[pulsar-common] add open Concurrent LongPair RangeSet

pulsar-common/src/main/java/org/apache/pulsar/common/util/collections/ConcurrentBitSet.java

@@ -0,0 +1,160 @@
+/**
+ * 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.pulsar.common.util.collections;
+
+import java.util.BitSet;
+import java.util.concurrent.locks.StampedLock;
+
+public class ConcurrentBitSet extends BitSet {
+
+    private static final long serialVersionUID = 1L;
+    private final StampedLock rwLock = new StampedLock();
+
+    /**
+     * Creates a bit set whose initial size is large enough to explicitly represent bits with indices in the range
+     * {@code 0} through {@code nbits-1}. All bits are initially {@code false}.
+     *
+     * @param nbits
+     *            the initial size of the bit set
+     * @throws NegativeArraySizeException
+     *             if the specified initial size is negative
+     */
+    public ConcurrentBitSet(int nbits) {
+        super(nbits);
+    }
+
+    @Override
+    public boolean get(int bitIndex) {
+        long stamp = rwLock.tryOptimisticRead();
+        boolean isSet = super.get(bitIndex);
+        if (!rwLock.validate(stamp)) {
+            stamp = rwLock.readLock();
+            try {
+                isSet = super.get(bitIndex);
+            } finally {
+                rwLock.unlockRead(stamp);
+            }
+        }
+        return isSet;
+    }
+
+    @Override
+    public void set(int bitIndex) {
+        long stamp = rwLock.tryOptimisticRead();
+        super.set(bitIndex);
+        if (!rwLock.validate(stamp)) {
+            stamp = rwLock.readLock();
+            try {
+                super.set(bitIndex);
+            } finally {
+                rwLock.unlockRead(stamp);
+            }
+        }
+    }
+
+    @Override
+    public void set(int fromIndex, int toIndex) {
+        long stamp = rwLock.tryOptimisticRead();
+        super.set(fromIndex, toIndex);
+        if (!rwLock.validate(stamp)) {
+            stamp = rwLock.readLock();
+            try {
+                super.set(fromIndex, toIndex);
+            } finally {
+                rwLock.unlockRead(stamp);
+            }
+        }
+    }
+
+    @Override
+    public int nextSetBit(int fromIndex) {
+        long stamp = rwLock.tryOptimisticRead();
+        int bit = super.nextSetBit(fromIndex);
+        if (!rwLock.validate(stamp)) {
+            stamp = rwLock.readLock();
+            try {
+                bit = super.nextSetBit(fromIndex);
+            } finally {
+                rwLock.unlockRead(stamp);
+            }
+        }
+        return bit;
+    }
+
+    @Override
+    public int nextClearBit(int fromIndex) {
+        long stamp = rwLock.tryOptimisticRead();
+        int bit = super.nextClearBit(fromIndex);
+        if (!rwLock.validate(stamp)) {
+            stamp = rwLock.readLock();
+            try {
+                bit = super.nextClearBit(fromIndex);
+            } finally {
+                rwLock.unlockRead(stamp);
+            }
+        }
+        return bit;
+    }
+
+    @Override
+    public int previousSetBit(int fromIndex) {
+        long stamp = rwLock.tryOptimisticRead();
+        int bit = super.previousSetBit(fromIndex);
+        if (!rwLock.validate(stamp)) {
+            stamp = rwLock.readLock();
+            try {
+                bit = super.previousSetBit(fromIndex);
+            } finally {
+                rwLock.unlockRead(stamp);
+            }
+        }
+        return bit;
+    }
+
+    @Override
+    public int previousClearBit(int fromIndex) {
+        long stamp = rwLock.tryOptimisticRead();
+        int bit = super.previousClearBit(fromIndex);
+        if (!rwLock.validate(stamp)) {
+            stamp = rwLock.readLock();
+            try {
+                bit = super.previousClearBit(fromIndex);
+            } finally {
+                rwLock.unlockRead(stamp);
+            }
+        }
+        return bit;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        long stamp = rwLock.tryOptimisticRead();
+        boolean isEmpty = super.isEmpty();
+        if (!rwLock.validate(stamp)) {
+            // Fallback to read lock
+            stamp = rwLock.readLock();
+            try {
+                isEmpty = super.isEmpty();
+            } finally {
+                rwLock.unlockRead(stamp);
+            }
+        }
+        return isEmpty;
+    }
+}