Root Cause

Summary

Removed global mutable cache state from the user configuration module. The previous implementation used module-level _config_fingerprint and _config_cache variables for a fast-path optimization that was likely premature for configuration file handling.

Context

The original load_config() function stored parsed config and its SHA-1 fingerprint in module globals to avoid re-parsing unchanged files. This added complexity and hidden state that could cause cache staleness issues.

Root Cause

The fast-path optimization was unnecessary overhead for configuration files that:

• Are small (typically < 1KB)
• Are read infrequently (once per session or on demand)
• May change externally between calls

The cost of hashing and comparing fingerprints likely exceeded the cost of simply parsing the JSON.

Changes

• Removed _config_fingerprint and _config_cache module-level globals
• Simplified load_config() to read and parse file directly
• Changed save_config() return type from bool to None (always returned True)
• Changed set_default_model() return type from bool to None
• Removed dead except ConfigurationError: raise code in set_default_model()

Behavioral Impact

• Config loading is now simpler and more predictable
• No functional change in behavior - callers already handled None returns and exceptions
• Slightly more straightforward debugging with no hidden cache state

Related Cards

• [[utils]] - Parent system