1 package org.treetank.filelistener.file.data;
2
3 import java.io.DataOutput;
4 import java.io.IOException;
5
6 import org.treetank.api.IData;
7 import org.treetank.exception.TTIOException;
8
9 import com.google.common.hash.Funnel;
10 import com.google.common.hash.PrimitiveSink;
11
12 /**
13 * A sequence of Filenodes represents a full file. A Filnode has a content size
14 * of 512 bytes and has a reference to the following node if such a node exists.
15 *
16 * The header filenode is being referenced by the page layer in a hash map. It
17 * consists of a relative path.
18 *
19 * @author andreas
20 *
21 */
22 public class FileData implements IData {
23
24 /**
25 * Enum for FileNodeFunnel.
26 *
27 * @author Sebastian Graf, University of Konstanz
28 *
29 */
30 enum FileNodeFunnel implements Funnel<IData> {
31 INSTANCE;
32 public void funnel(IData data, PrimitiveSink into) {
33 final FileData from = (FileData)data;
34 into.putLong(from.dataKey).putBytes(from.val).putBoolean(from.header).putBoolean(from.eof);
35 }
36 }
37
38 /**
39 * The nodes key value, which is equal with it's position in the list.
40 */
41 private final long dataKey;
42
43 /**
44 * The size of the filenode
45 */
46 public static final int FILENODESIZE = 1024 * 16;
47
48 /**
49 * The content of this node in form of a byte array.
50 */
51 private final byte[] val;
52
53 /**
54 * Determines whether or not this filenode is the first in the sequence.
55 */
56 private final boolean header;
57
58 /**
59 * Determines whether or not this filenode is the last in the sequence.
60 */
61 private final boolean eof;
62
63 /**
64 * Creates a Filenode with given bytes
65 *
66 * @param dataKey
67 * @param content
68 * , as byte array
69 */
70 public FileData(long dataKey, byte[] content, boolean header, boolean eof) {
71 this.dataKey = dataKey;
72 this.val = content;
73 this.header = header;
74 this.eof = eof;
75 }
76
77 /**
78 * Serializing to given dataput
79 *
80 * @throws TTIOException
81 */
82 public void serialize(final DataOutput output) throws TTIOException {
83 try {
84 output.writeLong(dataKey);
85 output.writeBoolean(header);
86 output.writeBoolean(eof);
87 output.writeInt(val.length);
88 output.write(val);
89 } catch (final IOException exc) {
90 throw new TTIOException(exc);
91 }
92 }
93
94 @Override
95 public long getDataKey() {
96 return this.dataKey;
97 }
98
99 /**
100 * Check whether or not this filenode is the first in the sequence.
101 *
102 * @return true if is a header element
103 */
104 public boolean isHeader() {
105 return header;
106 }
107
108 /**
109 * Check whether or not this filenode is the last in the sequence.
110 *
111 * @return true if this is the last element in the sequence
112 */
113 public boolean isEof() {
114 return eof;
115 }
116
117 /**
118 * @return value held by this node
119 */
120 public byte[] getVal() {
121 return val;
122 }
123
124 /**
125 * {@inheritDoc}
126 */
127 @Override
128 public Funnel<IData> getFunnel() {
129 return FileNodeFunnel.INSTANCE;
130 }
131
132 }