com.exonum.binding.core.storage.database

Class View

java.lang.Object

com.exonum.binding.core.proxy.AbstractNativeProxy

com.exonum.binding.core.storage.database.View

Direct Known Subclasses:

Fork, Snapshot

public abstract class View
extends AbstractNativeProxy

Represents a view of the database.

There are two sub-types:

• A snapshot, which is a read-only and immutable view.
• A fork, which is a read-write view.

As in some cases the clients need to detect any changes made to a database, a view also holds a modification counter, which any clients changing the database state must notify.

See Also:

Snapshot, Fork

Field Summary

Fields inherited from class com.exonum.binding.core.proxy.AbstractNativeProxy

nativeHandle

Method Summary

Modifier and Type	Method and Description
boolean	canModify() Returns true if this view allows modifications to the database state; false if it is immutable.
Optional<StorageIndex>	findOpenIndex(IndexAddress address) Finds an open index by the given address.
Cleaner	getCleaner() Returns the cleaner of this view.
long	getViewNativeHandle() Returns a native handle of this view.
void	registerIndex(StorageIndex index) Registers a new index created with this view.

Methods inherited from class com.exonum.binding.core.proxy.AbstractNativeProxy

getNativeHandle, isValidHandle

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

canModify

public boolean canModify()

Returns true if this view allows modifications to the database state; false if it is immutable.

getViewNativeHandle

public long getViewNativeHandle()

Returns a native handle of this view.

Throws:

IllegalStateException - if the view is invalid (closed or nullptr)

findOpenIndex

public Optional<StorageIndex> findOpenIndex(IndexAddress address)

Finds an open index by the given address.

This method is for internal use. It is not designed to be used by services, rather by index factories.

Parameters:

address - the index address

Returns:

an index with the given address; or Optional.empty() if no index with such address was open in this view

registerIndex

public void registerIndex(StorageIndex index)

Registers a new index created with this view.

This method is for internal use. It is not designed to be used by services, rather by index factories.

Parameters:

index - a new index to register

Throws:

IllegalArgumentException - if the index is already registered

See Also:

findOpenIndex(IndexAddress)

getCleaner

public Cleaner getCleaner()

Returns the cleaner of this view.