Add a TTL for the file vote cache.

Adds a locally trusted TTL to each vote locally, not using untrusted
remote timestamp. Add day-based ttl to FileVoteCache.

Fixes #15

bungeecord/src/main/java/com/vexsoftware/votifier/bungee/NuVotifier.java

@@ -221,7 +221,7 @@ protected void initChannel(NioSocketChannel channel) throws Exception {
                             public void operationComplete(ChannelFuture future) throws Exception {
                                 if (future.isSuccess()) {
                                     serverChannel = future.channel();
-                                    getLogger().info("Votifier enabled on socket "+serverChannel.localAddress()+".");
+                                    getLogger().info("Votifier enabled on socket " + serverChannel.localAddress() + ".");
                                 } else {
                                     SocketAddress socketAddress = future.channel().localAddress();
                                     if (socketAddress == null) {
@@ -255,8 +255,10 @@ public void operationComplete(ChannelFuture future) throws Exception {
                 getLogger().info("Using in-memory cache for votes that are not able to be delivered.");
             } else if ("file".equals(cacheMethod)) {
                 try {
-                    voteCache = new FileVoteCache(ProxyServer.getInstance().getServers().size(), this, new File(getDataFolder(),
-                            fwdCfg.getString("pluginMessaging.file.name")));
+                    voteCache = new FileVoteCache(
+                            ProxyServer.getInstance().getServers().size(), this,
+                            new File(getDataFolder(), fwdCfg.getString("pluginMessaging.file.name")),
+                            fwdCfg.getInt("pluginMessaging.file.cacheTime", -1));
                 } catch (IOException e) {
                     getLogger().log(Level.SEVERE, "Unload to load file cache. Votes will be lost!", e);
                 }
@@ -294,7 +296,7 @@ public void operationComplete(ChannelFuture future) throws Exception {
                 }
                 ProxyForwardingVoteSource.BackendServer server = new ProxyForwardingVoteSource.BackendServer(s,
                         new InetSocketAddress(address, section.getShort("port")),
-                        KeyCreator.createKeyFrom(section.getString("token",section.getString("key"))));
+                        KeyCreator.createKeyFrom(section.getString("token", section.getString("key"))));
                 serverList.add(server);
             }
 

bungeecord/src/main/java/com/vexsoftware/votifier/bungee/forwarding/cache/FileVoteCache.java

@@ -14,15 +14,21 @@
 import java.util.*;
 import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
+import java.util.logging.Logger;
 
 public class FileVoteCache extends MemoryVoteCache {
 
+    private final Logger l;
     private final File cacheFile;
+    private final int voteTTL;
     private final ScheduledTask saveTask;
 
-    public FileVoteCache(int initialMemorySize, final Plugin plugin, File cacheFile) throws IOException {
+    public FileVoteCache(int initialMemorySize, final Plugin plugin, File cacheFile, int voteTTL) throws IOException {
         super(initialMemorySize);
         this.cacheFile = cacheFile;
+        this.voteTTL = voteTTL;
+        this.l = plugin.getLogger();
+
         load();
 
         saveTask = ProxyServer.getInstance().getScheduler().schedule(plugin, new Runnable() {
@@ -31,7 +37,7 @@ public void run() {
                 try {
                     save();
                 } catch (IOException e) {
-                    plugin.getLogger().log(Level.SEVERE, "Unable to save cached votes, votes will be lost if you restart.", e);
+                    l.log(Level.SEVERE, "Unable to save cached votes, votes will be lost if you restart.", e);
                 }
             }
         }, 3, 3, TimeUnit.MINUTES);
@@ -52,22 +58,43 @@ private void load() throws IOException {
             List<Vote> votes = new ArrayList<>(voteArray.length());
             for (int i = 0; i < voteArray.length(); i++) {
                 JSONObject voteObject = voteArray.getJSONObject(i);
-                votes.add(new Vote(voteObject));
+                Vote v = new Vote(voteObject);
+                if (hasTimedOut(v))
+                    l.log(Level.WARNING, "Purging out of date vote.", v);
+                else
+                    votes.add(v);
             }
             voteCache.put(((String) server), votes);
         }
+
     }
 
