Github user animeshtrivedi commented on a diff in the pull request:
https://github.com/apache/incubator-crail/pull/16#discussion_r180315936
--- Diff:
storage-nvmf/src/main/java/org/apache/crail/storage/nvmf/client/NvmfStagingBufferCache.java
---
@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2018, IBM Corporation
+ *
+ * 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.crail.storage.nvmf.client;
+
+import org.apache.crail.CrailBuffer;
+import org.apache.crail.CrailBufferCache;
+import org.apache.crail.storage.StorageFuture;
+
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class NvmfStagingBufferCache {
+ private final Map<Long, BufferCacheEntry> remoteAddressMap;
+ private final Queue<CrailBuffer> freeBuffers;
+ private int buffersLeft;
+ private final int lbaDataSize;
+ private final CrailBufferCache bufferCache;
+
+ private final CrailBufferCache getBufferCache() {
+ return bufferCache;
+ }
+
+ NvmfStagingBufferCache(CrailBufferCache bufferCache, int maxEntries,
int lbaDataSize) {
+ if (maxEntries <= 0) {
+ throw new IllegalArgumentException("maximum entries <=
0");
+ }
+ if (lbaDataSize <= 0) {
+ throw new IllegalArgumentException("LBA data size <=
0");
+ }
+ this.remoteAddressMap = new ConcurrentHashMap<>(maxEntries);
+ this.freeBuffers = new ArrayBlockingQueue<>(maxEntries);
+ this.buffersLeft = maxEntries;
+ this.lbaDataSize = lbaDataSize;
+ this.bufferCache = bufferCache;
+ }
+
+ synchronized void allocateFreeBuffers() throws Exception {
+ if (!freeBuffers.isEmpty()) {
+ return;
+ }
+ if (buffersLeft == 0) {
+ /* TODO: make sure this happens rarely */
+ Iterator<BufferCacheEntry> iterator =
remoteAddressMap.values().iterator();
+ while (iterator.hasNext()) {
+ BufferCacheEntry currentEntry = iterator.next();
+ if (currentEntry.tryFree()) {
+ iterator.remove();
+
freeBuffers.add(currentEntry.getBuffer());
+ return;
+ }
+ }
+ throw new OutOfMemoryError();
+ }
+
+ CrailBuffer buffer = getBufferCache().allocateBuffer();
+ if (buffer == null) {
+ throw new OutOfMemoryError();
+ }
+ if (buffer.capacity() < lbaDataSize) {
--- End diff --
please print them so that user knows what went wrong.
---
