Merge branch '2013-db-method-for-amount-of-data-to-sync' into '1802-sync-via-removable-storage'

Add DB method for getting amount of data to sync

See merge request briar/briar!1452

bramble-core/src/main/java/org/briarproject/bramble/db/Database.java

@@ -347,6 +347,16 @@ interface Database<T> {
 	 */
 	Message getMessage(T txn, MessageId m) throws DbException;
 
+	/**
+	 * Returns the total length, including headers, of any messages that are
+	 * eligible to be sent to the given contact via a transport with the given
+	 * max latency.
+	 * <p/>
+	 * Read-only.
+	 */
+	long getMessageBytesToSend(T txn, ContactId c, int maxLatency)
+			throws DbException;
+
 	/**
 	 * Returns the IDs and states of all dependencies of the given message.
 	 * For missing dependencies and dependencies in other groups, the state

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseComponentImpl.java

@@ -575,6 +575,15 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getMessage(txn, m);
 	}
 
+	@Override
+	public long getMessageBytesToSend(Transaction transaction, ContactId c,
+			int maxLatency) throws DbException {
+		T txn = unbox(transaction);
+		if (!db.containsContact(txn, c))
+			throw new NoSuchContactException();
+		return db.getMessageBytesToSend(txn, c, maxLatency);
+	}
+
 	@Override
 	public Collection<MessageId> getMessageIds(Transaction transaction,
 			GroupId g) throws DbException {

bramble-core/src/main/java/org/briarproject/bramble/db/JdbcDatabase.java

@@ -1758,6 +1758,37 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public long getMessageBytesToSend(Connection txn, ContactId c,
+			int maxLatency) throws DbException {
+		long now = clock.currentTimeMillis();
+		long eta = now + maxLatency;
+		PreparedStatement ps = null;
+		ResultSet rs = null;
+		try {
+			String sql = "SELECT SUM(length) FROM statuses"
+					+ " WHERE contactId = ? AND state = ?"
+					+ " AND groupShared = TRUE AND messageShared = TRUE"
+					+ " AND deleted = FALSE AND seen = FALSE"
+					+ " AND (expiry <= ? OR eta > ?)";
+			ps = txn.prepareStatement(sql);
+			ps.setInt(1, c.getInt());
+			ps.setInt(2, DELIVERED.getValue());
+			ps.setLong(3, now);
+			ps.setLong(4, eta);
+			rs = ps.executeQuery();
+			rs.next();
+			long total = rs.getInt(1);
+			rs.close();
+			ps.close();
+			return total;
+		} catch (SQLException e) {
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public Collection<MessageId> getMessageIds(Connection txn, GroupId g)
 			throws DbException {