⚡️ Speed up method MiddlewareMixin.__acall__ by 16%

[codeflash-ai]

📄 16% (0.16x) speedup for MiddlewareMixin.__acall__ in django/utils/deprecation.py

⏱️ Runtime : 285 milliseconds → 246 milliseconds (best of 128 runs)

📝 Explanation and details

The optimization implements lazy initialization caching for sync_to_async closures, eliminating repeated overhead on every request.

Key Changes:

• Cached closure creation: Instead of calling sync_to_async() on every __acall__ invocation, the optimization caches the resulting closures as _sync_process_request and _sync_process_response instance attributes after first use.
• Reduced hasattr calls: The original code calls hasattr(self, "process_request") and hasattr(self, "process_response") on every request. The optimized version only performs these checks once during the lazy initialization phase.

Why This Achieves 16% Runtime Speedup:
The line profiler shows the optimization eliminates the most expensive operations:

• Original: Lines calling sync_to_async() consumed 92.3% of total time (48.6% + 43.7%)
• Optimized: The same sync_to_async() calls now only happen during initialization (2.6% + 1.8% = 4.4% total), executed just once per middleware instance instead of every request

Performance Characteristics by Test Case:

• High-volume concurrent requests: The optimization shines when middleware instances handle many requests, as the sync_to_async closure setup cost is amortized across all calls
• Middleware with both process_request and process_response: Maximum benefit since both closures are cached
• Single-request scenarios: Minimal improvement since initialization overhead is still incurred

The throughput remains constant at 146,944 operations/second because the optimization primarily reduces per-request latency rather than changing the fundamental async processing capacity.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	✅ 715 Passed
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	🔘 None Found
📊 Tests Coverage	100.0%

🌀 Generated Regression Tests and Runtime

import asyncio  # used to run async functions
from types import SimpleNamespace

import pytest  # used for our unit tests
# Function to test (copied EXACTLY as provided)
from asgiref.sync import (iscoroutinefunction, markcoroutinefunction,
                          sync_to_async)
from django.utils.deprecation import MiddlewareMixin

# ------------------ UNIT TESTS ------------------

# Helper: Dummy async get_response
async def dummy_get_response(request):
    # Simulate async processing, return something based on request
    return {"response": f"async-{request}"}

# Helper: Dummy async get_response that raises exception
async def dummy_get_response_exception(request):
    raise RuntimeError("get_response error")

# Helper: Dummy async get_response that returns None
async def dummy_get_response_none(request):
    return None

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

@pytest.mark.asyncio
async def test___acall___basic_async_get_response_only():
    """
    Basic: Test __acall__ with async get_response, no process_request/process_response.
    Should return result from get_response.
    """
    mw = MiddlewareMixin(dummy_get_response)
    result = await mw.__acall__("req1")

@pytest.mark.asyncio
async def test___acall___basic_with_process_request_and_response():
    """
    Basic: Test __acall__ with process_request and process_response defined.
    Should execute both and return final response.
    """
    class TestMW(MiddlewareMixin):
        def process_request(self, request):
            return {"process_request": f"pr-{request}"}
        def process_response(self, request, response):
            response["process_response"] = f"ps-{request}"
            return response
    mw = TestMW(dummy_get_response)
    result = await mw.__acall__("req2")
    # get_response is not called because process_request returns non-None

@pytest.mark.asyncio
async def test___acall___basic_with_process_request_none_and_response():
    """
    Basic: process_request returns None, so get_response is used.
    process_response modifies the result.
    """
    class TestMW(MiddlewareMixin):
        def process_request(self, request):
            return None
        def process_response(self, request, response):
            response["process_response"] = f"ps-{request}"
            return response
    mw = TestMW(dummy_get_response)
    result = await mw.__acall__("req3")

@pytest.mark.asyncio
async def test___acall___basic_with_process_response_none():
    """
    Basic: process_response returns None, so should return None.
    """
    class TestMW(MiddlewareMixin):
        def process_response(self, request, response):
            return None
    mw = TestMW(dummy_get_response)
    result = await mw.__acall__("req4")

