client.py

# -*- coding: utf-8 -*-
# Copyright 2020 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
from collections import OrderedDict
from distutils import util
import os
import re
from typing import (
    Callable,
    Dict,
    Optional,
    Iterable,
    Iterator,
    Sequence,
    Tuple,
    Type,
    Union,
)
import pkg_resources

from google.api_core import client_options as client_options_lib  # type: ignore
from google.api_core import exceptions as core_exceptions  # type: ignore
from google.api_core import gapic_v1  # type: ignore
from google.api_core import retry as retries  # type: ignore
from google.auth import credentials as ga_credentials  # type: ignore
from google.auth.transport import mtls  # type: ignore
from google.auth.transport.grpc import SslCredentials  # type: ignore
from google.auth.exceptions import MutualTLSChannelError  # type: ignore
from google.oauth2 import service_account  # type: ignore

from google.cloud.bigquery_storage_v1beta2.types import storage
from google.cloud.bigquery_storage_v1beta2.types import stream
from google.cloud.bigquery_storage_v1beta2.types import table
from google.protobuf import timestamp_pb2  # type: ignore
from google.rpc import status_pb2  # type: ignore
from .transports.base import BigQueryWriteTransport, DEFAULT_CLIENT_INFO
from .transports.grpc import BigQueryWriteGrpcTransport
from .transports.grpc_asyncio import BigQueryWriteGrpcAsyncIOTransport


class BigQueryWriteClientMeta(type):
    """Metaclass for the BigQueryWrite client.

    This provides class-level methods for building and retrieving
    support objects (e.g. transport) without polluting the client instance
    objects.
    """

    _transport_registry = OrderedDict()  # type: Dict[str, Type[BigQueryWriteTransport]]
    _transport_registry["grpc"] = BigQueryWriteGrpcTransport
    _transport_registry["grpc_asyncio"] = BigQueryWriteGrpcAsyncIOTransport

    def get_transport_class(cls, label: str = None,) -> Type[BigQueryWriteTransport]:
        """Returns an appropriate transport class.

        Args:
            label: The name of the desired transport. If none is
                provided, then the first transport in the registry is used.

        Returns:
            The transport class to use.
        """
        # If a specific transport is requested, return that one.
        if label:
            return cls._transport_registry[label]

        # No transport is requested; return the default (that is, the first one
        # in the dictionary).
        return next(iter(cls._transport_registry.values()))


class BigQueryWriteClient(metaclass=BigQueryWriteClientMeta):
    """BigQuery Write API.
    The Write API can be used to write data to BigQuery.
    """

    @staticmethod
    def _get_default_mtls_endpoint(api_endpoint):
        """Converts api endpoint to mTLS endpoint.

        Convert "*.sandbox.googleapis.com" and "*.googleapis.com" to
        "*.mtls.sandbox.googleapis.com" and "*.mtls.googleapis.com" respectively.
        Args:
            api_endpoint (Optional[str]): the api endpoint to convert.
        Returns:
            str: converted mTLS api endpoint.
        """
        if not api_endpoint:
            return api_endpoint

        mtls_endpoint_re = re.compile(
            r"(?P<name>[^.]+)(?P<mtls>\.mtls)?(?P<sandbox>\.sandbox)?(?P<googledomain>\.googleapis\.com)?"
        )

        m = mtls_endpoint_re.match(api_endpoint)
        name, mtls, sandbox, googledomain = m.groups()
        if mtls or not googledomain:
            return api_endpoint

        if sandbox:
            return api_endpoint.replace(
                "sandbox.googleapis.com", "mtls.sandbox.googleapis.com"
            )

        return api_endpoint.replace(".googleapis.com", ".mtls.googleapis.com")

    DEFAULT_ENDPOINT = "bigquerystorage.googleapis.com"
    DEFAULT_MTLS_ENDPOINT = _get_default_mtls_endpoint.__func__(  # type: ignore
        DEFAULT_ENDPOINT
    )

    @classmethod
    def from_service_account_info(cls, info: dict, *args, **kwargs):
        """Creates an instance of this client using the provided credentials
            info.

        Args:
            info (dict): The service account private key info.
            args: Additional arguments to pass to the constructor.
            kwargs: Additional arguments to pass to the constructor.

