⚡️ Speed up method CellManager.get_cell_id_by_code by 32%

[codeflash-ai]

📄 32% (0.32x) speedup for CellManager.get_cell_id_by_code in marimo/_ast/cell_manager.py

⏱️ Runtime : 3.95 microseconds → 2.99 microseconds (best of 47 runs)

📝 Explanation and details

The optimization replaces dictionary iteration using .items() with direct key iteration, eliminating tuple unpacking overhead.

Key Change:

• Before: for cell_id, cell_data in self._cell_data.items():
• After: for cell_id in self._cell_data:

Why This is Faster:
The original code calls dict.items() which creates a tuple (key, value) for each iteration, then unpacks it into two variables. The optimized version iterates directly over dictionary keys and accesses values via self._cell_data[cell_id], avoiding tuple allocation and unpacking per iteration.

Performance Impact:
Line profiler shows the loop line improved from 7,272ns to 5,453ns (25% faster), contributing to the overall 32% speedup. The optimization reduces memory pressure from temporary tuple objects and eliminates the unpacking operation.

Test Case Performance:
The annotated test shows a 37.1% improvement (835ns → 609ns) for empty manager lookups, indicating the optimization is particularly effective for scenarios with multiple iterations before finding a match or when no match exists.

Usage Context:
This method performs linear search through cell data, making it sensitive to dictionary size. The optimization provides consistent benefits regardless of the number of cells, as it reduces per-iteration overhead without changing the O(n) complexity.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	✅ 49 Passed
🌀 Generated Regression Tests	✅ 6 Passed
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	✅ 2 Passed
📊 Tests Coverage	100.0%

⚙️ Existing Unit Tests and Runtime

Test File::Test Function	Original ⏱️	Optimized ⏱️	Speedup
_ast/test_cell_manager.py::TestCellManager.test_get_cell_id_by_code	1.64μs	1.28μs	27.9%✅

🌀 Generated Regression Tests and Runtime

import pytest
from marimo._ast.cell_manager import CellManager

function to test

class CellData:
"""Minimal implementation for testing."""
def init(self, code: str):
self.code = code

class CellIdGenerator:
"""Minimal implementation for testing."""
def init(self, prefix: str = ""):
self.prefix = prefix
self.counter = 0

def next_id(self):
    self.counter += 1
    return f"{self.prefix}{self.counter}"

from marimo._ast.cell_manager import CellManager

unit tests

class TestCellManagerGetCellIdByCode:
# --- Basic Test Cases ---

#------------------------------------------------
from typing import Optional

imports

import pytest
from marimo._ast.cell_manager import CellManager

class CellData:
"""Minimal CellData mock for testing."""
def init(self, code: str):
self.code = code

class CellIdGenerator:
"""Minimal CellIdGenerator mock for testing."""
def init(self, prefix: str):
self.prefix = prefix
self.counter = 0

def new_id(self) -> str:
    self.counter += 1
    return f"{self.prefix}{self.counter}"

CellId_t = str # For testing purposes
from marimo._ast.cell_manager import CellManager

------------------------ UNIT TESTS ------------------------

Basic Test Cases

def test_empty_manager():
"""Should return None when no cells exist."""
cm = CellManager()
codeflash_output = cm.get_cell_id_by_code("anything"); result = codeflash_output # 835ns -> 609ns (37.1% faster)

Edge Test Cases

def test_manager_prefix_is_ignored():
"""Prefix in cell IDs should not affect code matching."""
cm1 = CellManager(prefix="A")
cm2 = CellManager(prefix="B")
cid1 = cm1.add_cell("foo")
cid2 = cm2.add_cell("foo")
codeflash_output = cm1.get_cell_id_by_code("foo")
codeflash_output = cm2.get_cell_id_by_code("foo")

#------------------------------------------------
from marimo._ast.cell_manager import CellManager

def test_CellManager_get_cell_id_by_code():
CellManager.get_cell_id_by_code(CellManager(prefix=''), '')

🔎 Concolic Coverage Tests and Runtime

Test File::Test Function	Original ⏱️	Optimized ⏱️	Speedup
codeflash_concolic_bps3n5s8/tmp7npshrmk/test_concolic_coverage.py::test_CellManager_get_cell_id_by_code	663ns	482ns	37.6%✅

To edit these changes git checkout codeflash/optimize-CellManager.get_cell_id_by_code-mhvh3uyy and push.