cheaper to generate random primitives than byte arrays (#1091)

Author: shaun-cox

opentelemetry-api/src/trace/span_context.rs

@@ -120,9 +120,9 @@ impl TraceId {
     }
 }
 
-impl From<[u8; 16]> for TraceId {
-    fn from(bytes: [u8; 16]) -> Self {
-        TraceId::from_bytes(bytes)
+impl From<u128> for TraceId {
+    fn from(value: u128) -> Self {
+        TraceId(value)
     }
 }
 
@@ -181,9 +181,9 @@ impl SpanId {
     }
 }
 
-impl From<[u8; 8]> for SpanId {
-    fn from(bytes: [u8; 8]) -> Self {
-        SpanId::from_bytes(bytes)
+impl From<u64> for SpanId {
+    fn from(value: u64) -> Self {
+        SpanId(value)
     }
 }
 

opentelemetry-contrib/src/trace/propagator/binary/binary_propagator.rs

@@ -69,8 +69,8 @@ impl BinaryFormat for BinaryPropagator {
         }
 
         let span_context = SpanContext::new(
-            TraceId::from(trace_id),
-            SpanId::from(span_id),
+            TraceId::from_bytes(trace_id),
+            SpanId::from_bytes(span_id),
             TraceFlags::new(trace_flags),
             true,
             // TODO traceparent and tracestate should both begin with a 0 byte, figure out how to differentiate

opentelemetry-datadog/src/lib.rs

@@ -201,14 +201,14 @@ mod propagator {
         fn extract_trace_id(&self, trace_id: &str) -> Result<TraceId, ExtractError> {
             trace_id
                 .parse::<u64>()
-                .map(|id| TraceId::from((id as u128).to_be_bytes()))
+                .map(|id| TraceId::from(id as u128))
                 .map_err(|_| ExtractError::TraceId)
         }
 
         fn extract_span_id(&self, span_id: &str) -> Result<SpanId, ExtractError> {
             span_id
                 .parse::<u64>()
-                .map(|id| SpanId::from(id.to_be_bytes()))
+                .map(SpanId::from)
                 .map_err(|_| ExtractError::SpanId)
         }
 

opentelemetry-sdk/src/trace/id_generator/mod.rs

@@ -25,11 +25,11 @@ pub struct RandomIdGenerator {
 
 impl IdGenerator for RandomIdGenerator {
     fn new_trace_id(&self) -> TraceId {
-        CURRENT_RNG.with(|rng| TraceId::from(rng.borrow_mut().gen::<[u8; 16]>()))
+        CURRENT_RNG.with(|rng| TraceId::from(rng.borrow_mut().gen::<u128>()))
     }
 
     fn new_span_id(&self) -> SpanId {
-        CURRENT_RNG.with(|rng| SpanId::from(rng.borrow_mut().gen::<[u8; 8]>()))
+        CURRENT_RNG.with(|rng| SpanId::from(rng.borrow_mut().gen::<u64>()))
     }
 }
 

opentelemetry-sdk/src/trace/sampler.rs

@@ -326,7 +326,7 @@ mod tests {
                     None
                 };
 
-                let trace_id = TraceId::from(rng.gen::<[u8; 16]>());
+                let trace_id = TraceId::from(rng.gen::<u128>());
                 if sampler
                     .should_sample(
                         parent_context.as_ref(),