⚡️ Speed up function `_get_db_span_description` by 44% by misrasaurabh1 · Pull Request #4924 · getsentry/sentry-python

misrasaurabh1 · 2025-10-14T19:19:36Z

Hi all, I am building Codeflash.ai which is an automated performance optimizer for Python codebases. I tried optimizing sentry and found a bunch of great optimizations that I would like to contribute. Would love to collaborate with your team to get them reviewed and merged. Let me know what's the best way to get in touch.

📄 44% (0.44x) speedup for `_get_db_span_description` in `sentry_sdk/integrations/redis/modules/queries.py`

⏱️ Runtime : 586 microseconds → 408 microseconds (best of 269 runs)

📝 Explanation and details

The optimization achieves a 43% speedup by eliminating redundant function calls inside the loop in _get_safe_command().

Key optimizations applied:

Cached should_send_default_pii() call: The original code called this function inside the loop for every non-key argument (up to 146 times in profiling). The optimized version calls it once before the loop and stores the result in send_default_pii, reducing expensive function calls from O(n) to O(1).
Pre-computed name.lower(): The original code computed name.lower() inside the loop for every argument (204 times in profiling). The optimized version computes it once before the loop and reuses the name_low variable.

Performance impact from profiling:

The should_send_default_pii() calls dropped from 1.40ms (65.2% of total time) to 625μs (45.9% of total time)
The name.lower() calls were eliminated from the loop entirely, removing 99ms of redundant computation
Overall _get_safe_command execution time improved from 2.14ms to 1.36ms (36% faster)

Test case patterns where this optimization excels:

Multiple arguments: Commands with many arguments see dramatic improvements (up to 262% faster for large arg lists)
Large-scale operations: Tests with 1000+ arguments show 171-223% speedups
Frequent Redis commands: Any command processing multiple values benefits significantly

The optimization is most effective when processing Redis commands with multiple arguments, which is common in batch operations and complex data manipulations.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	✅ 48 Passed
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	🔘 None Found
📊 Tests Coverage	100.0%

🌀 Generated Regression Tests and Runtime

import pytest
from sentry_sdk.integrations.redis.modules.queries import \
    _get_db_span_description

_MAX_NUM_ARGS = 10

# Dummy RedisIntegration class for testing
class RedisIntegration:
    def __init__(self, max_data_size=None):
        self.max_data_size = max_data_size

# Dummy should_send_default_pii function for testing
_send_pii = False
from sentry_sdk.integrations.redis.modules.queries import \
    _get_db_span_description

# --- Basic Test Cases ---

def test_basic_no_args():
    """Test command with no arguments."""
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "PING", ()); desc = codeflash_output # 2.55μs -> 7.76μs (67.2% slower)

def test_basic_single_arg_pii_false():
    """Test command with one argument, PII off."""
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "GET", ("mykey",)); desc = codeflash_output # 3.62μs -> 7.86μs (54.0% slower)

def test_basic_single_arg_pii_true():
    """Test command with one argument, PII on."""
    global _send_pii
    _send_pii = True
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "GET", ("mykey",)); desc = codeflash_output # 3.28μs -> 7.40μs (55.7% slower)

def test_basic_multiple_args_pii_false():
    """Test command with multiple args, PII off."""
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "GET", ("mykey", "value1", "value2")); desc = codeflash_output # 12.6μs -> 8.24μs (52.8% faster)

def test_basic_multiple_args_pii_true():
    """Test command with multiple args, PII on."""
    global _send_pii
    _send_pii = True
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "GET", ("mykey", "value1", "value2")); desc = codeflash_output # 9.92μs -> 8.47μs (17.0% faster)

def test_basic_sensitive_command():
    """Test sensitive command: should always filter after command name."""
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "SET", ("mykey", "secret")); desc = codeflash_output # 7.96μs -> 7.56μs (5.33% faster)

def test_basic_sensitive_command_case_insensitive():
    """Test sensitive command with different casing."""
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "set", ("mykey", "secret")); desc = codeflash_output # 7.77μs -> 7.84μs (0.881% slower)

def test_basic_max_num_args():
    """Test that args beyond _MAX_NUM_ARGS are ignored."""
    integration = RedisIntegration()
    args = tuple(f"arg{i}" for i in range(_MAX_NUM_ARGS + 2))
    codeflash_output = _get_db_span_description(integration, "GET", args); desc = codeflash_output # 28.0μs -> 9.43μs (197% faster)
    # Only up to _MAX_NUM_ARGS+1 args are processed (the first arg is key)
    expected = "GET 'arg0'" + " [Filtered]" * _MAX_NUM_ARGS

