com.graphhopper.storage

Interface Storable<T>

All Superinterfaces:

AutoCloseable, Closeable

All Known Subinterfaces:

DataAccess, GraphStorage, LocationIndex

All Known Implementing Classes:

AbstractDataAccess, CHGraphImpl, GraphHopperStorage, LandmarkStorage, Location2IDFullIndex, Location2IDFullWithEdgesIndex, LocationIndexTree, MMapDataAccess, RAMDataAccess, StorableProperties, StringIndex, SubnetworkStorage, TurnCostStorage

public interface Storable<T>
extends Closeable

Interface for a storage abstraction. Currently is serves just the purpose to ensure the same methods and names through all kind of 'storable' things in graphhopper.

Then the lifecycle is identical for all such objects:

1. object creation via new
2. optional configuration via additional setters and getters which are not in this interface
3. if(!storable.loadExisting()) storable.create()
4. usage storable and optional flush() calls in-between. Keep in mind that some data structure could require a call to increase memory while usage. E.g. DataAccess.ensureCapacity()
5. Finally do close() which does no flush()

Author:

Peter Karich

Method Summary

Modifier and Type	Method and Description
void	close() This method makes sure that the underlying used resources are released.
T	create(long byteCount) Creates the underlying storage.
void	flush() This method makes sure that the underlying data is written to the storage.
long	getCapacity()
boolean	isClosed()
boolean	loadExisting()

Method Detail

loadExisting

boolean loadExisting()

Returns:

true if successfully loaded from persistent storage.

create

T create(long byteCount)

Creates the underlying storage. First operation if it cannot be loaded.

flush

void flush()

This method makes sure that the underlying data is written to the storage. Keep in mind that a disc normally has an IO cache so that flush() is (less) probably not save against power loses.

close

void close()

This method makes sure that the underlying used resources are released. WARNING: it does NOT flush on close!

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

isClosed

boolean isClosed()

getCapacity

long getCapacity()

Returns:

the allocated storage size in bytes