WIP; tmp

driver-core/src/main/java/com/datastax/driver/core/Metadata.java

@@ -150,6 +150,17 @@ public class Metadata {
   Metadata(Cluster.Manager cluster) {
     this.cluster = cluster;
     this.tabletMap = TabletMap.emptyMap(cluster);
+    if (cluster.configuration.getQueryOptions().isMetadataEnabled()) {
+      cluster
+          .getCluster()
+          .register(
+              new TabletMapListener(tabletMap) {
+                @Override
+                public void onRegister(Cluster cluster) {
+                  System.out.println("Registered listener for tablet map");
+                }
+              });
+    }
   }
 
   // rebuilds the token map with the current hosts, typically when refreshing schema metadata

driver-core/src/main/java/com/datastax/driver/core/TabletMap.java

@@ -198,6 +198,14 @@ public TypeCodec<TupleValue> getTabletPayloadCodec() {
     return tabletPayloadCodec;
   }
 
+  public void removeTableMappings(KeyspaceTableNamePair key) {
+    this.mapping.remove(key);
+  }
+
+  public void removeTableMappings(String keyspace, String table) {
+    removeTableMappings(new KeyspaceTableNamePair(keyspace, table));
+  }
+
   /**
    * Simple class to hold UUID of a host and a shard number. Class itself makes no checks or
    * guarantees about existence of a shard on corresponding host.

driver-core/src/main/java/com/datastax/driver/core/TabletMapListener.java

@@ -0,0 +1,19 @@
+package com.datastax.driver.core;
+
+public class TabletMapListener extends SchemaChangeListenerBase {
+  private final TabletMap tabletMap;
+
+  public TabletMapListener(TabletMap tabletMap) {
+    this.tabletMap = tabletMap;
+  }
+
+  @Override
+  public void onTableChanged(TableMetadata current, TableMetadata previous) {
+    tabletMap.removeTableMappings(previous.getKeyspace().getName(), previous.getName());
+  }
+
+  @Override
+  public void onTableRemoved(TableMetadata table) {
+    tabletMap.removeTableMappings(table.getKeyspace().getName(), table.getName());
+  }
+}