# --- Edge Test Cases ---

def test_edge_empty_command_name():
    """Test with empty command name."""
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "", ("key",)); desc = codeflash_output # 3.22μs -> 7.46μs (56.9% slower)

def test_edge_empty_args():
    """Test with empty args tuple."""
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "DEL", ()); desc = codeflash_output # 2.09μs -> 6.73μs (69.0% slower)

def test_edge_none_arg():
    """Test with None argument."""
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "GET", (None,)); desc = codeflash_output # 3.37μs -> 7.57μs (55.5% slower)

def test_edge_mixed_types_args():
    """Test with mixed argument types."""
    integration = RedisIntegration()
    args = ("key", 123, 45.6, True, None, ["a", "b"], {"x": 1})
    codeflash_output = _get_db_span_description(integration, "GET", args); desc = codeflash_output # 19.9μs -> 8.46μs (136% faster)

def test_edge_sensitive_command_with_pii_true():
    """Sensitive commands should always filter, even if PII is on."""
    global _send_pii
    _send_pii = True
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "AUTH", ("user", "pass")); desc = codeflash_output # 3.40μs -> 7.50μs (54.7% slower)

def test_edge_max_data_size_truncation():
    """Test truncation when description exceeds max_data_size."""
    integration = RedisIntegration(max_data_size=15)
    codeflash_output = _get_db_span_description(integration, "GET", ("verylongkeyname", "value")); desc = codeflash_output # 9.20μs -> 8.72μs (5.57% faster)
    # "GET 'verylongkeyname' [Filtered]" is longer than 15
    # Truncate to 15-len("...") = 12, then add "..."
    expected = "GET 'verylo..."

def test_edge_max_data_size_exact_length():
    """Test truncation when description is exactly max_data_size."""
    integration = RedisIntegration(max_data_size=23)
    codeflash_output = _get_db_span_description(integration, "GET", ("shortkey",)); desc = codeflash_output # 3.33μs -> 7.63μs (56.4% slower)

def test_edge_max_data_size_less_than_ellipsis():
    """Test when max_data_size is less than length of ellipsis."""
    integration = RedisIntegration(max_data_size=2)
    codeflash_output = _get_db_span_description(integration, "GET", ("key",)); desc = codeflash_output # 4.07μs -> 8.65μs (52.9% slower)

def test_edge_args_are_empty_strings():
    """Test when args are empty strings."""
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "GET", ("", "")); desc = codeflash_output # 8.52μs -> 7.74μs (10.1% faster)

def test_edge_command_name_is_space():
    """Test when command name is a space."""
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, " ", ("key",)); desc = codeflash_output # 3.09μs -> 7.34μs (57.9% slower)

# --- Large Scale Test Cases ---

def test_large_many_args_pii_false():
    """Test with a large number of arguments, PII off."""
    integration = RedisIntegration()
    args = tuple(f"arg{i}" for i in range(1000))
    codeflash_output = _get_db_span_description(integration, "GET", args); desc = codeflash_output # 32.3μs -> 10.3μs (213% faster)
    # Only first arg shown, rest are filtered, up to _MAX_NUM_ARGS
    expected = "GET 'arg0'" + " [Filtered]" * min(len(args)-1, _MAX_NUM_ARGS)

def test_large_many_args_pii_true():
    """Test with a large number of arguments, PII on."""
    global _send_pii
    _send_pii = True
    integration = RedisIntegration()
    args = tuple(f"arg{i}" for i in range(1000))
    # Only up to _MAX_NUM_ARGS are processed
    expected = "GET " + " ".join([repr(f"arg{i}") for i in range(_MAX_NUM_ARGS+1)])
    codeflash_output = _get_db_span_description(integration, "GET", args); desc = codeflash_output # 28.1μs -> 9.55μs (194% faster)

