Commit 3ba49a0
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Optimize _find_class_node
The optimized code achieves a **14% runtime improvement** by eliminating redundant work in a recursive function that traverses abstract syntax trees.
**Key Optimization:**
The primary performance gain comes from moving the `type_declarations` dictionary to module-level as `_TYPE_DECLARATIONS`. In the original code, this dictionary was recreated on every recursive call (622 times based on profiler data), consuming ~36% of the function's runtime (lines allocating the dictionary took 8.8% + 6.2% + 6.4% + 5.8% = 27.2% combined). By creating it once at module load time, this overhead is completely eliminated.
**Additional Micro-optimization:**
The code also caches `node.type` in a local variable `node_type` before the dictionary lookup. While this provides minimal benefit (~1-2% based on profiler differences), it slightly reduces attribute access overhead in the hot path where `node.type` would otherwise be accessed twice (once for the `in` check, once for the dictionary lookup on match).
**Why This Works:**
The function performs recursive tree traversal, visiting each node exactly once. Since the type_declarations mapping is constant, recreating it 622 times (once per node visited) is pure waste. Python dictionary creation, even for small dictionaries, involves memory allocation and hash table setup - overhead that compounds significantly in recursive scenarios.
**Test Case Performance:**
The optimization shows consistent improvements across all test cases (7-20% faster), with the most significant gains in simpler cases like `test_basic_single_class_found` (19.8% faster) and `test_missing_name_field_does_not_crash_and_returns_none` (16.4% faster). These cases benefit most because a higher percentage of their runtime was spent on dictionary creation relative to other operations. The UTF-8 test case shows smaller gains (11%) because more time is spent in string decoding operations.
**Impact:**
This optimization is particularly valuable when `_find_type_node` (or its wrapper `_find_class_node`) is called frequently on large ASTs, as the savings multiply with tree size and call frequency. The function appears to be used for locating Java type declarations in parsed source code - a common operation in code analysis tools that could be invoked many times during batch processing.1 parent 41b08a9 commit 3ba49a0
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