refactor: split modules into files

src/channel.rs

@@ -0,0 +1,46 @@
+//! Channels that abstract over local or remote sending
+
+use std::io;
+
+use n0_error::stack_error;
+
+pub mod mpsc;
+pub mod none;
+pub mod oneshot;
+
+/// Error when sending a oneshot or mpsc message. For local communication,
+/// the only thing that can go wrong is that the receiver has been dropped.
+///
+/// For rpc communication, there can be any number of errors, so this is a
+/// generic io error.
+#[stack_error(derive, add_meta, from_sources)]
+pub enum SendError {
+    /// The receiver has been closed. This is the only error that can occur
+    /// for local communication.
+    #[error("Receiver closed")]
+    ReceiverClosed,
+    /// The message exceeded the maximum allowed message size (see [`MAX_MESSAGE_SIZE`]).
+    ///
+    /// [`MAX_MESSAGE_SIZE`]: crate::rpc::MAX_MESSAGE_SIZE
+    #[error("Maximum message size exceeded")]
+    MaxMessageSizeExceeded,
+    /// The underlying io error. This can occur for remote communication,
+    /// due to a network error or serialization error.
+    #[error("Io error")]
+    Io {
+        #[error(std_err)]
+        source: io::Error,
+    },
+}
+
+impl From<SendError> for io::Error {
+    fn from(e: SendError) -> Self {
+        match e {
+            SendError::ReceiverClosed { .. } => io::Error::new(io::ErrorKind::BrokenPipe, e),
+            SendError::MaxMessageSizeExceeded { .. } => {
+                io::Error::new(io::ErrorKind::InvalidData, e)
+            }
+            SendError::Io { source, .. } => source,
+        }
+    }
+}