Struct ExternalTransform 

pub struct ExternalTransform { /* private fields */ }

External (child-stdio) transform stage.

surreal-sync spawns the configured worker and talks on the worker’s stdin/stdout pipes — not the surreal-sync CLI’s stdin.

Exchanges are multiplexed by batch_id: ExternalTransport::write_request / ExternalTransport::try_read_response support overlapping in-flight batches (max_in_flight > 1). Each waiter reads only its own request’s response (request-keyed); payloads are never rebound onto another outstanding id. A mismatched echo fails the exchange (no sink / watermark advance).

Relations

Relation batches use the same NDJSON framing with WireItemKind::RelationChange / WireItemKind::Relation. There is no silent pass-through of relation events past External stages.

Implementations

impl ExternalTransform

pub fn with_transport(transport: Arc<dyn ExternalTransport>) -> Self

Build an external stage over an arbitrary multiplexed transport.

pub fn with_timeout(self, timeout: Option<Duration>) -> Self

Set per-exchange timeout for this stage (None clears it).

Intended as a builder step at construction time (before the stage is shared across in-flight batches).

pub fn with_retry(self, retry: RetryPolicy) -> Self

Set per-stage retry/backoff policy.

Intended as a builder step at construction time.

pub fn persistent_child( command: Vec<String>, framer: FramerKind, ) -> Result<Self>

Spawn a persistent child worker (default mode): one process, many batches.

pub fn transient_child(command: Vec<String>, framer: FramerKind) -> Result<Self>

Transient child worker: spawn → one exchange → exit, per batch.

pub fn child_stdio( mode: ChildStdioMode, command: Vec<String>, framer: FramerKind, ) -> Result<Self>

Convenience from mode + argv + framer.

pub fn command_from_bin(bin: impl Into<PathBuf>, args: &[&str]) -> Vec<String>

Path helper for tests locating a fixture binary.

pub async fn exchange_changes( &self, batch_id: u64, changes: Vec<Change>, ) -> Result<Vec<Change>>

Exchange a change batch with the worker (serialize → I/O → deserialize).

pub async fn exchange_rows( &self, batch_id: u64, rows: Vec<Row>, ) -> Result<Vec<Row>>

Exchange a row batch with the worker.

pub async fn exchange_relation_changes( &self, batch_id: u64, changes: Vec<RelationChange>, ) -> Result<Vec<RelationChange>>

Exchange a relation-change batch with the worker (NDJSON wire).

pub async fn exchange_relations( &self, batch_id: u64, relations: Vec<Relation>, ) -> Result<Vec<Relation>>

Exchange a full-sync relation batch with the worker.

Trait Implementations

impl Clone for ExternalTransform

fn clone(&self) -> ExternalTransform

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ExternalTransform

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.