        Returns:
            BigQueryWriteClient: The constructed client.
        """
        credentials = service_account.Credentials.from_service_account_info(info)
        kwargs["credentials"] = credentials
        return cls(*args, **kwargs)

    @classmethod
    def from_service_account_file(cls, filename: str, *args, **kwargs):
        """Creates an instance of this client using the provided credentials
            file.

        Args:
            filename (str): The path to the service account private key json
                file.
            args: Additional arguments to pass to the constructor.
            kwargs: Additional arguments to pass to the constructor.

        Returns:
            BigQueryWriteClient: The constructed client.
        """
        credentials = service_account.Credentials.from_service_account_file(filename)
        kwargs["credentials"] = credentials
        return cls(*args, **kwargs)

    from_service_account_json = from_service_account_file

    @property
    def transport(self) -> BigQueryWriteTransport:
        """Returns the transport used by the client instance.

        Returns:
            BigQueryWriteTransport: The transport used by the client
                instance.
        """
        return self._transport

    @staticmethod
    def table_path(project: str, dataset: str, table: str,) -> str:
        """Returns a fully-qualified table string."""
        return "projects/{project}/datasets/{dataset}/tables/{table}".format(
            project=project, dataset=dataset, table=table,
        )

    @staticmethod
    def parse_table_path(path: str) -> Dict[str, str]:
        """Parses a table path into its component segments."""
        m = re.match(
            r"^projects/(?P<project>.+?)/datasets/(?P<dataset>.+?)/tables/(?P<table>.+?)$",
            path,
        )
        return m.groupdict() if m else {}

    @staticmethod
    def write_stream_path(project: str, dataset: str, table: str, stream: str,) -> str:
        """Returns a fully-qualified write_stream string."""
        return "projects/{project}/datasets/{dataset}/tables/{table}/streams/{stream}".format(
            project=project, dataset=dataset, table=table, stream=stream,
        )

    @staticmethod
    def parse_write_stream_path(path: str) -> Dict[str, str]:
        """Parses a write_stream path into its component segments."""
        m = re.match(
            r"^projects/(?P<project>.+?)/datasets/(?P<dataset>.+?)/tables/(?P<table>.+?)/streams/(?P<stream>.+?)$",
            path,
        )
        return m.groupdict() if m else {}

    @staticmethod
    def common_billing_account_path(billing_account: str,) -> str:
        """Returns a fully-qualified billing_account string."""
        return "billingAccounts/{billing_account}".format(
            billing_account=billing_account,
        )

    @staticmethod
    def parse_common_billing_account_path(path: str) -> Dict[str, str]:
        """Parse a billing_account path into its component segments."""
        m = re.match(r"^billingAccounts/(?P<billing_account>.+?)$", path)
        return m.groupdict() if m else {}

    @staticmethod
    def common_folder_path(folder: str,) -> str:
        """Returns a fully-qualified folder string."""
        return "folders/{folder}".format(folder=folder,)

    @staticmethod
    def parse_common_folder_path(path: str) -> Dict[str, str]:
        """Parse a folder path into its component segments."""
        m = re.match(r"^folders/(?P<folder>.+?)$", path)
        return m.groupdict() if m else {}

    @staticmethod
    def common_organization_path(organization: str,) -> str:
        """Returns a fully-qualified organization string."""
        return "organizations/{organization}".format(organization=organization,)

    @staticmethod
    def parse_common_organization_path(path: str) -> Dict[str, str]:
        """Parse a organization path into its component segments."""
        m = re.match(r"^organizations/(?P<organization>.+?)$", path)
        return m.groupdict() if m else {}

    @staticmethod
    def common_project_path(project: str,) -> str:
        """Returns a fully-qualified project string."""
        return "projects/{project}".format(project=project,)

    @staticmethod
    def parse_common_project_path(path: str) -> Dict[str, str]:
        """Parse a project path into its component segments."""
        m = re.match(r"^projects/(?P<project>.+?)$", path)
        return m.groupdict() if m else {}

    @staticmethod
    def common_location_path(project: str, location: str,) -> str:
        """Returns a fully-qualified location string."""
        return "projects/{project}/locations/{location}".format(
            project=project, location=location,
        )

    @staticmethod
    def parse_common_location_path(path: str) -> Dict[str, str]:
        """Parse a location path into its component segments."""
        m = re.match(r"^projects/(?P<project>.+?)/locations/(?P<location>.+?)$", path)
        return m.groupdict() if m else {}

    def __init__(
        self,
        *,
        credentials: Optional[ga_credentials.Credentials] = None,
        transport: Union[str, BigQueryWriteTransport, None] = None,
        client_options: Optional[client_options_lib.ClientOptions] = None,
        client_info: gapic_v1.client_info.ClientInfo = DEFAULT_CLIENT_INFO,
    ) -> None:
        """Instantiates the big query write client.

