diff --git a/components/net/sf/briar/db/JdbcDatabase.java b/components/net/sf/briar/db/JdbcDatabase.java
index 562d90785ce068e983b02258bb2d252f97fd11da..c2ec4eeb0106e520bb07187911b01b976035de2c 100644
--- a/components/net/sf/briar/db/JdbcDatabase.java
+++ b/components/net/sf/briar/db/JdbcDatabase.java
@@ -42,6 +42,7 @@ import net.sf.briar.api.transport.ConnectionContext;
import net.sf.briar.api.transport.ConnectionContextFactory;
import net.sf.briar.api.transport.ConnectionWindow;
import net.sf.briar.api.transport.ConnectionWindowFactory;
+import net.sf.briar.util.ByteUtils;
import net.sf.briar.util.FileUtils;
/**
@@ -58,6 +59,12 @@ abstract class JdbcDatabase implements Database<Connection> {
+ " start BIGINT NOT NULL,"
+ " PRIMARY KEY (groupId))";
+ private static final String CREATE_SUBSCRIPTION_IDS =
+ "CREATE TABLE subscriptionIds"
+ + " (groupId HASH," // Null for the head of the list
+ + " nextId HASH," // Null for the tail of the list
+ + " deleted BIGINT NOT NULL)";
+
private static final String CREATE_CONTACTS =
"CREATE TABLE contacts"
+ " (contactId COUNTER,"
@@ -326,6 +333,7 @@ abstract class JdbcDatabase implements Database<Connection> {
try {
s = txn.createStatement();
s.executeUpdate(insertTypeNames(CREATE_SUBSCRIPTIONS));
+ s.executeUpdate(insertTypeNames(CREATE_SUBSCRIPTION_IDS));
s.executeUpdate(insertTypeNames(CREATE_CONTACTS));
s.executeUpdate(insertTypeNames(CREATE_MESSAGES));
s.executeUpdate(INDEX_MESSAGES_BY_PARENT);
@@ -721,7 +729,9 @@ abstract class JdbcDatabase implements Database<Connection> {
public void addSubscription(Connection txn, Group g) throws DbException {
PreparedStatement ps = null;
+ ResultSet rs = null;
try {
+ // Add the group to the subscriptions table
String sql = "INSERT INTO subscriptions"
+ " (groupId, groupName, groupKey, start)"
+ " VALUES (?, ?, ?, ?)";
@@ -733,7 +743,78 @@ abstract class JdbcDatabase implements Database<Connection> {
int affected = ps.executeUpdate();
if(affected != 1) throw new DbStateException();
ps.close();
+ // Insert the group ID into the linked list
+ byte[] id = g.getId().getBytes();
+ sql = "SELECT groupId, nextId, deleted FROM subscriptionIds"
+ + " ORDER BY groupId";
+ ps = txn.prepareStatement(sql);
+ rs = ps.executeQuery();
+ if(rs.next()) {
+ // The head pointer of the list exists
+ byte[] groupId = rs.getBytes(1);
+ if(groupId != null) throw new DbStateException();
+ byte[] nextId = rs.getBytes(2);
+ long deleted = rs.getLong(3);
+ // Scan through the list to find the insertion point
+ while(nextId != null && ByteUtils.compare(id, nextId) > 0) {
+ if(!rs.next()) throw new DbStateException();
+ groupId = rs.getBytes(1);
+ if(groupId == null) throw new DbStateException();
+ nextId = rs.getBytes(2);
+ deleted = rs.getLong(3);
+ }
+ rs.close();
+ ps.close();
+ // Update the previous element
+ if(groupId == null) {
+ // Inserting at the head of the list
+ sql = "UPDATE subscriptionIds SET nextId = ?"
+ + " WHERE groupId IS NULL";
+ ps = txn.prepareStatement(sql);
+ ps.setBytes(1, id);
+ } else {
+ // Inserting in the middle or at the tail of the list
+ sql = "UPDATE subscriptionIds SET nextId = ?"
