storage_service: Move get_generation_number to util/

This is purely utility helper routine. As a nice side effect the
inclusion of storage_service.hh is removed from several unrelated
places.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>

configure.py

@@ -517,6 +517,7 @@ scylla_core = (['database.cc',
                 'utils/limiting_data_source.cc',
                 'utils/updateable_value.cc',
                 'utils/directories.cc',
+                'utils/generation-number.cc',
                 'mutation_partition.cc',
                 'mutation_partition_view.cc',
                 'mutation_partition_serializer.cc',

db/system_keyspace.cc

@@ -45,7 +45,6 @@
 
 #include "system_keyspace.hh"
 #include "types.hh"
-#include "service/storage_service.hh"
 #include "service/storage_proxy.hh"
 #include "service/client_state.hh"
 #include "service/query_state.hh"
@@ -80,6 +79,7 @@
 #include "db/view/build_progress_virtual_reader.hh"
 #include "db/schema_tables.hh"
 #include "index/built_indexes_virtual_reader.hh"
+#include "utils/generation-number.hh"
 
 #include "idl/frozen_mutation.dist.hh"
 #include "serializer_impl.hh"
@@ -2080,11 +2080,11 @@ future<int> increment_and_get_generation() {
             // seconds-since-epoch isn't a foolproof new generation
             // (where foolproof is "guaranteed to be larger than the last one seen at this ip address"),
             // but it's as close as sanely possible
-            generation = service::get_generation_number();
+            generation = utils::get_generation_number();
         } else {
             // Other nodes will ignore gossip messages about a node that have a lower generation than previously seen.
             int stored_generation = rs->one().template get_as<int>("gossip_generation") + 1;
-            int now = service::get_generation_number();
+            int now = utils::get_generation_number();
             if (stored_generation >= now) {
                 slogger.warn("Using stored Gossip Generation {} as it is greater than current system time {}."
                             "See CASSANDRA-3654 if you experience problems", stored_generation, now);

gms/gossiper.cc

@@ -49,7 +49,6 @@
 #include "gms/failure_detector.hh"
 #include "gms/i_failure_detection_event_listener.hh"
 #include "gms/i_endpoint_state_change_subscriber.hh"
-#include "service/storage_service.hh"
 #include "message/messaging_service.hh"
 #include "database.hh"
 #include "log.hh"
@@ -62,6 +61,7 @@
 #include "db/config.hh"
 #include <boost/range/algorithm/set_algorithm.hpp>
 #include <boost/range/adaptors.hpp>
+#include "utils/generation-number.hh"
 
 namespace gms {
 
@@ -589,7 +589,7 @@ future<> gossiper::apply_state_locally(std::map<inet_address, endpoint_state> ma
                     int local_generation = local_ep_state_ptr.get_heart_beat_state().get_generation();
                     int remote_generation = remote_state.get_heart_beat_state().get_generation();
                     logger.trace("{} local generation {}, remote generation {}", ep, local_generation, remote_generation);
-                    if (remote_generation > service::get_generation_number() + MAX_GENERATION_DIFFERENCE) {
+                    if (remote_generation > utils::get_generation_number() + MAX_GENERATION_DIFFERENCE) {
                         // assume some peer has corrupted memory and is broadcasting an unbelievable generation about another peer (or itself)
                         logger.warn("received an invalid gossip generation for peer {}; local generation = {}, received generation = {}",
                             ep, local_generation, remote_generation);

service/storage_service.cc

@@ -82,6 +82,7 @@
 #include "cdc/generation.hh"
 #include "repair/repair.hh"
 #include "service/priority_manager.hh"
+#include "utils/generation-number.hh"
 
 using token = dht::token;
 using UUID = utils::UUID;
@@ -95,14 +96,6 @@ static logging::logger slogger("storage_service");
 
 distributed<storage_service> _the_storage_service;
 
-
-int get_generation_number() {
-    using namespace std::chrono;
-    auto now = high_resolution_clock::now().time_since_epoch();
-    int generation_number = duration_cast<seconds>(now).count();
-    return generation_number;
-}
-
 storage_service::storage_service(abort_source& abort_source, distributed<database>& db, gms::gossiper& gossiper, sharded<auth::service>& auth_service, sharded<db::system_distributed_keyspace>& sys_dist_ks,
         sharded<db::view::view_update_generator>& view_update_generator, gms::feature_service& feature_service, storage_service_config config, sharded<service::migration_notifier>& mn, locator::token_metadata& tm, bool for_testing)
         : _abort_source(abort_source)
@@ -1949,7 +1942,7 @@ future<> storage_service::start_gossiping(bind_messaging_port do_bind) {
                 ss.set_gossip_tokens(db::system_keyspace::get_local_tokens().get0(),
                         cdc_enabled ? std::make_optional(cdc::get_local_streams_timestamp().get0()) : std::nullopt);
                 ss._gossiper.force_newer_generation();
-                ss._gossiper.start_gossiping(get_generation_number(), gms::bind_messaging_port(bool(do_bind))).then([&ss] {
+                ss._gossiper.start_gossiping(utils::get_generation_number(), gms::bind_messaging_port(bool(do_bind))).then([&ss] {
                     ss._initialized = true;
                 }).get();
             }

service/storage_service.hh

@@ -99,8 +99,6 @@ inline storage_service& get_local_storage_service() {
     return _the_storage_service.local();
 }
 
-int get_generation_number();
-
 enum class disk_error { regular, commit };
 
 struct bind_messaging_port_tag {};

utils/generation-number.cc

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2020 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 <chrono>
+#include "generation-number.hh"
+
+namespace utils {
+
+int get_generation_number() {
+    using namespace std::chrono;
+    auto now = high_resolution_clock::now().time_since_epoch();
+    int generation_number = duration_cast<seconds>(now).count();
+    return generation_number;
+}
+
+}

utils/generation-number.hh

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2020 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
+
+namespace utils {
+
+int get_generation_number();
+
+}