added example

crates/artist-dht/src/error.rs

@@ -0,0 +1,65 @@
+//! Error types for the artist-dht library.
+
+/// Convenient result alias used across the library.
+pub type Result<T, E = ArtistDhtError> = std::result::Result<T, E>;
+
+/// All errors that can be returned by the public API of this library.
+#[derive(Debug, thiserror::Error)]
+#[non_exhaustive]
+pub enum ArtistDhtError {
+    /// A local database operation failed.
+    #[error("database error: {0}")]
+    Database(String),
+
+    /// The underlying network layer reported an error.
+    #[error("network error: {0}")]
+    Network(String),
+
+    /// The artist name is empty or normalizes to nothing.
+    #[error("invalid artist name")]
+    InvalidArtistName,
+
+    /// The artist name exceeds the maximum allowed length.
+    #[error("artist name is too long")]
+    ArtistNameTooLong,
+
+    /// No artist with the given id exists locally.
+    #[error("artist not found")]
+    ArtistNotFound,
+
+    /// Only locally created artists can be deleted.
+    #[error("cannot delete a remote artist")]
+    CannotDeleteRemoteArtist,
+
+    /// A DHT request did not receive a response in time.
+    #[error("request timed out")]
+    Timeout,
+
+    /// The lookup exhausted its request budget without finishing.
+    #[error("lookup budget exhausted")]
+    LookupBudgetExhausted,
+
+    /// A stored peer ticket could not be parsed.
+    #[error("invalid peer ticket: {0}")]
+    InvalidTicket(String),
+
+    /// A peer violated the DHT protocol.
+    #[error("protocol error: {0}")]
+    Protocol(String),
+
+    /// The service is shutting down and no longer accepts operations.
+    #[error("service is shutting down")]
+    ShuttingDown,
+}
+
+impl From<federation_net::NetworkError> for ArtistDhtError {
+    fn from(err: federation_net::NetworkError) -> Self {
+        use federation_net::NetworkError;
+        match err {
+            NetworkError::Timeout => Self::Timeout,
+            NetworkError::ShuttingDown => Self::ShuttingDown,
+            NetworkError::InvalidTicket(msg) => Self::InvalidTicket(msg),
+            other => Self::Network(other.to_string()),
+        }
+    }
+}