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.ObjBiDoubleToDoubleFunction.java

/**
 * Returns a memoized (caching) version of this {@link ObjBiDoubleToDoubleFunction}. 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  ava 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 ObjBiDoubleToDoubleFunction}.
 * @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 ObjBiDoubleToDoubleFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Double, Double>, Double> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiDoubleToDoubleFunction<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.ObjBiIntToDoubleFunction.java

/**
 * Returns a memoized (caching) version of this {@link ObjBiIntToDoubleFunction}. 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 .  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 ObjBiIntToDoubleFunction}.
 * @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 ObjBiIntToDoubleFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Integer, Integer>, Double> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiIntToDoubleFunction<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.ObjBiBooleanToCharFunction.java

/**
 * Returns a memoized (caching) version of this {@link ObjBiBooleanToCharFunction}. 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  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 ObjBiBooleanToCharFunction}.
 * @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 ObjBiBooleanToCharFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Boolean, Boolean>, Character> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiBooleanToCharFunction<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.ThrowableTriFloatFunction.java

/**
 * Returns a memoized (caching) version of this {@link ThrowableTriFloatFunction}. 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 va 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 ThrowableTriFloatFunction}.
 * @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 ThrowableTriFloatFunction<R, X> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<Float, Float, Float>, R> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ThrowableTriFloatFunction<R, X> & Memoized) (value1, value2, value3) -> {
            final R returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(value1, value2, value3), ThrowableFunction
                        .of(key -> applyThrows(key.getLeft(), key.getMiddle(), key.getRight())));
            }
            return returnValue;
        };
    }
}

---

From source file:at.gridtec.lambda4j.function.tri.ThrowableTriShortFunction.java

/**
 * Returns a memoized (caching) version of this {@link ThrowableTriShortFunction}. 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  .  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 ThrowableTriShortFunction}.
 * @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 ThrowableTriShortFunction<R, X> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<Short, Short, Short>, R> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ThrowableTriShortFunction<R, X> & Memoized) (value1, value2, value3) -> {
            final R returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(value1, value2, value3), ThrowableFunction
                        .of(key -> applyThrows(key.getLeft(), key.getMiddle(), key.getRight())));
            }
            return returnValue;
        };
    }
}

---

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

/**
 * Returns a memoized (caching) version of this {@link ObjBiBooleanToDoubleFunction}. 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 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 ObjBiBooleanToDoubleFunction}.
 * @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 ObjBiBooleanToDoubleFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Boolean, Boolean>, Double> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiBooleanToDoubleFunction<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.ObjBiCharToDoubleFunction.java

/**
 * Returns a memoized (caching) version of this {@link ObjBiCharToDoubleFunction}. 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. ja v  a 2  s .  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 ObjBiCharToDoubleFunction}.
 * @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 ObjBiCharToDoubleFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Character, Character>, Double> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiCharToDoubleFunction<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.ThrowableTriIntFunction.java

/**
 * Returns a memoized (caching) version of this {@link ThrowableTriIntFunction}. 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 ThrowableTriIntFunction}.
 * @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 ThrowableTriIntFunction<R, X> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<Integer, Integer, Integer>, R> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ThrowableTriIntFunction<R, X> & Memoized) (value1, value2, value3) -> {
            final R returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(value1, value2, value3), ThrowableFunction
                        .of(key -> applyThrows(key.getLeft(), key.getMiddle(), key.getRight())));
            }
            return returnValue;
        };
    }
}

---

From source file:at.gridtec.lambda4j.function.tri.ThrowableTriDoubleFunction.java

/**
 * Returns a memoized (caching) version of this {@link ThrowableTriDoubleFunction}. 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  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 ThrowableTriDoubleFunction}.
 * @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 ThrowableTriDoubleFunction<R, X> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<Double, Double, Double>, R> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ThrowableTriDoubleFunction<R, X> & Memoized) (value1, value2, value3) -> {
            final R returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(value1, value2, value3), ThrowableFunction
                        .of(key -> applyThrows(key.getLeft(), key.getMiddle(), key.getRight())));
            }
            return returnValue;
        };
    }
}

---

From source file:at.gridtec.lambda4j.function.tri.ThrowableTriBooleanFunction.java

/**
 * Returns a memoized (caching) version of this {@link ThrowableTriBooleanFunction}. 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  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 ThrowableTriBooleanFunction}.
 * @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 ThrowableTriBooleanFunction<R, X> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<Boolean, Boolean, Boolean>, R> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ThrowableTriBooleanFunction<R, X> & Memoized) (value1, value2, value3) -> {
            final R returnValue;
            synchronized (lock) {
                returnValue = cache.computeIfAbsent(Triple.of(value1, value2, value3), ThrowableFunction
                        .of(key -> applyThrows(key.getLeft(), key.getMiddle(), key.getRight())));
            }
            return returnValue;
        };
    }
}

---

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