Function emit_s3_call_event

core/src/workspace/s3.rs:1102–1118

Emit a structured `tracing` event for a single S3 API call. Hosts that want to meter S3 cost (call count, bytes transferred, latency) can subscribe to events from this module at `DEBUG` level and route on the `op` field. Fields emitted: | Field | Type | Meaning | |----------------|---------|--------------------------------------------

(
    op: &'static str,
    bucket: &str,
    target: &str,
    bytes: u64,
    ok: bool,
    elapsed: std::time::Duration,
)

///
/// Emitted at `DEBUG`; zero-cost when the level is disabled.
fn emit_s3_call_event(
    op: &'static str,
    bucket: &str,
    target: &str,
    bytes: u64,
    ok: bool,
    elapsed: std::time::Duration,
) {
    tracing::debug!(
        op = op,
        bucket = %bucket,
        target = %target,
        bytes = bytes,
        outcome = if ok { "ok" } else { "error" },
        duration_ms = elapsed.as_millis() as u64,
    );
}

/// Map a `PutObject` failure to either a [`WorkspaceVersionConflict`]
/// (HTTP 412 Precondition Failed from `If-Match`) or a generic write error.