CheckpointManager (IoTDB Server 0.14.0-preview2 API)

java.lang.Object
- org.apache.iotdb.db.wal.checkpoint.CheckpointManager

All Implemented Interfaces:

java.lang.AutoCloseable
```
public class CheckpointManager
extends java.lang.Object
implements java.lang.AutoCloseable
```
This class is used to manage checkpoints of one wal node

Field Summary

Fields
Modifier and Type	Field	Description
`protected java.lang.String`	`identifier`	WALNode identifier of this checkpoint manager
`protected java.lang.String`	`logDirectory`	directory to store .checkpoint file

Constructor Summary

Constructors
Constructor Description

CheckpointManager(java.lang.String identifier, java.lang.String logDirectory)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`
`long`	`getFirstValidWALVersionId()`	Get version id of first valid .wal file
`MemTableInfo`	`getOldestMemTableInfo()`	Get MemTableInfo of oldest MemTable, whose first version id is smallest
`long`	`getTotalCostOfActiveMemTables()`	Get total cost of active memTables
`void`	`makeCreateMemTableCP(MemTableInfo memTableInfo)`	make checkpoint for create memTable info
`void`	`makeFlushMemTableCP(long memTableId)`	make checkpoint for flush memTable info

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - identifier
```
protected final java.lang.String identifier
```
    WALNode identifier of this checkpoint manager
  - logDirectory
```
protected final java.lang.String logDirectory
```
    directory to store .checkpoint file
- Constructor Detail
  - CheckpointManager
```
public CheckpointManager(java.lang.String identifier,
                         java.lang.String logDirectory)
                  throws java.io.FileNotFoundException
```
    Throws:
    
    java.io.FileNotFoundException
- Method Detail
  - makeCreateMemTableCP
```
public void makeCreateMemTableCP(MemTableInfo memTableInfo)
```
    make checkpoint for create memTable info
  - makeFlushMemTableCP
```
public void makeFlushMemTableCP(long memTableId)
```
    make checkpoint for flush memTable info
  - getOldestMemTableInfo
```
public MemTableInfo getOldestMemTableInfo()
```
    Get MemTableInfo of oldest MemTable, whose first version id is smallest
  - getFirstValidWALVersionId
```
public long getFirstValidWALVersionId()
```
    Get version id of first valid .wal file
    
    Returns:
    
    Return Long.MIN_VALUE if no file is valid
  - getTotalCostOfActiveMemTables
```
public long getTotalCostOfActiveMemTables()
```
    Get total cost of active memTables
  - close
```
public void close()
```
    Specified by:
    
    close in interface java.lang.AutoCloseable