org.immutables.fixture.style.ImmutableJdkInterner Maven / Gradle / Ivy
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package org.immutables.fixture.style;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.Var;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.WeakHashMap;
import javax.annotation.CheckReturnValue;
import javax.annotation.Nullable;
import javax.annotation.ParametersAreNonnullByDefault;
import javax.annotation.concurrent.Immutable;
import javax.annotation.concurrent.NotThreadSafe;
import org.immutables.value.Generated;
/**
* Immutable implementation of {@link WeakInterningStyle.JdkInterner}.
*
* Use the builder to create immutable instances:
* {@code ImmutableJdkInterner.builder()}.
* Use the static factory method to create immutable instances:
* {@code ImmutableJdkInterner.of()}.
*/
@Generated(from = "WeakInterningStyle.JdkInterner", generator = "Immutables")
@SuppressWarnings({"all"})
@ParametersAreNonnullByDefault
@javax.annotation.processing.Generated("org.immutables.processor.ProxyProcessor")
@Immutable
@CheckReturnValue
public final class ImmutableJdkInterner implements WeakInterningStyle.JdkInterner {
private final int a;
private ImmutableJdkInterner(int a) {
this.a = a;
}
/**
* @return The value of the {@code a} attribute
*/
@Override
public int a() {
return a;
}
/**
* Copy the current immutable object by setting a value for the {@link WeakInterningStyle.JdkInterner#a() a} attribute.
* A value equality check is used to prevent copying of the same value by returning {@code this}.
* @param value A new value for a
* @return A modified copy of the {@code this} object
*/
public final ImmutableJdkInterner withA(int value) {
if (this.a == value) return this;
return validate(new ImmutableJdkInterner(value));
}
/**
* This instance is equal to all instances of {@code ImmutableJdkInterner} that have equal attribute values.
* @return {@code true} if {@code this} is equal to {@code another} instance
*/
@Override
public boolean equals(@Nullable Object another) {
if (this == another) return true;
return another instanceof ImmutableJdkInterner
&& equalTo(0, (ImmutableJdkInterner) another);
}
private boolean equalTo(int synthetic, ImmutableJdkInterner another) {
return a == another.a;
}
/**
* Computes a hash code from attributes: {@code a}.
* @return hashCode value
*/
@Override
public int hashCode() {
@Var int h = 5381;
h += (h << 5) + a;
return h;
}
/**
* Prints the immutable value {@code JdkInterner} with attribute values.
* @return A string representation of the value
*/
@Override
public String toString() {
return "JdkInterner{"
+ "a=" + a
+ "}";
}
private static final class InternerHolder {
static final Map> INTERNER =
new WeakHashMap<>();
}
/**
* Construct a new immutable {@code JdkInterner} instance.
* @param a The value for the {@code a} attribute
* @return An immutable JdkInterner instance
*/
public static ImmutableJdkInterner of(int a) {
return validate(new ImmutableJdkInterner(a));
}
private static ImmutableJdkInterner validate(ImmutableJdkInterner instance) {
synchronized (InternerHolder.INTERNER) {
@Nullable WeakReference reference = InternerHolder.INTERNER.get(instance);
@Nullable ImmutableJdkInterner interned = reference != null ? reference.get() : null;
if (interned == null) {
InternerHolder.INTERNER.put(instance, new WeakReference<>(instance));
interned = instance;
}
return interned;
}
}
/**
* Creates an immutable copy of a {@link WeakInterningStyle.JdkInterner} value.
* Uses accessors to get values to initialize the new immutable instance.
* If an instance is already immutable, it is returned as is.
* @param instance The instance to copy
* @return A copied immutable JdkInterner instance
*/
public static ImmutableJdkInterner copyOf(WeakInterningStyle.JdkInterner instance) {
if (instance instanceof ImmutableJdkInterner) {
return (ImmutableJdkInterner) instance;
}
return ImmutableJdkInterner.builder()
.from(instance)
.build();
}
/**
* Creates a builder for {@link ImmutableJdkInterner ImmutableJdkInterner}.
*
* ImmutableJdkInterner.builder()
* .a(int) // required {@link WeakInterningStyle.JdkInterner#a() a}
* .build();
*
* @return A new ImmutableJdkInterner builder
*/
public static ImmutableJdkInterner.Builder builder() {
return new ImmutableJdkInterner.Builder();
}
/**
* Builds instances of type {@link ImmutableJdkInterner ImmutableJdkInterner}.
* Initialize attributes and then invoke the {@link #build()} method to create an
* immutable instance.
* {@code Builder} is not thread-safe and generally should not be stored in a field or collection,
* but instead used immediately to create instances.
*/
@Generated(from = "WeakInterningStyle.JdkInterner", generator = "Immutables")
@NotThreadSafe
public static final class Builder {
private static final long INIT_BIT_A = 0x1L;
private long initBits = 0x1L;
private int a;
private Builder() {
}
/**
* Fill a builder with attribute values from the provided {@code JdkInterner} instance.
* Regular attribute values will be replaced with those from the given instance.
* Absent optional values will not replace present values.
* @param instance The instance from which to copy values
* @return {@code this} builder for use in a chained invocation
*/
@CanIgnoreReturnValue
public final Builder from(WeakInterningStyle.JdkInterner instance) {
Objects.requireNonNull(instance, "instance");
a(instance.a());
return this;
}
/**
* Initializes the value for the {@link WeakInterningStyle.JdkInterner#a() a} attribute.
* @param a The value for a
* @return {@code this} builder for use in a chained invocation
*/
@CanIgnoreReturnValue
public final Builder a(int a) {
this.a = a;
initBits &= ~INIT_BIT_A;
return this;
}
/**
* Builds a new {@link ImmutableJdkInterner ImmutableJdkInterner}.
* @return An immutable instance of JdkInterner
* @throws java.lang.IllegalStateException if any required attributes are missing
*/
public ImmutableJdkInterner build() {
if (initBits != 0) {
throw new IllegalStateException(formatRequiredAttributesMessage());
}
return ImmutableJdkInterner.validate(new ImmutableJdkInterner(a));
}
private String formatRequiredAttributesMessage() {
List attributes = new ArrayList<>();
if ((initBits & INIT_BIT_A) != 0) attributes.add("a");
return "Cannot build JdkInterner, some of required attributes are not set " + attributes;
}
}
}