can work in
+    // the old Doris version without breaking the compatibility.
+    public BarrierLog(long dbId, long tableId, TBinlogType binlogType, String binlog) {
+        this.dbId = dbId;
+        this.tableId = tableId;
+        this.binlogType = binlogType.getValue();
+        this.binlog = binlog;
+    }
+
+    public boolean hasBinlog() {
+        return binlog != null;
+    }
+
+    public String getBinlog() {
+        return binlog;
+    }
+
+    // null is returned if binlog is not set or binlogType is not recognized.
+    public TBinlogType getBinlogType() {
+        return binlog == null ? null : TBinlogType.findByValue(binlogType);
+    }
+
     public long getDbId() {
         return dbId;
     }