Extracted ooo-user bits into separate library.

src/main/java/com/threerings/user/ReferralRepository.java

@@ -0,0 +1,169 @@
+//
+// $Id$
+
+package com.threerings.user;
+
+import java.sql.Connection;
+import java.sql.Date;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+import com.samskivert.io.PersistenceException;
+import com.samskivert.jdbc.ConnectionProvider;
+import com.samskivert.jdbc.JDBCUtil;
+import com.samskivert.jdbc.DatabaseLiaison;
+import com.samskivert.jdbc.JORARepository;
+import com.samskivert.jdbc.jora.Table;
+
+import static com.threerings.user.Log.log;
+
+/**
+ * Tracks the data needed for our personal referral system whereby one
+ * user sends a referral link (or email) to their friend and we track the
+ * original referring user if their referred friend actually registers
+ * within some reasonable time frame (like a couple of weeks).
+ */
+public class ReferralRepository extends JORARepository
+{
+    /**
+     * The database identifier used when establishing a database
+     * connection. This value being <code>referraldb</code>.
+     */
+    public static final String REFERRAL_DB_IDENT = "referraldb";
+
+    /**
+     * Creates the repository and prepares it for operation.
+     *
+     * @param provider the database connection provider.
+     */
+    public ReferralRepository (ConnectionProvider provider)
+        throws PersistenceException
+    {
+        super(provider, REFERRAL_DB_IDENT);
+
+        // figure out whether or not the referral system is in use
+        execute(new Operation<Void>() {
+            public Void invoke (Connection conn, DatabaseLiaison liaison)
+                throws PersistenceException, SQLException
+            {
+                _active = JDBCUtil.tableExists(conn, "REFERRAL");
+                if (!_active) {
+                    log.info("No referral table. Disabling.");
+                }
+                return null;
+            }
+        });
+    }
+
+    /**
+     * Records a new referral record in the system and returns the unique
+     * identifier for said record.
+     */
+    public int recordReferral (int referrerId, String data)
+        throws PersistenceException
+    {
+        if (!_active) {
+            throw new PersistenceException("Referral repository is not available.");
+        }
+
+        final ReferralRecord record = new ReferralRecord();
+        record.recorded = new Date(System.currentTimeMillis());
+        record.referrerId = referrerId;
+        record.data = data;
+        record.referralId = insert(_rtable, record);
+
+        checkPurge();
+        return record.referralId;
+    }
+
+    /**
+     * Looks up a referral record with the specified id, returning null if
+     * no matching record could be found.
+     */
+    public ReferralRecord lookupReferral (int referralId)
+        throws PersistenceException
+    {
+        return lookupReferralBy("where REFERRAL_ID = " + referralId);
+    }
+
+    /**
+     * Looks up a referral record with the specified referring user id,
+     * returning null if no matching record could be found.
+     */
+    public ReferralRecord lookupReferrer (int referrerId)
+        throws PersistenceException
+    {
+        return lookupReferralBy("where REFERRER_ID = " + referrerId);
+    }
+
+    /** Looks up a referral record matching the specified query. */
+    protected ReferralRecord lookupReferralBy (final String query)
+        throws PersistenceException
+    {
+        if (!_active) {
+            return null;
+        }
+
+        ReferralRecord record = load(_rtable, query);
+        checkPurge();
+        return record;
+    }
+
+    /**
+     * Used to periodically purge old referral records from the
+     * repository.
+     */
+    protected void checkPurge ()
+    {
+        long now = System.currentTimeMillis();
+        if (now - _lastPurge > PURGE_INTERVAL) {
+            _lastPurge = now;
+            try {
+                purgeStaleReferrals();
+            } catch (PersistenceException pe) {
+                log.warning("Error purging referrals: " + pe);
+            }
+        }
+    }
+
+    /**
+     * Purges stale referral records from the repository.
+     */
+    protected void purgeStaleReferrals ()
+        throws PersistenceException
+    {
+        executeUpdate(new Operation<Void>() {
+            public Void invoke (Connection conn, DatabaseLiaison liaison)
+                throws SQLException, PersistenceException
+            {
+                String pquery = "delete from REFERRAL " +
+                    "where DATE_SUB(NOW(), INTERVAL 1 MONTH) > RECORDED;";
+                Statement stmt = conn.createStatement();
+                try {
+                    stmt.executeUpdate(pquery);
+                } finally {
+                    JDBCUtil.close(stmt);
+                }
+                return null;
+            }
+        });
+    }
+
+    @Override
+    protected void createTables ()
+    {
+        _rtable = new Table<ReferralRecord>(ReferralRecord.class, "REFERRAL", "REFERRAL_ID", true);
+    }
+
+    /** The table used to new billing actions that have taken place. */
+    protected Table<ReferralRecord> _rtable;
+
+    /** If we don't detect our tables, we deactivate ourselves. */
+    protected boolean _active;
+
+    /** The last time we purged the repository of stale records. */
+    protected long _lastPurge;
+
+    /** We purge the repository every three hours of stale records. */
+    protected static final long PURGE_INTERVAL = 3 * 60 * 60 * 1000L;
+}