⚡️ Speed up function _key_as_string by 23%

[codeflash-ai]

📄 23% (0.23x) speedup for _key_as_string in sentry_sdk/integrations/redis/utils.py

⏱️ Runtime : 2.07 milliseconds → 1.69 milliseconds (best of 176 runs)

📝 Explanation and details

The optimization primarily replaces the generator expression (_safe_decode(x) for x in key) with map(_safe_decode, key) in the _key_as_string function when handling dict, list, and tuple types. Additionally, all branches now return directly instead of assigning to a variable first.

Key changes:

• Generator to map() replacement: ", ".join(_safe_decode(x) for x in key) becomes ", ".join(map(_safe_decode, key))
• Direct returns: Each branch returns immediately instead of assigning to key variable and returning at the end

Why this is faster:
The map() function is implemented in C and creates an iterator more efficiently than Python's generator expressions. When str.join() consumes the iterator, map() avoids the Python function call overhead that generator expressions incur for each element. The line profiler shows the critical line (joining elements) improved from 866,894ns per hit to 790,411ns per hit - an 8.8% improvement on the hottest code path.

Performance characteristics:

• Best gains on large collections: Large-scale tests show 22-34% speedups (e.g., 1000-element collections)
• Consistent improvements on mixed types: Tests with bytes, integers, and complex nested structures show 10-25% gains
• Minimal overhead on simple cases: Single-value tests show modest 2-17% improvements
• No regression on edge cases: Unicode decode errors and complex nested structures maintain performance

The optimization is particularly effective because _key_as_string is likely called frequently in Redis integration scenarios where keys are often collections that need string conversion for logging or monitoring purposes.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	✅ 91 Passed
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	🔘 None Found
📊 Tests Coverage	100.0%

🌀 Generated Regression Tests and Runtime

import pytest  # used for our unit tests
from sentry_sdk.integrations.redis.utils import _key_as_string

# unit tests

# --- Basic Test Cases ---

def test_string_input():
    # Test with a simple string
    codeflash_output = _key_as_string("hello") # 984ns -> 965ns (1.97% faster)

def test_integer_input():
    # Test with an integer
    codeflash_output = _key_as_string(123) # 1.18μs -> 1.02μs (14.6% faster)

def test_float_input():
    # Test with a float
    codeflash_output = _key_as_string(123.45) # 2.56μs -> 2.71μs (5.50% slower)

def test_bytes_input_ascii():
    # Test with bytes containing ASCII
    codeflash_output = _key_as_string(b"abc") # 1.39μs -> 1.18μs (17.8% faster)

def test_list_of_strings():
    # Test with a list of strings
    codeflash_output = _key_as_string(["a", "b", "c"]) # 2.78μs -> 2.45μs (13.3% faster)

def test_tuple_of_ints():
    # Test with a tuple of integers
    codeflash_output = _key_as_string((1, 2, 3)) # 2.98μs -> 2.76μs (7.85% faster)

def test_dict_as_key():
    # Test with a dictionary as key (should join keys)
    codeflash_output = _key_as_string({"x": 1, "y": 2}) # 2.38μs -> 1.95μs (22.0% faster)

def test_none_input():
    # Test with None input
    codeflash_output = _key_as_string(None) # 862ns -> 820ns (5.12% faster)

# --- Edge Test Cases ---

def test_empty_string():
    # Test with empty string
    codeflash_output = _key_as_string("") # 1.02μs -> 1.01μs (1.49% faster)

def test_empty_list():
    # Test with empty list
    codeflash_output = _key_as_string([]) # 1.75μs -> 1.62μs (7.38% faster)

def test_empty_tuple():
    # Test with empty tuple
    codeflash_output = _key_as_string(()) # 1.80μs -> 1.68μs (7.01% faster)

def test_empty_dict():
    # Test with empty dict
    codeflash_output = _key_as_string({}) # 1.62μs -> 1.40μs (15.8% faster)

def test_bytes_non_utf8():
    # Test with bytes that can't be decoded as UTF-8
    codeflash_output = _key_as_string(b'\xff\xfe\xfd') # 4.30μs -> 4.26μs (0.869% faster)

def test_list_with_bytes():
    # Test with list containing bytes
    codeflash_output = _key_as_string([b"a", b"b", b"c"]) # 2.58μs -> 2.27μs (13.4% faster)

def test_tuple_with_mixed_types():
    # Test with tuple containing mixed types
    codeflash_output = _key_as_string((1, "a", b"b")) # 3.20μs -> 2.85μs (12.4% faster)

def test_dict_with_non_string_keys():
    # Test with dict with non-string keys
    codeflash_output = _key_as_string({1: "a", 2: "b"}) # 2.70μs -> 2.33μs (15.7% faster)

