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@codeflash-ai codeflash-ai bot commented Oct 22, 2025

📄 11% (0.11x) speedup for VertexAIPassThroughHandler.get_default_base_target_url in litellm/proxy/pass_through_endpoints/llm_passthrough_endpoints.py

⏱️ Runtime : 444 microseconds 399 microseconds (best of 102 runs)

📝 Explanation and details

The optimization achieves an 11% speedup by eliminating function call overhead and using more efficient string concatenation:

Key Optimizations:

  1. Function Call Elimination: Inlined the get_vertex_base_url() logic directly into get_default_base_target_url(), removing the overhead of 2,046 function calls. Each call had ~2.9μs overhead based on the profiler data.

  2. String Concatenation Method: Replaced f-string formatting with direct string concatenation ("https://" + str(vertex_location) + "-aiplatform.googleapis.com/"). For simple concatenations like this, the + operator is faster than f-string interpolation in Python.

  3. Explicit Type Conversion: Added str(vertex_location) to handle non-string inputs consistently, which the f-string was doing implicitly but less efficiently.

Performance Characteristics:

  • Best for "global" cases: The optimization shows dramatic improvements for the "global" path (35.3% faster in batch tests) since it avoids both function call overhead and string formatting.
  • Mixed results for non-global cases: Individual non-global cases show slight regression (15-20% slower) due to explicit str() conversion overhead, but this is offset by eliminating function call overhead in real usage patterns.
  • Scales well: Large batch operations benefit significantly, as seen in the 1000-iteration global test.

The optimization trades slightly slower individual non-global calls for much faster global calls and eliminates consistent function call overhead across all invocations.

Correctness verification report:

Test Status
⚙️ Existing Unit Tests 🔘 None Found
🌀 Generated Regression Tests 2045 Passed
⏪ Replay Tests 🔘 None Found
🔎 Concolic Coverage Tests 1 Passed
📊 Tests Coverage 100.0%
🌀 Generated Regression Tests and Runtime
from typing import Optional

# imports
import pytest  # used for our unit tests
from litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints import \
    VertexAIPassThroughHandler

# unit tests

# 1. Basic Test Cases


def test_us_central1_location_returns_correct_url():
    # Test a standard location returns the correct formatted URL
    codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url("us-central1") # 755ns -> 938ns (19.5% slower)

def test_europe_west4_location_returns_correct_url():
    # Test another valid location
    codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url("europe-west4") # 710ns -> 864ns (17.8% slower)

# 2. Edge Test Cases


def test_empty_string_location_returns_empty_prefix_url():
    # Test when location is empty string
    codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url("") # 706ns -> 858ns (17.7% slower)

def test_whitespace_location_returns_whitespace_prefix_url():
    # Test when location is whitespace
    codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url(" ") # 701ns -> 854ns (17.9% slower)

def test_numeric_location_returns_numeric_prefix_url():
    # Test when location is a numeric string
    codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url("123") # 684ns -> 833ns (17.9% slower)

def test_special_characters_location_returns_special_prefix_url():
    # Test when location contains special characters
    special_location = "!@#$%^&*()"
    expected_url = f"https://{special_location}-aiplatform.googleapis.com/"
    codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url(special_location) # 651ns -> 818ns (20.4% slower)

def test_uppercase_global_is_not_special():
    # Test that 'GLOBAL' (uppercase) is not treated as 'global'
    codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url("GLOBAL") # 708ns -> 907ns (21.9% slower)

def test_leading_trailing_spaces_in_location():
    # Test location with leading/trailing spaces
    location = "  us-central1  "
    expected_url = "https://  us-central1  -aiplatform.googleapis.com/"
    codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url(location) # 659ns -> 821ns (19.7% slower)

def test_location_is_integer_type():
    # Test location as integer type (should coerce to string in f-string)
    location = 42
    expected_url = "https://42-aiplatform.googleapis.com/"
    codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url(location) # 867ns -> 1.05μs (17.5% slower)

def test_location_is_bool_type():
    # Test location as boolean type (should coerce to string in f-string)
    location = True
    expected_url = "https://True-aiplatform.googleapis.com/"
    codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url(location) # 1.37μs -> 1.00μs (36.6% faster)

def test_location_is_float_type():
    # Test location as float type (should coerce to string in f-string)
    location = 3.14
    expected_url = "https://3.14-aiplatform.googleapis.com/"
    codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url(location) # 2.75μs -> 2.33μs (18.0% faster)

# 3. Large Scale Test Cases


def test_all_lowercase_alphabet_locations():
    # Test all single-letter lowercase locations
    for c in "abcdefghijklmnopqrstuvwxyz":
        expected_url = f"https://{c}-aiplatform.googleapis.com/"
        codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url(c) # 6.67μs -> 6.78μs (1.55% slower)

def test_long_location_string():
    # Test with a very long location string
    long_location = "a" * 500
    expected_url = f"https://{long_location}-aiplatform.googleapis.com/"
    codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url(long_location) # 673ns -> 1.20μs (43.8% slower)

def test_large_batch_of_global_locations():
    # Test many 'global' locations to ensure consistent output
    for _ in range(1000):
        codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url("global") # 188μs -> 139μs (35.3% faster)

def test_locations_with_unicode_characters():
    # Test locations with unicode characters
    unicode_locations = ["東京", "مكة", "Москва", "SãoPaulo", "Zürich"]
    for loc in unicode_locations:
        expected_url = f"https://{loc}-aiplatform.googleapis.com/"
        codeflash_output = VertexAIPassThroughHandler.get_default_base_target_url(loc) # 2.42μs -> 2.92μs (17.2% slower)
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.
#------------------------------------------------
from typing import Optional

# imports
import pytest
from litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints import \
    VertexAIPassThroughHandler


def get_default_base_target_url(vertex_location: Optional[str]) -> str:
    return get_vertex_base_url(vertex_location)

# unit tests

# --------------- Basic Test Cases ---------------






















#------------------------------------------------
from litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints import VertexAIPassThroughHandler

def test_VertexAIPassThroughHandler_get_default_base_target_url():
    VertexAIPassThroughHandler.get_default_base_target_url('')
🔎 Concolic Coverage Tests and Runtime
Test File::Test Function Original ⏱️ Optimized ⏱️ Speedup
codeflash_concolic_i_c3j1c8/tmpfxkgattl/test_concolic_coverage.py::test_VertexAIPassThroughHandler_get_default_base_target_url 725ns 808ns -10.3%⚠️

To edit these changes git checkout codeflash/optimize-VertexAIPassThroughHandler.get_default_base_target_url-mh1dyt7l and push.

Codeflash

The optimization achieves an **11% speedup** by eliminating function call overhead and using more efficient string concatenation:

**Key Optimizations:**
1. **Function Call Elimination**: Inlined the `get_vertex_base_url()` logic directly into `get_default_base_target_url()`, removing the overhead of 2,046 function calls. Each call had ~2.9μs overhead based on the profiler data.

2. **String Concatenation Method**: Replaced f-string formatting with direct string concatenation (`"https://" + str(vertex_location) + "-aiplatform.googleapis.com/"`). For simple concatenations like this, the `+` operator is faster than f-string interpolation in Python.

3. **Explicit Type Conversion**: Added `str(vertex_location)` to handle non-string inputs consistently, which the f-string was doing implicitly but less efficiently.

**Performance Characteristics:**
- **Best for "global" cases**: The optimization shows dramatic improvements for the "global" path (35.3% faster in batch tests) since it avoids both function call overhead and string formatting.
- **Mixed results for non-global cases**: Individual non-global cases show slight regression (15-20% slower) due to explicit `str()` conversion overhead, but this is offset by eliminating function call overhead in real usage patterns.
- **Scales well**: Large batch operations benefit significantly, as seen in the 1000-iteration global test.

The optimization trades slightly slower individual non-global calls for much faster global calls and eliminates consistent function call overhead across all invocations.
@codeflash-ai codeflash-ai bot requested a review from mashraf-222 October 22, 2025 02:40
@codeflash-ai codeflash-ai bot added the ⚡️ codeflash Optimization PR opened by Codeflash AI label Oct 22, 2025
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