# ------------------ EDGE TEST CASES ------------------

@pytest.mark.asyncio
async def test___acall___edge_process_request_exception():
    """
    Edge: process_request raises exception, should propagate.
    """
    class TestMW(MiddlewareMixin):
        def process_request(self, request):
            raise RuntimeError("process_request error")
    mw = TestMW(dummy_get_response)
    with pytest.raises(RuntimeError, match="process_request error"):
        await mw.__acall__("req5")

@pytest.mark.asyncio
async def test___acall___edge_process_response_exception():
    """
    Edge: process_response raises exception, should propagate.
    """
    class TestMW(MiddlewareMixin):
        def process_response(self, request, response):
            raise RuntimeError("process_response error")
    mw = TestMW(dummy_get_response)
    with pytest.raises(RuntimeError, match="process_response error"):
        await mw.__acall__("req6")

@pytest.mark.asyncio
async def test___acall___edge_get_response_exception():
    """
    Edge: get_response raises exception, should propagate.
    """
    mw = MiddlewareMixin(dummy_get_response_exception)
    with pytest.raises(RuntimeError, match="get_response error"):
        await mw.__acall__("req7")

@pytest.mark.asyncio
async def test___acall___edge_get_response_none():
    """
    Edge: get_response returns None, process_response not defined.
    Should return None.
    """
    mw = MiddlewareMixin(dummy_get_response_none)
    result = await mw.__acall__("req8")

@pytest.mark.asyncio
async def test___acall___edge_concurrent_execution():
    """
    Edge: Test concurrent execution of __acall__ with multiple requests.
    Should process each independently.
    """
    mw = MiddlewareMixin(dummy_get_response)
    requests = [f"concurrent-{i}" for i in range(10)]
    results = await asyncio.gather(*(mw.__acall__(req) for req in requests))
    for i, result in enumerate(results):
        pass

# ------------------ LARGE SCALE TEST CASES ------------------

@pytest.mark.asyncio
async def test___acall___large_scale_many_concurrent_requests():
    """
    Large Scale: Test __acall__ with many concurrent requests.
    """
    mw = MiddlewareMixin(dummy_get_response)
    requests = [f"large-{i}" for i in range(100)]
    results = await asyncio.gather(*(mw.__acall__(req) for req in requests))
    for i, result in enumerate(results):
        pass

@pytest.mark.asyncio
async def test___acall___large_scale_with_process_request_and_response():
    """
    Large Scale: process_request and process_response defined, many concurrent requests.
    """
    class TestMW(MiddlewareMixin):
        def process_request(self, request):
            return {"process_request": f"pr-{request}"}
        def process_response(self, request, response):
            response["process_response"] = f"ps-{request}"
            return response
    mw = TestMW(dummy_get_response)
    requests = [f"ls-{i}" for i in range(50)]
    results = await asyncio.gather(*(mw.__acall__(req) for req in requests))
    for i, result in enumerate(results):
        pass

# ------------------ THROUGHPUT TEST CASES ------------------

@pytest.mark.asyncio
async def test___acall___throughput_small_load():
    """
    Throughput: Small load, 5 concurrent requests.
    """
    mw = MiddlewareMixin(dummy_get_response)
    requests = [f"small-{i}" for i in range(5)]
    results = await asyncio.gather(*(mw.__acall__(req) for req in requests))
    for i, result in enumerate(results):
        pass

@pytest.mark.asyncio
async def test___acall___throughput_medium_load():
    """
    Throughput: Medium load, 50 concurrent requests.
    """
    mw = MiddlewareMixin(dummy_get_response)
    requests = [f"medium-{i}" for i in range(50)]
    results = await asyncio.gather(*(mw.__acall__(req) for req in requests))
    for i, result in enumerate(results):
        pass

@pytest.mark.asyncio
async def test___acall___throughput_high_load():
    """
    Throughput: High load, 200 concurrent requests.
    """
    mw = MiddlewareMixin(dummy_get_response)
    requests = [f"high-{i}" for i in range(200)]
    results = await asyncio.gather(*(mw.__acall__(req) for req in requests))
    for i, result in enumerate(results):
        pass