def test_dict_with_bytes_keys():
    # Test with dict with bytes keys
    codeflash_output = _key_as_string({b"a": 1, b"b": 2}) # 2.23μs -> 1.94μs (15.4% faster)

def test_list_with_none():
    # Test with list containing None
    codeflash_output = _key_as_string([None, "a", 1]) # 3.02μs -> 2.78μs (8.89% faster)

def test_tuple_with_bytes_non_utf8():
    # Test with tuple containing bytes that cannot be decoded
    codeflash_output = _key_as_string((b'\xff', b'a')) # 5.48μs -> 4.89μs (12.1% faster)

def test_list_with_nested_list():
    # Test with list containing a nested list
    codeflash_output = _key_as_string(["a", [1, 2]]) # 3.65μs -> 3.20μs (14.2% faster)

def test_dict_with_tuple_keys():
    # Test with dict with tuple keys
    codeflash_output = _key_as_string({(1, 2): "a", (3, 4): "b"}) # 3.73μs -> 3.18μs (17.3% faster)

def test_bool_input():
    # Test with boolean input
    codeflash_output = _key_as_string(True) # 1.51μs -> 1.37μs (9.99% faster)
    codeflash_output = _key_as_string(False) # 705ns -> 629ns (12.1% faster)

def test_set_input():
    # Test with set input (should treat as str)
    s = set([1, 2])
    codeflash_output = _key_as_string(s) # 2.91μs -> 2.67μs (9.23% faster)

def test_frozenset_input():
    # Test with frozenset input (should treat as str)
    fs = frozenset([1, 2])
    codeflash_output = _key_as_string(fs) # 2.83μs -> 2.70μs (4.89% faster)

def test_object_input():
    # Test with custom object input (should use str)
    class Dummy:
        def __str__(self):
            return "dummy"
    codeflash_output = _key_as_string(Dummy()) # 1.50μs -> 1.54μs (2.99% slower)

# --- Large Scale Test Cases ---

def test_large_list_of_ints():
    # Test with a large list of integers
    data = list(range(1000))
    expected = ", ".join(str(i) for i in range(1000))
    codeflash_output = _key_as_string(data) # 221μs -> 182μs (21.2% faster)

def test_large_tuple_of_bytes():
    # Test with a large tuple of bytes
    data = tuple(bytes([97]) for _ in range(1000))  # b'a' * 1000
    expected = ", ".join("a" for _ in range(1000))
    codeflash_output = _key_as_string(data) # 143μs -> 106μs (34.2% faster)

def test_large_dict_of_str_keys():
    # Test with a large dict of string keys
    data = {str(i): i for i in range(1000)}
    expected = ", ".join(str(i) for i in range(1000))
    codeflash_output = _key_as_string(data) # 168μs -> 130μs (29.4% faster)

def test_large_dict_of_int_keys():
    # Test with a large dict of integer keys
    data = {i: str(i) for i in range(1000)}
    expected = ", ".join(str(i) for i in range(1000))
    codeflash_output = _key_as_string(data) # 226μs -> 185μs (22.0% faster)

def test_large_list_of_mixed_types():
    # Test with a large list of mixed types
    data = [i if i % 2 == 0 else b"a" for i in range(1000)]
    expected = ", ".join(str(i) if i % 2 == 0 else "a" for i in range(1000))
    codeflash_output = _key_as_string(data) # 195μs -> 156μs (24.8% faster)

def test_large_list_with_none_and_bytes():
    # Test with a large list containing None and bytes
    data = [None if i % 3 == 0 else b"a" for i in range(1000)]
    expected = ", ".join("" if i % 3 == 0 else "a" for i in range(1000))
    codeflash_output = _key_as_string(data) # 175μs -> 139μs (26.1% faster)

def test_large_dict_with_bytes_keys_non_utf8():
    # Test with a large dict with bytes keys, some non-UTF8
    data = {b"a": 1, b"b": 2}
    # Add some non-UTF8 keys
    for i in range(998):
        data[bytes([255])] = i
    # The non-UTF8 keys decode to ""
    expected = "a, b" + ", " + ", ".join("" for _ in range(998))
    # The order of keys in dict is not guaranteed before Python 3.7, but for test purposes, we can check counts
    codeflash_output = _key_as_string(data); result = codeflash_output # 5.67μs -> 5.02μs (13.0% faster)

