* feat(lock_store): make locking backend overridable
Allow the centralised lock factory to use a pluggable backend instead of
the hardcoded Redis/file selection. Backends are resolved with precedence
override > CREWAI_LOCK_FACTORY env > built-in default:
- set_lock_backend()/reset_lock_backend() and a scoped lock_backend()
context manager for programmatic overrides
- CREWAI_LOCK_FACTORY="module:callable" env import-path, resolved lazily
and cached, with clear errors on malformed or non-callable specs
- LockBackend Protocol documenting the contract (raw name in, context
manager out; backend owns its namespacing)
Default Redis/file behavior is unchanged when nothing is overridden.
* refactor(lock_store): use explicit body for LockBackend protocol method
Replace the no-op `...` body with `raise NotImplementedError` to satisfy
the CodeQL ineffectual-statement check while keeping the Protocol
structural-typing only.
* refactor(lock_store): drop scoped lock_backend context manager
Keep the backend overridable via set_lock_backend/reset_lock_backend and
the CREWAI_LOCK_FACTORY env path, but remove the scoped lock_backend()
context manager. It was speculative surface and the only thread-unsafe
piece (racy save/restore of the module global); nothing depends on it.
* refactor(lock_store): drop reset_lock_backend alias
reset_lock_backend() was just set_lock_backend(None); callers use that
directly. Clearing the override is documented on set_lock_backend.
* style(lock_store): apply ruff format
* refactor(lock_store): simplify overridable backend to a single setter
Reduce the override surface to just set_lock_backend(): lock() uses the
custom backend when one is set, otherwise the unchanged Redis/file default.
Drop the CREWAI_LOCK_FACTORY env import-path, the runtime_checkable
Protocol, the precedence resolver, and the getter — a custom backend is
now any callable(name, *, timeout) -> context manager, registered in
process.
* fix(lock_store): snapshot backend to avoid check-then-call race
Read the module-global backend once into a local before the None check
and the call, so a concurrent set_lock_backend(None) cannot make lock()
invoke None.
* docs(lock_store): clarify name handling for custom backends
The default namespaces the lock name; custom backends receive it
verbatim. Correct the lock() docstring which implied namespacing always
happens.
* docs(lock_store): note set_lock_backend is for one-time startup setup
* Fix lock_store crash when redis package is not installed
`REDIS_URL` being set was enough to trigger a Redis lock, which would
raise `ImportError` if the `redis` package wasn't available. Added
`_redis_available()` to guard on both the env var and the import.
* Simplify tests
* Simplify tests #2