+ + " WHERE groupId = ?";
+ ps = txn.prepareStatement(sql);
+ ps.setBytes(1, id);
+ ps.setBytes(2, groupId);
+ }
+ affected = ps.executeUpdate();
+ if(affected != 1) throw new DbStateException();
+ ps.close();
+ // Insert the new element
+ sql = "INSERT INTO subscriptionIds (groupId, nextId, deleted)"
+ + " VALUES (?, ?, ?)";
+ ps = txn.prepareStatement(sql);
+ ps.setBytes(1, id);
+ if(nextId == null) ps.setNull(2, Types.BINARY); // At the tail
+ else ps.setBytes(2, nextId); // In the middle
+ ps.setLong(3, deleted);
+ affected = ps.executeUpdate();
+ if(affected != 1) throw new DbStateException();
+ ps.close();
+ } else {
+ // The head pointer of the list does not exist
+ rs.close();
+ ps.close();
+ sql = "INSERT INTO subscriptionIds (nextId, deleted)"
+ + " VALUES (?, ZERO())";
+ ps = txn.prepareStatement(sql);
+ ps.setBytes(1, id);
+ affected = ps.executeUpdate();
+ if(affected != 1) throw new DbStateException();
+ ps.close();
+ sql = "INSERT INTO subscriptionIds (groupId, deleted)"
+ + " VALUES (?, ZERO())";
+ ps = txn.prepareStatement(sql);
+ ps.setBytes(1, id);
+ affected = ps.executeUpdate();
+ if(affected != 1) throw new DbStateException();
+ ps.close();
+ }
} catch(SQLException e) {
+ tryToClose(rs);
tryToClose(ps);
throw new DbException(e);
}
@@ -2096,14 +2177,43 @@ abstract class JdbcDatabase implements Database<Connection> {
public void removeSubscription(Connection txn, GroupId g)
throws DbException {
PreparedStatement ps = null;
+ ResultSet rs = null;
try {
+ // Remove the group from the subscriptions table
String sql = "DELETE FROM subscriptions WHERE groupId = ?";
ps = txn.prepareStatement(sql);
ps.setBytes(1, g.getBytes());
int affected = ps.executeUpdate();
if(affected != 1) throw new DbStateException();
ps.close();
+ // Remove the group ID from the linked list
+ sql = "SELECT nextId FROM subscriptionIds WHERE groupId = ?";
+ ps = txn.prepareStatement(sql);
+ ps.setBytes(1, g.getBytes());
+ rs = ps.executeQuery();
+ if(!rs.next()) throw new DbStateException();
+ byte[] nextId = rs.getBytes(1);
+ if(rs.next()) throw new DbStateException();
+ rs.close();
+ ps.close();
+ sql = "DELETE FROM subscriptionIds WHERE groupId = ?";
+ ps = txn.prepareStatement(sql);
+ ps.setBytes(1, g.getBytes());
+ affected = ps.executeUpdate();
+ if(affected != 1) throw new DbStateException();
+ ps.close();
+ sql = "UPDATE subscriptionIds SET nextId = ?, deleted = ?"
+ + " WHERE nextId = ?";
+ ps = txn.prepareStatement(sql);
+ if(nextId == null) ps.setNull(1, Types.BINARY); // At the tail
+ else ps.setBytes(1, nextId); // At the head or in the middle
+ ps.setLong(2, System.currentTimeMillis());
+ ps.setBytes(3, g.getBytes());
+ affected = ps.executeUpdate();
+ if(affected != 1) throw new DbStateException();
+ ps.close();
} catch(SQLException e) {
+ tryToClose(rs);
tryToClose(ps);
throw new DbException(e);
}
diff --git a/test/net/sf/briar/db/H2DatabaseTest.java b/test/net/sf/briar/db/H2DatabaseTest.java
index cbc223c06f1192fe437461640e9a156bd710408e..6cdad47d48ccf04dd0c7dcae33e26680a9f0ef36 100644
--- a/test/net/sf/briar/db/H2DatabaseTest.java
+++ b/test/net/sf/briar/db/H2DatabaseTest.java
@@ -10,6 +10,7 @@ import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
+import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.concurrent.CountDownLatch;
@@ -1882,6 +1883,29 @@ public class H2DatabaseTest extends BriarTestCase {
db.close();
}
+ @Test
+ public void testMultipleSubscriptionsAndUnsubscriptions() throws Exception {
+ // Create some groups
+ List<Group> groups = new ArrayList<Group>();
+ for(int i = 0; i < 100; i++) {
+ GroupId id = new GroupId(TestUtils.getRandomId());
+ groups.add(groupFactory.createGroup(id, "Group name", null));
+ }
+
+ Database<Connection> db = open(false);
+ Connection txn = db.startTransaction();
+
+ // Add the groups to the database
+ for(Group g : groups) db.addSubscription(txn, g);
+
+ // Remove the groups in a different order
+ Collections.shuffle(groups);
+ for(Group g : groups) db.removeSubscription(txn, g.getId());
+
+ db.commitTransaction(txn);
+ db.close();
+ }
+
@Test
public void testExceptionHandling() throws Exception {
Database<Connection> db = open(false);
diff --git a/util/net/sf/briar/util/ByteUtils.java b/util/net/sf/briar/util/ByteUtils.java
index e19c7e3ca39ce68393b7e6a6bb24e9597ab3397a..d858b8f9b07f28d3eb6e2aefe96459bbc2cf8bdf 100644
--- a/util/net/sf/briar/util/ByteUtils.java
+++ b/util/net/sf/briar/util/ByteUtils.java
@@ -62,4 +62,22 @@ public class ByteUtils {
assert result < 1 << bits;
return result;
}
+
+ /**
+ * Compares two byte arrays and returns -1, 0, or +1 if the first array is
+ * less than, equal to, or greater than the second array, respectively.
+ * <p>
+ * If one of the arrays is a prefix of the other, the longer array is
+ * considered to be greater. Bytes are treated as unsigned.
+ */
+ public static int compare(byte[] b1, byte[] b2) {
+ for(int i = 0; i < b1.length || i < b2.length; i++) {
+ if(i == b1.length) return -1;
+ if(i == b2.length) return 1;
+ int b1i = b1[i] & 0xff, b2i = b2[i] & 0xff;
+ if(b1i < b2i) return -1;
+ if(b1i > b2i) return 1;
+ }
+ return 0;
+ }
}