        Args:
            credentials (Optional[google.auth.credentials.Credentials]): The
                authorization credentials to attach to requests. These
                credentials identify the application to the service; if none
                are specified, the client will attempt to ascertain the
                credentials from the environment.
            transport (Union[str, BigQueryWriteTransport]): The
                transport to use. If set to None, a transport is chosen
                automatically.
            client_options (google.api_core.client_options.ClientOptions): Custom options for the
                client. It won't take effect if a ``transport`` instance is provided.
                (1) The ``api_endpoint`` property can be used to override the
                default endpoint provided by the client. GOOGLE_API_USE_MTLS_ENDPOINT
                environment variable can also be used to override the endpoint:
                "always" (always use the default mTLS endpoint), "never" (always
                use the default regular endpoint) and "auto" (auto switch to the
                default mTLS endpoint if client certificate is present, this is
                the default value). However, the ``api_endpoint`` property takes
                precedence if provided.
                (2) If GOOGLE_API_USE_CLIENT_CERTIFICATE environment variable
                is "true", then the ``client_cert_source`` property can be used
                to provide client certificate for mutual TLS transport. If
                not provided, the default SSL client certificate will be used if
                present. If GOOGLE_API_USE_CLIENT_CERTIFICATE is "false" or not
                set, no client certificate will be used.
            client_info (google.api_core.gapic_v1.client_info.ClientInfo):
                The client info used to send a user-agent string along with
                API requests. If ``None``, then default info will be used.
                Generally, you only need to set this if you're developing
                your own client library.

        Raises:
            google.auth.exceptions.MutualTLSChannelError: If mutual TLS transport
                creation failed for any reason.
        """
        if isinstance(client_options, dict):
            client_options = client_options_lib.from_dict(client_options)
        if client_options is None:
            client_options = client_options_lib.ClientOptions()

        # Create SSL credentials for mutual TLS if needed.
        use_client_cert = bool(
            util.strtobool(os.getenv("GOOGLE_API_USE_CLIENT_CERTIFICATE", "false"))
        )

        client_cert_source_func = None
        is_mtls = False
        if use_client_cert:
            if client_options.client_cert_source:
                is_mtls = True
                client_cert_source_func = client_options.client_cert_source
            else:
                is_mtls = mtls.has_default_client_cert_source()
                if is_mtls:
                    client_cert_source_func = mtls.default_client_cert_source()
                else:
                    client_cert_source_func = None

        # Figure out which api endpoint to use.
        if client_options.api_endpoint is not None:
            api_endpoint = client_options.api_endpoint
        else:
            use_mtls_env = os.getenv("GOOGLE_API_USE_MTLS_ENDPOINT", "auto")
            if use_mtls_env == "never":
                api_endpoint = self.DEFAULT_ENDPOINT
            elif use_mtls_env == "always":
                api_endpoint = self.DEFAULT_MTLS_ENDPOINT
            elif use_mtls_env == "auto":
                if is_mtls:
                    api_endpoint = self.DEFAULT_MTLS_ENDPOINT
                else:
                    api_endpoint = self.DEFAULT_ENDPOINT
            else:
                raise MutualTLSChannelError(
                    "Unsupported GOOGLE_API_USE_MTLS_ENDPOINT value. Accepted "
                    "values: never, auto, always"
                )

        # Save or instantiate the transport.
        # Ordinarily, we provide the transport, but allowing a custom transport
        # instance provides an extensibility point for unusual situations.
        if isinstance(transport, BigQueryWriteTransport):
            # transport is a BigQueryWriteTransport instance.
            if credentials or client_options.credentials_file:
                raise ValueError(
                    "When providing a transport instance, "
                    "provide its credentials directly."
                )
            if client_options.scopes:
                raise ValueError(
                    "When providing a transport instance, provide its scopes "
                    "directly."
                )
            self._transport = transport
        else:
            Transport = type(self).get_transport_class(transport)
            self._transport = Transport(
                credentials=credentials,
                credentials_file=client_options.credentials_file,
                host=api_endpoint,
                scopes=client_options.scopes,
                client_cert_source_for_mtls=client_cert_source_func,
                quota_project_id=client_options.quota_project_id,
                client_info=client_info,
                always_use_jwt_access=(
                    Transport == type(self).get_transport_class("grpc")
                    or Transport == type(self).get_transport_class("grpc_asyncio")
                ),
            )

