From c10165efe713a400de91bdeb24cb77c3ac4c1e30 Mon Sep 17 00:00:00 2001
From: "codeflash-ai[bot]"
 <148906541+codeflash-ai[bot]@users.noreply.github.com>
Date: Fri, 20 Feb 2026 04:13:14 +0000
Subject: [PATCH] Optimize _extract_context_subscriptions
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The optimization replaces `finditer()` with `findall()` for regex matching, achieving a **29% speedup** in runtime (from 1.32ms to 1.02ms).

**What Changed:**
Instead of iterating over match objects and calling `.group(1)` on each (`[match.group(1) for match in _CONTEXT_RE.finditer(component_source)]`), the code now uses `_CONTEXT_RE.findall(component_source)` to directly extract captured groups.

**Why It's Faster:**
1. **Eliminates intermediate objects**: `finditer()` returns an iterator of match objects, each requiring instantiation and a method call to `group(1)`. `findall()` with a capturing group directly returns the captured strings as a list.

2. **Reduces overhead**: The list comprehension in the original code introduces iteration overhead and function call overhead for each match. `findall()` is implemented in C within Python's regex engine, making it significantly more efficient.

3. **Memory efficiency**: No intermediate match objects need to be created, reducing allocations and garbage collection pressure.

**Performance Impact:**
The test results show consistent speedups across all cases:
- Simple cases (single context): **89-98% faster** (4.28μs → 2.26μs)
- Multiple contexts: **52-67% faster**
- Large-scale tests (1000 contexts): **37-39% faster** (454μs → 330μs)
- Edge cases (empty strings): **206% faster** (1.65μs → 541ns)

**Workload Benefits:**
Based on the function references, `_extract_context_subscriptions` is called during React component analysis for detecting context dependencies. While not in a tight loop, this function processes potentially large source files (test shows 1500+ line files). The optimization particularly benefits:
- Codebases with many context subscriptions (the 100-context test shows 39% speedup)
- Large source files (1000+ line files show 12-37% improvement)
- Batch analysis of multiple components

The optimization is universally beneficial across all input patterns with no regressions, making it a pure performance win.
---
 codeflash/languages/javascript/frameworks/react/context.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/codeflash/languages/javascript/frameworks/react/context.py b/codeflash/languages/javascript/frameworks/react/context.py
index 83b927ed3..84d56e6a3 100644
--- a/codeflash/languages/javascript/frameworks/react/context.py
+++ b/codeflash/languages/javascript/frameworks/react/context.py
@@ -174,7 +174,7 @@ def _extract_child_components(component_source: str, analyzer: TreeSitterAnalyze
 
 def _extract_context_subscriptions(component_source: str) -> list[str]:
     """Find React context subscriptions via useContext calls."""
-    return [match.group(1) for match in _CONTEXT_RE.finditer(component_source)]
+    return _CONTEXT_RE.findall(component_source)
 
 
 def _find_type_definition(type_name: str, source: str, analyzer: TreeSitterAnalyzer) -> str | None: