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@codeflash-ai codeflash-ai bot commented Oct 24, 2025

📄 23% (0.23x) speedup for validate_int in src/mistralai/utils/serializers.py

⏱️ Runtime : 3.11 milliseconds 2.54 milliseconds (best of 79 runs)

📝 Explanation and details

The optimization achieves a 22% speedup by restructuring the conditional logic to reduce the number of isinstance() calls, which are expensive operations in Python.

Key Changes:

  1. Combined conditions: The first check now handles both None and int types in a single line: if b is None or isinstance(b, int):
  2. Separate Unset check: Unset is now checked independently with if b is Unset:, using the faster identity comparison (is) instead of isinstance()

Why This is Faster:

  • Reduced isinstance() calls: In the original code, every input goes through isinstance(b, (int, Unset)) which checks against a tuple of types. The optimized version uses the faster identity check b is None first, and only calls isinstance() for integer checking when needed.
  • Early returns: Integer inputs (the most common case based on test results) now return immediately after the first condition, avoiding the subsequent Unset check entirely.
  • Optimized type checking: Separating the Unset check allows using is comparison, which is faster than isinstance() for singleton objects.

Performance Benefits by Test Case:

  • String parsing sees the biggest gains (35-108% faster) as the logic reorganization reduces overhead before reaching the int() conversion
  • Integer inputs are 9-19% faster due to earlier returns
  • Invalid inputs are 8-77% faster as they reach the error condition more efficiently
  • Large-scale operations benefit significantly (36-45% faster) due to the cumulative effect of reduced function call overhead

The optimization is particularly effective for workloads with mixed input types, where integers and strings are common, as evidenced by the substantial performance improvements in the annotated tests.

Correctness verification report:

Test Status
⚙️ Existing Unit Tests 🔘 None Found
🌀 Generated Regression Tests 7563 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 mistralai.utils.serializers import validate_int


# function to test
class Unset:
    """Dummy Unset class for testing purposes."""
    pass
from mistralai.utils.serializers import validate_int

# unit tests

# --- Basic Test Cases ---

def test_none_returns_none():
    # Test that None input returns None
    codeflash_output = validate_int(None) # 357ns -> 393ns (9.16% slower)

def test_integer_returns_integer():
    # Test that an integer input returns the same integer
    codeflash_output = validate_int(42) # 550ns -> 461ns (19.3% faster)
    codeflash_output = validate_int(0) # 204ns -> 191ns (6.81% faster)
    codeflash_output = validate_int(-7) # 168ns -> 149ns (12.8% faster)


def test_string_integer_returns_integer():
    # Test that a string representing an integer returns the correct integer
    codeflash_output = validate_int("123") # 1.75μs -> 930ns (88.0% faster)
    codeflash_output = validate_int("-456") # 604ns -> 447ns (35.1% faster)
    codeflash_output = validate_int("0") # 455ns -> 336ns (35.4% faster)

def test_string_with_leading_trailing_spaces():
    # Test that a string with leading/trailing spaces is parsed correctly
    codeflash_output = validate_int("  789  ") # 1.27μs -> 818ns (55.7% faster)
    codeflash_output = validate_int("   -321") # 565ns -> 386ns (46.4% faster)

# --- Edge Test Cases ---

def test_empty_string_raises_valueerror():
    # Test that an empty string raises ValueError
    with pytest.raises(ValueError):
        validate_int("") # 3.10μs -> 2.69μs (15.4% faster)

def test_string_with_non_numeric_characters_raises_valueerror():
    # Test that a string with non-numeric characters raises ValueError
    with pytest.raises(ValueError):
        validate_int("12abc") # 2.80μs -> 2.40μs (17.0% faster)
    with pytest.raises(ValueError):
        validate_int("abc12") # 1.25μs -> 1.04μs (20.4% faster)
    with pytest.raises(ValueError):
        validate_int("!@#") # 1.21μs -> 1.11μs (8.94% faster)

def test_float_string_raises_valueerror():
    # Test that a string representing a float raises ValueError
    with pytest.raises(ValueError):
        validate_int("3.14") # 2.43μs -> 2.05μs (18.5% faster)
    with pytest.raises(ValueError):
        validate_int("-2.718") # 1.39μs -> 1.12μs (23.2% faster)


def test_bytes_input_raises_valueerror():
    # Test that bytes input raises ValueError
    with pytest.raises(ValueError):
        validate_int(b"123") # 1.93μs -> 1.14μs (69.0% faster)

def test_list_input_raises_valueerror():
    # Test that list input raises ValueError
    with pytest.raises(ValueError):
        validate_int([1,2,3]) # 1.48μs -> 945ns (56.3% faster)

