Example usage for java.util Map computeIfAbsent

Introduction

In this page you can find the example usage for java.util Map computeIfAbsent.

Prototype

default V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction)

Source Link

Document

If the specified key is not already associated with a value (or is mapped to null ), attempts to compute its value using the given mapping function and enters it into this map unless null .

Usage

From source file:at.gridtec.lambda4j.function.tri.to.ThrowableToLongTriFunction.java

/**
 * Returns a memoized (caching) version of this {@link ThrowableToLongTriFunction}. Whenever it is called, the
 * mapping between the input parameters and the return value is preserved in a cache, making subsequent calls
 * returning the memoized value instead of computing the return value again.
 * <p>// ww w.  j  a va2 s  .  c om
 * Unless the function and therefore the used cache will be garbage-collected, it will keep all memoized values
 * forever.
 *
 * @return A memoized (caching) version of this {@code ThrowableToLongTriFunction}.
 * @implSpec This implementation does not allow the input parameters or return value to be {@code null} for the
 * resulting memoized function, as the cache used internally does not permit {@code null} keys or values.
 * @implNote The returned memoized function can be safely used concurrently from multiple threads which makes it
 * thread-safe.
 */
@Nonnull
default ThrowableToLongTriFunction<T, U, V, X> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, U, V>, Long> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ThrowableToLongTriFunction<T, U, V, X> & Memoized) (t, u, v) -> {
            final long returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, u, v), ThrowableFunction
                        .of(key -> applyAsLongThrows(key.getLeft(), key.getMiddle(), key.getRight())));
            }
            return returnValue;
        };
    }
}

From source file:at.gridtec.lambda4j.function.bi.obj.ThrowableObjBooleanFunction.java

/**
 * Returns a memoized (caching) version of this {@link ThrowableObjBooleanFunction}. Whenever it is called, the
 * mapping between the input parameters and the return value is preserved in a cache, making subsequent calls
 * returning the memoized value instead of computing the return value again.
 * <p>//from   w ww  .  j  a v a2  s.  c o  m
 * Unless the function and therefore the used cache will be garbage-collected, it will keep all memoized values
 * forever.
 *
 * @return A memoized (caching) version of this {@code ThrowableObjBooleanFunction}.
 * @implSpec This implementation does not allow the input parameters or return value to be {@code null} for the
 * resulting memoized function, as the cache used internally does not permit {@code null} keys or values.
 * @implNote The returned memoized function can be safely used concurrently from multiple threads which makes it
 * thread-safe.
 */
@Nonnull
default ThrowableObjBooleanFunction<T, R, X> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Pair<T, Boolean>, R> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ThrowableObjBooleanFunction<T, R, X> & Memoized) (t, value) -> {
            final R returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Pair.of(t, value),
                        ThrowableFunction.of(key -> applyThrows(key.getLeft(), key.getRight())));
            }
            return returnValue;
        };
    }
}

From source file:at.gridtec.lambda4j.function.tri.to.ThrowableToIntTriFunction.java

/**
 * Returns a memoized (caching) version of this {@link ThrowableToIntTriFunction}. Whenever it is called, the
 * mapping between the input parameters and the return value is preserved in a cache, making subsequent calls
 * returning the memoized value instead of computing the return value again.
 * <p>//w w w  .j  ava  2  s  .c o m
 * Unless the function and therefore the used cache will be garbage-collected, it will keep all memoized values
 * forever.
 *
 * @return A memoized (caching) version of this {@code ThrowableToIntTriFunction}.
 * @implSpec This implementation does not allow the input parameters or return value to be {@code null} for the
 * resulting memoized function, as the cache used internally does not permit {@code null} keys or values.
 * @implNote The returned memoized function can be safely used concurrently from multiple threads which makes it
 * thread-safe.
 */
@Nonnull
default ThrowableToIntTriFunction<T, U, V, X> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, U, V>, Integer> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ThrowableToIntTriFunction<T, U, V, X> & Memoized) (t, u, v) -> {
            final int returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, u, v), ThrowableFunction
                        .of(key -> applyAsIntThrows(key.getLeft(), key.getMiddle(), key.getRight())));
            }
            return returnValue;
        };
    }
}