# --- Deterministic and Mutation-Resistant Tests ---

def test_bytes_vs_str():
    # Ensure bytes and str with same content yield same result
    codeflash_output = _key_as_string(b"abc") # 1.36μs -> 1.17μs (16.3% faster)

def test_list_order_preserved():
    # Ensure order of elements in list is preserved
    data = ["first", "second", "third"]
    codeflash_output = _key_as_string(data) # 2.60μs -> 2.30μs (13.2% faster)

def test_tuple_order_preserved():
    # Ensure order of elements in tuple is preserved
    data = ("x", "y", "z")
    codeflash_output = _key_as_string(data) # 2.79μs -> 2.48μs (12.7% faster)

def test_dict_keys_order_preserved():
    # Python 3.7+ preserves dict key order
    data = {"a": 1, "b": 2, "c": 3}
    codeflash_output = _key_as_string(data) # 2.58μs -> 2.12μs (21.5% faster)

def test_unicode_string():
    # Test with unicode string
    codeflash_output = _key_as_string("你好") # 1.03μs -> 958ns (7.41% faster)

def test_bytes_utf8_unicode():
    # Test with bytes containing UTF-8 encoded unicode
    codeflash_output = _key_as_string("你好".encode("utf-8")) # 2.20μs -> 1.92μs (14.5% faster)

def test_bytes_invalid_then_valid():
    # Test with list containing invalid and valid bytes
    data = [b'\xff', b'abc']
    codeflash_output = _key_as_string(data) # 5.22μs -> 4.77μs (9.59% faster)

def test_nested_dict_as_key():
    # Test with dict containing dict as key
    data = {frozenset({"a": 1}.items()): 1}
    # Should use str representation of the key
    expected = str(frozenset({"a": 1}.items()))
    codeflash_output = _key_as_string(data) # 3.29μs -> 2.81μs (17.0% faster)
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.
#------------------------------------------------
import pytest  # used for our unit tests
from sentry_sdk.integrations.redis.utils import _key_as_string

# -------------------------
# UNIT TESTS FOR _key_as_string
# -------------------------

# Basic Test Cases
def test_string_input():
    # Should return the string itself
    codeflash_output = _key_as_string("hello") # 1.05μs -> 985ns (6.80% faster)
    codeflash_output = _key_as_string("123") # 589ns -> 575ns (2.43% faster)
    codeflash_output = _key_as_string("") # 368ns -> 480ns (23.3% slower)

def test_int_input():
    # Should convert int to string
    codeflash_output = _key_as_string(42) # 1.14μs -> 1.11μs (2.53% faster)
    codeflash_output = _key_as_string(0) # 708ns -> 595ns (19.0% faster)
    codeflash_output = _key_as_string(-7) # 564ns -> 557ns (1.26% faster)

def test_float_input():
    # Should convert float to string
    codeflash_output = _key_as_string(3.14) # 2.72μs -> 2.59μs (4.86% faster)
    codeflash_output = _key_as_string(-2.718) # 1.17μs -> 1.10μs (6.38% faster)
    codeflash_output = _key_as_string(0.0) # 778ns -> 800ns (2.75% slower)

def test_bytes_input():
    # Should decode bytes to string using utf-8
    codeflash_output = _key_as_string(b"abc") # 1.39μs -> 1.22μs (13.4% faster)
    codeflash_output = _key_as_string(b"") # 735ns -> 683ns (7.61% faster)
    # Should handle bytes that are numbers
    codeflash_output = _key_as_string(bytes([49,50,51])) # 466ns -> 563ns (17.2% slower)

def test_none_input():
    # Should return empty string for None
    codeflash_output = _key_as_string(None) # 823ns -> 803ns (2.49% faster)

def test_list_input():
    # Should join elements with comma and space, decoding bytes
    codeflash_output = _key_as_string([1, "a", b"b"]) # 3.25μs -> 2.80μs (16.2% faster)
    codeflash_output = _key_as_string([]) # 1.22μs -> 957ns (27.2% faster)
    codeflash_output = _key_as_string([b"x", b"y"]) # 1.38μs -> 1.03μs (33.5% faster)

def test_tuple_input():
    # Should join elements with comma and space, decoding bytes
    codeflash_output = _key_as_string((1, "a", b"b")) # 3.04μs -> 2.65μs (14.7% faster)
    codeflash_output = _key_as_string(()) # 1.14μs -> 948ns (20.7% faster)
    codeflash_output = _key_as_string((b"x", b"y")) # 1.26μs -> 1.01μs (24.9% faster)

def test_dict_input():
    # Should join keys with comma and space, decoding bytes
    codeflash_output = _key_as_string({1: "a", b"b": "c"}) # 2.56μs -> 2.24μs (14.4% faster)
    codeflash_output = _key_as_string({}) # 1.10μs -> 867ns (26.8% faster)
    codeflash_output = _key_as_string({b"x": 1, b"y": 2}) # 1.14μs -> 954ns (19.9% faster)

