| 1 | package com.renomad.minum.utils; | |
| 2 | ||
| 3 | import java.io.Serial; | |
| 4 | import java.util.LinkedHashMap; | |
| 5 | import java.util.Map; | |
| 6 | ||
| 7 | /** | |
| 8 | * A simple Least-Recently Used Cache | |
| 9 | * See <a href="https://en.wikipedia.org/wiki/Cache_replacement_policies#Least_recently_used_(LRU)">LRU</a> | |
| 10 | */ | |
| 11 | public final class LRUCache<K,V> extends LinkedHashMap<K, V> { | |
| 12 | ||
| 13 | @Serial | |
| 14 | private static final long serialVersionUID = -8687744696157499778L; | |
| 15 | ||
| 16 | // max number of entries allowed in this cache | |
| 17 | private static final int DEFAULT_MAX_ENTRIES = 100; | |
| 18 | private final int maxSize; | |
| 19 | ||
| 20 | @Override | |
| 21 | protected boolean removeEldestEntry(Map.Entry<K, V> eldest) { | |
| 22 |
3
1. removeEldestEntry : negated conditional → KILLED 2. removeEldestEntry : replaced boolean return with true for com/renomad/minum/utils/LRUCache::removeEldestEntry → KILLED 3. removeEldestEntry : changed conditional boundary → KILLED |
return size() > maxSize; |
| 23 | } | |
| 24 | ||
| 25 | private LRUCache(int maxSize) { | |
| 26 | // uses the same load factor as found in java.util.Hashmap.DEFAULT_LOAD_FACTOR | |
| 27 |
1
1. <init> : Replaced integer addition with subtraction → KILLED |
super(maxSize + 1, 0.75f, true); |
| 28 | this.maxSize = maxSize; | |
| 29 | } | |
| 30 | ||
| 31 | /** | |
| 32 | * Builds a map that functions as a least-recently used cache. | |
| 33 | * Sets the max size to DEFAULT_MAX_ENTRIES. If you want to specify the max size, | |
| 34 | * use the constructor at {@link #getLruCache(int)} | |
| 35 | * <br> | |
| 36 | * Make sure, when using this, to assign it to a fully-defined | |
| 37 | * type, e.g. {@code Map<String, String> foo = getLruCache()} | |
| 38 | * This is necessary since we provide this as a generic method, | |
| 39 | * and the assignment is what enables Java to determine | |
| 40 | * what types to build. | |
| 41 | */ | |
| 42 | public static <K,V> Map<K, V> getLruCache() { | |
| 43 |
1
1. getLruCache : replaced return value with Collections.emptyMap for com/renomad/minum/utils/LRUCache::getLruCache → KILLED |
return getLruCache(DEFAULT_MAX_ENTRIES); |
| 44 | } | |
| 45 | ||
| 46 | /** | |
| 47 | * Creates an LRUCache, allowing you to specify the max size. | |
| 48 | * Alternately, see {@link #getLruCache()}. | |
| 49 | * <br> | |
| 50 | * Make sure, when using this, to assign it to a fully-defined | |
| 51 | * type, e.g. {@code Map<String, String> foo = getLruCache(2)} | |
| 52 | * This is necessary since we provide this as a generic method, | |
| 53 | * and the assignment is what enables Java to determine | |
| 54 | * what types to build. | |
| 55 | */ | |
| 56 | public static <K,V> Map<K, V> getLruCache(int maxSize) { | |
| 57 |
1
1. getLruCache : replaced return value with Collections.emptyMap for com/renomad/minum/utils/LRUCache::getLruCache → KILLED |
return new LRUCache<>(maxSize); |
| 58 | } | |
| 59 | } | |
Mutations | ||
| 22 |
1.1 2.2 3.3 |
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| 27 |
1.1 |
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| 43 |
1.1 |
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| 57 |
1.1 |