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Diffstat (limited to '.venv/lib/python3.12/site-packages/httpcore/_synchronization.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/httpcore/_synchronization.py | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/httpcore/_synchronization.py b/.venv/lib/python3.12/site-packages/httpcore/_synchronization.py new file mode 100644 index 00000000..2ecc9e9c --- /dev/null +++ b/.venv/lib/python3.12/site-packages/httpcore/_synchronization.py @@ -0,0 +1,318 @@ +from __future__ import annotations + +import threading +import types + +from ._exceptions import ExceptionMapping, PoolTimeout, map_exceptions + +# Our async synchronization primatives use either 'anyio' or 'trio' depending +# on if they're running under asyncio or trio. + +try: + import trio +except (ImportError, NotImplementedError): # pragma: nocover + trio = None # type: ignore + +try: + import anyio +except ImportError: # pragma: nocover + anyio = None # type: ignore + + +def current_async_library() -> str: + # Determine if we're running under trio or asyncio. + # See https://sniffio.readthedocs.io/en/latest/ + try: + import sniffio + except ImportError: # pragma: nocover + environment = "asyncio" + else: + environment = sniffio.current_async_library() + + if environment not in ("asyncio", "trio"): # pragma: nocover + raise RuntimeError("Running under an unsupported async environment.") + + if environment == "asyncio" and anyio is None: # pragma: nocover + raise RuntimeError( + "Running with asyncio requires installation of 'httpcore[asyncio]'." + ) + + if environment == "trio" and trio is None: # pragma: nocover + raise RuntimeError( + "Running with trio requires installation of 'httpcore[trio]'." + ) + + return environment + + +class AsyncLock: + """ + This is a standard lock. + + In the sync case `Lock` provides thread locking. + In the async case `AsyncLock` provides async locking. + """ + + def __init__(self) -> None: + self._backend = "" + + def setup(self) -> None: + """ + Detect if we're running under 'asyncio' or 'trio' and create + a lock with the correct implementation. + """ + self._backend = current_async_library() + if self._backend == "trio": + self._trio_lock = trio.Lock() + elif self._backend == "asyncio": + self._anyio_lock = anyio.Lock() + + async def __aenter__(self) -> AsyncLock: + if not self._backend: + self.setup() + + if self._backend == "trio": + await self._trio_lock.acquire() + elif self._backend == "asyncio": + await self._anyio_lock.acquire() + + return self + + async def __aexit__( + self, + exc_type: type[BaseException] | None = None, + exc_value: BaseException | None = None, + traceback: types.TracebackType | None = None, + ) -> None: + if self._backend == "trio": + self._trio_lock.release() + elif self._backend == "asyncio": + self._anyio_lock.release() + + +class AsyncThreadLock: + """ + This is a threading-only lock for no-I/O contexts. + + In the sync case `ThreadLock` provides thread locking. + In the async case `AsyncThreadLock` is a no-op. + """ + + def __enter__(self) -> AsyncThreadLock: + return self + + def __exit__( + self, + exc_type: type[BaseException] | None = None, + exc_value: BaseException | None = None, + traceback: types.TracebackType | None = None, + ) -> None: + pass + + +class AsyncEvent: + def __init__(self) -> None: + self._backend = "" + + def setup(self) -> None: + """ + Detect if we're running under 'asyncio' or 'trio' and create + a lock with the correct implementation. + """ + self._backend = current_async_library() + if self._backend == "trio": + self._trio_event = trio.Event() + elif self._backend == "asyncio": + self._anyio_event = anyio.Event() + + def set(self) -> None: + if not self._backend: + self.setup() + + if self._backend == "trio": + self._trio_event.set() + elif self._backend == "asyncio": + self._anyio_event.set() + + async def wait(self, timeout: float | None = None) -> None: + if not self._backend: + self.setup() + + if self._backend == "trio": + trio_exc_map: ExceptionMapping = {trio.TooSlowError: PoolTimeout} + timeout_or_inf = float("inf") if timeout is None else timeout + with map_exceptions(trio_exc_map): + with trio.fail_after(timeout_or_inf): + await self._trio_event.wait() + elif self._backend == "asyncio": + anyio_exc_map: ExceptionMapping = {TimeoutError: PoolTimeout} + with map_exceptions(anyio_exc_map): + with