⚡️ Speed up method SyncConversationCursorPage._get_page_items by 23%

[codeflash-ai]

📄 23% (0.23x) speedup for SyncConversationCursorPage._get_page_items in src/openai/pagination.py

⏱️ Runtime : 16.5 microseconds → 13.4 microseconds (best of 106 runs)

📝 Explanation and details

The optimized code eliminates an unnecessary conditional check and variable assignment. The original code first assigns self.data to a local variable data, then checks if it's falsy (if not data:), and returns either an empty list [] or the data itself.

The key insight is that according to the class definition, self.data is typed as List[_T], meaning it's always a list. When a list is empty, returning [] vs returning the empty list itself produces the same result but with different performance characteristics.

Specific optimizations:

1. Removed unnecessary variable assignment: Eliminates the data = self.data line that creates a local reference
2. Removed conditional check: Eliminates the if not data: check and early return
3. Direct return: Simply returns self.data directly

Why this is faster:

• Fewer operations: Reduces from 3-4 operations down to 1 (just the return statement)
• No branching: Eliminates the conditional branch that adds CPU overhead
• No extra allocation: For empty lists, avoids creating a new [] object

The test results show consistent speedups across all scenarios:

• Empty collections: 28-40% faster (biggest gains since they avoid the unnecessary [] allocation)
• Non-empty collections: 10-35% faster (benefit from eliminating the conditional check)
• Large datasets: 17-30% faster (showing the optimization scales well)

This optimization is particularly effective for pagination scenarios where empty pages are common, as it eliminates both the conditional overhead and unnecessary empty list creation.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	✅ 70 Passed
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	🔘 None Found
📊 Tests Coverage	100.0%

🌀 Generated Regression Tests and Runtime

from typing import Generic, List, Optional, TypeVar

# imports
import pytest  # used for our unit tests
from openai.pagination import SyncConversationCursorPage

# function to test
_T = TypeVar("_T")

class BasePage(Generic[_T]):
    pass

class BaseSyncPage(Generic[_T]):
    pass
from openai.pagination import SyncConversationCursorPage

# unit tests

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

def test_basic_non_empty_list():
    # Should return the same list if data is a non-empty list
    page = SyncConversationCursorPage(data=[1, 2, 3])
    codeflash_output = page._get_page_items() # 445ns -> 397ns (12.1% faster)

def test_basic_empty_list():
    # Should return an empty list if data is an empty list
    page = SyncConversationCursorPage(data=[])
    codeflash_output = page._get_page_items() # 469ns -> 365ns (28.5% faster)


def test_basic_string_items():
    # Should work with lists of strings
    page = SyncConversationCursorPage(data=["a", "b", "c"])
    codeflash_output = page._get_page_items() # 552ns -> 488ns (13.1% faster)

def test_basic_mixed_types():
    # Should work with lists of mixed types
    page = SyncConversationCursorPage(data=[1, "two", 3.0])
    codeflash_output = page._get_page_items() # 460ns -> 370ns (24.3% faster)

# -------------------- Edge Test Cases --------------------

def test_edge_single_item_list():
    # Should return the single item in a list
    page = SyncConversationCursorPage(data=[42])
    codeflash_output = page._get_page_items() # 490ns -> 362ns (35.4% faster)

def test_edge_data_is_falsey_but_not_none_or_list():
    # Should return [] if data is None, but NOT if data is [0], [False], etc.
    page = SyncConversationCursorPage(data=[0])
    codeflash_output = page._get_page_items() # 460ns -> 329ns (39.8% faster)
    page = SyncConversationCursorPage(data=[False])
    codeflash_output = page._get_page_items() # 209ns -> 163ns (28.2% faster)
    page = SyncConversationCursorPage(data=[None])
    codeflash_output = page._get_page_items() # 173ns -> 157ns (10.2% faster)

def test_edge_data_is_tuple():
    # Should fail if data is a tuple, since the function expects a list or None
    # But the function doesn't check type, so it will return the tuple
    page = SyncConversationCursorPage(data=(1, 2, 3))  # type: ignore
    codeflash_output = page._get_page_items() # 398ns -> 326ns (22.1% faster)

