account

Account Management Module

account.rs

This module provides a simple in-memory account management system using Rust, intended for use in a backend running on the Internet Computer (IC) or a similar environment.

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Imports and Type Definitions

use std::collections::HashSet;
type Address = String;

• HashSet is used to store account addresses without duplicates.

• Address is defined as a type alias for String, representing a user’s account address.

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State Structure

#[derive(Default)]
struct State {
    accounts: HashSet<Address>,
}

• State holds the current set of accounts in memory.

• #[derive(Default)] automatically generates a default constructor for the State struct, initializing accounts as an empty set.

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Thread-local State

thread_local! {
    static STATE: std::cell::RefCell<State> = std::cell::RefCell::new(State::default());
}

• thread_local! ensures that each thread has its own copy of the state, which is required for safe mutable access in a concurrent environment.

• RefCell allows interior mutability, meaning the State can be modified even when it is behind an immutable reference.

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Create Account Function

pub fn create_account(address: String) -> String {
    STATE.with(|s| {
        let mut state = s.borrow_mut();
        if state.accounts.contains(&address) {
            return "Already exists".into();
        } else {
            state.accounts.insert(address);
            return "Account created".into();
        }
    })
}

• Purpose: Adds a new account address if it doesn’t already exist.

• Logic:

  1. Borrow the state mutably.

  2. Check if the given address is already in the set.

  3. If it exists, return "Already exists".

  4. If not, insert it into the set and return "Account created".

• This function could be exposed as an update method in an IC canister (the #[ic_cdk::update] attribute is currently commented out).

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Get Accounts Function

pub fn get_accounts() -> Vec<String> {
    STATE.with(|s| {
        s.borrow().accounts.iter().cloned().collect()
    })
}

• Purpose: Returns a list of all registered account addresses.

• Logic:

  1. Borrow the state immutably.

  2. Convert the HashSet of addresses into a Vec<String>.

  3. Return the vector to the caller.

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