Package org.apache.groovy.util.concurrent.concurrentlinkedhashmap

Class Weighers

    • Method Detail

      • asEntryWeigher

        public static <K,​V> EntryWeigher<K,​V> asEntryWeigher​(Weigher<? super V> weigher)
        A entry weigher backed by the specified weigher. The weight of the value determines the weight of the entry.
        Parameters:
        weigher - the weigher to be "wrapped" in a entry weigher.
        Returns:
        A entry weigher view of the specified weigher.

      • entrySingleton

        public static <K,​V> EntryWeigher<K,​V> entrySingleton()
        A weigher where an entry has a weight of 1. A map bounded with this weigher will evict when the number of key-value pairs exceeds the capacity.
        Returns:
        A weigher where a value takes one unit of capacity.

      • singleton

        public static <V> Weigher<V> singleton()
        A weigher where a value has a weight of 1. A map bounded with this weigher will evict when the number of key-value pairs exceeds the capacity.
        Returns:
        A weigher where a value takes one unit of capacity.

      • byteArray

        public static Weigher<byte[]> byteArray()
        A weigher where the value is a byte array and its weight is the number of bytes. A map bounded with this weigher will evict when the number of bytes exceeds the capacity rather than the number of key-value pairs in the map. This allows for restricting the capacity based on the memory-consumption and is primarily for usage by dedicated caching servers that hold the serialized data.

        A value with a weight of 0 will be rejected by the map. If a value with this weight can occur then the caller should eagerly evaluate the value and treat it as a removal operation. Alternatively, a custom weigher may be specified on the map to assign an empty value a positive weight.

        Returns:
        A weigher where each byte takes one unit of capacity.

      • iterable

        public static <E> Weigher<? super Iterable<E>> iterable()
        A weigher where the value is a Iterable and its weight is the number of elements. This weigher only should be used when the alternative collection() weigher cannot be, as evaluation takes O(n) time. A map bounded with this weigher will evict when the total number of elements exceeds the capacity rather than the number of key-value pairs in the map.

        A value with a weight of 0 will be rejected by the map. If a value with this weight can occur then the caller should eagerly evaluate the value and treat it as a removal operation. Alternatively, a custom weigher may be specified on the map to assign an empty value a positive weight.

        Returns:
        A weigher where each element takes one unit of capacity.

      • collection

        public static <E> Weigher<? super Collection<E>> collection()
        A weigher where the value is a Collection and its weight is the number of elements. A map bounded with this weigher will evict when the total number of elements exceeds the capacity rather than the number of key-value pairs in the map.

        A value with a weight of 0 will be rejected by the map. If a value with this weight can occur then the caller should eagerly evaluate the value and treat it as a removal operation. Alternatively, a custom weigher may be specified on the map to assign an empty value a positive weight.

        Returns:
        A weigher where each element takes one unit of capacity.

      • list

        public static <E> Weigher<? super List<E>> list()
        A weigher where the value is a List and its weight is the number of elements. A map bounded with this weigher will evict when the total number of elements exceeds the capacity rather than the number of key-value pairs in the map.

        A value with a weight of 0 will be rejected by the map. If a value with this weight can occur then the caller should eagerly evaluate the value and treat it as a removal operation. Alternatively, a custom weigher may be specified on the map to assign an empty value a positive weight.

        Returns:
        A weigher where each element takes one unit of capacity.

      • set

        public static <E> Weigher<? super Set<E>> set()
        A weigher where the value is a Set and its weight is the number of elements. A map bounded with this weigher will evict when the total number of elements exceeds the capacity rather than the number of key-value pairs in the map.

        A value with a weight of 0 will be rejected by the map. If a value with this weight can occur then the caller should eagerly evaluate the value and treat it as a removal operation. Alternatively, a custom weigher may be specified on the map to assign an empty value a positive weight.

        Returns:
        A weigher where each element takes one unit of capacity.

      • map

        public static <A,​B> Weigher<? super Map<A,​B>> map()
        A weigher where the value is a Map and its weight is the number of entries. A map bounded with this weigher will evict when the total number of entries across all values exceeds the capacity rather than the number of key-value pairs in the map.

        A value with a weight of 0 will be rejected by the map. If a value with this weight can occur then the caller should eagerly evaluate the value and treat it as a removal operation. Alternatively, a custom weigher may be specified on the map to assign an empty value a positive weight.

        Returns:
        A weigher where each entry takes one unit of capacity.