From 1fd880d0e98f10d406d05a66f8ffb570294ef913 Mon Sep 17 00:00:00 2001
From: Alexey Orlenko <alex@aqrln.net>
Date: Wed, 20 Nov 2024 21:35:22 +0100
Subject: [PATCH] Introduce SerializableNonZeroU64

---
 libs/telemetry/src/capturing/ng/collector.rs | 19 +++++++++++++++++--
 libs/telemetry/src/capturing/ng/layer.rs     |  6 +++---
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/libs/telemetry/src/capturing/ng/collector.rs b/libs/telemetry/src/capturing/ng/collector.rs
index 853c95bfd1f..e4c7fdb34a7 100644
--- a/libs/telemetry/src/capturing/ng/collector.rs
+++ b/libs/telemetry/src/capturing/ng/collector.rs
@@ -6,12 +6,27 @@ use tracing::Level;
 
 use crate::models::{LogLevel, SpanKind, TraceSpan};
 
+#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+struct SerializableNonZeroU64(NonZeroU64);
+
+impl Serialize for SerializableNonZeroU64 {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        // Serialize as string to preserve full u64 precision in JavaScript. Otherwise values
+        // larger than 2^53 - 1 will be parsed as floats on the client side, making it possible for
+        // IDs to collide.
+        self.0.to_string().serialize(serializer)
+    }
+}
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize)]
-pub struct SpanId(NonZeroU64);
+pub struct SpanId(SerializableNonZeroU64);
 
 impl From<&tracing::span::Id> for SpanId {
     fn from(id: &tracing::span::Id) -> Self {
-        Self(id.into_non_zero_u64())
+        Self(SerializableNonZeroU64(id.into_non_zero_u64()))
     }
 }
 
diff --git a/libs/telemetry/src/capturing/ng/layer.rs b/libs/telemetry/src/capturing/ng/layer.rs
index 3d92873fd6e..a4013f2a840 100644
--- a/libs/telemetry/src/capturing/ng/layer.rs
+++ b/libs/telemetry/src/capturing/ng/layer.rs
@@ -285,15 +285,15 @@ mod tests {
     /// IDs (as libtest runs every test in its own thread).
     fn redact_id() -> Redaction {
         thread_local! {
-            static SPAN_ID_TO_SEQUENTIAL_ID: RefCell<HashMap<u64, u64>> = <_>::default();
+            static SPAN_ID_TO_SEQUENTIAL_ID: RefCell<HashMap<String, u64>> = <_>::default();
             static NEXT_ID: RefCell<u64> = const { RefCell::new(1) };
         }
 
         fn redact_recursive(value: Content) -> Content {
             match value {
                 Content::NewtypeStruct("SpanId", ref nested) => match **nested {
-                    Content::U64(original_id) => SPAN_ID_TO_SEQUENTIAL_ID.with_borrow_mut(|map| {
-                        let id = map.entry(original_id).or_insert_with(|| {
+                    Content::String(ref original_id) => SPAN_ID_TO_SEQUENTIAL_ID.with_borrow_mut(|map| {
+                        let id = map.entry(original_id.clone()).or_insert_with(|| {
                             NEXT_ID.with_borrow_mut(|next_id| {
                                 let id = *next_id;
                                 *next_id += 1;