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1   /**
2    * Copyright The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  package org.apache.hadoop.hbase.io.hfile;
21  
22  import java.util.Iterator;
23  
24  import org.apache.hadoop.classification.InterfaceAudience;
25  
26  /**
27   * Iterator over an array of BlockCache CachedBlocks.
28   */
29  @InterfaceAudience.Private
30  class BlockCachesIterator implements Iterator<CachedBlock> {
31    int index = 0;
32    final BlockCache [] bcs;
33    Iterator<CachedBlock> current;
34  
35    BlockCachesIterator(final BlockCache [] blockCaches) {
36      this.bcs = blockCaches;
37      this.current = this.bcs[this.index].iterator();
38    }
39  
40    @Override
41    public boolean hasNext() {
42      if (current.hasNext()) return true;
43      this.index++;
44      if (this.index >= this.bcs.length) return false;
45      this.current = this.bcs[this.index].iterator();
46      return hasNext();
47    }
48  
49    @Override
50    public CachedBlock next() {
51      return this.current.next();
52    }
53  
54    @Override
55    public void remove() {
56      throw new UnsupportedOperationException();
57    }
58  }