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.ObjBiFloatToShortFunction.java

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

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

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

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

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

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

---

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

/**
 * Returns a memoized (caching) version of this {@link ObjBiFloatToCharFunction}. 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  ww w .j  a v  a2 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 ObjBiFloatToCharFunction}.
 * @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 ObjBiFloatToCharFunction<T> memoized() {
    if (isMemoized()) {
        return this;
    } else {
        final Map<Triple<T, Float, Float>, Character> cache = new ConcurrentHashMap<>();
        final Object lock = new Object();
        return (ObjBiFloatToCharFunction<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.ObjBiIntToCharFunction.java

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

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

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

---

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