Package com.univocity.parsers.common

Class StringCache<T>

  • Type Parameters:
    T - the type of entry to be stored in the cache
    public abstract class StringCache<T>
extends java.lang.Object
    A simple cache of values associated with strings. It is built to simply prevent generating the same value over and over again over a short period of time. Once its size limit is reached, the cache will be fully cleared. Do not use this as a general purpose caching solution. This meant for storing values that can be cheaply produced and re-generating them every now and then won't incur in any major performance impact.

    • Constructor Summary

      Constructors 
      Constructor Description
      StringCache()  

    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      void clear()
      Removes all entries stored in this cache.
      boolean containsKey​(java.lang.String input)
      Tests whether the cache contains the given key
      T get​(java.lang.String input)
      Returns the value associated with the given string.
      int getMaxStringLength()
      Returns the maximum length a String key can have to be used as a key in this cache.
      int getSizeLimit()
      Returns the size limit of this string cache.
      protected abstract T process​(java.lang.String input)
      Converts a given string to a value
      void put​(java.lang.String input, T value)
      Associates a value to a string
      void setMaxStringLength​(int maxStringLength)
      Returns the maximum length a String key can have to be used as a key in this cache.
      void setSizeLimit​(int sizeLimit)
      Defines the size limit of this string cache (16,384 by default).

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • DEFAULT_MAX_STRING_LENGTH

        private static final int DEFAULT_MAX_STRING_LENGTH
        See Also:
        Constant Field Values

      • stringCache

        private final java.util.Map<java.lang.String,​java.lang.ref.SoftReference<T>> stringCache

      • sizeLimit

        private int sizeLimit

      • maxStringLength

        private int maxStringLength

    • Constructor Detail

      • StringCache

        public StringCache()

    • Method Detail

      • process

        protected abstract T process​(java.lang.String input)
        Converts a given string to a value
        Parameters:
        input - the input to be converted and stored in the cache
        Returns:
        the value generated from the given string/

      • containsKey

        public boolean containsKey​(java.lang.String input)
        Tests whether the cache contains the given key
        Parameters:
        input - a string that might have a value associated to it.
        Returns:
        true if the cache contains (or contained) a value associated with the given key.

      • getSizeLimit

        public int getSizeLimit()
        Returns the size limit of this string cache. Defaults to 16,384. For simplicity, when this limit is reached, the entire cache is cleared.
        Returns:
        the maximum number of entries that can be stored in this string cache.

      • setSizeLimit

        public void setSizeLimit​(int sizeLimit)
        Defines the size limit of this string cache (16,384 by default). For simplicity, when this limit is reached, the entire cache is cleared.
        Parameters:
        sizeLimit - the maximum number of entries that can be stored in this string cache.

      • put

        public void put​(java.lang.String input,
                T value)
        Associates a value to a string
        Parameters:
        input - the string to be associated with a given value
        value - the value associated with the given string

      • get

        public T get​(java.lang.String input)
        Returns the value associated with the given string. If it doesn't exist, or if it has been evicted, a value will be populated using process(String)
        Parameters:
        input - the string whose associated value will be returned
        Returns:
        the value associated with the given string.

      • clear

        public void clear()
        Removes all entries stored in this cache.

      • getMaxStringLength

        public int getMaxStringLength()
        Returns the maximum length a String key can have to be used as a key in this cache. If the String length exceeds this limit, the value associated with it won't be cached. Defaults to 1024
        Returns:
        the maximum length a String key can have

      • setMaxStringLength

        public void setMaxStringLength​(int maxStringLength)
        Returns the maximum length a String key can have to be used as a key in this cache. If the String length exceeds this limit, the value associated with it won't be cached. Defaults to 1024
        Parameters:
        maxStringLength - the maximum length a String key can have