⚡️ Speed up function some_api_call by 48%

[codeflash-ai]

📄 48% (0.48x) speedup for some_api_call in code_to_optimize/async_examples/concurrency.py

⏱️ Runtime : 31.3 seconds → 21.2 seconds (best of 5 runs)

📝 Explanation and details

The optimization transforms sequential async execution into concurrent execution using asyncio.gather().

Key Changes:

• Original: Awaits each fake_api_call one at a time in a loop, creating a sequential bottleneck
• Optimized: Creates all tasks upfront in a list comprehension, then uses asyncio.gather(*tasks) to run them concurrently

Why This is Faster:
The original code has a fundamental async anti-pattern - it waits for each API call to complete before starting the next one, negating the benefits of async programming. With random delays of 0.5-2.0 seconds per call, the total runtime grows linearly with the number of URLs.

The optimized version leverages async concurrency properly by:

1. Creating all coroutine tasks immediately (no blocking)
2. Using asyncio.gather() to execute them simultaneously
3. Waiting only for the slowest task to complete, not the sum of all tasks

Performance Impact:

• 47% speedup demonstrates the power of proper async concurrency
• Line profiler shows the optimized version processes many more calls (1030 vs 45 hits) in similar total time, indicating concurrent execution
• Most effective for workloads with multiple I/O-bound operations that can run independently

Test Case Performance:
This optimization excels with larger URL lists where the concurrent execution advantage multiplies, while maintaining identical correctness for all edge cases including empty lists, special characters, and mixed data types.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	✅ 18 Passed
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	🔘 None Found
📊 Tests Coverage	100.0%

🌀 Generated Regression Tests and Runtime

import asyncio
# function to test
import random

# imports
import pytest  # used for our unit tests
from code_to_optimize.async_examples.concurrency import some_api_call

# unit tests

# Helper to run async tests with pytest
def run_async(coro):
    return asyncio.get_event_loop().run_until_complete(coro)

# ---------- BASIC TEST CASES ----------















def test_error_handling_non_iterable():
    # Test with a non-iterable input (should raise TypeError)
    with pytest.raises(TypeError):
        run_async(some_api_call(None))


#------------------------------------------------
import asyncio
# function to test
import random

# imports
import pytest  # used for our unit tests
from code_to_optimize.async_examples.concurrency import some_api_call

# unit tests

@pytest.mark.asyncio
@pytest.mark.parametrize(
    "input_urls,expected",
    [
        # Basic case: single URL
        (["http://example.com"], ["Processed: http://example.com"]),
        # Basic case: multiple URLs
        (
            ["http://a.com", "http://b.com"],
            ["Processed: http://a.com", "Processed: http://b.com"],
        ),
        # Basic case: empty list
        ([], []),
        # Basic case: URLs with query params
        (
            ["http://site.com?x=1", "https://test.org/path"],
            ["Processed: http://site.com?x=1", "Processed: https://test.org/path"],
        ),
    ],
)
async def test_some_api_call_basic(input_urls, expected):
    # Test basic expected behavior for various normal inputs
    result = await some_api_call(input_urls)

@pytest.mark.asyncio
async def test_some_api_call_edge_empty_string():
    # Edge case: URLs with empty string
    input_urls = [""]
    expected = ["Processed: "]
    result = await some_api_call(input_urls)

@pytest.mark.asyncio
async def test_some_api_call_edge_non_str():
    # Edge case: URLs with non-string types
    input_urls = [123, None, True, 45.6]
    expected = [
        "Processed: 123",
        "Processed: None",
        "Processed: True",
        "Processed: 45.6",
    ]
    result = await some_api_call(input_urls)

@pytest.mark.asyncio
async def test_some_api_call_edge_special_chars():
    # Edge case: URLs with special characters
    input_urls = ["http://weird.com/!@#$%^&*()_+", "中文.com", "http://[::1]"]
    expected = [
        "Processed: http://weird.com/!@#$%^&*()_+",
        "Processed: 中文.com",
        "Processed: http://[::1]",
    ]
    result = await some_api_call(input_urls)

@pytest.mark.asyncio
async def test_some_api_call_edge_duplicates():
    # Edge case: Duplicate URLs
    input_urls = ["http://dup.com", "http://dup.com"]
    expected = ["Processed: http://dup.com", "Processed: http://dup.com"]
    result = await some_api_call(input_urls)

@pytest.mark.asyncio
async def test_some_api_call_edge_long_string():
    # Edge case: Very long URL string
    long_url = "http://example.com/" + "a" * 500
    input_urls = [long_url]
    expected = [f"Processed: {long_url}"]
    result = await some_api_call(input_urls)

@pytest.mark.asyncio
async def test_some_api_call_edge_mixed_types():
    # Edge case: Mixed valid and invalid types
    input_urls = ["http://valid.com", None, 42]
    expected = [
        "Processed: http://valid.com",
        "Processed: None",
        "Processed: 42",
    ]
    result = await some_api_call(input_urls)

@pytest.mark.asyncio
async def test_some_api_call_edge_nested_list():
    # Edge case: Nested list as input (should be processed as string)
    input_urls = [["http://nested.com"], {"url": "http://dict.com"}]
    expected = [
        "Processed: ['http://nested.com']",
        "Processed: {'url': 'http://dict.com'}",
    ]
    result = await some_api_call(input_urls)

@pytest.mark.asyncio
async

To edit these changes git checkout codeflash/optimize-some_api_call-me39pf17 and push.