anyio.fail_after(timeout): + await self._anyio_event.wait() + + +class AsyncSemaphore: + def __init__(self, bound: int) -> None: + self._bound = bound + self._backend = "" + + def setup(self) -> None: + """ + Detect if we're running under 'asyncio' or 'trio' and create + a semaphore with the correct implementation. + """ + self._backend = current_async_library() + if self._backend == "trio": + self._trio_semaphore = trio.Semaphore( + initial_value=self._bound, max_value=self._bound + ) + elif self._backend == "asyncio": + self._anyio_semaphore = anyio.Semaphore( + initial_value=self._bound, max_value=self._bound + ) + + async def acquire(self) -> None: + if not self._backend: + self.setup() + + if self._backend == "trio": + await self._trio_semaphore.acquire() + elif self._backend == "asyncio": + await self._anyio_semaphore.acquire() + + async def release(self) -> None: + if self._backend == "trio": + self._trio_semaphore.release() + elif self._backend == "asyncio": + self._anyio_semaphore.release() + + +class AsyncShieldCancellation: + # For certain portions of our codebase where we're dealing with + # closing connections during exception handling we want to shield + # the operation from being cancelled. + # + # with AsyncShieldCancellation(): + # ... # clean-up operations, shielded from cancellation. + + def __init__(self) -> None: + """ + Detect if we're running under 'asyncio' or 'trio' and create + a shielded scope with the correct implementation. + """ + self._backend = current_async_library() + + if self._backend == "trio": + self._trio_shield = trio.CancelScope(shield=True) + elif self._backend == "asyncio": + self._anyio_shield = anyio.CancelScope(shield=True) + + def __enter__(self) -> AsyncShieldCancellation: + if self._backend == "trio": + self._trio_shield.__enter__() + elif self._backend == "asyncio": + self._anyio_shield.__enter__() + return self + + def __exit__( + self, + exc_type: type[BaseException] | None = None, + exc_value: BaseException | None = None, + traceback: types.TracebackType | None = None, + ) -> None: + if self._backend == "trio": + self._trio_shield.__exit__(exc_type, exc_value, traceback) + elif self._backend == "asyncio": + self._anyio_shield.__exit__(exc_type, exc_value, traceback) + + +# Our thread-based synchronization primitives... + + +class Lock: + """ + This is a standard lock. + + In the sync case `Lock` provides thread locking. + In the async case `AsyncLock` provides async locking. + """ + + def __init__(self) -> None: + self._lock = threading.Lock() + + def __enter__(self) -> Lock: + self._lock.acquire() + return self + + def __exit__( + self, + exc_type: type[BaseException] | None = None, + exc_value: BaseException | None = None, + traceback: types.TracebackType | None = None, + ) -> None: + self._lock.release() + + +class ThreadLock: + """ + This is a threading-only lock for no-I/O contexts. + + In the sync case `ThreadLock` provides thread locking. + In the async case `AsyncThreadLock` is a no-op. + """ + + def __init__(self) -> None: + self._lock = threading.Lock() + + def __enter__(self) -> ThreadLock: + self._lock.acquire() + return self + + def __exit__( + self, + exc_type: type[BaseException] | None = None, + exc_value: BaseException | None = None, + traceback: types.TracebackType | None = None, + ) -> None: + self._lock.release() + + +class Event: + def __init__(self) -> None: + self._event = threading.Event() + + def set(self) -> None: + self._event.set() + + def wait(self, timeout: float | None = None) -> None: + if timeout == float("inf"): # pragma: no cover + timeout = None + if not self._event.wait(timeout=timeout): + raise PoolTimeout() # pragma: nocover + + +class Semaphore: + def __init__(self, bound: int) -> None: + self._semaphore = threading.Semaphore(value=bound) + + def acquire(self) -> None: + self._semaphore.acquire() + + def release(self) -> None: + self._semaphore.release() + + +class ShieldCancellation: + # Thread-synchronous codebases don't support cancellation semantics. + # We have this class because we need to mirror the async and sync + # cases within our package, but it's just a no-op. + def __enter__(self) -> ShieldCancellation: + return self + + def __exit__( + self, + exc_type: type[BaseException] | None = None, + exc_value: BaseException | None = None, + traceback: types.TracebackType | None = None, + ) -> None: + pass |