org.apache.jackrabbit.oak.index.indexer.document.flatfile

Interface MemoryManager

All Known Implementing Classes:

DefaultMemoryManager

public interface MemoryManager

Implementations of this interface can be used to get updates about remaining heap memory.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	MemoryManager.Type Indicates type of memory management this instance does.

Method Summary

Modifier and Type	Method and Description
void	changeMemoryUsedBy(long memory) Adds the provided memory value to existing memory usage.
boolean	deregisterClient(java.lang.String registrationID) Deregister a client with the given registrationID.
MemoryManager.Type	getType()
boolean	isMemoryLow() Checks if available memory is low.
java.util.Optional<java.lang.String>	registerClient(MemoryManagerClient client) Register a client with this memory manager.

Method Detail

getType

MemoryManager.Type getType()

registerClient

java.util.Optional<java.lang.String> registerClient(MemoryManagerClient client)

Register a client with this memory manager. All registered clients are informed when available memory level is low. If memory level is already low, client is not registered. NOTE - this method should only be used with MemoryManager.Type.JMX_BASED instance types, otherwise it throws UnsupportedOperationException

Parameters:

client - client to register

Returns:

an optional containing registration id if registration was successful, empty optional otherwise

deregisterClient

boolean deregisterClient(java.lang.String registrationID)

Deregister a client with the given registrationID. NOTE - this method should only be used with MemoryManager.Type.JMX_BASED instance types, otherwise it throws UnsupportedOperationException

Parameters:

registrationID - registration id of client to deregister

Returns:

true if deregistration was successful, false otherwise.

isMemoryLow

boolean isMemoryLow()

Checks if available memory is low. NOTE - this method should only be used with MemoryManager.Type.SELF_MANAGED instance types, otherwise it throws UnsupportedOperationException

Returns:

true if available memory is low, false otherwise.

changeMemoryUsedBy

void changeMemoryUsedBy(long memory)

Adds the provided memory value to existing memory usage. Callers of this method could also provide negative values to indicate reduction in memory usage. NOTE - this method should only be used with MemoryManager.Type.SELF_MANAGED instance types, otherwise it throws UnsupportedOperationException