Package tech.guilhermekaua.spigotboot.inventoryapi.internal.state

Class MutableStateImpl<T>

java.lang.Object

tech.guilhermekaua.spigotboot.inventoryapi.internal.state.MutableStateImpl<T>

Type Parameters:

T - the value type

All Implemented Interfaces:

IdentifiableToken, MutableState<T>, State<T>, StateToken

@Internal
public final class MutableStateImpl<T>
extends Object
implements MutableState<T>, IdentifiableToken

Mutable per-context state token; values live in the session's StateStore. The initial value is computed per context on the first read; an explicitly stored null is kept (not re-initialized) via a private sentinel.

Constructor Summary

Constructors

Constructor	Description
MutableStateImpl(@NotNull View owner, @NotNull TokenTable table, @NotNull Function<ViewContext,T> initialValue)	Creates and registers the token.

Method Summary

Modifier and Type	Method	Description
T	get(@NotNull ViewContext context)	Reads this token's value for the given context.
int	id()	Returns the table-assigned token id, the index into the per-session state store.
void	set(@NotNull ViewContext context, T value)	Writes this token's value for the given context and marks watchers dirty.
int	tokenId()
void	update(@NotNull ViewContext context, @NotNull UnaryOperator<T> fn)	Read-modify-write convenience: applies fn to the current value and stores the result.

Methods inherited from class java.lang.Object

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

Constructor Details

MutableStateImpl

public MutableStateImpl(@NotNull
 @NotNull View owner,
 @NotNull
 @NotNull TokenTable table,
 @NotNull
 @NotNull Function<ViewContext,T> initialValue)

Creates and registers the token.

Parameters:

owner - the view declaring the token

table - the owner's token table

initialValue - the per-context initial value factory

Throws:

IllegalStateException - when the table is already frozen

Method Details

id

public int id()

Returns the table-assigned token id, the index into the per-session state store.

Returns:

the token id

tokenId

public int tokenId()

Specified by:

tokenId in interface IdentifiableToken

Returns:

the token id assigned by the owning view's token table

get

@Nullable
public T get(@NotNull
 @NotNull ViewContext context)

Description copied from interface: State

Reads this token's value for the given context. Callable from any thread, but values are only coherent on the main thread.

Specified by:

get in interface State<T>

Parameters:

context - an active context of the owning view

Returns:

the current value, possibly null

set

public void set(@NotNull
 @NotNull ViewContext context,
 @Nullable
 T value)

Description copied from interface: MutableState

Writes this token's value for the given context and marks watchers dirty.

Specified by:

set in interface MutableState<T>

Parameters:

context - an active context of the owning view

value - the new value, possibly null

update

public void update(@NotNull
 @NotNull ViewContext context,
 @NotNull
 @NotNull UnaryOperator<T> fn)

Description copied from interface: MutableState

Read-modify-write convenience: applies fn to the current value and stores the result. Main thread only.

Specified by:

update in interface MutableState<T>

Parameters:

context - an active context of the owning view

fn - the function producing the new value from the current one; invoked exactly once on the current value. Side effects inside fn are safe (unlike SharedState.update(java.util.function.UnaryOperator<T>))