optimize data structure selection

Choose data structures and algorithms based on their computational complexity and access patterns rather than convenience. Consider performance implications when selecting between alternatives.

Key principles:

1. Match data structure to access patterns: Use np.array instead of Python lists when performing mathematical operations, as numpy can optimize operations internally without type conversion overhead.

2. Choose algorithms based on constraints: Select streaming algorithms when memory usage matters more than speed, and batch algorithms when speed is critical and memory is available.

3. Avoid expensive operations in hot paths: Replace costly operations like inspect.getmodule() with simpler alternatives such as direct I/O operations or cached lookups.

4. Make implementations algorithm-agnostic: Design interfaces that work with different underlying implementations (e.g., queue.clear() vs creating new queue instances).

Example from the codebase:

# Before: Python list requiring conversion
self.posenet_stds = [POSENET_STD_INITIAL_VALUE] * (POSENET_STD_HIST_HALF * 2)
old_mean = np.mean(self.posenet_stds[:POSENET_STD_HIST_HALF])  # Converts list to array internally

# After: Direct numpy array for better performance
self.posenet_stds = np.array([POSENET_STD_INITIAL_VALUE] * (POSENET_STD_HIST_HALF * 2))
old_mean = np.mean(self.posenet_stds[:POSENET_STD_HIST_HALF])  # No conversion needed

When choosing between algorithmic approaches, document the trade-offs. For instance, zstd.decompress() is faster for files with size headers, while streaming decompression handles variable-size data but with slight performance cost. Choose based on your data characteristics and constraints.