Lines
0 %
Functions
Branches
100 %
//! Tracing exporter to write spans to a file in the OTLP JSON format.
// TODO: If https://github.com/open-telemetry/opentelemetry-rust/issues/2602 gets fixed, we can
// replace this entire file with whatever upstream has for doing this.
use opentelemetry_proto::transform::common::tonic::ResourceAttributesWithSchema;
use opentelemetry_proto::transform::trace::tonic::group_spans_by_resource_and_scope;
use opentelemetry_sdk::{
Resource,
error::{OTelSdkError, OTelSdkResult},
trace::SpanExporter,
};
use std::{
fmt::Debug,
io::{LineWriter, Write},
sync::{Arc, Mutex},
/// Tracing exporter to write OTLP JSON to a file (or anything else that implements [`LineWriter`].
#[derive(Debug)]
pub(crate) struct FileExporter<W: Write + Send + Debug> {
/// The [`LineWriter`] to write to.
writer: Arc<Mutex<LineWriter<W>>>,
/// The [`Resource`] to associate spans with.
resource: Resource,
}
impl<W: Write + Send + Debug> FileExporter<W> {
/// Create a new [`FileExporter`]
pub(crate) fn new(writer: W, resource: Resource) -> Self {
Self {
writer: Arc::new(Mutex::new(LineWriter::new(writer))),
resource,
// Note that OpenTelemetry can only represent events as children of spans, so this exporter only
// works on spans. If you want a event to be exported, you need to make sure it exists within some
// span.
impl<W: Write + Send + Debug> SpanExporter for FileExporter<W> {
fn export(
&self,
batch: Vec<opentelemetry_sdk::trace::SpanData>,
) -> impl futures::Future<
Output = std::result::Result<(), opentelemetry_sdk::error::OTelSdkError>,
> + std::marker::Send {
let resource = ResourceAttributesWithSchema::from(&self.resource);
let data = group_spans_by_resource_and_scope(batch, &resource);
let mut writer = self.writer.lock().expect("Lock poisoned");
Box::pin(std::future::ready('write: {
// See https://opentelemetry.io/docs/specs/otel/protocol/file-exporter/ for format
if let Err(err) = serde_json::to_writer(
writer.get_mut(),
&serde_json::json!({"resourceSpans": data}),
) {
break 'write Err(OTelSdkError::InternalFailure(err.to_string()));
if let Err(err) = writer.write(b"\n") {
Ok(())
}))
fn force_flush(&mut self) -> OTelSdkResult {
let mut writer = self
.writer
.lock()
.map_err(|e| OTelSdkError::InternalFailure(e.to_string()))?;
writer
.flush()
.map_err(|e| OTelSdkError::InternalFailure(e.to_string()))
fn set_resource(&mut self, res: &opentelemetry_sdk::Resource) {
self.resource = res.clone();