    def create_write_stream(
        self,
        request: storage.CreateWriteStreamRequest = None,
        *,
        parent: str = None,
        write_stream: stream.WriteStream = None,
        retry: retries.Retry = gapic_v1.method.DEFAULT,
        timeout: float = None,
        metadata: Sequence[Tuple[str, str]] = (),
    ) -> stream.WriteStream:
        r"""Creates a write stream to the given table. Additionally, every
        table has a special COMMITTED stream named '_default' to which
        data can be written. This stream doesn't need to be created
        using CreateWriteStream. It is a stream that can be used
        simultaneously by any number of clients. Data written to this
        stream is considered committed as soon as an acknowledgement is
        received.

        Args:
            request (google.cloud.bigquery_storage_v1beta2.types.CreateWriteStreamRequest):
                The request object. Request message for
                `CreateWriteStream`.
            parent (str):
                Required. Reference to the table to which the stream
                belongs, in the format of
                ``projects/{project}/datasets/{dataset}/tables/{table}``.

                This corresponds to the ``parent`` field
                on the ``request`` instance; if ``request`` is provided, this
                should not be set.
            write_stream (google.cloud.bigquery_storage_v1beta2.types.WriteStream):
                Required. Stream to be created.
                This corresponds to the ``write_stream`` field
                on the ``request`` instance; if ``request`` is provided, this
                should not be set.
            retry (google.api_core.retry.Retry): Designation of what errors, if any,
                should be retried.
            timeout (float): The timeout for this request.
            metadata (Sequence[Tuple[str, str]]): Strings which should be
                sent along with the request as metadata.

        Returns:
            google.cloud.bigquery_storage_v1beta2.types.WriteStream:
                Information about a single stream
                that gets data inside the storage
                system.

        """
        # Create or coerce a protobuf request object.
        # Sanity check: If we got a request object, we should *not* have
        # gotten any keyword arguments that map to the request.
        has_flattened_params = any([parent, write_stream])
        if request is not None and has_flattened_params:
            raise ValueError(
                "If the `request` argument is set, then none of "
                "the individual field arguments should be set."
            )

        # Minor optimization to avoid making a copy if the user passes
        # in a storage.CreateWriteStreamRequest.
        # There's no risk of modifying the input as we've already verified
        # there are no flattened fields.
        if not isinstance(request, storage.CreateWriteStreamRequest):
            request = storage.CreateWriteStreamRequest(request)
            # If we have keyword arguments corresponding to fields on the
            # request, apply these.
            if parent is not None:
                request.parent = parent
            if write_stream is not None:
                request.write_stream = write_stream

        # Wrap the RPC method; this adds retry and timeout information,
        # and friendly error handling.
        rpc = self._transport._wrapped_methods[self._transport.create_write_stream]

        # Certain fields should be provided within the metadata header;
        # add these here.
        metadata = tuple(metadata) + (
            gapic_v1.routing_header.to_grpc_metadata((("parent", request.parent),)),
        )

        # Send the request.
        response = rpc(request, retry=retry, timeout=timeout, metadata=metadata,)

        # Done; return the response.
        return response

    def append_rows(
        self,
        requests: Iterator[storage.AppendRowsRequest] = None,
        *,
        retry: retries.Retry = gapic_v1.method.DEFAULT,
        timeout: float = None,
        metadata: Sequence[Tuple[str, str]] = (),
    ) -> Iterable[storage.AppendRowsResponse]:
        r"""Appends data to the given stream.

        If ``offset`` is specified, the ``offset`` is checked against
        the end of stream. The server returns ``OUT_OF_RANGE`` in
        ``AppendRowsResponse`` if an attempt is made to append to an
        offset beyond the current end of the stream or
        ``ALREADY_EXISTS`` if user provids an ``offset`` that has
        already been written to. User can retry with adjusted offset
        within the same RPC stream. If ``offset`` is not specified,
        append happens at the end of the stream.

