Method _error_catcher

src/urllib3/response.py:893–952

Catch low-level python exceptions, instead re-raising urllib3 variants, so that low-level exceptions are not leaked in the high-level api. On exit, release the connection back to the pool.

(self)

    @contextmanager
    def _error_catcher(self) -> typing.Generator[None]:
        """
        Catch low-level python exceptions, instead re-raising urllib3
        variants, so that low-level exceptions are not leaked in the
        high-level api.

        On exit, release the connection back to the pool.
        """
        clean_exit = False

        try:
            try:
                yield

            except SocketTimeout as e:
                # FIXME: Ideally we'd like to include the url in the ReadTimeoutError but
                # there is yet no clean way to get at it from this context.
                raise ReadTimeoutError(self._pool, None, "Read timed out.") from e  # type: ignore[arg-type]

            except BaseSSLError as e:
                # SSL errors related to framing/MAC get wrapped and reraised here
                raise SSLError(e) from e

            except IncompleteRead as e:
                if (
                    e.expected is not None
                    and e.partial is not None
                    and e.expected == -e.partial
                ):
                    arg = "Response may not contain content."
                else:
                    arg = f"Connection broken: {e!r}"
                raise ProtocolError(arg, e) from e

            except (HTTPException, OSError) as e:
                raise ProtocolError(f"Connection broken: {e!r}", e) from e

            # If no exception is thrown, we should avoid cleaning up
            # unnecessarily.
            clean_exit = True
        finally:
            # If we didn't terminate cleanly, we need to throw away our
            # connection.
            if not clean_exit:
                # The response may not be closed but we're not going to use it
                # anymore so close it now to ensure that the connection is
                # released back to the pool.
                if self._original_response:
                    self._original_response.close()

                # Closing the response may not actually be sufficient to close
                # everything, so if we have a hold of the connection close that
                # too.
                if self._connection:
                    self._connection.close()

            # If we hold the original response but it's closed now, we should
            # return the connection back to the pool.