driver-core/src/test/java/com/datastax/driver/core/TabletMapListenerTest.java

@@ -0,0 +1,184 @@
+package com.datastax.driver.core;
+
+import static com.datastax.driver.core.Assertions.assertThat;
+import static com.datastax.driver.core.Metadata.handleId;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.timeout;
+import static org.mockito.Mockito.verify;
+
+import com.datastax.driver.core.policies.RoundRobinPolicy;
+import com.datastax.driver.core.utils.ScyllaVersion;
+import com.google.common.collect.Lists;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import org.mockito.ArgumentCaptor;
+import org.testng.annotations.AfterClass;
+import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Test;
+
+@CCMConfig(
+    createCluster = false,
+    numberOfNodes = 2,
+    jvmArgs = {
+      "--experimental-features=consistent-topology-changes",
+      "--experimental-features=tablets"
+    })
+@ScyllaVersion(minOSS = "6.0.0", minEnterprise = "2024.2", description = "Needs to support tablets")
+public class TabletMapListenerTest extends CCMTestsSupport {
+  private static final int INITIAL_TABLETS = 32;
+  private static final String KEYSPACE_NAME = "listenerTest";
+  private static final String TABLE_NAME = "testTable";
+  private static final String CREATE_TABLETS_KEYSPACE_QUERY =
+      "CREATE KEYSPACE "
+          + KEYSPACE_NAME
+          + " WITH replication = {'class': "
+          + "'NetworkTopologyStrategy', "
+          + "'replication_factor': '1'}  AND durable_writes = true AND tablets = "
+          + "{'initial': "
+          + INITIAL_TABLETS
+          + "};";
+
+  private static final String CREATE_KEYSPACE = CREATE_TABLETS_KEYSPACE_QUERY;
+  private static final String ALTER_KEYSPACE =
+      "ALTER KEYSPACE " + KEYSPACE_NAME + " WITH durable_writes = false";
+  private static final String DROP_KEYSPACE = "DROP KEYSPACE " + KEYSPACE_NAME;
+
+  private static final String CREATE_TABLE =
+      "CREATE TABLE " + KEYSPACE_NAME + "." + TABLE_NAME + "(i int primary key)";
+  private static final String INSERT_QUERY_TEMPLATE =
+      "INSERT INTO " + KEYSPACE_NAME + "." + TABLE_NAME + " (i) VALUES (%s)";
+  private static final String INSERT_ALTERED_TEMPLATE =
+      "INSERT INTO " + KEYSPACE_NAME + "." + TABLE_NAME + " (i,j) VALUES (%s,%s)";
+  private static final String SELECT_PK_WHERE =
+      "SELECT i FROM " + KEYSPACE_NAME + "." + TABLE_NAME + " WHERE  i = ?";
+  private static final String ALTER_TABLE =
+      "ALTER TABLE " + KEYSPACE_NAME + "." + TABLE_NAME + " ADD j int";
+  private static final String DROP_TABLE = "DROP TABLE " + KEYSPACE_NAME + "." + TABLE_NAME;
+
+  /** The maximum time that the test will wait to check that listeners have been notified. */
+  private static final long NOTIF_TIMEOUT_MS = TimeUnit.MINUTES.toMillis(1);
+
+  Cluster cluster;
+  Session session;
+  SchemaChangeListener listener;
+  List<SchemaChangeListener> listeners;
+
+  @BeforeClass(groups = "short")
+  public void setup() throws InterruptedException {
+    cluster =
+        createClusterBuilderNoDebouncing().withLoadBalancingPolicy(new RoundRobinPolicy()).build();
+
+    session = cluster.connect();
+
+    cluster.register(listener = mock(TabletMapListener.class));
+    listeners = Lists.newArrayList(listener);
+  }
+
+  // Checks for tablet removal both on table update and removal
+  @Test(groups = "short")
+  public void should_remove_tablets_on_table_alterations() throws InterruptedException {
+
+    session.execute(CREATE_KEYSPACE);
+    ArgumentCaptor<KeyspaceMetadata> added = null;
+    for (SchemaChangeListener listener : listeners) {
+      added = ArgumentCaptor.forClass(KeyspaceMetadata.class);
+      verify(listener, timeout(NOTIF_TIMEOUT_MS).times(1)).onKeyspaceAdded(added.capture());
+      assertThat(added.getValue()).hasName(handleId(KEYSPACE_NAME));
+    }
+    assert added != null;
+
+    TabletMap tabletMap;
+    tabletMap = cluster.getMetadata().getTabletMap();
+
+    session.execute(CREATE_TABLE);
+    assertThat(tabletMap.getMapping())
+        .doesNotContainKey(
+            new TabletMap.KeyspaceTableNamePair(handleId(KEYSPACE_NAME), handleId(TABLE_NAME)));
+
