feat: Adopt TraceExporter's Telemetry stuff

crates/capabilities/Cargo.toml

@@ -16,8 +16,8 @@ bytes = "1.4"
 futures-core = "0.3"
 anyhow = "1"
 # TODO: Replace this temporary libdatadog PR rev with the official release/tag
-# that contains DataDog/libdatadog#2235, then regenerate Cargo.lock.
-libdd-capabilities = { git = "https://github.com/DataDog/libdatadog.git", rev = "8cd68ab922fb7aade0f089ccfc91291d874673af" }
+# that contains DataDog/libdatadog#2172, then regenerate Cargo.lock.
+libdd-capabilities = { git = "https://github.com/DataDog/libdatadog.git", rev = "73f23a2c03be39971c966e444785d63b6fd52e81" }
 
 [dev-dependencies]
 wasm-bindgen-test = "0.3"

crates/pipeline/Cargo.toml

@@ -15,17 +15,18 @@ serde = { version = "1.0", features = ["derive"] }
 serde_json = "1"
 libdatadog-nodejs-capabilities = { path = "../capabilities" }
 # TODO: Replace these temporary libdatadog PR revs with the official release/tag
-# that contains DataDog/libdatadog#2235, then regenerate Cargo.lock.
-libdd-capabilities = { git = "https://github.com/DataDog/libdatadog.git", rev = "8cd68ab922fb7aade0f089ccfc91291d874673af" }
-libdd-common = { git = "https://github.com/DataDog/libdatadog.git", rev = "8cd68ab922fb7aade0f089ccfc91291d874673af", default-features = false }
-libdd-data-pipeline = { git = "https://github.com/DataDog/libdatadog.git", rev = "8cd68ab922fb7aade0f089ccfc91291d874673af", default-features = false }
-libdd-trace-utils = { git = "https://github.com/DataDog/libdatadog.git", rev = "8cd68ab922fb7aade0f089ccfc91291d874673af", default-features = false, features = ["change-buffer"] }
-libdd-trace-stats = { git = "https://github.com/DataDog/libdatadog.git", rev = "8cd68ab922fb7aade0f089ccfc91291d874673af", default-features = false }
-libdd-trace-protobuf = { git = "https://github.com/DataDog/libdatadog.git", rev = "8cd68ab922fb7aade0f089ccfc91291d874673af", default-features = false }
-libdd-shared-runtime = { git = "https://github.com/DataDog/libdatadog.git", rev = "8cd68ab922fb7aade0f089ccfc91291d874673af", default-features = false }
+# that contains DataDog/libdatadog#2172, then regenerate Cargo.lock.
+libdd-capabilities = { git = "https://github.com/DataDog/libdatadog.git", rev = "73f23a2c03be39971c966e444785d63b6fd52e81" }
+libdd-common = { git = "https://github.com/DataDog/libdatadog.git", rev = "73f23a2c03be39971c966e444785d63b6fd52e81", default-features = false }
+libdd-data-pipeline = { git = "https://github.com/DataDog/libdatadog.git", rev = "73f23a2c03be39971c966e444785d63b6fd52e81", default-features = false, features = ["telemetry"] }
+libdd-trace-utils = { git = "https://github.com/DataDog/libdatadog.git", rev = "73f23a2c03be39971c966e444785d63b6fd52e81", default-features = false, features = ["change-buffer"] }
+libdd-trace-stats = { git = "https://github.com/DataDog/libdatadog.git", rev = "73f23a2c03be39971c966e444785d63b6fd52e81", default-features = false }
+libdd-trace-protobuf = { git = "https://github.com/DataDog/libdatadog.git", rev = "73f23a2c03be39971c966e444785d63b6fd52e81", default-features = false }
+libdd-shared-runtime = { git = "https://github.com/DataDog/libdatadog.git", rev = "73f23a2c03be39971c966e444785d63b6fd52e81", default-features = false }
 rmp-serde = "1"
 bytes = "1"
 http = "1"
+web-time = "1"
 console_error_panic_hook = "0.1"
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]

