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.ObjBiDoubleToShortFunction.java

/**
 * Returns a memoized (caching) version of this {@link ObjBiDoubleToShortFunction}. 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  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 ObjBiDoubleToShortFunction}.
 * @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 ObjBiDoubleToShortFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Double, Double>, Short> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiDoubleToShortFunction<T> & Memoized) (t, value1, value2) -> {
            final short returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, value1, value2),
                        key -> applyAsShort(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

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

/**
 * Returns a memoized (caching) version of this {@link ObjBiFloatToDoubleFunction}. 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  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 ObjBiFloatToDoubleFunction}.
 * @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 ObjBiFloatToDoubleFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Float, Float>, Double> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiFloatToDoubleFunction<T> & Memoized) (t, value1, value2) -> {
            final double returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, value1, value2),
                        key -> applyAsDouble(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

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

/**
 * Returns a memoized (caching) version of this {@link ObjBiShortToDoubleFunction}. 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  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 ObjBiShortToDoubleFunction}.
 * @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 ObjBiShortToDoubleFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Short, Short>, Double> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiShortToDoubleFunction<T> & Memoized) (t, value1, value2) -> {
            final double returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, value1, value2),
                        key -> applyAsDouble(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

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

/**
 * Returns a memoized (caching) version of this {@link ObjBiBooleanToIntFunction}. 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 .  ja  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 ObjBiBooleanToIntFunction}.
 * @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 ObjBiBooleanToIntFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Boolean, Boolean>, Integer> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiBooleanToIntFunction<T> & Memoized) (t, value1, value2) -> {
            final int returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, value1, value2),
                        key -> applyAsInt(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

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

/**
 * Returns a memoized (caching) version of this {@link ObjBiCharToCharFunction}. 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  . jav a2s  . 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 ObjBiCharToCharFunction}.
 * @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 ObjBiCharToCharFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Character, Character>, Character> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiCharToCharFunction<T> & Memoized) (t, value1, value2) -> {
            final char returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, value1, value2),
                        key -> applyAsChar(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

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

/**
 * Returns a memoized (caching) version of this {@link ObjBiBooleanToFloatFunction}. 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  v  a 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 ObjBiBooleanToFloatFunction}.
 * @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 ObjBiBooleanToFloatFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Boolean, Boolean>, Float> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiBooleanToFloatFunction<T> & Memoized) (t, value1, value2) -> {
            final float returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, value1, value2),
                        key -> applyAsFloat(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

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

/**
 * Returns a memoized (caching) version of this {@link ObjBiBooleanToShortFunction}. 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 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 ObjBiBooleanToShortFunction}.
 * @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 ObjBiBooleanToShortFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Boolean, Boolean>, Short> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiBooleanToShortFunction<T> & Memoized) (t, value1, value2) -> {
            final short returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, value1, value2),
                        key -> applyAsShort(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

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

/**
 * Returns a memoized (caching) version of this {@link ObjBiCharToFloatFunction}. 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 a v  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 ObjBiCharToFloatFunction}.
 * @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 ObjBiCharToFloatFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Character, Character>, Float> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiCharToFloatFunction<T> & Memoized) (t, value1, value2) -> {
            final float returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, value1, value2),
                        key -> applyAsFloat(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

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

/**
 * Returns a memoized (caching) version of this {@link ObjBiCharToShortFunction}. 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  a  v  a 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 ObjBiCharToShortFunction}.
 * @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 ObjBiCharToShortFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Character, Character>, Short> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiCharToShortFunction<T> & Memoized) (t, value1, value2) -> {
            final short returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, value1, value2),
                        key -> applyAsShort(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

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

/**
 * Returns a memoized (caching) version of this {@link ObjBiDoubleToCharFunction}. 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  va2s  .  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 ObjBiDoubleToCharFunction}.
 * @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 ObjBiDoubleToCharFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Double, Double>, Character> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiDoubleToCharFunction<T> & Memoized) (t, value1, value2) -> {
            final char returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(t, value1, value2),
                        key -> applyAsChar(key.getLeft(), key.getMiddle(), key.getRight()));
            }
            return returnValue;
        };
    }
}

---

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