@pytest.mark.asyncio
async def test___acall___throughput_with_process_request_and_response():
    """
    Throughput: process_request and process_response defined, 30 concurrent requests.
    """
    class TestMW(MiddlewareMixin):
        def process_request(self, request):
            return {"process_request": f"pr-{request}"}
        def process_response(self, request, response):
            response["process_response"] = f"ps-{request}"
            return response
    mw = TestMW(dummy_get_response)
    requests = [f"tp-{i}" for i in range(30)]
    results = await asyncio.gather(*(mw.__acall__(req) for req in requests))
    for i, result in enumerate(results):
        pass
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.
#------------------------------------------------
import asyncio  # used to run async functions

import pytest  # used for our unit tests
# Function to test (EXACTLY as provided)
from asgiref.sync import (iscoroutinefunction, markcoroutinefunction,
                          sync_to_async)
from django.utils.deprecation import MiddlewareMixin

# ---------------------
# Unit tests for __acall__
# ---------------------

# Helper async get_response function
async def async_get_response(request):
    # Simulate a simple async response
    return f"response:{request}"

# Helper sync get_response function
def sync_get_response(request):
    # Simulate a simple sync response
    return f"response:{request}"

# Helper process_request and process_response for middleware
def process_request(request):
    # Simulate modifying request
    return f"processed:{request}"

def process_response(request, response):
    # Simulate modifying response
    return f"{response}|finalized:{request}"

# Basic Test Case 1: Middleware with only async get_response
@pytest.mark.asyncio
async def test___acall___basic_async_get_response():
    """Test __acall__ with only async get_response"""
    mw = MiddlewareMixin(async_get_response)
    result = await mw.__acall__("req1")

# Basic Test Case 2: Middleware with only sync get_response
@pytest.mark.asyncio

async def test___acall___with_process_request_and_response_sync():
    """Test __acall__ with sync process_request and process_response"""
    class MW(MiddlewareMixin):
        def process_request(self, request):
            return process_request(request)
        def process_response(self, request, response):
            return process_response(request, response)
    mw = MW(async_get_response)
    result = await mw.__acall__("req3")

# Basic Test Case 4: Middleware with process_request returning None, process_response modifies response
@pytest.mark.asyncio
async def test___acall___process_request_none_process_response_sync():
    """Test __acall__ with process_request returning None, process_response modifies response"""
    class MW(MiddlewareMixin):
        def process_request(self, request):
            # returns None, so get_response is called
            return None
        def process_response(self, request, response):
            return process_response(request, response)
    mw = MW(async_get_response)
    result = await mw.__acall__("req4")

# Edge Test Case 1: process_request raises exception
@pytest.mark.asyncio
async def test___acall___process_request_raises_exception():
    """Test __acall__ when process_request raises an exception"""
    class MW(MiddlewareMixin):
        def process_request(self, request):
            raise ValueError("bad request")
    mw = MW(async_get_response)
    with pytest.raises(ValueError):
        await mw.__acall__("req5")

# Edge Test Case 2: process_response raises exception
@pytest.mark.asyncio
async def test___acall___process_response_raises_exception():
    """Test __acall__ when process_response raises an exception"""
    class MW(MiddlewareMixin):
        def process_response(self, request, response):
            raise RuntimeError("bad response")
    mw = MW(async_get_response)
    with pytest.raises(RuntimeError):
        await mw.__acall__("req6")

# Edge Test Case 3: process_request returns falsy value (empty string), get_response is called
@pytest.mark.asyncio
async def test___acall___process_request_returns_empty_string():
    """Test __acall__ when process_request returns empty string (falsy), get_response is called"""
    class MW(MiddlewareMixin):
        def process_request(self, request):
            return ""
    mw = MW(async_get_response)
    result = await mw.__acall__("req7")

# Edge Test Case 4: process_response returns None, should return get_response's output
@pytest.mark.asyncio
async def test___acall___process_response_returns_none():
    """Test __acall__ when process_response returns None"""
    class MW(MiddlewareMixin):
        def process_response(self, request, response):
            return None
    mw = MW(async_get_response)
    result = await mw.__acall__("req8")

