SOLR-7355: Switch from ConcurrentLinkedHashMap to Caffeine. Trunk-only change, as it requires java 8.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1672133 13f79535-47bb-0310-9956-ffa450edef68

solr/CHANGES.txt

@@ -58,6 +58,9 @@ Other Changes
 
 * SOLR-6954: Deprecated SolrClient.shutdown() method removed (Alan Woodward)
 
+* SOLR-7355: Switch from Google's ConcurrentLinkedHashMap to Caffeine.  Only
+  affects HDFS support. (Ben Manes via Shawn Heisey)
+
 ==================  5.2.0 ==================
 
 Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release

solr/core/ivy.xml

@@ -66,7 +66,7 @@
     <dependency org="commons-collections" name="commons-collections" rev="${/commons-collections/commons-collections}" conf="compile.hadoop"/>
     
     <dependency org="com.google.protobuf" name="protobuf-java" rev="${/com.google.protobuf/protobuf-java}" conf="compile.hadoop"/>
-    <dependency org="com.googlecode.concurrentlinkedhashmap" name="concurrentlinkedhashmap-lru" rev="${/com.googlecode.concurrentlinkedhashmap/concurrentlinkedhashmap-lru}" conf="compile.hadoop"/>
+    <dependency org="com.github.ben-manes.caffeine" name="caffeine" rev="${/com.github.ben-manes.caffeine/caffeine}" conf="compile.hadoop"/>
     <dependency org="org.htrace" name="htrace-core" rev="${/org.htrace/htrace-core}" conf="compile.hadoop"/>
     
     <!-- Hadoop DfsMiniCluster Dependencies-->

solr/core/src/java/org/apache/solr/store/blockcache/BlockCache.java

@@ -21,8 +21,9 @@ import java.nio.ByteBuffer;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.atomic.AtomicInteger;
 
-import com.googlecode.concurrentlinkedhashmap.ConcurrentLinkedHashMap;
-import com.googlecode.concurrentlinkedhashmap.EvictionListener;
+import com.github.benmanes.caffeine.cache.Cache;
+import com.github.benmanes.caffeine.cache.Caffeine;
+import com.github.benmanes.caffeine.cache.RemovalListener;
 
 /**
  * @lucene.experimental
@@ -31,7 +32,7 @@ public class BlockCache {
   
   public static final int _128M = 134217728;
   public static final int _32K = 32768;
-  private final ConcurrentMap<BlockCacheKey,BlockCacheLocation> cache;
+  private final Cache<BlockCacheKey,BlockCacheLocation> cache;
   private final ByteBuffer[] banks;
   private final BlockLocks[] locks;
   private final AtomicInteger[] lockCounters;
@@ -68,20 +69,18 @@ public class BlockCache {
       locks[i] = new BlockLocks(numberOfBlocksPerBank);
       lockCounters[i] = new AtomicInteger();
     }
-    
-    EvictionListener<BlockCacheKey,BlockCacheLocation> listener = new EvictionListener<BlockCacheKey,BlockCacheLocation>() {
-      @Override
-      public void onEviction(BlockCacheKey key, BlockCacheLocation location) {
-        releaseLocation(location);
-      }
-    };
-    cache = new ConcurrentLinkedHashMap.Builder<BlockCacheKey,BlockCacheLocation>()
-        .maximumWeightedCapacity(maxEntries).listener(listener).build();
+
+    RemovalListener<BlockCacheKey,BlockCacheLocation> listener = 
+        notification -> releaseLocation(notification.getValue());
+    cache = Caffeine.newBuilder()
+        .removalListener(listener)
+        .maximumSize(maxEntries)
+        .build();
     this.blockSize = blockSize;
   }
   
   public void release(BlockCacheKey key) {
-    releaseLocation(cache.remove(key));
+    cache.invalidate(key);
   }
   
   private void releaseLocation(BlockCacheLocation location) {
@@ -104,7 +103,7 @@ public class BlockCache {
           + blockSize + "] got length [" + length + "] with blockOffset ["
           + blockOffset + "]");
     }
-    BlockCacheLocation location = cache.get(blockCacheKey);
+    BlockCacheLocation location = cache.getIfPresent(blockCacheKey);
     boolean newLocation = false;
     if (location == null) {
       newLocation = true;
@@ -122,7 +121,7 @@ public class BlockCache {
     bank.position(bankOffset + blockOffset);
     bank.put(data, offset, length);
     if (newLocation) {
-      releaseLocation(cache.put(blockCacheKey.clone(), location));
+      cache.put(blockCacheKey.clone(), location);
       metrics.blockCacheSize.incrementAndGet();
     }
     return true;
@@ -130,7 +129,7 @@ public class BlockCache {
   
   public boolean fetch(BlockCacheKey blockCacheKey, byte[] buffer,
       int blockOffset, int off, int length) {
-    BlockCacheLocation location = cache.get(blockCacheKey);
+    BlockCacheLocation location = cache.getIfPresent(blockCacheKey);
     if (location == null) {
       return false;
     }
@@ -201,6 +200,6 @@ public class BlockCache {
   }
   
   public int getSize() {
-    return cache.size();
+    return cache.asMap().size();
   }
 }

solr/core/src/test/org/apache/solr/store/blockcache/BlockDirectoryTest.java

@@ -22,6 +22,8 @@ import java.io.IOException;
 import java.util.Map;
 import java.util.Random;
 
+import com.github.benmanes.caffeine.cache.Caffeine;
+
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.FSDirectory;
 import org.apache.lucene.store.IOContext;
@@ -34,12 +36,13 @@ import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 
-import com.googlecode.concurrentlinkedhashmap.ConcurrentLinkedHashMap;
-
 public class BlockDirectoryTest extends SolrTestCaseJ4 {
 
   private class MapperCache implements Cache {
-    public Map<String, byte[]> map = new ConcurrentLinkedHashMap.Builder<String, byte[]>().maximumWeightedCapacity(8).build();
+    public Map<String, byte[]> map = Caffeine.newBuilder()
+        .maximumSize(8)
+        .<String, byte[]>build()
+        .asMap();
 
     @Override
     public void update(String name, long blockId, int blockOffset, byte[] buffer, int offset, int length) {
@@ -167,7 +170,10 @@ public class BlockDirectoryTest extends SolrTestCaseJ4 {
 
   @Test
   public void testRandomAccessWritesLargeCache() throws IOException {
-    mapperCache.map = new ConcurrentLinkedHashMap.Builder<String, byte[]>().maximumWeightedCapacity(10000).build();
+    mapperCache.map = Caffeine.newBuilder()
+        .maximumSize(10_000)
+        .<String, byte[]>build()
+        .asMap();
     testRandomAccessWrites();
   }
 

solr/licenses/caffeine-1.0.1.jar.sha1

@@ -0,0 +1 @@
+eb95a1eb55cb02018b8e0bc1609ce569b455ea98

solr/licenses/caffeine-NOTICE.txt

@@ -0,0 +1 @@
+Copyright 2015 by Ben Manes

solr/licenses/concurrentlinkedhashmap-lru-1.2.jar.sha1

@@ -1 +0,0 @@
-4316d710b6619ffe210c98deb2b0893587dad454