public class ByteStreamStateHandle extends Object implements StreamStateHandle
Constructor and Description |
---|
ByteStreamStateHandle(String handleName,
byte[] data)
Creates a new ByteStreamStateHandle containing the given data.
|
Modifier and Type | Method and Description |
---|---|
Optional<byte[]> |
asBytesIfInMemory() |
void |
discardState()
Discards the state referred to and solemnly owned by this handle, to free up resources in the
persistent storage.
|
boolean |
equals(Object o) |
byte[] |
getData() |
String |
getHandleName() |
long |
getStateSize()
Returns the size of the state in bytes.
|
PhysicalStateHandleID |
getStreamStateHandleID() |
int |
hashCode() |
FSDataInputStream |
openInputStream()
Returns an
FSDataInputStream that can be used to read back the data that was
previously written to the stream. |
String |
toString() |
public ByteStreamStateHandle(String handleName, byte[] data)
public FSDataInputStream openInputStream() throws IOException
StreamStateHandle
FSDataInputStream
that can be used to read back the data that was
previously written to the stream.openInputStream
in interface StreamStateHandle
IOException
public Optional<byte[]> asBytesIfInMemory()
asBytesIfInMemory
in interface StreamStateHandle
public PhysicalStateHandleID getStreamStateHandleID()
getStreamStateHandleID
in interface StreamStateHandle
public byte[] getData()
public String getHandleName()
public void discardState()
StateObject
discardState
in interface StateObject
public long getStateSize()
StateObject
0
.
The values produced by this method are only used for informational purposes and for metrics/monitoring. If this method returns wrong values, the checkpoints and recovery will still behave correctly. However, efficiency may be impacted (wrong space pre-allocation) and functionality that depends on metrics (like monitoring) will be impacted.
Note for implementors: This method should not perform any I/O operations while obtaining
the state size (hence it does not declare throwing an IOException
). Instead, the
state size should be stored in the state object, or should be computable from the state
stored in this object. The reason is that this method is called frequently by several parts
of the checkpointing and issuing I/O requests from this method accumulates a heavy I/O load
on the storage system at higher scale.
getStateSize
in interface StateObject
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