# Edge Test Cases
def test_bytes_with_unicode_decode_error():
    # Should return empty string for undecodable bytes
    codeflash_output = _key_as_string(b"\xff\xfe") # 4.09μs -> 3.84μs (6.54% faster)

def test_list_with_bytes_with_unicode_decode_error():
    # Should decode what it can, empty string for undecodable bytes
    codeflash_output = _key_as_string([b"ok", b"\xff\xfe"]) # 4.61μs -> 4.07μs (13.2% faster)

def test_tuple_with_none_and_bytes():
    # Should handle None and bytes together
    codeflash_output = _key_as_string((None, b"abc")) # 2.62μs -> 2.52μs (4.05% faster)

def test_dict_with_non_string_keys():
    # Should join keys as string
    d = {1: "a", 2.5: "b", None: "c"}
    codeflash_output = _key_as_string(d) # 4.21μs -> 4.25μs (1.06% slower)
    # Should handle bytes with decode error
    d2 = {b"\xff": "bad", b"good": "ok"}
    codeflash_output = _key_as_string(d2) # 3.97μs -> 3.31μs (19.9% faster)

def test_nested_list_tuple_dict():
    # Should only process the top-level, not recursively
    codeflash_output = _key_as_string([["a", "b"], ("c", "d")]) # 4.57μs -> 4.25μs (7.43% faster)
    codeflash_output = _key_as_string({"x": ["y", "z"]}) # 1.33μs -> 1.06μs (25.4% faster)

def test_bool_input():
    # Should convert bool to string
    codeflash_output = _key_as_string(True) # 1.48μs -> 1.34μs (10.1% faster)
    codeflash_output = _key_as_string(False) # 682ns -> 619ns (10.2% faster)

def test_custom_object_input():
    # Should use str() of the object
    class Foo:
        def __str__(self):
            return "FooStr"
    codeflash_output = _key_as_string(Foo()) # 1.48μs -> 1.46μs (0.956% faster)

def test_list_with_none():
    # Should convert None to empty string
    codeflash_output = _key_as_string([None, 1, "x"]) # 3.06μs -> 2.77μs (10.4% faster)

def test_tuple_with_bytes_and_int():
    # Should decode bytes and convert int
    codeflash_output = _key_as_string((b"abc", 123)) # 2.89μs -> 2.60μs (11.1% faster)

def test_dict_with_tuple_keys():
    # Should join tuple keys as string
    d = {(1,2): "a", (3,4): "b"}
    codeflash_output = _key_as_string(d) # 3.83μs -> 3.46μs (10.6% faster)

# Large Scale Test Cases
def test_large_list():
    # Should handle large lists efficiently
    large_list = [str(i) for i in range(1000)]
    codeflash_output = _key_as_string(large_list); result = codeflash_output # 163μs -> 127μs (28.1% faster)

def test_large_tuple():
    # Should handle large tuples efficiently
    large_tuple = tuple(str(i) for i in range(1000))
    codeflash_output = _key_as_string(large_tuple); result = codeflash_output # 163μs -> 127μs (28.3% faster)

def test_large_dict():
    # Should handle large dicts efficiently
    large_dict = {i: str(i) for i in range(1000)}
    codeflash_output = _key_as_string(large_dict); result = codeflash_output # 253μs -> 218μs (16.0% faster)
    # All keys from 0 to 999 should be present as strings
    for i in range(1000):
        pass

def test_large_bytes():
    # Should decode large bytes correctly
    large_bytes = b"a" * 1000
    codeflash_output = _key_as_string(large_bytes) # 1.92μs -> 1.70μs (12.8% faster)

def test_large_list_with_bytes_and_ints():
    # Should decode bytes and convert ints, joining all
    large_list = [b"x"] * 500 + [123] * 500
    codeflash_output = _key_as_string(large_list); result = codeflash_output # 184μs -> 148μs (24.1% faster)

# Determinism Test
def test_deterministic_output():
    # Should always produce same output for same input
    input_data = [b"foo", 42, None, "bar"]
    codeflash_output = _key_as_string(input_data); output1 = codeflash_output # 3.05μs -> 2.96μs (2.93% faster)
    codeflash_output = _key_as_string(input_data); output2 = codeflash_output # 1.69μs -> 1.28μs (31.4% faster)

# Type robustness
@pytest.mark.parametrize("input_val,expected", [
    ({"a": 1, "b": 2}, "a, b"),
    ([b"abc", 123, None], "abc, 123, "),
    ((b"abc", 123, None), "abc, 123, "),
    (b"abc", "abc"),
    (None, ""),
    (42, "42"),
    (3.14, "3.14"),
    ("test", "test"),
])
def test_various_types(input_val, expected):
    # Should handle all supported types correctly
    codeflash_output = _key_as_string(input_val) # 16.0μs -> 14.7μs (8.36% 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-_key_as_string-mg9l6nq2 and push.