crates/pipeline/src/lib.rs

@@ -1,7 +1,7 @@
 use libdatadog_nodejs_capabilities::WasmCapabilities;
 use libdd_data_pipeline::trace_exporter::agent_response::AgentResponse;
 use libdd_data_pipeline::trace_exporter::{
-    TraceExporter, TraceExporterBuilder, TraceExporterOutputFormat,
+    TelemetryConfig, TraceExporter, TraceExporterBuilder, TraceExporterOutputFormat,
 };
 use libdd_data_pipeline::OtlpProtocol;
 use libdd_shared_runtime::LocalRuntime;
@@ -204,6 +204,11 @@ pub struct WasmSpanState {
     /// Extra HTTP headers for OTLP export (e.g. collector auth), as key/value
     /// pairs. Only applied when `otlp_endpoint` is set.
     otlp_headers: RefCell<Vec<(String, String)>>,
+    /// When set, the lazily-built exporter has telemetry enabled with this
+    /// config (`heartbeat`/`runtime_id`/`debug_enabled` — see libdatadog's
+    /// `TelemetryConfig`). Only takes effect if set before the first send
+    /// (when the exporter is built).
+    telemetry_config: RefCell<Option<TelemetryConfig>>,
     /// Latched message from a failed lazy `build_async`. Building is one-shot and
     /// a failure is fatal (bad config), so once set every send returns it (as a
     /// distinguishable error) instead of a misleading "builder already consumed",
@@ -338,6 +343,7 @@ impl WasmSpanState {
             otlp_endpoint: RefCell::new(None),
             otlp_protocol: Cell::new(None),
             otlp_headers: RefCell::new(Vec::new()),
+            telemetry_config: RefCell::new(None),
             build_error: RefCell::new(None),
         })
     }
@@ -374,6 +380,29 @@ impl WasmSpanState {
         Ok(())
     }
 
+    /// Enable telemetry on the lazily-built trace exporter. Off by default —
+    /// dd-trace-js opts in from JS. `heartbeat_ms`sets the metric-flush cadence
+    /// (0 defers to libdatadog's default interval), `runtime_id` tags telemetry
+    /// payloads with the tracer's runtime id when provided, and `debug_enabled`
+    /// toggles libdd-telemetry's verbose logging.
+    ///
+    /// Must be called before the first `sendPreparedChunk` — the exporter is
+    /// built lazily on first send and telemetry config is fixed at build time,
+    /// so later calls have no effect.
+    #[wasm_bindgen(js_name = "enableTelemetry")]
+    pub fn enable_telemetry(
+        &self,
+        heartbeat_ms: u32,
+        runtime_id: Option<String>,
+        debug_enabled: bool,
+    ) {
+        *self.telemetry_config.borrow_mut() = Some(TelemetryConfig {
+            heartbeat: heartbeat_ms as u64,
+            runtime_id,
+            debug_enabled,
+        });
+    }
+
     /// Set extra HTTP headers for OTLP export as a flat `[key, value, ...]`
     /// array (the host flattens its key/value map). Only takes effect with an
     /// OTLP endpoint set, before the first send. A trailing unpaired element on
@@ -530,6 +559,9 @@ impl WasmSpanState {
                     builder.set_otlp_headers(headers.clone());
                 }
             }
+            if let Some(cfg) = self.telemetry_config.borrow().clone() {
+                builder.enable_telemetry(cfg);
+            }
             match builder.build_async::<WasmCapabilities>().await {
                 Ok(built) => *exporter_slot = Some(built),
                 Err(e) => {

crates/pipeline/src/stats.rs

@@ -7,13 +7,14 @@
 //! HTTP transport for flushing stats to the Datadog agent's `/v0.6/stats`
 //! endpoint.
 
-use std::time::{Duration, SystemTime};
+use std::time::Duration;
+use web_time::SystemTime;
 
-/// Wall-clock now() for wasm. `std::time::SystemTime::now()` is unimplemented on
-/// `wasm32-unknown-unknown` (it panics/traps), so derive the time from JS
-/// `Date.now()` (milliseconds since the Unix epoch).
+/// Wall-clock now() for wasm. Delegates to `web_time::SystemTime::now()`,
+/// which routes to JS `Date.now()` on `wasm32-unknown-unknown` (native
+/// `std::time::SystemTime::now()` is unimplemented on that target and traps).
 fn now() -> SystemTime {
-    SystemTime::UNIX_EPOCH + Duration::from_millis(js_sys::Date::now() as u64)
+    SystemTime::now()
 }
 
 use bytes::Bytes;