apache · steveloughran · Jul 14, 2023 · Jun 17, 2023 · Jun 24, 2023 · Jun 24, 2023
diff --git a/...t/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/prefetch/CachingBlockManager.java b/...t/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/prefetch/CachingBlockManager.java
@@ -110,6 +110,7 @@ public abstract class CachingBlockManager extends BlockManager {
    * @param prefetchingStatistics statistics for this stream.
    * @param conf the configuration.
    * @param localDirAllocator the local dir allocator instance.
+   * @param maxBlocksCount max blocks count to be kept in cache at any time.
    * @throws IllegalArgumentException if bufferPoolSize is zero or negative.
    */
   public CachingBlockManager(
@@ -118,7 +119,8 @@ public CachingBlockManager(
       int bufferPoolSize,
       PrefetchingStatistics prefetchingStatistics,
       Configuration conf,
-      LocalDirAllocator localDirAllocator) {
+      LocalDirAllocator localDirAllocator,
+      int maxBlocksCount) {
     super(blockData);
 
     Validate.checkPositiveInteger(bufferPoolSize, "bufferPoolSize");
@@ -129,16 +131,16 @@ public CachingBlockManager(
     this.numReadErrors = new AtomicInteger();
     this.cachingDisabled = new AtomicBoolean();
     this.prefetchingStatistics = requireNonNull(prefetchingStatistics);
+    this.conf = requireNonNull(conf);
 
     if (this.getBlockData().getFileSize() > 0) {
       this.bufferPool = new BufferPool(bufferPoolSize, this.getBlockData().getBlockSize(),
           this.prefetchingStatistics);
-      this.cache = this.createCache();
+      this.cache = this.createCache(maxBlocksCount);
    }
 
     this.ops = new BlockOperations();
     this.ops.setDebug(false);
-    this.conf = requireNonNull(conf);
     this.localDirAllocator = localDirAllocator;
   }
 
@@ -557,8 +559,8 @@ private void addToCacheAndRelease(BufferData data, Future<Void> blockFuture,
     }
   }
 
-  protected BlockCache createCache() {
-    return new SingleFilePerBlockCache(prefetchingStatistics);
+  protected BlockCache createCache(int maxBlocksCount) {
+    return new SingleFilePerBlockCache(prefetchingStatistics, maxBlocksCount);
   }
 
   protected void cachePut(int blockNumber, ByteBuffer buffer) throws IOException {

diff --git a/...ect/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/prefetch/PrefetchConstants.java b/...ect/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/prefetch/PrefetchConstants.java
@@ -0,0 +1,44 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.hadoop.fs.impl.prefetch;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Constants used by prefetch implementations.
+ */
+public final class PrefetchConstants {
+
+  private PrefetchConstants() {
+  }
+
+  /**
+   * Timeout to be used by close, while acquiring prefetch block write lock.
+   * Value = {@value PREFETCH_WRITE_LOCK_TIMEOUT}
+   */
+  static final int PREFETCH_WRITE_LOCK_TIMEOUT = 5;
+
+  /**
+   * Lock timeout unit to be used by the thread while acquiring prefetch block write lock.
+   * Value = {@value PREFETCH_WRITE_LOCK_TIMEOUT_UNIT}
+   */
+  static final TimeUnit PREFETCH_WRITE_LOCK_TIMEOUT_UNIT = TimeUnit.SECONDS;
+
+}