+    session.execute(String.format(INSERT_QUERY_TEMPLATE, "42"));
+    session.execute(session.prepare(SELECT_PK_WHERE).bind(42));
+    session.execute(session.prepare(SELECT_PK_WHERE).bind(42));
+    assertThat(tabletMap.getMapping())
+        .containsKey(
+            new TabletMap.KeyspaceTableNamePair(handleId(KEYSPACE_NAME), handleId(TABLE_NAME)));
+
+    session.execute(ALTER_TABLE);
+    for (SchemaChangeListener listener : listeners) {
+      ArgumentCaptor<TableMetadata> current = ArgumentCaptor.forClass(TableMetadata.class);
+      ArgumentCaptor<TableMetadata> previous = ArgumentCaptor.forClass(TableMetadata.class);
+      verify(listener, timeout(NOTIF_TIMEOUT_MS).times(1))
+          .onTableChanged(current.capture(), previous.capture());
+      assertThat(previous.getValue().getKeyspace()).hasName(handleId(KEYSPACE_NAME));
+      assertThat(previous.getValue()).hasName(handleId(TABLE_NAME));
+    }
+    assertThat(tabletMap.getMapping())
+        .doesNotContainKey(
+            new TabletMap.KeyspaceTableNamePair(handleId(KEYSPACE_NAME), handleId(TABLE_NAME)));
+
+    session.execute(String.format(INSERT_ALTERED_TEMPLATE, "42", "42"));
+    session.execute(session.prepare(SELECT_PK_WHERE).bind(42));
+    session.execute(session.prepare(SELECT_PK_WHERE).bind(42));
+    assertThat(tabletMap.getMapping())
+        .containsKey(
+            new TabletMap.KeyspaceTableNamePair(handleId(KEYSPACE_NAME), handleId(TABLE_NAME)));
+
+    session.execute(DROP_TABLE);
+    ArgumentCaptor<TableMetadata> removed = null;
+    for (SchemaChangeListener listener : listeners) {
+      removed = ArgumentCaptor.forClass(TableMetadata.class);
+      verify(listener, timeout(NOTIF_TIMEOUT_MS).times(1)).onTableRemoved(removed.capture());
+      assertThat(removed.getValue().getKeyspace()).hasName(handleId(KEYSPACE_NAME));
+      assertThat(removed.getValue()).hasName(handleId(TABLE_NAME));
+    }
+    assert removed != null;
+    assertThat(tabletMap.getMapping())
+        .doesNotContainKey(
+            new TabletMap.KeyspaceTableNamePair(handleId(KEYSPACE_NAME), handleId(TABLE_NAME)));
+
+    session.execute(DROP_KEYSPACE);
+  }
+
+  @Test(groups = "short")
+  public void should_remove_tablets_on_keyspace_alterations() throws InterruptedException {
+    session.execute(CREATE_KEYSPACE);
+    ArgumentCaptor<KeyspaceMetadata> added = null;
+    for (SchemaChangeListener listener : listeners) {
+      added = ArgumentCaptor.forClass(KeyspaceMetadata.class);
+      verify(listener, timeout(NOTIF_TIMEOUT_MS).times(1)).onKeyspaceAdded(added.capture());
+      assertThat(added.getValue()).hasName(handleId(KEYSPACE_NAME));
+    }
+    assert added != null;
+
+    TabletMap tabletMap;
+    tabletMap = cluster.getMetadata().getTabletMap();
+
+    session.execute(CREATE_TABLE);
+    session.execute(String.format(INSERT_QUERY_TEMPLATE, "42"));
+    session.execute(session.prepare(SELECT_PK_WHERE).bind(42));
+    session.execute(session.prepare(SELECT_PK_WHERE).bind(42));
+    assertThat(tabletMap.getMapping())
+        .containsKey(
+            new TabletMap.KeyspaceTableNamePair(handleId(KEYSPACE_NAME), handleId(TABLE_NAME)));
+
+    assertThat(cluster.getMetadata().getKeyspace(KEYSPACE_NAME).isDurableWrites()).isTrue();
+
+    session.execute(ALTER_KEYSPACE);
+    for (SchemaChangeListener listener : listeners) {
+      ArgumentCaptor<TableMetadata> current = ArgumentCaptor.forClass(TableMetadata.class);
+      ArgumentCaptor<TableMetadata> previous = ArgumentCaptor.forClass(TableMetadata.class);
+      verify(listener, timeout(NOTIF_TIMEOUT_MS).times(1))
+          .onTableChanged(current.capture(), previous.capture());
+      assertThat(previous.getValue().getKeyspace()).hasName(handleId(KEYSPACE_NAME));
+      assertThat(previous.getValue()).hasName(handleId(TABLE_NAME));
+    }
+    assertThat(cluster.getMetadata().getKeyspace(KEYSPACE_NAME)).isNotDurableWrites();
+    assertThat(tabletMap.getMapping())
+        .doesNotContainKey(
+            new TabletMap.KeyspaceTableNamePair(handleId(KEYSPACE_NAME), handleId(TABLE_NAME)));
+  }
+
+  @AfterClass(groups = "short", alwaysRun = true)
+  public void teardown() {
+    cluster.close();
+  }
+}