new method is_empty for LoginsStore

to check whether the database is empty

CHANGELOG.md

@@ -24,9 +24,16 @@ pub fn add(&self, entry: LoginEntry) -> ApiResult<Login>
 pub fn add_or_update(&self, entry: LoginEntry) -> ApiResult<Login>
 ```
 
+New LoginsStore methods:
+```
+// Checking whether the database contains logins (does not utilize the `EncryptorDecryptor`):
+is_empty(&self) -> ApiResult<bool>
+// Checking for the Existence of Logins for a given base domain (also does not utilize the `EncryptorDecryptor`):
+has_logins_by_base_domain(&self, base_domain: &str) -> ApiResult<bool>
+```
+
 The crypto primitives `encrypt`, `decrypt`, `encrypt_struct` and `decrypt_struct` are not exposed anymore via UniFFI, as well as `EncryptedLogin` will not be exposed anymore. In addition we also do not expose the structs `RecordFields`, `LoginFields` and `SecureLoginFields` anymore.
 
-Checking for the Existence of Logins for a given Base Domain In order to check for the existence of stored logins for a given base domain, we provide an additional store method, has_logins_by_base_domain(&self, base_domain: &str), which does not utilize the `EncryptorDecryptor`.
 
 ##### SyncEngine
 The logins sync engine has been adapted for above EncryptorDecryptor trait and therefore does not support a `set_local_encryption_key` method anymore.

components/logins/android/src/main/java/mozilla/appservices/logins/DatabaseLoginsStorage.kt

@@ -60,13 +60,27 @@ class DatabaseLoginsStorage(dbPath: String, keyManager: KeyManager) : AutoClosea
         }
     }
 
+    @Throws(LoginsApiException::class)
+    fun isEmpty(): Boolean {
+        return readQueryCounters.measure {
+            store.isEmpty()
+        }
+    }
+
     @Throws(LoginsApiException::class)
     fun list(): List<Login> {
         return readQueryCounters.measure {
             store.list()
         }
     }
 
+    @Throws(LoginsApiException::class)
+    fun hasLoginsByBaseDomain(baseDomain: String): Boolean {
+        return readQueryCounters.measure {
+            store.hasLoginsByBaseDomain(baseDomain)
+        }
+    }
+
     @Throws(LoginsApiException::class)
     fun getByBaseDomain(baseDomain: String): List<Login> {
         return readQueryCounters.measure {

components/logins/ios/Logins/LoginsStorage.swift

@@ -68,13 +68,27 @@ open class LoginsStorage {
         }
     }
 
+    /// Check whether the database is empty.
+    open func isEmpty() throws -> Bool {
+        return try queue.sync {
+            try self.store.isEmpty()
+        }
+    }
+
     /// Get the entire list of records.
     open func list() throws -> [Login] {
         return try queue.sync {
             try self.store.list()
         }
     }
 
+    /// Check whether logins exist for some base domain.
+    open func hasLoginsByBaseDomain(baseDomain: String) throws -> Bool {
+        return try queue.sync {
+            try self.store.hasLoginsByBaseDomain(baseDomain: baseDomain)
+        }
+    }
+
     /// Get the list of records for some base domain.
     open func getByBaseDomain(baseDomain: String) throws -> [Login] {
         return try queue.sync {

components/logins/src/logins.udl

@@ -149,6 +149,9 @@ interface LoginStore {
     [Throws=LoginsApiError]
     void touch([ByRef] string id);
 
+    [Throws=LoginsApiError]
+    boolean is_empty();
+
     [Throws=LoginsApiError]
     sequence<Login> list();
 

components/logins/src/store.rs

@@ -71,6 +71,11 @@ impl LoginStore {
         Ok(Self { db, encdec })
     }
 
+    #[handle_error(Error)]
+    pub fn is_empty(&self) -> ApiResult<bool> {
+        self.db.lock().get_all().map(|logins| logins.is_empty())
+    }
+
     #[handle_error(Error)]
     pub fn list(&self) -> ApiResult<Vec<Login>> {
         self.db.lock().get_all().and_then(|logins| {