def test_dict_input_raises_valueerror():
    # Test that dict input raises ValueError
    with pytest.raises(ValueError):
        validate_int({"a": 1}) # 1.43μs -> 1.15μs (24.6% faster)

def test_tuple_input_raises_valueerror():
    # Test that tuple input raises ValueError
    with pytest.raises(ValueError):
        validate_int((1,2)) # 1.51μs -> 1.07μs (40.7% faster)

def test_large_integer_string():
    # Test parsing a large integer string
    large_num = str(2**63)
    codeflash_output = validate_int(large_num) # 1.44μs -> 965ns (49.1% faster)

def test_string_with_plus_sign():
    # Test that string with explicit plus sign parses correctly
    codeflash_output = validate_int("+42") # 1.31μs -> 811ns (61.2% faster)

def test_string_with_multiple_spaces_raises_valueerror():
    # Test that a string with spaces inside the number raises ValueError
    with pytest.raises(ValueError):
        validate_int("1 234") # 3.11μs -> 2.77μs (12.3% faster)
    with pytest.raises(ValueError):
        validate_int("12 34") # 1.57μs -> 1.25μs (25.9% faster)

def test_string_with_newline_and_tabs():
    # Test that string with newline/tab characters parses correctly if valid
    codeflash_output = validate_int("\n123\t") # 1.25μs -> 895ns (39.2% faster)
    codeflash_output = validate_int("\t-456\n") # 693ns -> 545ns (27.2% faster)

def test_string_with_only_spaces_raises_valueerror():
    # Test that a string with only whitespace raises ValueError
    with pytest.raises(ValueError):
        validate_int("    ") # 2.75μs -> 2.51μs (9.36% faster)

# --- Large Scale Test Cases ---

def test_many_valid_string_inputs():
    # Test a large number of valid string integer inputs
    for i in range(1000):
        s = str(i)
        codeflash_output = validate_int(s) # 320μs -> 234μs (36.8% faster)

def test_many_negative_string_inputs():
    # Test a large number of valid negative string integer inputs
    for i in range(1, 1000):
        s = str(-i)
        codeflash_output = validate_int(s) # 322μs -> 234μs (37.6% faster)

def test_many_invalid_string_inputs():
    # Test a large number of invalid string inputs
    for i in range(1000):
        s = f"{i}abc"
        with pytest.raises(ValueError):
            validate_int(s)

def test_large_integer_input():
    # Test with a very large integer input
    big_int = 10**100
    codeflash_output = validate_int(big_int) # 582ns -> 585ns (0.513% slower)


def test_large_none_list():
    # Test that multiple None inputs are handled correctly
    for _ in range(1000):
        codeflash_output = validate_int(None) # 120μs -> 123μs (2.16% slower)

def test_performance_large_scale_valid():
    # Test performance for a mix of valid string and integer inputs
    for i in range(500):
        codeflash_output = validate_int(str(i)) # 172μs -> 124μs (38.6% faster)
        codeflash_output = validate_int(i)

def test_performance_large_scale_invalid():
    # Test performance for a mix of invalid inputs
    for i in range(500):
        with pytest.raises(ValueError):
            validate_int(f"{i}.0")
        with pytest.raises(ValueError):
            validate_int([i])
        with pytest.raises(ValueError):
            validate_int({i: i})
# 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 mistralai.utils.serializers import validate_int


# function to test
# Copied from mistralai/utils/serializers.py
class UnsetType:
    """A dummy Unset type for testing, since mistralai.types.basemodel.Unset is not available."""
    pass

Unset = UnsetType()
from mistralai.utils.serializers import validate_int

# unit tests

# ------------------------------
# 1. Basic Test Cases
# ------------------------------

def test_validate_int_with_int():
    # Should return the integer as is
    codeflash_output = validate_int(5) # 624ns -> 564ns (10.6% faster)
    codeflash_output = validate_int(0) # 241ns -> 219ns (10.0% faster)
    codeflash_output = validate_int(-123) # 161ns -> 147ns (9.52% faster)

def test_validate_int_with_str_int():
    # Should convert string representations of integers to int
    codeflash_output = validate_int("42") # 1.48μs -> 710ns (108% faster)
    codeflash_output = validate_int("-17") # 672ns -> 494ns (36.0% faster)
    codeflash_output = validate_int("0") # 507ns -> 381ns (33.1% faster)

def test_validate_int_with_none():
    # Should return None if input is None
    codeflash_output = validate_int(None) # 336ns -> 350ns (4.00% slower)


def test_validate_int_with_empty_string():
    # Should raise ValueError for empty string
    with pytest.raises(ValueError):
        validate_int("") # 3.76μs -> 3.04μs (23.7% faster)

