Trait JsonBufferReader 

pub trait JsonBufferReader: Send {
    // Required methods
    fn poll_recv_json(
        &mut self,
        cx: &mut Context<'_>,
    ) -> Poll<Result<Value, DbError>>;
    fn try_recv_json(&mut self) -> Result<Value, DbError>;

    // Provided methods
    fn poll_recv_json_bytes(
        &mut self,
        cx: &mut Context<'_>,
    ) -> Poll<Result<Vec<u8>, DbError>> { ... }
    fn try_recv_json_bytes(&mut self) -> Result<Vec<u8>, DbError> { ... }
}

Reader trait for consuming JSON-serialized values from a buffer.

Type-erased reader that subscribes to a typed buffer and emits either serde_json::Value or already-serialized JSON bytes. Used by the remote access protocol for subscriptions.

This trait enables subscribing to a buffer without knowing the concrete type T at compile time, by serializing values to JSON on each poll.

Object-safe and poll-based for the same reason as BufferReader. Consumers use the JsonReader handle, whose receive methods are async wrappers over the corresponding poll methods and do not box a per-message future.

Requirements

• Record must be configured with .with_remote_access()
• Only available with the remote feature (requires serde_json)

Required Methods

fn poll_recv_json( &mut self, cx: &mut Context<'_>, ) -> Poll<Result<Value, DbError>>

Poll for the next value, serialized to JSON.

Returns Poll::Ready(Ok(json)) when a value is available and serializes successfully, Poll::Ready(Err(..)) on lag/closure/serialize failure, or Poll::Pending after registering cx.waker().

Returns

• Ok(JsonValue) - Successfully received and serialized value
• Err(BufferLagged) - Missed messages (can continue reading)
• Err(BufferClosed) - Buffer closed (graceful shutdown)
• Err(SerializationFailed) - Failed to serialize value to JSON

fn try_recv_json(&mut self) -> Result<Value, DbError>

Non-blocking receive as JSON — returns immediately.

Returns Err(DbError::BufferEmpty) if no pending values.

Provided Methods

fn poll_recv_json_bytes( &mut self, cx: &mut Context<'_>, ) -> Poll<Result<Vec<u8>, DbError>>

Poll for the next value as owned JSON bytes.

Existing implementations inherit a compatibility path that calls poll_recv_json and serializes the returned tree. Typed record readers override this to encode T directly.

fn try_recv_json_bytes(&mut self) -> Result<Vec<u8>, DbError>

Non-blocking receive as owned JSON bytes.

Existing implementations inherit a compatibility path through try_recv_json.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors