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
|
package com.orbekk.paxos;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class PaxosServiceImpl implements PaxosService {
private Logger logger = LoggerFactory.getLogger(getClass());
private int roundId = 0;
private int highestPromise = 0;
private String tag = "";
@Override
public boolean propose(String clientUrl, int roundId, int proposalNumber) {
if (roundId > this.roundId) {
newRound(roundId);
}
if (roundId < this.roundId) {
logger.info(tag + "propose({}, {}, {}) = rejected " +
"(current round: {})",
new Object[]{clientUrl, roundId, proposalNumber,
this.roundId});
return false;
}
if (proposalNumber > highestPromise) {
highestPromise = proposalNumber;
logger.info(tag + "propose({}, {}, {}) = accepted",
new Object[]{clientUrl, roundId, proposalNumber);
return true;
} else {
logger.info(tag + "propose({}, {}, {}) = rejected " +
"(promised: {})",
new Object[]{clientUrl, roundId, proposalNumber,
highestPromise});
return false;
}
}
@Override
public boolean acceptRequest(String clientUrl, int roundId,
int proposalNumber) {
if (roundId == this.roundId && proposalNumber == highestPromise) {
logger.info(tag + "acceptRequest({}, {}, {}) = accepted",
new Object[]{clientUrl, roundId, proposalNumber});
return true;
} else {
logger.info(tag + "acceptRequest({}, {}, {}) = rejected " +
"(roundId={}, promise={})",
new Object[]{clientUrl, roundId, proposalNumber,
this.roundId, highestPromise});
return false;
}
}
private void newRound(int roundId) {
logger.info(tag + "new round: {}", roundId);
this.roundId = roundId;
highestPromise = 0;
}
}
|
