KeyValueStateIterator (Flink : 2.0-SNAPSHOT API)

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

HeapKeyValueStateIterator, RocksStatesPerKeyGroupMergeIterator
```
public interface KeyValueStateIterator
extends AutoCloseable
```
Iterator that over all key-value state entries in a KeyedStateBackend. For use during snapshotting.
This is required to partition all states into contiguous key-groups. The resulting iteration sequence is ordered by (key-group, kv-state).

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`close()`
`boolean`	`isNewKeyGroup()`	Indicates if current key starts a new key-group, i.e. belong to a different key-group than it's predecessor.
`boolean`	`isNewKeyValueState()`	Indicates if current key starts a new k/v-state, i.e. belong to a different k/v-state than it's predecessor.
`boolean`	`isValid()`	Check if the iterator is still valid.
`byte[]`	`key()`
`int`	`keyGroup()`	Returns the key-group for the current key.
`int`	`kvStateId()`	Returns the Id of the K/V state to which the current key belongs.
`void`	`next()`	Advances the iterator.
`byte[]`	`value()`

- Method Detail
  - next
```
void next()
   throws IOException
```
    Advances the iterator. Should only be called if isValid() returned true. Valid flag can only change after calling next().
    
    Throws:
    
    IOException
  - keyGroup
```
int keyGroup()
```
    Returns the key-group for the current key.
  - key
```
byte[] key()
```
  - value
```
byte[] value()
```
  - kvStateId
```
int kvStateId()
```
    Returns the Id of the K/V state to which the current key belongs.
  - isNewKeyValueState
```
boolean isNewKeyValueState()
```
    Indicates if current key starts a new k/v-state, i.e. belong to a different k/v-state than it's predecessor.
    
    Returns:
    
    true iff the current key belong to a different k/v-state than it's predecessor.
  - isNewKeyGroup
```
boolean isNewKeyGroup()
```
    Indicates if current key starts a new key-group, i.e. belong to a different key-group than it's predecessor.
    
    Returns:
    
    true iff the current key belong to a different key-group than it's predecessor.
  - isValid
```
boolean isValid()
```
    Check if the iterator is still valid. Getters like key(), value(), etc. as well as next() should only be called if valid returned true. Should be checked after each call to next() before accessing iterator state.
    
    Returns:
    
    True iff this iterator is valid.
  - close
```
void close()
```
    Specified by:
    
    close in interface AutoCloseable