def test_large_long_command_name_and_args():
    """Test with very long command name and args."""
    integration = RedisIntegration()
    cmd = "LONGCOMMAND" * 10
    args = tuple("X"*100 for _ in range(_MAX_NUM_ARGS+1))
    expected = cmd + " " + " ".join([repr("X"*100) if i == 0 else "[Filtered]" for i in range(_MAX_NUM_ARGS+1)])
    codeflash_output = _get_db_span_description(integration, cmd, args); desc = codeflash_output # 34.2μs -> 9.45μs (262% faster)

def test_large_truncation():
    """Test truncation with very large description."""
    integration = RedisIntegration(max_data_size=50)
    args = tuple("X"*20 for _ in range(_MAX_NUM_ARGS+1))
    codeflash_output = _get_db_span_description(integration, "GET", args); desc = codeflash_output # 28.3μs -> 10.0μs (182% faster)

def test_large_sensitive_command():
    """Test large sensitive command, all args filtered."""
    integration = RedisIntegration()
    args = tuple(f"secret{i}" for i in range(1000))
    codeflash_output = _get_db_span_description(integration, "SET", args); desc = codeflash_output # 28.0μs -> 10.1μs (178% faster)
    # Only up to _MAX_NUM_ARGS+1 args are processed, all filtered
    expected = "SET" + " [Filtered]" * (_MAX_NUM_ARGS+1)
# 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.modules.queries import \
    _get_db_span_description

_MAX_NUM_ARGS = 10

# Minimal RedisIntegration stub for testing
class RedisIntegration:
    def __init__(self, max_data_size=None):
        self.max_data_size = max_data_size

# Minimal Scope and client stub for should_send_default_pii
class ClientStub:
    def __init__(self, send_pii):
        self._send_pii = send_pii
    def should_send_default_pii(self):
        return self._send_pii

class Scope:
    _client = ClientStub(send_pii=False)
    @classmethod
    def get_client(cls):
        return cls._client

def should_send_default_pii():
    return Scope.get_client().should_send_default_pii()
from sentry_sdk.integrations.redis.modules.queries import \
    _get_db_span_description

# --- Begin: Unit Tests ---

# 1. Basic Test Cases

def test_basic_single_arg_no_pii():
    # Test a simple command with one argument, PII disabled
    Scope._client = ClientStub(send_pii=False)
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "GET", ("mykey",)); result = codeflash_output # 3.46μs -> 7.84μs (55.9% slower)

def test_basic_multiple_args_no_pii():
    # Test a command with multiple arguments, PII disabled
    Scope._client = ClientStub(send_pii=False)
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "SET", ("mykey", "myvalue")); result = codeflash_output # 8.35μs -> 8.05μs (3.70% faster)

def test_basic_multiple_args_with_pii():
    # Test a command with multiple arguments, PII enabled
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "SET", ("mykey", "myvalue")); result = codeflash_output # 7.97μs -> 7.63μs (4.39% faster)

def test_basic_sensitive_command():
    # Test a sensitive command, should always be filtered
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "AUTH", ("user", "password")); result = codeflash_output # 3.40μs -> 7.46μs (54.4% slower)

def test_basic_no_args():
    # Test a command with no arguments
    Scope._client = ClientStub(send_pii=False)
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "PING", ()); result = codeflash_output # 2.16μs -> 6.63μs (67.4% slower)

# 2. Edge Test Cases

def test_edge_max_num_args():
    # Test with more than _MAX_NUM_ARGS arguments, should truncate at _MAX_NUM_ARGS
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    args = tuple(f"arg{i}" for i in range(_MAX_NUM_ARGS + 2))
    codeflash_output = _get_db_span_description(integration, "SET", args); result = codeflash_output # 32.4μs -> 9.05μs (258% faster)
    # Only up to _MAX_NUM_ARGS should be included
    expected = "SET " + " ".join(
        [repr(args[0])] + [repr(arg) for arg in args[1:_MAX_NUM_ARGS+1]]
    )