     public void save() throws IOException {
         cacheLock.lock();
         JSONObject votesObject = new JSONObject();
         try {
-            // Create a copy of the votes.
-            for (Map.Entry<String, Collection<Vote>> entry : voteCache.entrySet()) {
+            Iterator<Map.Entry<String, Collection<Vote>>> entryItr = voteCache.entrySet().iterator();
+            while (entryItr.hasNext()) {
+                Map.Entry<String, Collection<Vote>> entry = entryItr.next();
                 JSONArray array = new JSONArray();
-                for (Vote vote : entry.getValue()) {
-                    array.put(vote.serialize());
+                Iterator<Vote> voteItr = entry.getValue().iterator();
+                while (voteItr.hasNext()) {
+                    Vote vote = voteItr.next();
+
+                    // if the vote is no longer valid, notify and remove
+                    if (hasTimedOut(vote)) {
+                        l.log(Level.WARNING, "Purging out of date vote.", vote);
+                        voteItr.remove();
+                    } else {
+                        array.put(vote.serialize());
+                    }
+
                 }
+
+                // if, during our iteration, we TTL invalidated all of the votes
+                if (entry.getValue().isEmpty())
+                    entryItr.remove();
+
                 votesObject.put(entry.getKey(), array);
             }
         } finally {
@@ -79,6 +106,12 @@ public void save() throws IOException {
         }
     }
 
+    private boolean hasTimedOut(Vote v) {
+        if (voteTTL == -1) return false;
+        // scale voteTTL to milliseconds
+        return v.getLocalTimestamp() + voteTTL * 24 * 60 * 60 * 1000 < System.currentTimeMillis();
+    }
+
     public void halt() throws IOException {
         saveTask.cancel();
         save();

bungeecord/src/main/resources/bungeeConfig.yml

@@ -53,6 +53,8 @@ forwarding:
     # Options for file caching.
     file:
       name: cached-votes.json
+      # days before a vote is considered 'dead' - removed from cache with a console warning
+      voteTTL: 10
   # Specify servers to proxy votes for.
   proxy:
     Hub:

common/src/main/java/com/vexsoftware/votifier/model/Vote.java

@@ -47,15 +47,26 @@ public class Vote {
      */
     private String timeStamp;
 
+    /**
+     * Timestamp (unix-millis) normalized and taken from a known source
+     */
+    private final long localTimestamp;
+
     @Deprecated
     public Vote() {
+        localTimestamp = System.currentTimeMillis();
     }
 
     public Vote(String serviceName, String username, String address, String timeStamp) {
+        this(serviceName, username, address, timeStamp, System.currentTimeMillis());
+    }
+
+    public Vote(String serviceName, String username, String address, String timeStamp, long localTimestamp) {
         this.serviceName = serviceName;
         this.username = username;
         this.address = address;
         this.timeStamp = timeStamp;
+        this.localTimestamp = localTimestamp;
     }
 
     private static String getTimestamp(JSONObject object) {
@@ -67,13 +78,19 @@ private static String getTimestamp(JSONObject object) {
     }
 
     public Vote(JSONObject jsonObject) {
-        this(jsonObject.getString("serviceName"), jsonObject.getString("username"), jsonObject.getString("address"), getTimestamp(jsonObject));
+        this(jsonObject.getString("serviceName"),
+                jsonObject.getString("username"),
+                jsonObject.getString("address"),
+                getTimestamp(jsonObject),
+                // maintained for backwards compatibility with <2.3.6 peers
+                (jsonObject.has("localTimestamp") ? jsonObject.getLong("localTimestamp") : System.currentTimeMillis()));
     }
 
     @Override
     public String toString() {
         return "Vote (from:" + serviceName + " username:" + username
-                + " address:" + address + " timeStamp:" + timeStamp + ")";
+                + " address:" + address + " timeStamp:" + timeStamp
+                + " localTimestamp:" + localTimestamp + ")";
     }
 
     /**
@@ -152,12 +169,22 @@ public String getTimeStamp() {
         return timeStamp;
     }
 
+    /**
+     * Gets the local timestamp, in unix-millis. Calculated locally by a NuVotifier instance
+     *
+     * @return The local timestamp
+     */
+    public long getLocalTimestamp() {
+        return localTimestamp;
+    }
+
     public JSONObject serialize() {
         JSONObject ret = new JSONObject();
         ret.put("serviceName", serviceName);
         ret.put("username", username);
         ret.put("address", address);
         ret.put("timestamp", timeStamp);
+        ret.put("localTimestamp", localTimestamp);
         return ret;
     }
 
@@ -172,7 +199,6 @@ public boolean equals(Object o) {
         if (!username.equals(vote.username)) return false;
         if (!address.equals(vote.address)) return false;
         return timeStamp.equals(vote.timeStamp);
-
     }
 
     @Override