# Edge Test Case 5: Middleware with async process_request and process_response
@pytest.mark.asyncio

async def test___acall___large_scale_concurrent_requests():
    """Test __acall__ with many concurrent requests"""
    mw = MiddlewareMixin(async_get_response)
    requests = [f"req{i}" for i in range(50)]  # 50 concurrent requests
    results = await asyncio.gather(*(mw.__acall__(req) for req in requests))
    for i, result in enumerate(results):
        pass

# Large Scale Test Case 2: Multiple concurrent requests with process_request and process_response
@pytest.mark.asyncio
async def test___acall___large_scale_concurrent_requests_with_processing():
    """Test __acall__ with many concurrent requests and processing"""
    class MW(MiddlewareMixin):
        def process_request(self, request):
            return process_request(request)
        def process_response(self, request, response):
            return process_response(request, response)
    mw = MW(async_get_response)
    requests = [f"req{i}" for i in range(20)]  # 20 concurrent requests
    results = await asyncio.gather(*(mw.__acall__(req) for req in requests))
    for i, result in enumerate(results):
        pass

# Large Scale Test Case 3: Middleware with sync get_response, concurrent requests
@pytest.mark.asyncio

async def test___acall___throughput_small_load():
    """Test throughput with small load (10 requests)"""
    mw = MiddlewareMixin(async_get_response)
    requests = [f"req{i}" for i in range(10)]
    results = await asyncio.gather(*(mw.__acall__(req) for req in requests))

# Throughput Test Case 2: Medium load
@pytest.mark.asyncio
async def test___acall___throughput_medium_load():
    """Test throughput with medium load (100 requests)"""
    mw = MiddlewareMixin(async_get_response)
    requests = [f"req{i}" for i in range(100)]
    results = await asyncio.gather(*(mw.__acall__(req) for req in requests))

# Throughput Test Case 3: With process_request and process_response under load
@pytest.mark.asyncio
async def test___acall___throughput_with_processing():
    """Test throughput with process_request and process_response under load (40 requests)"""
    class MW(MiddlewareMixin):
        def process_request(self, request):
            return process_request(request)
        def process_response(self, request, response):
            return process_response(request, response)
    mw = MW(async_get_response)
    requests = [f"req{i}" for i in range(40)]
    results = await asyncio.gather(*(mw.__acall__(req) for req in requests))
    for i, result in enumerate(results):
        pass

# Throughput Test Case 4: High volume with sync get_response
@pytest.mark.asyncio

async def test___acall___no_process_methods():
    """Test __acall__ when only get_response is present"""
    mw = MiddlewareMixin(async_get_response)
    result = await mw.__acall__("req10")

# Edge Test Case 7: process_request returns None and process_response returns None
@pytest.mark.asyncio
async def test___acall___process_methods_return_none():
    """Test __acall__ when both process_request and process_response return None"""
    class MW(MiddlewareMixin):
        def process_request(self, request):
            return None
        def process_response(self, request, response):
            return None
    mw = MW(async_get_response)
    result = await mw.__acall__("req11")

# Edge Test Case 8: process_request returns object, process_response returns object
@pytest.mark.asyncio
async def test___acall___process_methods_return_object():
    """Test __acall__ when process_request and process_response return custom objects"""
    class CustomResponse:
        def __init__(self, value):
            self.value = value
        def __eq__(self, other):
            return isinstance(other, CustomResponse) and self.value == other.value
    class MW(MiddlewareMixin):
        def process_request(self, request):
            return CustomResponse(f"custom:{request}")
        def process_response(self, request, response):
            return CustomResponse(f"{response.value}|finalized:{request}")
    mw = MW(async_get_response)
    result = await mw.__acall__("req12")

# Edge Test Case 9: process_request returns False, get_response is called
@pytest.mark.asyncio
async def test___acall___process_request_returns_false():
    """Test __acall__ when process_request returns False (falsy), get_response is called"""
    class MW(MiddlewareMixin):
        def process_request(self, request):
            return False
    mw = MW(async_get_response)
    result = await mw.__acall__("req13")
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.

To edit these changes git checkout codeflash/optimize-MiddlewareMixin.__acall__-mh6pebke and push.