fix(profiler) prevent emitting empty profiles (#2397)

* panic!

* do not send empty samples to the other thread

* ignore empty samples in sampling thread

* Update profiling/src/profiling/mod.rs

Co-authored-by: Levi Morrison <[email protected]>

* if profiling is disabled, we do not need any other checks

---------

Co-authored-by: Levi Morrison <[email protected]>

profiling/src/profiling/mod.rs

@@ -346,6 +346,12 @@ impl TimeCollector {
         profiles: &mut HashMap<ProfileIndex, InternalProfile>,
         started_at: &WallTime,
     ) {
+        if message.key.sample_types.len() == 0 {
+            // profiling disabled, this should not happen!
+            warn!("A sample with no sample types was recorded in the profiler. Please report this to Datadog.");
+            return;
+        }
+
         let profile: &mut InternalProfile = if let Some(value) = profiles.get_mut(&message.key) {
             value
         } else {
@@ -1034,6 +1040,7 @@ impl Profiler {
 
         let mut sample_types = Vec::with_capacity(SAMPLE_TYPES.len());
         let mut sample_values = Vec::with_capacity(SAMPLE_TYPES.len());
+
         if locals.profiling_enabled {
             // sample, wall-time, cpu-time
             let len = 2 + locals.profiling_experimental_cpu_time_enabled as usize;