Update field in Map's value in hazelcast without completely overriding a struct

Question

I have a struct in C++

struct Person
{
    std::string name;
    bool male;
    int32_t age;
};

and built a IMap<int, Person> and fill it with values.

auto map = hz.get_map("map").get();
auto p1 = Person{"Mike", true, 10};
auto p2 = Person{"Maria", false, 15};
map->put(1, p1).get();
map->put(2, p2).get();
//
p2.age = 18;
//
// Some code here to update Maria's age...

How to update age of Maria without fully rewriting a p2 struct?

This example is too naive but if the Person struct has many fields of different types (POD, vectors, etc) then full overriding/serialization becomes an expensive operation.

Small example of code would be greatly appreciated.

This question is related to similar question which has no answer with a clue.

Answer 1

If it's simple update, something like

UPDATE person SET age = 55 WHERE name = 'Maria'

might be enough.

For more complex needs and you have Java coding ability, then a server side EntryProcessor Java / EntryProcessor C++ is specifically designed for in-situ updates. It's a function invoked by the C++ client that runs on the Java server.