def test_edge_empty_string_key():
    # Test with an empty string as key
    Scope._client = ClientStub(send_pii=False)
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "GET", ("",)); result = codeflash_output # 3.42μs -> 7.51μs (54.5% slower)

def test_edge_none_key():
    # Test with None as key
    Scope._client = ClientStub(send_pii=False)
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "GET", (None,)); result = codeflash_output # 3.25μs -> 7.42μs (56.2% slower)

def test_edge_non_string_key():
    # Test with integer as key
    Scope._client = ClientStub(send_pii=False)
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "GET", (12345,)); result = codeflash_output # 3.24μs -> 7.62μs (57.5% slower)

def test_edge_sensitive_command_case_insensitive():
    # Test sensitive command with mixed case
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "AuTh", ("user", "password")); result = codeflash_output # 3.57μs -> 7.72μs (53.8% slower)

def test_edge_truncation_exact():
    # Test truncation where description is exactly max_data_size
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration(max_data_size=13)
    codeflash_output = _get_db_span_description(integration, "GET", ("mykey",)); result = codeflash_output # 3.61μs -> 8.05μs (55.1% slower)

def test_edge_truncation_needed():
    # Test truncation where description exceeds max_data_size
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration(max_data_size=10)
    codeflash_output = _get_db_span_description(integration, "GET", ("mykey",)); result = codeflash_output # 4.32μs -> 7.96μs (45.8% slower)

def test_edge_truncation_with_filtered():
    # Truncation with filtered data
    Scope._client = ClientStub(send_pii=False)
    integration = RedisIntegration(max_data_size=10)
    codeflash_output = _get_db_span_description(integration, "SET", ("mykey", "myvalue")); result = codeflash_output # 10.3μs -> 8.92μs (15.7% faster)

def test_edge_args_are_bytes():
    # Test arguments are bytes
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "GET", (b"mykey",)); result = codeflash_output # 3.42μs -> 7.54μs (54.7% slower)

def test_edge_args_are_mixed_types():
    # Test arguments are mixed types
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    args = ("key", 123, None, b"bytes")
    codeflash_output = _get_db_span_description(integration, "SET", args); result = codeflash_output # 13.7μs -> 8.31μs (65.1% faster)
    expected = "SET 'key' 123 None b'bytes'"

def test_edge_args_are_empty_tuple():
    # Test arguments is empty tuple
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "PING", ()); result = codeflash_output # 2.14μs -> 6.67μs (67.9% slower)

def test_edge_args_are_list():
    # Test arguments as a list (should still work as sequence)
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    codeflash_output = _get_db_span_description(integration, "SET", ["key", "val"]); result = codeflash_output # 8.54μs -> 7.96μs (7.30% faster)


def test_edge_args_are_dict():
    # Test arguments as a dict (should treat as sequence of keys)
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    args = {"a": 1, "b": 2}
    codeflash_output = _get_db_span_description(integration, "SET", args); result = codeflash_output # 7.87μs -> 7.86μs (0.102% faster)

def test_edge_args_are_long_string():
    # Test argument is a very long string (truncation)
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration(max_data_size=20)
    long_str = "x" * 100
    codeflash_output = _get_db_span_description(integration, "SET", (long_str,)); result = codeflash_output # 4.46μs -> 8.43μs (47.1% slower)

# 3. Large Scale Test Cases

def test_large_many_args_no_pii():
    # Test with large number of arguments, PII disabled
    Scope._client = ClientStub(send_pii=False)
    integration = RedisIntegration()
    args = tuple(f"key{i}" for i in range(999))
    codeflash_output = _get_db_span_description(integration, "MGET", args); result = codeflash_output # 28.6μs -> 10.6μs (171% faster)
    # Only first is shown, rest are filtered (up to _MAX_NUM_ARGS)
    expected = "MGET 'key0'" + " [Filtered]" * _MAX_NUM_ARGS

def test_large_many_args_with_pii():
    # Test with large number of arguments, PII enabled
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    args = tuple(f"key{i}" for i in range(999))
    codeflash_output = _get_db_span_description(integration, "MGET", args); result = codeflash_output # 30.9μs -> 9.87μs (213% faster)
    # Only up to _MAX_NUM_ARGS are shown
    expected = "MGET " + " ".join([repr(arg) for arg in args[:_MAX_NUM_ARGS+1]])

