blob: 99ca21005025e426149ae126095ddb8d60b73e3b (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
|
// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.search.predicate.index;
import com.yahoo.search.predicate.serialization.SerializationHelper;
import org.eclipse.collections.api.map.primitive.LongObjectMap;
import org.eclipse.collections.api.tuple.primitive.LongObjectPair;
import org.eclipse.collections.impl.map.mutable.primitive.LongObjectHashMap;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* An index mapping keys of type Long to lists of postings of generic data.
*
* @author Magnar Nedland
* @author bjorncs
*/
public class SimpleIndex {
private final LongObjectMap<Entry> dictionary;
public SimpleIndex(LongObjectMap<Entry> dictionary) {
this.dictionary = dictionary;
}
/**
* Retrieves a posting list for a given key
*
* @param key the key to lookup
* @return list of postings
*/
public Entry getPostingList(long key) {
return dictionary.get(key);
}
public void writeToOutputStream(DataOutputStream out) throws IOException {
out.writeInt(dictionary.size());
for (LongObjectPair<Entry> pair : dictionary.keyValuesView()) {
out.writeLong(pair.getOne());
Entry entry = pair.getTwo();
SerializationHelper.writeIntArray(entry.docIds, out);
SerializationHelper.writeIntArray(entry.dataRefs, out);
}
}
public static SimpleIndex fromInputStream(DataInputStream in) throws IOException {
int nEntries = in.readInt();
LongObjectHashMap<Entry> dictionary = new LongObjectHashMap<>(nEntries);
for (int i = 0; i < nEntries; i++) {
long key = in.readLong();
int[] docIds = SerializationHelper.readIntArray(in);
int[] dataRefs = SerializationHelper.readIntArray(in);
dictionary.put(key, new Entry(docIds, dataRefs));
}
dictionary.compact();
return new SimpleIndex(dictionary);
}
public static class Entry {
public final int[] docIds;
public final int[] dataRefs;
private Entry(int[] docIds, int[] dataRefs) {
this.docIds = docIds;
this.dataRefs = dataRefs;
}
}
public static class Builder {
private final HashMap<Long, List<Posting>> dictionaryBuilder = new HashMap<>();
private int entryCount;
/**
* Inserts an object with an id for a key.
* @param key Key to map from
* @param posting Entry for the posting list
*/
public void insert(long key, Posting posting) {
dictionaryBuilder.computeIfAbsent(key, (k) -> new ArrayList<>()).add(posting);
++entryCount;
}
public SimpleIndex build() {
LongObjectHashMap<Entry> dictionary = new LongObjectHashMap<>();
for (Map.Entry<Long, List<Posting>> entry : dictionaryBuilder.entrySet()) {
List<Posting> postings = entry.getValue();
Collections.sort(postings);
int size = postings.size();
int[] docIds = new int[size];
int[] dataRefs = new int[size];
for (int i = 0; i < size; i++) {
Posting posting = postings.get(i);
docIds[i] = posting.getId();
dataRefs[i] = posting.getDataRef();
}
dictionary.put(entry.getKey(), new Entry(docIds, dataRefs));
}
dictionary.compact();
return new SimpleIndex(dictionary);
}
public int getEntryCount() { return entryCount; }
public int getKeyCount() { return dictionaryBuilder.size(); }
}
}
|