def test_edge_data_is_empty_tuple():
    # Should return [] if data is an empty tuple (since not data is True for empty tuple)
    page = SyncConversationCursorPage(data=())  # type: ignore
    codeflash_output = page._get_page_items() # 437ns -> 320ns (36.6% faster)

def test_edge_data_is_set():
    # Should return the set if data is a non-empty set
    page = SyncConversationCursorPage(data={1, 2, 3})  # type: ignore
    codeflash_output = page._get_page_items() # 400ns -> 320ns (25.0% faster)

def test_edge_data_is_empty_set():
    # Should return [] if data is an empty set
    page = SyncConversationCursorPage(data=set())  # type: ignore
    codeflash_output = page._get_page_items() # 465ns -> 335ns (38.8% faster)






def test_edge_data_is_object_with_len_and_iter():
    # Should return the object if it is non-empty and has __len__ and __iter__
    class Custom:
        def __len__(self): return 1
        def __iter__(self): return iter([42])
    obj = Custom()
    page = SyncConversationCursorPage(data=obj)  # type: ignore
    codeflash_output = page._get_page_items() # 547ns -> 493ns (11.0% faster)

def test_edge_data_is_object_with_len_zero():
    # Should return [] if the object has __len__ returning 0
    class Custom:
        def __len__(self): return 0
        def __iter__(self): return iter([])
    obj = Custom()
    page = SyncConversationCursorPage(data=obj)  # type: ignore
    codeflash_output = page._get_page_items() # 485ns -> 409ns (18.6% faster)

# -------------------- Large Scale Test Cases --------------------

def test_large_list_of_ints():
    # Should return the same large list
    large_data = list(range(1000))
    page = SyncConversationCursorPage(data=large_data)
    codeflash_output = page._get_page_items() # 488ns -> 405ns (20.5% faster)

def test_large_list_of_strings():
    # Should return the same large list of strings
    large_data = [str(i) for i in range(1000)]
    page = SyncConversationCursorPage(data=large_data)
    codeflash_output = page._get_page_items() # 458ns -> 356ns (28.7% faster)

def test_large_list_of_objects():
    # Should return the same large list of custom objects
    class Dummy:
        def __init__(self, x): self.x = x
        def __eq__(self, other): return isinstance(other, Dummy) and self.x == other.x
        def __repr__(self): return f"Dummy({self.x})"
    large_data = [Dummy(i) for i in range(1000)]
    page = SyncConversationCursorPage(data=large_data)
    codeflash_output = page._get_page_items() # 491ns -> 398ns (23.4% faster)

def test_large_empty_list():
    # Should return an empty list for a large empty list
    page = SyncConversationCursorPage(data=[])
    codeflash_output = page._get_page_items() # 451ns -> 392ns (15.1% faster)


def test_mutation_of_returned_list_does_not_affect_original():
    # Should return the same list object, so mutation affects original
    data = [1, 2, 3]
    page = SyncConversationCursorPage(data=data)
    codeflash_output = page._get_page_items(); items = codeflash_output # 533ns -> 476ns (12.0% faster)
    items.append(4)


def test_returned_empty_list_is_new_object_for_empty_list():
    # Should return the same empty list object if data is []
    page = SyncConversationCursorPage(data=[])
    codeflash_output = page._get_page_items(); items = codeflash_output # 541ns -> 493ns (9.74% faster)
    items.append(1)

def test_returned_empty_list_is_new_object_for_empty_tuple():
    # Should return a new empty list if data is an empty tuple
    page = SyncConversationCursorPage(data=())  # type: ignore
    codeflash_output = page._get_page_items(); items = codeflash_output # 515ns -> 369ns (39.6% faster)
    items.append(1)
# 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 Generic, List, Optional, TypeVar

# imports
import pytest  # used for our unit tests
from openai.pagination import SyncConversationCursorPage

# function to test
_T = TypeVar("_T")

class BasePage(Generic[_T]):
    pass

class BaseSyncPage(Generic[_T]):
    pass
from openai.pagination import SyncConversationCursorPage

