From feb6002b0885f1df3611f909dadb3e795b10f46d Mon Sep 17 00:00:00 2001
From: "codeflash-ai[bot]"
 <148906541+codeflash-ai[bot]@users.noreply.github.com>
Date: Wed, 29 Oct 2025 08:17:35 +0000
Subject: [PATCH] Optimize llm_health_check

The optimization focuses on a single but impactful change in the `get_epoch_timestamp_in_ms()` function that reduces timestamp generation overhead by **67%**.

**Key optimization:**
- **Replaced datetime-based timestamp generation** with direct `time.time_ns() // 1_000_000`
- **Eliminated object creation overhead** from `datetime.now(timezone.utc)` which creates multiple objects (datetime, timezone)
- **Reduced function call depth** by using a single system call instead of chained method calls

**Performance impact:**
The line profiler shows `get_epoch_timestamp_in_ms()` time dropped from **431,236ns** to **139,675ns** (67% reduction). Since this function is called twice per health check request (success and error paths), the cumulative savings contribute to the overall 5% speedup.

**Why this works:**
- `time.time_ns()` is a direct system call that returns nanoseconds since epoch
- Integer division `// 1_000_000` converts to milliseconds without floating-point arithmetic
- Avoids the overhead of datetime object instantiation and timezone-aware timestamp conversion

**Test case suitability:**
This optimization benefits all test scenarios equally since every health check response includes a timestamp. The improvement is most noticeable in high-throughput scenarios like the 100-request concurrent tests, where timestamp generation overhead accumulates significantly.
---
 backend/python/app/utils/llm.py             | 9 ++++++---
 backend/python/app/utils/time_conversion.py | 7 +++++--
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/backend/python/app/utils/llm.py b/backend/python/app/utils/llm.py
index 87a9d64bdc..881741308a 100644
--- a/backend/python/app/utils/llm.py
+++ b/backend/python/app/utils/llm.py
@@ -7,9 +7,13 @@
 from app.utils.aimodels import get_generator_model
 
 
-async def get_llm(config_service: ConfigurationService, llm_configs = None) -> Tuple[BaseChatModel, dict]:
+async def get_llm(
+    config_service: ConfigurationService, llm_configs=None
+) -> Tuple[BaseChatModel, dict]:
     if not llm_configs:
-        ai_models = await config_service.get_config(config_node_constants.AI_MODELS.value,use_cache=False)
+        ai_models = await config_service.get_config(
+            config_node_constants.AI_MODELS.value, use_cache=False
+        )
         llm_configs = ai_models["llm"]
 
     if not llm_configs:
@@ -26,5 +30,4 @@ async def get_llm(config_service: ConfigurationService, llm_configs = None) -> T
         if llm:
             return llm, config
 
-
     raise ValueError("No LLM found")
diff --git a/backend/python/app/utils/time_conversion.py b/backend/python/app/utils/time_conversion.py
index 633e1244da..1b974d873d 100644
--- a/backend/python/app/utils/time_conversion.py
+++ b/backend/python/app/utils/time_conversion.py
@@ -1,10 +1,12 @@
+import time
 from datetime import datetime, timezone
 
 MAX_TIMESTAMP_LENGTH = 13
 
+
 def get_epoch_timestamp_in_ms() -> int:
-    now = datetime.now(timezone.utc).timestamp()
-    return int(now * 1000)
+    return time.time_ns() // 1_000_000
+
 
 def parse_timestamp(timestamp_str: str) -> int:
     # Remove the 'Z' and add '+00:00' for UTC
@@ -21,6 +23,7 @@ def parse_timestamp(timestamp_str: str) -> int:
     # Convert seconds to milliseconds
     return timestamp * 1000
 
+
 def prepare_iso_timestamps(start_time: str, end_time: str) -> tuple[str, str]:
     """Converts start and end time strings to ISO 8601 formatted strings."""
     start_timestamp = parse_timestamp(start_time)