def test_validate_int_with_non_numeric_string():
    # Should raise ValueError for non-numeric string
    with pytest.raises(ValueError):
        validate_int("abc")
    with pytest.raises(ValueError):
        validate_int("12.3")
    with pytest.raises(ValueError):
        validate_int("123abc")
    with pytest.raises(ValueError):
        validate_int(" 42 ")  # spaces are not allowed by int() without strip

def test_validate_int_with_float():
    # Should raise ValueError for float input type
    with pytest.raises(ValueError):
        validate_int(3.14) # 1.96μs -> 1.16μs (69.1% faster)
    with pytest.raises(ValueError):
        validate_int(-0.0) # 765ns -> 614ns (24.6% faster)


def test_validate_int_with_list_dict_tuple():
    # Should raise ValueError for list, dict, tuple input
    with pytest.raises(ValueError):
        validate_int([1, 2, 3]) # 2.00μs -> 1.13μs (77.8% faster)
    with pytest.raises(ValueError):
        validate_int({'a': 1}) # 993ns -> 873ns (13.7% faster)
    with pytest.raises(ValueError):
        validate_int((1, 2)) # 635ns -> 484ns (31.2% faster)

def test_validate_int_with_large_string_number():
    # Should correctly parse a large integer string
    big_num = str(2**63)
    codeflash_output = validate_int(big_num) # 1.38μs -> 901ns (53.2% faster)

def test_validate_int_with_leading_zeros():
    # Should parse strings with leading zeros correctly
    codeflash_output = validate_int("000123") # 1.29μs -> 837ns (54.1% faster)
    codeflash_output = validate_int("-000123") # 605ns -> 449ns (34.7% faster)



def test_validate_int_with_plus_sign():
    # Should parse strings with plus sign correctly
    codeflash_output = validate_int("+123") # 1.81μs -> 1.01μs (79.2% faster)

def test_validate_int_with_non_ascii():
    # Should raise ValueError for non-ascii characters
    with pytest.raises(ValueError):
        validate_int("123abc") # 4.38μs -> 3.85μs (13.9% faster)

# ------------------------------
# 3. Large Scale Test Cases
# ------------------------------

def test_validate_int_many_valid_strings():
    # Test a large number of valid string integers
    for i in range(-500, 500):
        codeflash_output = validate_int(str(i)) # 327μs -> 231μs (41.4% faster)

def test_validate_int_many_invalid_strings():
    # Test a large number of invalid string inputs
    for i in range(100):
        with pytest.raises(ValueError):
            validate_int(f"abc{i}")
        with pytest.raises(ValueError):
            validate_int(f"{i}.0")
        with pytest.raises(ValueError):
            validate_int(f" {i}")

def test_validate_int_performance_large_numbers():
    # Test with very large integers as string and int
    for i in [10**10, 10**50, -10**99, 0]:
        s = str(i)
        codeflash_output = validate_int(s) # 3.86μs -> 2.65μs (45.6% faster)
        codeflash_output = validate_int(i)

To edit these changes git checkout codeflash/optimize-validate_int-mh4j6dxn and push.

Codeflash

The optimization achieves a **22% speedup** by restructuring the conditional logic to reduce the number of `isinstance()` calls, which are expensive operations in Python.

**Key Changes:**
1. **Combined conditions**: The first check now handles both `None` and `int` types in a single line: `if b is None or isinstance(b, int):`
2. **Separate Unset check**: `Unset` is now checked independently with `if b is Unset:`, using the faster identity comparison (`is`) instead of `isinstance()`

**Why This is Faster:**
- **Reduced isinstance() calls**: In the original code, every input goes through `isinstance(b, (int, Unset))` which checks against a tuple of types. The optimized version uses the faster identity check `b is None` first, and only calls `isinstance()` for integer checking when needed.
- **Early returns**: Integer inputs (the most common case based on test results) now return immediately after the first condition, avoiding the subsequent `Unset` check entirely.
- **Optimized type checking**: Separating the `Unset` check allows using `is` comparison, which is faster than `isinstance()` for singleton objects.

**Performance Benefits by Test Case:**
- **String parsing** sees the biggest gains (35-108% faster) as the logic reorganization reduces overhead before reaching the `int()` conversion
- **Integer inputs** are 9-19% faster due to earlier returns
- **Invalid inputs** are 8-77% faster as they reach the error condition more efficiently
- **Large-scale operations** benefit significantly (36-45% faster) due to the cumulative effect of reduced function call overhead

The optimization is particularly effective for workloads with mixed input types, where integers and strings are common, as evidenced by the substantial performance improvements in the annotated tests.
@codeflash-ai codeflash-ai bot requested a review from mashraf-222 October 24, 2025 07:29
@codeflash-ai codeflash-ai bot added the ⚡️ codeflash Optimization PR opened by Codeflash AI label Oct 24, 2025
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