storage_service: Include range tombstones feature

This patch adds the range tombstones feature, which is not enabled
yet, to the storage_service, so that consumers can query for it.

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

service/storage_service.cc

@@ -78,6 +78,8 @@ namespace service {
 
 static logging::logger logger("storage_service");
 
+static const sstring RANGE_TOMBSTONES_FEATURE = "RANGE_TOMBSTONES";
+
 distributed<storage_service> _the_storage_service;
 
 int get_generation_number() {
@@ -1148,6 +1150,10 @@ future<> storage_service::init_server(int delay) {
             }
             logger.info("Not joining ring as requested. Use JMX (StorageService->joinRing()) to initiate ring joining");
         }
+
+        get_storage_service().invoke_on_all([] (auto& ss) {
+            ss._range_tombstones_feature = gms::feature(RANGE_TOMBSTONES_FEATURE);
+        }).get();
     });
 }
 

service/storage_service.hh

@@ -58,6 +58,7 @@
 #include "streaming/stream_plan.hh"
 #include <seastar/core/distributed.hh>
 #include "disk-error-handler.hh"
+#include "gms/feature.hh"
 
 namespace transport {
     class cql_server;
@@ -266,6 +267,8 @@ private:
 private:
     std::unordered_set<token> _bootstrap_tokens;
 
+    gms::feature _range_tombstones_feature;
+
 public:
     void finish_bootstrapping() {
         _is_bootstrap_mode = false;
@@ -2356,6 +2359,10 @@ private:
     void do_isolate_on_error(disk_error type);
 public:
     static sstring get_config_supported_features();
+
+    bool cluster_supports_range_tombstones() {
+        return bool(_range_tombstones_feature);
+    }
 };
 
 inline future<> init_storage_service(distributed<database>& db) {