feat(rust/rbac-registration): Use HashSet instead of Vec to return a list of role 0 stake addresses (#304)

* Use HashSet instead of Vec to return a list of role 0 stake addresses

* Update after merge

Author: stanislav-tkach

rust/rbac-registration/src/cardano/cip509/cip509.rs

@@ -2,7 +2,10 @@
 //! Doc Reference: <https://github.com/input-output-hk/catalyst-CIPs/tree/x509-envelope-metadata/CIP-XXXX>
 //! CDDL Reference: <https://github.com/input-output-hk/catalyst-CIPs/blob/x509-envelope-metadata/CIP-XXXX/x509-envelope.cddl>
 
-use std::{borrow::Cow, collections::HashMap};
+use std::{
+    borrow::Cow,
+    collections::{HashMap, HashSet},
+};
 
 use anyhow::{anyhow, Context};
 use cardano_blockchain_types::{
@@ -261,7 +264,7 @@ impl Cip509 {
 
     /// Returns a list of role 0 stake addresses.
     #[must_use]
-    pub fn role_0_stake_addresses(&self) -> Vec<StakeAddress> {
+    pub fn role_0_stake_addresses(&self) -> HashSet<StakeAddress> {
         self.metadata
             .as_ref()
             .map(|m| m.certificate_uris.stake_addresses(0))

rust/rbac-registration/src/cardano/cip509/utils/cip134_uri_set.rs

@@ -1,6 +1,9 @@
 //! A set of [`Cip0134Uri`].
 
-use std::{collections::HashMap, sync::Arc};
+use std::{
+    collections::{HashMap, HashSet},
+    sync::Arc,
+};
 
 use c509_certificate::{
     extensions::{alt_name::GeneralNamesOrText, extension::ExtensionValue},
@@ -70,8 +73,8 @@ impl Cip0134UriSet {
 
     /// Returns a list of stake addresses by the given index.
     #[must_use]
-    pub fn stake_addresses(&self, index: usize) -> Vec<StakeAddress> {
-        let mut result = Vec::new();
+    pub fn stake_addresses(&self, index: usize) -> HashSet<StakeAddress> {
+        let mut result = HashSet::new();
 
         if let Some(uris) = self.x_uris().get(&index) {
             result.extend(convert_stake_addresses(uris));

rust/rbac-registration/src/registration/cardano/mod.rs

@@ -2,7 +2,10 @@
 
 mod update_rbac;
 
-use std::{collections::HashMap, sync::Arc};
+use std::{
+    collections::{HashMap, HashSet},
+    sync::Arc,
+};
 
 use anyhow::bail;
 use c509_certificate::c509::C509;
@@ -208,9 +211,9 @@ impl RegistrationChain {
             .and_then(|rdr| rdr.encryption_key_from_rotation(rotation))
     }
 
-    /// Returns a list of role 0 stake addresses.
+    /// Returns a set of role 0 stake addresses.
     #[must_use]
-    pub fn role_0_stake_addresses(&self) -> Vec<StakeAddress> {
+    pub fn role_0_stake_addresses(&self) -> HashSet<StakeAddress> {
         self.inner.certificate_uris.stake_addresses(0)
     }
 }