From 30bfea741e2138145bf7d3556746f3373ba82cd6 Mon Sep 17 00:00:00 2001 From: Jason Tedor Date: Thu, 1 Oct 2015 00:37:18 +0200 Subject: [PATCH] Cleanup formatting --- .../org/elasticsearch/common/cache/Cache.java | 28 +++++++------ .../common/cache/CacheTests.java | 41 ++++++++++--------- 2 files changed, 36 insertions(+), 33 deletions(-) diff --git a/core/src/main/java/org/elasticsearch/common/cache/Cache.java b/core/src/main/java/org/elasticsearch/common/cache/Cache.java index ae07f5d5289..3f4177ecc50 100644 --- a/core/src/main/java/org/elasticsearch/common/cache/Cache.java +++ b/core/src/main/java/org/elasticsearch/common/cache/Cache.java @@ -32,12 +32,12 @@ import java.util.function.ToLongBiFunction; /** * A simple concurrent cache. - *

+ *

* Cache is a simple concurrent cache that supports time-based and weight-based evictions, with notifications for all * evictions. The design goals for this cache were simplicity and read performance. This means that we are willing to * accept reduced write performance in exchange for easy-to-understand code. Cache statistics for hits, misses and * evictions are exposed. - *

+ *

* The design of the cache is relatively simple. The cache is segmented into 256 segments which are backed by HashMaps. * The segments are protected by a re-entrant read/write lock. The read/write locks permit multiple concurrent readers * without contention, and the segments gives us write throughput without impacting readers (so readers are blocked only @@ -47,12 +47,12 @@ import java.util.function.ToLongBiFunction; * LRU list is protected by a lock that serializes all writes to it. There are opportunities for improvements * here if write throughput is a concern. *

    - *
  1. LRU list mutations could be inserted into a blocking queue that a single thread is reading from - * and applying to the LRU list.
    2. - *
  2. Promotions could be deferred for entries that were "recently" promoted.
    3. - *
  3. Locks on the list could be taken per node being modified instead of globally.
    4. + *
  4. LRU list mutations could be inserted into a blocking queue that a single thread is reading from + * and applying to the LRU list.
    5. + *
  5. Promotions could be deferred for entries that were "recently" promoted.
    6. + *
  6. Locks on the list could be taken per node being modified instead of globally.
    7. *
- * + *

* Evictions only occur after a mutation to the cache (meaning an entry promotion, a cache insertion, or a manual * invalidation) or an explicit call to {@link #refresh()}. * @@ -124,7 +124,9 @@ public class Cache { } // the state of an entry in the LRU list - enum State {NEW, EXISTING, DELETED} + enum State { + NEW, EXISTING, DELETED + } static class Entry { final K key; @@ -144,7 +146,7 @@ public class Cache { /** * A cache segment. - * + *

* A CacheSegment is backed by a HashMap and is protected by a read/write lock. * * @param the type of the keys @@ -184,9 +186,9 @@ public class Cache { /** * put an entry into the segment * - * @param key the key of the entry to add to the cache + * @param key the key of the entry to add to the cache * @param value the value of the entry to add to the cache - * @param now the access time of this entry + * @param now the access time of this entry * @return a tuple of the new entry and the existing entry, if there was one otherwise null */ Tuple, Entry> put(K key, V value, long now) { @@ -270,7 +272,7 @@ public class Cache { * 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. * - * @param key the key whose associated value is to be returned or computed for if non-existant + * @param key the key whose associated value is to be returned or computed for if non-existant * @param mappingFunction the function to compute a value given a key * @return the current (existing or computed) value associated with the specified key, or null if the computed * value is null @@ -297,7 +299,7 @@ public class Cache { * Associates the specified value with the specified key in this map. If the map previously contained a mapping for * the key, the old value is replaced. * - * @param key key with which the specified value is to be associated + * @param key key with which the specified value is to be associated * @param value value to be associated with the specified key */ public void put(K key, V value) { diff --git a/core/src/test/java/org/elasticsearch/common/cache/CacheTests.java b/core/src/test/java/org/elasticsearch/common/cache/CacheTests.java index bb348b378f9..3c932e4171b 100644 --- a/core/src/test/java/org/elasticsearch/common/cache/CacheTests.java +++ b/core/src/test/java/org/elasticsearch/common/cache/CacheTests.java @@ -22,13 +22,14 @@ package org.elasticsearch.common.cache; import org.elasticsearch.test.ESTestCase; import org.junit.Before; -import java.util.*; +import java.util.ArrayList; +import java.util.HashSet; +import java.util.List; +import java.util.Set; import java.util.concurrent.atomic.AtomicInteger; import java.util.concurrent.atomic.AtomicLong; import java.util.concurrent.atomic.AtomicReferenceArray; -import static org.hamcrest.Matchers.not; - public class CacheTests extends ESTestCase { private int numberOfEntries; @@ -71,7 +72,7 @@ public class CacheTests extends ESTestCase { } assertEquals(hits, cache.stats().getHits()); assertEquals(misses, cache.stats().getMisses()); - assertEquals((int)Math.ceil(numberOfEntries / 2.0), evictions.get()); + assertEquals((int) Math.ceil(numberOfEntries / 2.0), evictions.get()); assertEquals(evictions.get(), cache.stats().getEvictions()); } @@ -319,11 +320,11 @@ public class CacheTests extends ESTestCase { Set notifications = new HashSet<>(); Cache cache = CacheBuilder.builder() - .removalListener(notification -> { - assertEquals(RemovalNotification.RemovalReason.INVALIDATED, notification.getRemovalReason()); - notifications.add(notification.getKey()); - }) - .build(); + .removalListener(notification -> { + assertEquals(RemovalNotification.RemovalReason.INVALIDATED, notification.getRemovalReason()); + notifications.add(notification.getKey()); + }) + .build(); for (int i = 0; i < numberOfEntries; i++) { cache.put(i, Integer.toString(i)); } @@ -353,11 +354,11 @@ public class CacheTests extends ESTestCase { Set notifications = new HashSet<>(); Cache cache = CacheBuilder.builder() - .removalListener(notification -> { - assertEquals(RemovalNotification.RemovalReason.INVALIDATED, notification.getRemovalReason()); - notifications.add(notification.getKey()); - }) - .build(); + .removalListener(notification -> { + assertEquals(RemovalNotification.RemovalReason.INVALIDATED, notification.getRemovalReason()); + notifications.add(notification.getKey()); + }) + .build(); Set invalidated = new HashSet<>(); for (int i = 0; i < numberOfEntries; i++) { cache.put(i, Integer.toString(i)); @@ -446,12 +447,12 @@ public class CacheTests extends ESTestCase { } for (int i = 0; i < numberOfThreads; i++) { Thread thread = new Thread(() -> { - for (int j = 0; j < numberOfEntries; j++) { - cache.computeIfAbsent(j, key -> { - assertTrue(flags.compareAndSet(key, false, true)); - return Integer.toString(key); - }); - } + for (int j = 0; j < numberOfEntries; j++) { + cache.computeIfAbsent(j, key -> { + assertTrue(flags.compareAndSet(key, false, true)); + return Integer.toString(key); + }); + } }); threads.add(thread); thread.start();