From source file:at.gridtec.lambda4j.function.tri.conversion.TriByteToFloatFunction.java

/**
 * Returns a memoized (caching) version of this {@link TriByteToFloatFunction}. Whenever it is called, the mapping
 * between the input parameters and the return value is preserved in a cache, making subsequent calls returning the
 * memoized value instead of computing the return value again.
 * <p>/* w w w .j a v  a 2 s.  co m*/
 * Unless the function and therefore the used cache will be garbage-collected, it will keep all memoized values
 * forever.
 *
 * @return A memoized (caching) version of this {@code TriByteToFloatFunction}.
 * @implSpec This implementation does not allow the input parameters or return value to be {@code null} for the
 * resulting memoized function, as the cache used internally does not permit {@code null} keys or values.
 * @implNote The returned memoized function can be safely used concurrently from multiple threads which makes it
 * thread-safe.
 */
@Nonnull
default TriByteToFloatFunction memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<Byte, Byte, Byte>, Float> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (TriByteToFloatFunction & Memoized) (value1, value2, value3) -> {
            final float returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(value1, value2, value3),
                        key -> applyAsFloat(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

From source file:at.gridtec.lambda4j.function.tri.conversion.TriByteToShortFunction.java

/**
 * Returns a memoized (caching) version of this {@link TriByteToShortFunction}. Whenever it is called, the mapping
 * between the input parameters and the return value is preserved in a cache, making subsequent calls returning the
 * memoized value instead of computing the return value again.
 * <p>//from   w w w.  jav  a  2  s .c o m
 * Unless the function and therefore the used cache will be garbage-collected, it will keep all memoized values
 * forever.
 *
 * @return A memoized (caching) version of this {@code TriByteToShortFunction}.
 * @implSpec This implementation does not allow the input parameters or return value to be {@code null} for the
 * resulting memoized function, as the cache used internally does not permit {@code null} keys or values.
 * @implNote The returned memoized function can be safely used concurrently from multiple threads which makes it
 * thread-safe.
 */
@Nonnull
default TriByteToShortFunction memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<Byte, Byte, Byte>, Short> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (TriByteToShortFunction & Memoized) (value1, value2, value3) -> {
            final short returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(value1, value2, value3),
                        key -> applyAsShort(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

From source file:at.gridtec.lambda4j.function.tri.conversion.TriLongToFloatFunction.java

/**
 * Returns a memoized (caching) version of this {@link TriLongToFloatFunction}. Whenever it is called, the mapping
 * between the input parameters and the return value is preserved in a cache, making subsequent calls returning the
 * memoized value instead of computing the return value again.
 * <p>/*from www . jav  a  2 s  .c om*/
 * Unless the function and therefore the used cache will be garbage-collected, it will keep all memoized values
 * forever.
 *
 * @return A memoized (caching) version of this {@code TriLongToFloatFunction}.
 * @implSpec This implementation does not allow the input parameters or return value to be {@code null} for the
 * resulting memoized function, as the cache used internally does not permit {@code null} keys or values.
 * @implNote The returned memoized function can be safely used concurrently from multiple threads which makes it
 * thread-safe.
 */
@Nonnull
default TriLongToFloatFunction memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<Long, Long, Long>, Float> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (TriLongToFloatFunction & Memoized) (value1, value2, value3) -> {
            final float returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(value1, value2, value3),
                        key -> applyAsFloat(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

From source file:at.gridtec.lambda4j.function.tri.conversion.TriLongToShortFunction.java

