All Superinterfaces:

Serializable

All Known Implementing Classes:

LocalSnapshotDirectoryProviderImpl
```
public interface LocalSnapshotDirectoryProvider
extends Serializable
```
Provides directories for local backup or local recovery. It offers access to the allocation base directories (i.e. the root directories for all local state that is created under the same allocation id) and the subtask-specific paths, which contain the local state for one subtask. Access by checkpoint id rotates over all root directory indexes, in case that there is more than one. Selection methods are provided to pick the directory under a certain index. Directory structures are of the following shape:
```
 |-----allocationBaseDirectory------|
 |-----subtaskBaseDirectory--------------------------------------|
 |-----subtaskSpecificCheckpointDirectory------------------------------|

 ../local_state_root_1/allocation_id/job_id/vertex_id_subtask_idx/chk_1/(state)
 ../local_state_root_2/allocation_id/job_id/vertex_id_subtask_idx/chk_2/(state)

 (...)
 
```

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`File`	`allocationBaseDirectory(long checkpointId)`	Returns the local state allocation base directory for given checkpoint id w.r.t. our rotation over all available allocation base directories.
`int`	`allocationBaseDirsCount()`	Returns the total number of allocation base directories.
`File`	`selectAllocationBaseDirectory(int idx)`	Returns a specific allocation base directory.
`File`	`selectSubtaskBaseDirectory(int idx)`	Returns a specific subtask base directory.
`File`	`subtaskBaseDirectory(long checkpointId)`	Returns the local state directory for the owning subtask the given checkpoint id w.r.t. our rotation over all available available allocation base directories.
`File`	`subtaskSpecificCheckpointDirectory(long checkpointId)`	Returns the local state directory for the specific operator subtask and the given checkpoint id w.r.t. our rotation over all available root dirs.

- Method Detail
  - allocationBaseDirectory
```
File allocationBaseDirectory(long checkpointId)
```
    Returns the local state allocation base directory for given checkpoint id w.r.t. our rotation over all available allocation base directories.
  - subtaskBaseDirectory
```
File subtaskBaseDirectory(long checkpointId)
```
    Returns the local state directory for the owning subtask the given checkpoint id w.r.t. our rotation over all available available allocation base directories. This directory is contained in the directory returned by allocationBaseDirectory(long) for the same checkpoint id.
  - subtaskSpecificCheckpointDirectory
```
File subtaskSpecificCheckpointDirectory(long checkpointId)
```
    Returns the local state directory for the specific operator subtask and the given checkpoint id w.r.t. our rotation over all available root dirs. This directory is contained in the directory returned by subtaskBaseDirectory(long) for the same checkpoint id.
  - selectAllocationBaseDirectory
```
File selectAllocationBaseDirectory(int idx)
```
    Returns a specific allocation base directory. The index must be between 0 (incl.) and allocationBaseDirsCount() (excl.).
  - selectSubtaskBaseDirectory
```
File selectSubtaskBaseDirectory(int idx)
```
    Returns a specific subtask base directory. The index must be between 0 (incl.) and allocationBaseDirsCount() (excl.). This directory is direct a child of selectSubtaskBaseDirectory(int) given the same index.
  - allocationBaseDirsCount
```
int allocationBaseDirsCount()
```
    Returns the total number of allocation base directories.

Interface LocalSnapshotDirectoryProvider

Method Summary

Method Detail

allocationBaseDirectory

subtaskBaseDirectory

subtaskSpecificCheckpointDirectory

selectAllocationBaseDirectory

selectSubtaskBaseDirectory

allocationBaseDirsCount