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package com.orbekk.paxos;
import java.util.ArrayList;
import java.util.List;
import com.orbekk.same.ConnectionManager;
public class MasterProposer implements Runnable {
private String myUrl;
private int roundId = 0;
private int proposalNumber = 0;
private List<String> paxosUrls = new ArrayList<String>();
private Runnable roundFailedAction;
private Runnable masterAction;
private ConnectionManager connections;
public static Runnable getTimeoutAction(final long milliseconds) {
return new Runnable() {
@Override public void run() {
try {
Thread.sleep(milliseconds);
} catch (InterruptedException e) {
// Ignore interrupts.
}
}
};
}
MasterProposer(String clientUrl, List<String> paxosUrls, int roundId,
ConnectionManager connections, Runnable roundFailedAction,
Runnable masterAction) {
this.myUrl = clientUrl;
this.paxosUrls = paxosUrls;
this.roundId = roundId;
this.connections = connections;
this.roundFailedAction = roundFailedAction;
this.masterAction = masterAction;
}
private boolean propose(int roundId, int proposalNumber) {
int promises = 0;
for (String url : paxosUrls) {
PaxosService paxos = connections.getPaxos(url);
boolean success = paxos.propose(myUrl, roundId, proposalNumber);
if (success) {
promises += 1;
}
}
return promises > paxosUrls.size() / 2;
}
private boolean acceptRequest(int roundId, int proposalNumber) {
int accepts = 0;
for (String url : paxosUrls) {
PaxosService paxos = connections.getPaxos(url);
boolean success = paxos.acceptRequest(myUrl, roundId, proposalNumber);
if (success) {
accepts += 1;
}
}
return accepts > paxosUrls.size() / 2;
}
@Override public void run() {
boolean success = false;
success = propose(roundId + 1, proposalNumber + 1);
if (success) {
success = acceptRequest(roundId + 1, proposalNumber + 1);
}
if (success) {
masterAction.run();
} else {
roundFailedAction.run();
// TODO: Next round?
}
}
}
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