§ ˜è[jJ ãóZ—dZddlmZddlZddlmZeje¦«Zd d „Z dd „Z dS)u®Best-effort accessors for the single-writer stream fence (#65991). The fence itself lives on ``AIAgent`` (``_claim_stream_writer`` / ``_stream_writer_is_current`` in ``run_agent.py``), but the streaming code paths that use it live in *other* modules — ``chat_completion_helpers`` (chat / anthropic / bedrock) and ``codex_runtime`` (codex responses). Calling the fence directly as ``agent._claim_stream_writer()`` from those modules makes them hard-depend on the method being present on whatever object is passed in as ``agent``. That coupling is a latent crash: a partially-updated checkout (the streaming helper module newer than ``run_agent``), a hot-reloaded gateway, a duck-typed agent, or a test double without the method turns an *additive* safety net into a fatal ``AttributeError`` that aborts the whole turn. A cron job died exactly this way with ``'AIAgent' object has no attribute '_claim_stream_writer'``. The fence is only ever allowed to drop a *provably* superseded stream — never the sole legitimate writer. So when the guard is unavailable (or raises), the correct degradation is "no fence": keep streaming. These helpers make the claim/check best-effort to guarantee that. é)Ú annotationsN)ÚAnyÚagentrÚreturnÚintcóΗt|dd¦«}t|¦«rD t|¦«¦«S#t$rt dd¬¦«YnwxYwdS)a€Claim the delta sink for the calling stream attempt, best-effort. Returns the agent's monotonic writer token when the fence is available, or ``0`` when the agent doesn't expose it (or the claim raised). A ``0`` token pairs with :func:`stream_writer_is_current` always returning ``True``, so a guard-less agent is simply never fenced instead of crashing the turn. Ú_claim_stream_writerNz7stream single-writer: claim failed; proceeding unfencedT©Úexc_infor)ÚgetattrÚcallablerÚ ExceptionÚloggerÚdebug)rÚclaims ú¾&A'Á&A')rrrr)rrrrrr) Ú__doc__Ú __future__rÚloggingÚtypingrÚ getLoggerÚ__name__rrr©órúr"s‚ðððð,#Ð"Ð"Ð"Ð"Ð"à€€€ØÐÐÐÐÐà ˆÔ ˜8Ñ $Ô $€ð ð ð ð ð(ðððððr!