/**
 * Returns a memoized (caching) version of this {@link TriLongToShortFunction}. Whenever it is called, the mapping
 * between the input parameters and the return value is preserved in a cache, making subsequent calls returning the
 * memoized value instead of computing the return value again.
 * <p>//ww w  .j a  va  2s  .  c o  m
 * Unless the function and therefore the used cache will be garbage-collected, it will keep all memoized values
 * forever.
 *
 * @return A memoized (caching) version of this {@code TriLongToShortFunction}.
 * @implSpec This implementation does not allow the input parameters or return value to be {@code null} for the
 * resulting memoized function, as the cache used internally does not permit {@code null} keys or values.
 * @implNote The returned memoized function can be safely used concurrently from multiple threads which makes it
 * thread-safe.
 */
@Nonnull
default TriLongToShortFunction memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<Long, Long, Long>, Short> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (TriLongToShortFunction & Memoized) (value1, value2, value3) -> {
            final short returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(value1, value2, value3),
                        key -> applyAsShort(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

From source file:at.gridtec.lambda4j.function.tri.conversion.TriFloatToByteFunction.java

/**
 * Returns a memoized (caching) version of this {@link TriFloatToByteFunction}. Whenever it is called, the mapping
 * between the input parameters and the return value is preserved in a cache, making subsequent calls returning the
 * memoized value instead of computing the return value again.
 * <p>/*from  w w w .  j  a  va 2 s.  c  o m*/
 * Unless the function and therefore the used cache will be garbage-collected, it will keep all memoized values
 * forever.
 *
 * @return A memoized (caching) version of this {@code TriFloatToByteFunction}.
 * @implSpec This implementation does not allow the input parameters or return value to be {@code null} for the
 * resulting memoized function, as the cache used internally does not permit {@code null} keys or values.
 * @implNote The returned memoized function can be safely used concurrently from multiple threads which makes it
 * thread-safe.
 */
@Nonnull
default TriFloatToByteFunction memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<Float, Float, Float>, Byte> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (TriFloatToByteFunction & Memoized) (value1, value2, value3) -> {
            final byte returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(value1, value2, value3),
                        key -> applyAsByte(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

From source file:at.gridtec.lambda4j.function.tri.conversion.TriFloatToLongFunction.java

/**
 * Returns a memoized (caching) version of this {@link TriFloatToLongFunction}. Whenever it is called, the mapping
 * between the input parameters and the return value is preserved in a cache, making subsequent calls returning the
 * memoized value instead of computing the return value again.
 * <p>/*from   www. j ava 2  s . co m*/
 * Unless the function and therefore the used cache will be garbage-collected, it will keep all memoized values
 * forever.
 *
 * @return A memoized (caching) version of this {@code TriFloatToLongFunction}.
 * @implSpec This implementation does not allow the input parameters or return value to be {@code null} for the
 * resulting memoized function, as the cache used internally does not permit {@code null} keys or values.
 * @implNote The returned memoized function can be safely used concurrently from multiple threads which makes it
 * thread-safe.
 */
@Nonnull
default TriFloatToLongFunction memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<Float, Float, Float>, Long> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (TriFloatToLongFunction & Memoized) (value1, value2, value3) -> {
            final long returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(value1, value2, value3),
                        key -> applyAsLong(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

From source file:at.gridtec.lambda4j.function.tri.conversion.TriShortToByteFunction.java

/**
 * Returns a memoized (caching) version of this {@link TriShortToByteFunction}. Whenever it is called, the mapping
 * between the input parameters and the return value is preserved in a cache, making subsequent calls returning the
 * memoized value instead of computing the return value again.
 * <p>/*  w  w  w .j av a2s  .com*/
 * Unless the function and therefore the used cache will be garbage-collected, it will keep all memoized values
 * forever.
 *
 * @return A memoized (caching) version of this {@code TriShortToByteFunction}.
 * @implSpec This implementation does not allow the input parameters or return value to be {@code null} for the
 * resulting memoized function, as the cache used internally does not permit {@code null} keys or values.
 * @implNote The returned memoized function can be safely used concurrently from multiple threads which makes it
 * thread-safe.
 */
@Nonnull
default TriShortToByteFunction memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<Short, Short, Short>, Byte> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (TriShortToByteFunction & Memoized) (value1, value2, value3) -> {
            final byte returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(value1, value2, value3),
                        key -> applyAsByte(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}