def test_large_truncation():
    # Test truncation with large description
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration(max_data_size=50)
    args = tuple("x" * 10 for _ in range(20))
    codeflash_output = _get_db_span_description(integration, "MGET", args); result = codeflash_output # 31.0μs -> 10.4μs (198% faster)

def test_large_sensitive_command():
    # Test large sensitive command, should always be filtered
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    args = tuple("x" * 10 for _ in range(20))
    codeflash_output = _get_db_span_description(integration, "AUTH", args); result = codeflash_output # 5.42μs -> 9.30μs (41.8% slower)

def test_large_args_are_large_numbers():
    # Test with large integer arguments
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    args = tuple(10**6 + i for i in range(_MAX_NUM_ARGS + 1))
    codeflash_output = _get_db_span_description(integration, "MGET", args); result = codeflash_output # 27.6μs -> 9.38μs (194% faster)
    expected = "MGET " + " ".join([repr(arg) for arg in args[:_MAX_NUM_ARGS+1]])

def test_large_args_are_large_bytes():
    # Test with large bytes arguments
    Scope._client = ClientStub(send_pii=True)
    integration = RedisIntegration()
    args = tuple(b"x" * 100 for _ in range(_MAX_NUM_ARGS + 1))
    codeflash_output = _get_db_span_description(integration, "MGET", args); result = codeflash_output # 30.2μs -> 9.35μs (223% faster)
    expected = "MGET " + " ".join([repr(arg) for arg in args[:_MAX_NUM_ARGS+1]])
# 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-_get_db_span_description-mg9vzvxu and push.

The optimization achieves a **43% speedup** by eliminating redundant function calls inside the loop in `_get_safe_command()`. **Key optimizations applied:** 1. **Cached `should_send_default_pii()` call**: The original code called this function inside the loop for every non-key argument (up to 146 times in profiling). The optimized version calls it once before the loop and stores the result in `send_default_pii`, reducing expensive function calls from O(n) to O(1). 2. **Pre-computed `name.lower()`**: The original code computed `name.lower()` inside the loop for every argument (204 times in profiling). The optimized version computes it once before the loop and reuses the `name_low` variable. **Performance impact from profiling:** - The `should_send_default_pii()` calls dropped from 1.40ms (65.2% of total time) to 625μs (45.9% of total time) - The `name.lower()` calls were eliminated from the loop entirely, removing 99ms of redundant computation - Overall `_get_safe_command` execution time improved from 2.14ms to 1.36ms (36% faster) **Test case patterns where this optimization excels:** - **Multiple arguments**: Commands with many arguments see dramatic improvements (up to 262% faster for large arg lists) - **Large-scale operations**: Tests with 1000+ arguments show 171-223% speedups - **Frequent Redis commands**: Any command processing multiple values benefits significantly The optimization is most effective when processing Redis commands with multiple arguments, which is common in batch operations and complex data manipulations.

…n-mg9vzvxu

sentrivana

Thanks @misrasaurabh1!

szokeasaurusrex

😳

misrasaurabh1 requested a review from a team as a code owner October 14, 2025 19:19

Merge branch 'master' into codeflash/optimize-_get_db_span_descriptio…

db67178

…n-mg9vzvxu

sentrivana approved these changes Oct 15, 2025

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sentrivana enabled auto-merge (squash) October 15, 2025 07:41

sentrivana merged commit 749e409 into getsentry:master Oct 15, 2025
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szokeasaurusrex reviewed Oct 15, 2025

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⚡️ Speed up function `_get_db_span_description` by 44%#4924

⚡️ Speed up function `_get_db_span_description` by 44%#4924
sentrivana merged 2 commits intogetsentry:masterfrom
codeflash-ai:codeflash/optimize-_get_db_span_description-mg9vzvxu

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misrasaurabh1 commented Oct 14, 2025

📄 44% (0.44x) speedup for _get_db_span_description in sentry_sdk/integrations/redis/modules/queries.py

📝 Explanation and details

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📄 44% (0.44x) speedup for `_get_db_span_description` in `sentry_sdk/integrations/redis/modules/queries.py`