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.obj.BiObjCharToFloatFunction.java

/**
 * Returns a memoized (caching) version of this {@link BiObjCharToFloatFunction}. 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  .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 BiObjCharToFloatFunction}.
 * @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 BiObjCharToFloatFunction<T, U> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, U, Character>, Float> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (BiObjCharToFloatFunction<T, U> & Memoized) (t, u, value) -> {
            final float returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, u, value),
                        key -> applyAsFloat(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

From source file:at.gridtec.lambda4j.function.tri.obj.BiObjCharToShortFunction.java

/**
 * Returns a memoized (caching) version of this {@link BiObjCharToShortFunction}. 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 av  a 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 BiObjCharToShortFunction}.
 * @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 BiObjCharToShortFunction<T, U> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, U, Character>, Short> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (BiObjCharToShortFunction<T, U> & Memoized) (t, u, value) -> {
            final short returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, u, value),
                        key -> applyAsShort(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

From source file:at.gridtec.lambda4j.function.tri.obj.BiObjDoubleToFloatFunction.java

/**
 * Returns a memoized (caching) version of this {@link BiObjDoubleToFloatFunction}. 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 v  a 2s .  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 BiObjDoubleToFloatFunction}.
 * @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 BiObjDoubleToFloatFunction<T, U> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, U, Double>, Float> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (BiObjDoubleToFloatFunction<T, U> & Memoized) (t, u, value) -> {
            final float returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, u, value),
                        key -> applyAsFloat(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

From source file:at.gridtec.lambda4j.function.tri.obj.BiObjDoubleToIntFunction.java

/**
 * Returns a memoized (caching) version of this {@link BiObjDoubleToIntFunction}. 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>/*  www. j  a  v a 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 BiObjDoubleToIntFunction}.
 * @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 BiObjDoubleToIntFunction<T, U> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, U, Double>, Integer> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (BiObjDoubleToIntFunction<T, U> & Memoized) (t, u, value) -> {
            final int returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, u, value),
                        key -> applyAsInt(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

From source file:at.gridtec.lambda4j.function.tri.obj.BiObjDoubleToShortFunction.java

/**
 * Returns a memoized (caching) version of this {@link BiObjDoubleToShortFunction}. 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  ww .j  a v  a2s . 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 BiObjDoubleToShortFunction}.
 * @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 BiObjDoubleToShortFunction<T, U> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, U, Double>, Short> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (BiObjDoubleToShortFunction<T, U> & Memoized) (t, u, value) -> {
            final short returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, u, value),
                        key -> applyAsShort(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

From source file:at.gridtec.lambda4j.function.tri.obj.BiObjLongToDoubleFunction.java

/**
 * Returns a memoized (caching) version of this {@link BiObjLongToDoubleFunction}. 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 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 BiObjLongToDoubleFunction}.
 * @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 BiObjLongToDoubleFunction<T, U> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, U, Long>, Double> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (BiObjLongToDoubleFunction<T, U> & Memoized) (t, u, value) -> {
            final double returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, u, value),
                        key -> applyAsDouble(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

From source file:at.gridtec.lambda4j.function.tri.obj.BiObjBooleanToFloatFunction.java

/**
 * Returns a memoized (caching) version of this {@link BiObjBooleanToFloatFunction}. 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 . ja va2 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 BiObjBooleanToFloatFunction}.
 * @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 BiObjBooleanToFloatFunction<T, U> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, U, Boolean>, Float> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (BiObjBooleanToFloatFunction<T, U> & Memoized) (t, u, value) -> {
            final float returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, u, value),
                        key -> applyAsFloat(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

From source file:at.gridtec.lambda4j.function.tri.obj.BiObjBooleanToShortFunction.java

/**
 * Returns a memoized (caching) version of this {@link BiObjBooleanToShortFunction}. 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 2s . 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 BiObjBooleanToShortFunction}.
 * @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 BiObjBooleanToShortFunction<T, U> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, U, Boolean>, Short> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (BiObjBooleanToShortFunction<T, U> & Memoized) (t, u, value) -> {
            final short returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, u, value),
                        key -> applyAsShort(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

From source file:at.gridtec.lambda4j.function.tri.obj.BiObjDoubleToCharFunction.java

/**
 * Returns a memoized (caching) version of this {@link BiObjDoubleToCharFunction}. 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 v  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 BiObjDoubleToCharFunction}.
 * @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 BiObjDoubleToCharFunction<T, U> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, U, Double>, Character> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (BiObjDoubleToCharFunction<T, U> & Memoized) (t, u, value) -> {
            final char returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, u, value),
                        key -> applyAsChar(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

From source file:at.gridtec.lambda4j.function.tri.obj.BiObjFloatToDoubleFunction.java

/**
 * Returns a memoized (caching) version of this {@link BiObjFloatToDoubleFunction}. 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 BiObjFloatToDoubleFunction}.
 * @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 BiObjFloatToDoubleFunction<T, U> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, U, Float>, Double> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (BiObjFloatToDoubleFunction<T, U> & Memoized) (t, u, value) -> {
            final double returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, u, value),
                        key -> applyAsDouble(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

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