Skip loggable operation copy when slow-request collector is off

remove_details deep-copies every update operation (per named vector: a
String clone, a small Vec alloc, and a SipHash insert into a fresh
HashMap) before the update runs, only to feed the slow-request
collector. When the collector was never initialized this work is pure
overhead on every update; it showed up as a top CPU consumer in
model_testing profiles.

Build the loggable copy only when the collector is initialized.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

lib/collection/src/profiling/interface.rs

@@ -8,6 +8,13 @@ use crate::profiling::slow_requests_log::LogEntry;
 static REQUESTS_COLLECTOR: OnceCell<crate::profiling::slow_requests_collector::RequestsCollector> =
     OnceCell::const_new();
 
+/// Whether the requests profile collector has been initialized.
+///
+/// Allows callers to skip building loggable copies of requests when profiling is disabled.
+pub fn is_requests_profile_collector_initialized() -> bool {
+    REQUESTS_COLLECTOR.get().is_some()
+}
+
 /// This function should be used to log request profiles into the shared log structure.
 /// This structure is later can be read via API.
 pub fn log_request_to_collector<F, L>(

lib/collection/src/update_workers/update_worker.rs

@@ -13,7 +13,9 @@ use tokio_util::task::AbortOnDropHandle;
 use crate::collection_manager::collection_updater::CollectionUpdater;
 use crate::operations::generalizer::Generalizer;
 use crate::operations::types::{CollectionError, CollectionResult, UpdateStatus};
-use crate::profiling::interface::log_request_to_collector;
+use crate::profiling::interface::{
+    is_requests_profile_collector_initialized, log_request_to_collector,
+};
 use crate::shards::CollectionId;
 use crate::shards::update_tracker::UpdateTracker;
 use crate::update_handler::{OperationData, OptimizerSignal, UpdateSignal};
@@ -326,7 +328,8 @@ impl UpdateWorkers {
 
         // This represents the operation without vectors and payloads for logging purposes
         // Do not use for anything else
-        let loggable_operation = operation.remove_details();
+        let loggable_operation =
+            is_requests_profile_collector_initialized().then(|| operation.remove_details());
 
         let cpu_utilization = hw_measurements.cpu_utilization();
 
@@ -349,9 +352,11 @@ impl UpdateWorkers {
             None
         };
 
-        log_request_to_collector(&collection_name, duration, cpu_usage_ratio, move || {
-            loggable_operation
-        });
+        if let Some(loggable_operation) = loggable_operation {
+            log_request_to_collector(&collection_name, duration, cpu_usage_ratio, move || {
+                loggable_operation
+            });
+        }
 
         result
     }