Rework SQLite again to use thread local connections - closes #492

proxy/src/main/java/net/md_5/bungee/reconnect/SQLReconnectHandler.java

@@ -1,10 +1,13 @@
 package net.md_5.bungee.reconnect;
 
+import com.google.common.base.Throwables;
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.util.HashSet;
+import java.util.Set;
 import java.util.logging.Level;
 import net.md_5.bungee.api.ProxyServer;
 import net.md_5.bungee.api.config.ServerInfo;
@@ -13,14 +16,31 @@ import net.md_5.bungee.api.connection.ProxiedPlayer;
 public class SQLReconnectHandler extends AbstractReconnectManager
 {
 
-    private final Connection connection;
+    private final Set<Connection> allConnections = new HashSet<>();
+    private final ThreadLocal<Connection> connectionPool = new ThreadLocal<Connection>()
+    {
+        @Override
+        protected Connection initialValue()
+        {
+            Connection con = null;
+            try
+            {
+                con = DriverManager.getConnection( "jdbc:sqlite:bungee.sqlite" );
+            } catch ( SQLException ex )
+            {
+                Throwables.propagate( ex );
+            }
+
+            allConnections.add( con );
+            return con;
+        }
+    };
 
     public SQLReconnectHandler() throws ClassNotFoundException, SQLException
     {
         Class.forName( "org.sqlite.JDBC" );
-        connection = DriverManager.getConnection( "jdbc:sqlite:bungee.sqlite" );
 
-        try ( PreparedStatement ps = connection.prepareStatement(
+        try ( PreparedStatement ps = connectionPool.get().prepareStatement(
                 "CREATE TABLE IF NOT EXISTS players ("
                 + "playerId INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,"
                 + "username TEXT NOT NULL UNIQUE COLLATE NOCASE,"
@@ -33,10 +53,10 @@ public class SQLReconnectHandler extends AbstractReconnectManager
     }
 
     @Override
-    protected synchronized ServerInfo getStoredServer(ProxiedPlayer player)
+    protected ServerInfo getStoredServer(ProxiedPlayer player)
     {
         String server = null;
-        try ( PreparedStatement ps = connection.prepareStatement( "SELECT server FROM players WHERE username = ?" ) )
+        try ( PreparedStatement ps = connectionPool.get().prepareStatement( "SELECT server FROM players WHERE username = ?" ) )
         {
             ps.setString( 1, player.getName() );
             try ( ResultSet rs = ps.executeQuery() )
@@ -46,7 +66,7 @@ public class SQLReconnectHandler extends AbstractReconnectManager
                     server = rs.getString( 1 );
                 } else
                 {
-                    try ( PreparedStatement playerUpdate = connection.prepareStatement( "INSERT INTO players( username ) VALUES( ? )" ) )
+                    try ( PreparedStatement playerUpdate = connectionPool.get().prepareStatement( "INSERT INTO players( username ) VALUES( ? )" ) )
                     {
                         playerUpdate.setString( 1, player.getName() );
                         playerUpdate.executeUpdate();
@@ -62,10 +82,10 @@ public class SQLReconnectHandler extends AbstractReconnectManager
     }
 
     @Override
-    public synchronized void setServer(ProxiedPlayer player)
+    public void setServer(ProxiedPlayer player)
     {
 
-        try ( PreparedStatement ps = connection.prepareStatement( "UPDATE players SET server = ?, seen = ? WHERE username = ?" ) )
+        try ( PreparedStatement ps = connectionPool.get().prepareStatement( "UPDATE players SET server = ?, seen = ? WHERE username = ?" ) )
         {
             ps.setString( 1, player.getServer().getInfo().getName() );
             ps.setInt( 2, (int) ( System.currentTimeMillis() / 1000L ) );
@@ -83,14 +103,18 @@ public class SQLReconnectHandler extends AbstractReconnectManager
     }
 
     @Override
-    public synchronized void close()
+    public void close()
+    {
+        for ( Connection con : allConnections )
         {
             try
             {
-            connection.close();
+                con.close();
             } catch ( SQLException ex )
             {
                 ProxyServer.getInstance().getLogger().log( Level.WARNING, "Error closing SQLite connection", ex );
             }
         }
+        allConnections.clear();
+    }
 }