# unit tests

# 1. Basic Test Cases

def test_basic_non_empty_list():
    # Test with a simple non-empty list
    page = SyncConversationCursorPage(data=[1, 2, 3])
    codeflash_output = page._get_page_items(); result = codeflash_output # 489ns -> 368ns (32.9% faster)

def test_basic_empty_list():
    # Test with an empty list
    page = SyncConversationCursorPage(data=[])
    codeflash_output = page._get_page_items(); result = codeflash_output # 440ns -> 358ns (22.9% faster)


def test_basic_various_types():
    # Test with data containing different types
    page = SyncConversationCursorPage(data=["a", 2, 3.0, None])
    codeflash_output = page._get_page_items(); result = codeflash_output # 565ns -> 490ns (15.3% faster)

def test_basic_has_more_and_last_id_ignored():
    # Ensure has_more and last_id don't affect output
    page = SyncConversationCursorPage(data=[1, 2], has_more=True, last_id="abc")
    codeflash_output = page._get_page_items(); result = codeflash_output # 487ns -> 374ns (30.2% faster)

# 2. Edge Test Cases

def test_edge_single_element_list():
    # Test with a single element list
    page = SyncConversationCursorPage(data=[42])
    codeflash_output = page._get_page_items(); result = codeflash_output # 461ns -> 363ns (27.0% faster)


def test_edge_data_is_tuple():
    # Test with data as a tuple (should be treated as falsy and return [])
    page = SyncConversationCursorPage(data=())
    codeflash_output = page._get_page_items(); result = codeflash_output # 545ns -> 478ns (14.0% faster)

def test_edge_data_is_set():
    # Test with data as a set (should be treated as falsy and return [])
    page = SyncConversationCursorPage(data=set())
    codeflash_output = page._get_page_items(); result = codeflash_output # 526ns -> 377ns (39.5% faster)




def test_edge_data_is_non_empty_tuple():
    # Test with data as a non-empty tuple (should return the tuple)
    page = SyncConversationCursorPage(data=(1, 2))
    codeflash_output = page._get_page_items(); result = codeflash_output # 528ns -> 435ns (21.4% faster)

def test_edge_data_is_non_empty_set():
    # Test with data as a non-empty set (should return the set)
    page = SyncConversationCursorPage(data={1, 2})
    codeflash_output = page._get_page_items(); result = codeflash_output # 500ns -> 389ns (28.5% faster)






def test_large_scale_1000_elements():
    # Test with a large list (1000 elements)
    large_list = list(range(1000))
    page = SyncConversationCursorPage(data=large_list)
    codeflash_output = page._get_page_items(); result = codeflash_output # 560ns -> 464ns (20.7% faster)

def test_large_scale_1000_strings():
    # Test with a large list of strings
    large_list = [str(i) for i in range(1000)]
    page = SyncConversationCursorPage(data=large_list)
    codeflash_output = page._get_page_items(); result = codeflash_output # 509ns -> 391ns (30.2% faster)

def test_large_scale_1000_dicts():
    # Test with a large list of dicts
    large_list = [{"num": i} for i in range(1000)]
    page = SyncConversationCursorPage(data=large_list)
    codeflash_output = page._get_page_items(); result = codeflash_output # 495ns -> 423ns (17.0% faster)

def test_large_scale_1000_none():
    # Test with a large list of None
    large_list = [None] * 1000
    page = SyncConversationCursorPage(data=large_list)
    codeflash_output = page._get_page_items(); result = codeflash_output # 482ns -> 394ns (22.3% faster)

def test_large_scale_mixed_types():
    # Test with a large list of mixed types
    large_list = [i if i % 2 == 0 else str(i) for i in range(1000)]
    page = SyncConversationCursorPage(data=large_list)
    codeflash_output = page._get_page_items(); result = codeflash_output # 478ns -> 374ns (27.8% faster)
# 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-SyncConversationCursorPage._get_page_items-mhdj3uko and push.