multiversx_sc_modules/
users.rs

1multiversx_sc::imports!();
2
3/// Standard smart contract module that when added to a smart contract manages a list of users.
4///
5/// It was created before there was such a thing as storage mappers.
6/// The `UserMapper` is a more elegant solution nowadays that solves the same problem.
7///
8/// It provides a bi-directional map:
9/// * from user address to a unique user id
10/// * from user id to address
11#[multiversx_sc::module]
12pub trait UsersModule {
13    /// Each user gets a user id. This is in order to be able to iterate over their data.
14    /// This is a mapping from user address to user id.
15    /// The key is the bytes "user_id" concatenated with their public key.
16    /// The value is the user id.
17    #[view(getUserId)]
18    #[storage_get("user_id")]
19    fn get_user_id(&self, address: &ManagedAddress) -> usize;
20
21    #[storage_set("user_id")]
22    fn set_user_id(&self, address: &ManagedAddress, user_id: usize);
23
24    #[view(getUserAddress)]
25    #[storage_get("user_address")]
26    fn get_user_address(&self, user_id: usize) -> ManagedAddress;
27
28    #[storage_set("user_address")]
29    fn set_user_address(&self, user_id: usize, address: &ManagedAddress);
30
31    /// Retrieves the number of delegtors, including the owner,
32    /// even if they no longer have anything in the contract.
33    #[view(getNumUsers)]
34    #[storage_get("num_users")]
35    fn get_num_users(&self) -> usize;
36
37    /// Yields how accounts are registered in the contract.
38    /// Note that not all of them must have stakes greater than zero.
39    #[storage_set("num_users")]
40    fn set_num_users(&self, num_users: usize);
41
42    fn get_or_create_user(&self, address: &ManagedAddress) -> usize {
43        let mut user_id = self.get_user_id(address);
44        if user_id == 0 {
45            let mut num_users = self.get_num_users();
46            num_users += 1;
47            self.set_num_users(num_users);
48            user_id = num_users;
49            self.set_user_id(address, user_id);
50            self.set_user_address(user_id, address);
51        }
52        user_id
53    }
54
55    #[endpoint(updateUserAddress)]
56    fn update_user_address(&self, addresses: MultiValueEncoded<ManagedAddress>) {
57        for address in &addresses.to_vec() {
58            let user_id = self.get_user_id(&address);
59            require!(user_id > 0, "unknown address");
60            self.set_user_address(user_id, &address);
61        }
62    }
63}