chore(tracer): tighten v1 comments

Author: Leiyks

components-rs/agent_info.rs

@@ -96,9 +96,8 @@ pub extern "C" fn ddog_agent_info_json_free(ptr: *mut c_char) {
     }
 }
 
-/// Returns true when the agent /info `endpoints` list advertises `endpoint`
-/// (e.g. `/v1.0/traces`).  Returns false when no info has been received yet, so the
-/// caller safely treats "agent info unknown" as "endpoint not advertised".
+/// Returns whether the agent /info `endpoints` list advertises `endpoint` (e.g. `/v1.0/traces`);
+/// false when no info has been received yet ("unknown" == "not advertised").
 ///
 /// # Safety
 /// `reader` must be a valid pointer to an `AgentInfoReader`.

tracer/auto_flush.c

@@ -69,10 +69,8 @@ ZEND_RESULT_CODE ddtrace_flush_tracer(bool force_on_startup, bool collect_cycles
                 .buffer_size = get_global_DD_TRACE_BUFFER_SIZE(),
                 .url = (ddog_CharSlice) {.ptr = url, .len = strlen(url)},
             };
-            // V1 wire (POST /v1.0/traces) is used only when BOTH the config resolves to
-            // "1"/"1.0" AND the agent /info advertises "/v1.0/traces". Otherwise (default
-            // "0.4", explicit 1.0 but agent doesn't advertise it, or agent info not yet
-            // known) fall back to the unchanged V0.4 path -- the safe default.
+            // Use the V1 wire only when the protocol config is "1"/"1.0" AND the agent /info
+            // advertises "/v1.0/traces"; otherwise fall back to the default V0.4 path.
             zend_string *protocol_version = get_global_DD_TRACE_AGENT_PROTOCOL_VERSION();
             bool use_v1 = (zend_string_equals_literal(protocol_version, "1") ||
                            zend_string_equals_literal(protocol_version, "1.0")) &&

tracer/dogstatsd_client.c

@@ -1,4 +1,3 @@
-// TODO: remove this file and put it in the sidecar.
 #include "dogstatsd_client.h"
 
 #include <dogstatsd_client/client.h>

tracer/serializer.c

@@ -1089,17 +1089,15 @@ static void dd_serialize_span_events(zend_array *events, smart_str *buf) {
 }
 
 // --- Native V1 span links/events (DD_TRACE_AGENT_PROTOCOL_VERSION=1/1.0) ---
-// On the V1 wire, links/events are emitted into libdatadog's native span structures
-// (span_links field 11, span_events field 12) rather than the JSON-in-meta V0.4 form.
+// On the V1 wire these go into libdatadog's native span structures, not the V0.4 JSON-in-meta form.
 
 static bool dd_v1_native_span_enabled(void) {
     zend_string *pv = get_global_DD_TRACE_AGENT_PROTOCOL_VERSION();
     return zend_string_equals_literal(pv, "1") || zend_string_equals_literal(pv, "1.0");
 }
 
-// Emit each SpanLink into the native span. trace_id/span_id are hex strings; the V1 link
-// wire has no flags source on the PHP side and no dropped_attributes_count field, so both
-// are omitted. Link attributes are a string map.
+// Emit each SpanLink into the native span. The V1 link wire omits flags and
+// dropped_attributes_count (no PHP-side source); attributes are a string map.
 static void dd_span_links_to_native(zend_array *links, ddog_SpanBytes *rust_span) {
     zval *val;
     ZEND_HASH_FOREACH_VAL(links, val) {
@@ -1143,7 +1141,6 @@ static void dd_span_links_to_native(zend_array *links, ddog_SpanBytes *rust_span
     } ZEND_HASH_FOREACH_END();
 }
 
-// Dispatch a single event attribute to the typed native setter based on its zval type.
 static void dd_event_attribute_to_native(ddog_SpanEventBytes *event, ddog_CharSlice key, zval *val) {
     ZVAL_DEREF(val);
     switch (Z_TYPE_P(val)) {