cql3: Add alter view statement

This patch adds the alter_view_statement, which enables users to
change the properties of a materialized view.

Signed-off-by: Duarte Nunes <duarte@scylladb.com>

configure.py

@@ -357,6 +357,7 @@ scylla_core = (['database.cc',
                  'cql3/statements/create_index_statement.cc',
                  'cql3/statements/truncate_statement.cc',
                  'cql3/statements/alter_table_statement.cc',
+                 'cql3/statements/alter_view_statement.cc',
                  'cql3/statements/alter_user_statement.cc',
                  'cql3/statements/drop_user_statement.cc',
                  'cql3/statements/list_users_statement.cc',

cql3/statements/alter_view_statement.cc

@@ -0,0 +1,121 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Copyright 2016 ScyllaDB
+ *
+ * Modified by ScyllaDB
+ */
+
+/*
+ * This file is part of Scylla.
+ *
+ * Scylla is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Scylla is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Scylla.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "cql3/statements/alter_view_statement.hh"
+#include "cql3/statements/prepared_statement.hh"
+#include "service/migration_manager.hh"
+#include "validation.hh"
+
+namespace cql3 {
+
+namespace statements {
+
+alter_view_statement::alter_view_statement(::shared_ptr<cf_name> view_name, ::shared_ptr<cf_prop_defs> properties)
+        : schema_altering_statement{std::move(view_name)}
+        , _properties{std::move(properties)}
+{
+}
+
+future<> alter_view_statement::check_access(const service::client_state& state)
+{
+    try {
+        auto&& s = service::get_local_storage_proxy().get_db().local().find_schema(keyspace(), column_family());
+        if (s->is_view())  {
+            return state.has_column_family_access(keyspace(), s->view_info()->base_name(), auth::permission::ALTER);
+        }
+    } catch (const no_such_column_family& e) {
+        // Will be validated afterwards.
+    }
+    return make_ready_future<>();
+}
+
+void alter_view_statement::validate(distributed<service::storage_proxy>&, const service::client_state& state)
+{
+    // validated in announce_migration()
+}
+
+future<bool> alter_view_statement::announce_migration(distributed<service::storage_proxy>& proxy, bool is_local_only)
+{
+    auto&& db = proxy.local().get_db().local();
+    schema_ptr schema = validation::validate_column_family(db, keyspace(), column_family());
+    if (!schema->is_view()) {
+        throw exceptions::invalid_request_exception("Cannot use ALTER MATERIALIZED VIEW on Table");
+    }
+
+    if (!_properties) {
+        throw exceptions::invalid_request_exception("ALTER MATERIALIZED VIEW WITH invoked, but no parameters found");
+    }
+
+    _properties->validate();
+
+    auto builder = schema_builder(schema);
+    _properties->apply_to_builder(builder);
+
+    if (builder.get_gc_grace_seconds() == 0) {
+        throw exceptions::invalid_request_exception(
+                "Cannot alter gc_grace_seconds of a materialized view to 0, since this "
+                "value is used to TTL undelivered updates. Setting gc_grace_seconds too "
+                "low might cause undelivered updates to expire before being replayed.");
+    }
+
+    return service::get_local_migration_manager().announce_view_update(view_ptr(builder.build()), is_local_only).then([] {
+        return true;
+    });
+}
+
+shared_ptr<transport::event::schema_change> alter_view_statement::change_event()
+{
+    using namespace transport;
+
+    return make_shared<event::schema_change>(event::schema_change::change_type::UPDATED,
+                                             event::schema_change::target_type::TABLE,
+                                             keyspace(),
+                                             column_family());
+}
+
+shared_ptr<cql3::statements::prepared_statement>
+alter_view_statement::prepare(database& db, cql_stats& stats) {
+    return make_shared<prepared_statement>(make_shared<alter_view_statement>(*this));
+}
+
+}
+
+}

cql3/statements/alter_view_statement.hh

@@ -0,0 +1,74 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Copyright 2016 ScyllaDB
+ *
+ * Modified by ScyllaDB
+ */
+
+/*
+ * This file is part of Scylla.
+ *
+ * Scylla is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Scylla is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Scylla.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <seastar/core/shared_ptr.hh>
+
+#include "database.hh"
+#include "cql3/statements/cf_prop_defs.hh"
+#include "cql3/statements/schema_altering_statement.hh"
+#include "cql3/cf_name.hh"
+
+namespace cql3 {
+
+namespace statements {
+
+/** An <code>ALTER MATERIALIZED VIEW</code> parsed from a CQL query statement. */
+class alter_view_statement : public schema_altering_statement {
+private:
+    ::shared_ptr<cf_prop_defs> _properties;
+public:
+    alter_view_statement(::shared_ptr<cf_name> view_name, ::shared_ptr<cf_prop_defs> properties);
+
+    virtual future<> check_access(const service::client_state& state) override;
+
+    virtual void validate(distributed<service::storage_proxy>&, const service::client_state& state) override;
+
+    virtual future<bool> announce_migration(distributed<service::storage_proxy>& proxy, bool is_local_only) override;
+
+    virtual shared_ptr<transport::event::schema_change> change_event() override;
+
+    virtual shared_ptr<prepared> prepare(database& db, cql_stats& stats) override;
+};
+
+}
+}