crypto: Return an Option instead of an empty result for the key uploads.

matrix_sdk_base/src/client.rs

@@ -1337,12 +1337,12 @@ impl BaseClient {
     /// Returns an empty error if no keys need to be uploaded.
     #[cfg(feature = "encryption")]
     #[cfg_attr(feature = "docs", doc(cfg(encryption)))]
-    pub async fn keys_for_upload(&self) -> StdResult<KeysUploadRequest, ()> {
+    pub async fn keys_for_upload(&self) -> Option<KeysUploadRequest> {
         let olm = self.olm.lock().await;
 
         match &*olm {
             Some(o) => o.keys_for_upload().await,
-            None => Err(()),
+            None => None,
         }
     }
 

matrix_sdk_crypto/src/machine.rs

@@ -18,7 +18,6 @@ use std::{
     collections::{BTreeMap, HashSet},
     convert::{TryFrom, TryInto},
     mem,
-    result::Result as StdResult,
     sync::Arc,
 };
 
@@ -26,15 +25,14 @@ use dashmap::DashMap;
 use serde_json::Value;
 use tracing::{debug, error, info, instrument, trace, warn};
 
-use api::r0::{
-    keys::{claim_keys, get_keys, upload_keys, OneTimeKey},
-    sync::sync_events::Response as SyncResponse,
-    to_device::{
-        send_event_to_device::IncomingRequest as OwnedToDeviceRequest, DeviceIdOrAllDevices,
-    },
-};
 use matrix_sdk_common::{
-    api,
+    api::r0::{
+        keys::{claim_keys, get_keys, upload_keys, OneTimeKey},
+        sync::sync_events::Response as SyncResponse,
+        to_device::{
+            send_event_to_device::IncomingRequest as OwnedToDeviceRequest, DeviceIdOrAllDevices,
+        },
+    },
     encryption::DeviceKeys,
     events::{
         forwarded_room_key::ForwardedRoomKeyEventContent,
@@ -631,17 +629,17 @@ impl OlmMachine {
 
     /// Get a request to upload E2EE keys to the server.
     ///
-    /// Returns an empty error if no keys need to be uploaded.
+    /// Returns None if no keys need to be uploaded.
     ///
     /// The response of a successful key upload requests needs to be passed to
     /// the [`OlmMachine`] with the [`receive_keys_upload_response`].
     ///
     /// [`receive_keys_upload_response`]: #method.receive_keys_upload_response
     /// [`OlmMachine`]: struct.OlmMachine.html
-    pub async fn keys_for_upload(&self) -> StdResult<upload_keys::Request, ()> {
+    pub async fn keys_for_upload(&self) -> Option<upload_keys::Request> {
         let (device_keys, one_time_keys) = self.account.keys_for_upload().await?;
 
-        Ok(upload_keys::Request {
+        Some(upload_keys::Request {
             device_keys,
             one_time_keys,
         })
@@ -1813,7 +1811,7 @@ pub(crate) mod test {
             .unwrap();
 
         let ret = machine.keys_for_upload().await;
-        assert!(ret.is_err());
+        assert!(ret.is_none());
     }
 
     #[tokio::test]

matrix_sdk_crypto/src/olm/account.rs

@@ -200,18 +200,15 @@ impl Account {
 
     /// Get a tuple of device and one-time keys that need to be uploaded.
     ///
-    /// Returns an empty error if no keys need to be uploaded.
+    /// Returns None if no keys need to be uploaded.
     pub(crate) async fn keys_for_upload(
         &self,
-    ) -> Result<
-        (
-            Option<DeviceKeys>,
-            Option<BTreeMap<DeviceKeyId, OneTimeKey>>,
-        ),
-        (),
-    > {
+    ) -> Option<(
+        Option<DeviceKeys>,
+        Option<BTreeMap<DeviceKeyId, OneTimeKey>>,
+    )> {
         if !self.should_upload_keys().await {
-            return Err(());
+            return None;
         }
 
         let device_keys = if !self.shared() {
@@ -222,7 +219,7 @@ impl Account {
 
         let one_time_keys = self.signed_one_time_keys().await.ok();
 
-        Ok((device_keys, one_time_keys))
+        Some((device_keys, one_time_keys))
     }
 
     /// Mark the current set of one-time keys as being published.