1 /**
2 * Copyright (c) 2011, University of Konstanz, Distributed Systems Group
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 * * Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * * Neither the name of the University of Konstanz nor the
13 * names of its contributors may be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
20 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 package org.treetank.bucket;
29
30 import static com.google.common.base.Objects.toStringHelper;
31
32 import java.io.DataOutput;
33 import java.io.IOException;
34 import java.util.Map;
35 import java.util.Set;
36 import java.util.concurrent.ConcurrentHashMap;
37
38 import org.treetank.access.conf.StandardSettings;
39 import org.treetank.api.IMetaEntry;
40 import org.treetank.bucket.interfaces.IBucket;
41 import org.treetank.exception.TTIOException;
42
43 import com.google.common.hash.HashCode;
44 import com.google.common.hash.Hasher;
45
46 /**
47 * <h1>MetaBucket</h1>
48 *
49 * <p>
50 * This bucket stored variable key -> value mappings, whereas elements must implement the {@link IMetaEntry}s.
51 * </p>
52 *
53 * @author Sebastian Graf, University of Konstanz
54 * @author Marc Kramis, University of Konstanz
55 */
56 public final class MetaBucket implements IBucket {
57
58 /** Map the hash of a name to its name. */
59 private final ConcurrentHashMap<IMetaEntry, IMetaEntry> mMetaMap;
60
61 /** Key of this bucket. */
62 private final long mBucketKey;
63
64 /**
65 * Create name bucket.
66 *
67 * @param pBucketKey
68 * key of this bucket
69 */
70 public MetaBucket(final long pBucketKey) {
71 mMetaMap = new ConcurrentHashMap<IMetaEntry, IMetaEntry>();
72 mBucketKey = pBucketKey;
73 }
74
75 /**
76 * Putting an entry to the map.
77 *
78 * @param pKey
79 * to be stored.
80 * @param pVal
81 * to be stored.
82 * @return if entry already existing, return that one.
83 * @see ConcurrentHashMap#put(Object, Object)
84 */
85 public IMetaEntry put(final IMetaEntry pKey, final IMetaEntry pVal) {
86 return mMetaMap.put(pKey, pVal);
87 }
88
89 /**
90 * Getting an entry.
91 *
92 * @param pKey
93 * to be retrieved
94 * @return the suitable value, if present. Null otherwise
95 * @see ConcurrentHashMap#get(Object)
96 */
97 public IMetaEntry get(final IMetaEntry pKey) {
98 return mMetaMap.get(pKey);
99 }
100
101 /**
102 * Getting the size.
103 *
104 * @return the number of entries in this bucket
105 * @see ConcurrentHashMap#size()
106 */
107 public int size() {
108 return mMetaMap.size();
109 }
110
111 /**
112 * Getting the entry set of the bucket.
113 *
114 * @return the entry set of this bucket
115 * @see ConcurrentHashMap#entrySet()
116 */
117 public Set<Map.Entry<IMetaEntry, IMetaEntry>> entrySet() {
118 return mMetaMap.entrySet();
119 }
120
121 /**
122 * Removing an element within this bucket
123 *
124 * @param pKey
125 * to be removed
126 * @return the element removed, null otherwise
127 * @see ConcurrentHashMap#remove(Object)
128 */
129 public IMetaEntry remove(final IMetaEntry pKey) {
130 return mMetaMap.remove(pKey);
131 }
132
133 /**
134 * {@inheritDoc}
135 */
136 @Override
137 public void serialize(final DataOutput pOutput) throws TTIOException {
138 try {
139 pOutput.writeInt(IConstants.METABUCKET);
140 pOutput.writeLong(mBucketKey);
141 pOutput.writeInt(mMetaMap.size());
142 for (final Map.Entry<IMetaEntry, IMetaEntry> key : mMetaMap.entrySet()) {
143 key.getKey().serialize(pOutput);
144 key.getValue().serialize(pOutput);
145 }
146 } catch (final IOException exc) {
147 throw new TTIOException(exc);
148 }
149 }
150
151 /**
152 * {@inheritDoc}
153 */
154 @Override
155 public long getBucketKey() {
156 return mBucketKey;
157 }
158
159 /**
160 * {@inheritDoc}
161 */
162 @Override
163 public String toString() {
164 return toStringHelper(this).add("mBucketKey", mBucketKey).add("mMetaMap", mMetaMap).toString();
165 }
166
167 /**
168 * {@inheritDoc}
169 */
170 @Override
171 public int hashCode() {
172 final int prime = 42677;
173 int result = 1;
174 result = prime * result + (int)(mBucketKey ^ (mBucketKey >>> 32));
175 result = prime * result + ((mMetaMap == null) ? 0 : mMetaMap.hashCode());
176 return result;
177 }
178
179 /**
180 * {@inheritDoc}
181 */
182 @Override
183 public boolean equals(Object obj) {
184 return obj.hashCode()==this.hashCode();
185 }
186
187 /**
188 * {@inheritDoc}
189 */
190 @Override
191 public HashCode secureHash() {
192 final Hasher code = StandardSettings.HASHFUNC.newHasher().putLong(mBucketKey);
193 for (final IMetaEntry key : mMetaMap.keySet()) {
194 final IMetaEntry val = mMetaMap.get(key);
195 code.putObject(key, key.getFunnel());
196 code.putObject(val, val.getFunnel());
197 }
198 return code.hash();
199 }
200
201 }