SQL Partition Aware review fixes (#1188)

* review fixes

* review fixes

Author: akeles85

hazelcast/include/hazelcast/client/sql/impl/read_optimized_lru_cache.h

@@ -73,43 +73,36 @@ class read_optimized_lru_cache
      * @returns Returns the value to which the specified key is cached,
      * or default value if this cache contains no mapping for the key.
      */
-    std::shared_ptr<V> get_or_default(const K& key,
-                                      const std::shared_ptr<V>& default_value)
+    V get_or_default(const K& key, const V& default_value)
     {
         const auto existing_value = get(key);
-        return (existing_value != nullptr) ? existing_value : default_value;
+        return existing_value ? *existing_value : default_value;
     }
 
     /**
      * @param key the key of the cache entry
      * Returns the value to which the specified key is cached,
-     * or {@code null} if this cache contains no mapping for the key.
+     * or {@code boost::none} if this cache contains no mapping for the key.
      * @returns Returns the value to which the specified key is cached
      */
-    std::shared_ptr<V> get(const K& key)
+    boost::optional<V> get(const K& key)
     {
         auto value_from_cache = cache_.get(key);
         if (value_from_cache == nullptr) {
-            return nullptr;
+            return boost::none;
         }
         value_from_cache->touch();
-        return std::make_shared<int32_t>(value_from_cache->value_);
+        return boost::make_optional(value_from_cache->value_);
     }
 
     /**
      * @param key the key of the cache entry
      * @param value the value of the cache entry
-     * @throws exception::illegal_argument if the value equals to nullptr
      */
-    void put(const K& key, const std::shared_ptr<V>& value)
+    void put(const K& key, const V& value)
     {
-        if (value == nullptr) {
-            BOOST_THROW_EXCEPTION(client::exception::illegal_argument(
-              "Null values are disallowed"));
-        }
-
         auto old_value =
-          cache_.put(key, std::make_shared<value_and_timestamp<V>>(*value));
+          cache_.put(key, std::make_shared<value_and_timestamp<V>>(value));
         if (old_value == nullptr && cache_.size() > cleanup_threshold_) {
             do_cleanup();
         }
@@ -130,15 +123,15 @@ class read_optimized_lru_cache
     {
     public:
         const T value_;
-        int64_t timestamp_;
+        std::atomic<int64_t> timestamp_;
 
         value_and_timestamp(T value)
           : value_(value)
         {
             touch();
         }
 
-        void touch() { timestamp_ = util::current_time_nanos(); }
+        void touch() { timestamp_.store(util::current_time_nanos()); }
     };
 
     util::SynchronizedMap<K, value_and_timestamp<V>> cache_;

hazelcast/src/hazelcast/client/sql.cpp

@@ -77,13 +77,13 @@ sql_service::execute(const sql_statement& statement)
 
     auto arg_index = statement_par_arg_index != -1
                        ? statement_par_arg_index
-                       : *(partition_argument_index_cache_->get_or_default(
-                           statement.sql(), std::make_shared<int32_t>(-1)));
+                       : (partition_argument_index_cache_->get_or_default(
+                           statement.sql(), -1));
 
     auto partition_id = extract_partition_id(statement, arg_index);
     std::shared_ptr<connection::Connection> query_conn =
-      partition_id != boost::none ? query_connection(partition_id.value())
-                                  : query_connection();
+      partition_id ? query_connection(partition_id.value())
+                   : query_connection();
 
     sql::impl::query_id qid = create_query_id(query_conn);
 
@@ -259,8 +259,7 @@ sql_service::handle_execute_response(
                                    original_partition_argument_index) {
             if (response.partition_argument_index != -1) {
                 partition_argument_index_cache_->put(
-                  sql_query,
-                  std::make_shared<int32_t>(response.partition_argument_index));
+                  sql_query, response.partition_argument_index);
 
                 if (auto argument_index = statement_par_arg_index_ptr.lock()) {
                     argument_index->store(response.partition_argument_index);
@@ -358,7 +357,7 @@ sql_service::extract_partition_id(const sql_statement& statement,
         return boost::none;
     }
 
-    const auto key = statement.serialized_parameters_[arg_index];
+    const auto& key = statement.serialized_parameters_[arg_index];
 
     return client_context_.get_partition_service().get_partition_id(key);
 }