DirectoryStrategy (IoTDB Server 0.14.0-preview2 API)

java.lang.Object
- org.apache.iotdb.db.conf.directories.strategy.DirectoryStrategy

Direct Known Subclasses:

MaxDiskUsableSpaceFirstStrategy, MinFolderOccupiedSpaceFirstStrategy, RandomOnDiskUsableSpaceStrategy, SequenceStrategy
```
public abstract class DirectoryStrategy
extends java.lang.Object
```
The basic class of all the strategies of multiple directories. If a user wants to define his own strategy, his strategy has to extend this class and implement the abstract method.

Field Summary

Fields
Modifier and Type Field Description

protected static org.slf4j.Logger logger

Constructor Summary

Constructors
Constructor Description

DirectoryStrategy()

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`abstract int`	`nextFolderIndex()`	Choose a folder to allocate.
`void`	`setFolders(java.util.List<java.lang.String> folders)`	To init folders.

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

- Field Detail
  - logger
```
protected static final org.slf4j.Logger logger
```
- Constructor Detail
  - DirectoryStrategy
```
public DirectoryStrategy()
```
- Method Detail
  - setFolders
```
public void setFolders(java.util.List<java.lang.String> folders)
                throws DiskSpaceInsufficientException
```
    To init folders. Do not recommend to overwrite. This method guarantees that at least one folder has available space.
    
    Parameters:
    
    folders - the folders from conf
    
    Throws:
    
    DiskSpaceInsufficientException
  - nextFolderIndex
```
public abstract int nextFolderIndex()
                             throws DiskSpaceInsufficientException
```
    Choose a folder to allocate. The user should implement this method to define his own strategy.
    
    Returns:
    
    the index of folder that will be allocated
    
    Throws:
    
    DiskSpaceInsufficientException