        The response contains the offset at which the append happened.
        Responses are received in the same order in which requests are
        sent. There will be one response for each successful request. If
        the ``offset`` is not set in response, it means append didn't
        happen due to some errors. If one request fails, all the
        subsequent requests will also fail until a success request is
        made again.

        If the stream is of ``PENDING`` type, data will only be
        available for read operations after the stream is committed.

        Args:
            requests (Iterator[google.cloud.bigquery_storage_v1beta2.types.AppendRowsRequest]):
                The request object iterator. Request message for `AppendRows`.
            retry (google.api_core.retry.Retry): Designation of what errors, if any,
                should be retried.
            timeout (float): The timeout for this request.
            metadata (Sequence[Tuple[str, str]]): Strings which should be
                sent along with the request as metadata.

        Returns:
            Iterable[google.cloud.bigquery_storage_v1beta2.types.AppendRowsResponse]:
                Response message for AppendRows.
        """

        # Wrap the RPC method; this adds retry and timeout information,
        # and friendly error handling.
        rpc = self._transport._wrapped_methods[self._transport.append_rows]

        # Certain fields should be provided within the metadata header;
        # add these here.
        metadata = tuple(metadata) + (gapic_v1.routing_header.to_grpc_metadata(()),)

        # Send the request.
        response = rpc(requests, retry=retry, timeout=timeout, metadata=metadata,)

        # Done; return the response.
        return response

    def get_write_stream(
        self,
        request: storage.GetWriteStreamRequest = None,
        *,
        name: str = None,
        retry: retries.Retry = gapic_v1.method.DEFAULT,
        timeout: float = None,
        metadata: Sequence[Tuple[str, str]] = (),
    ) -> stream.WriteStream:
        r"""Gets a write stream.

        Args:
            request (google.cloud.bigquery_storage_v1beta2.types.GetWriteStreamRequest):
                The request object. Request message for
                `GetWriteStreamRequest`.
            name (str):
                Required. Name of the stream to get, in the form of
                ``projects/{project}/datasets/{dataset}/tables/{table}/streams/{stream}``.

                This corresponds to the ``name`` field
                on the ``request`` instance; if ``request`` is provided, this
                should not be set.
            retry (google.api_core.retry.Retry): Designation of what errors, if any,
                should be retried.
            timeout (float): The timeout for this request.
            metadata (Sequence[Tuple[str, str]]): Strings which should be
                sent along with the request as metadata.

        Returns:
            google.cloud.bigquery_storage_v1beta2.types.WriteStream:
                Information about a single stream
                that gets data inside the storage
                system.

        """
        # Create or coerce a protobuf request object.
        # Sanity check: If we got a request object, we should *not* have
        # gotten any keyword arguments that map to the request.
        has_flattened_params = any([name])
        if request is not None and has_flattened_params:
            raise ValueError(
                "If the `request` argument is set, then none of "
                "the individual field arguments should be set."
            )

        # Minor optimization to avoid making a copy if the user passes
        # in a storage.GetWriteStreamRequest.
        # There's no risk of modifying the input as we've already verified
        # there are no flattened fields.
        if not isinstance(request, storage.GetWriteStreamRequest):
            request = storage.GetWriteStreamRequest(request)
            # If we have keyword arguments corresponding to fields on the
            # request, apply these.
            if name is not None:
                request.name = name

        # Wrap the RPC method; this adds retry and timeout information,
        # and friendly error handling.
        rpc = self._transport._wrapped_methods[self._transport.get_write_stream]

        # Certain fields should be provided within the metadata header;
        # add these here.
        metadata = tuple(metadata) + (
            gapic_v1.routing_header.to_grpc_metadata((("name", request.name),)),
        )

        # Send the request.
        response = rpc(request, retry=retry, timeout=timeout, metadata=metadata,)

        # Done; return the response.
        return response

    def finalize_write_stream(
        self,
        request: storage.FinalizeWriteStreamRequest = None,
        *,
        name: str = None,
        retry: retries.Retry = gapic_v1.method.DEFAULT,
        timeout: float = None,
        metadata: Sequence[Tuple[str, str]] = (),
    ) -> storage.FinalizeWriteStreamResponse:
        r"""Finalize a write stream so that no new data can be appended to
        the stream. Finalize is not supported on the '_default' stream.

        Args:
            request (google.cloud.bigquery_storage_v1beta2.types.FinalizeWriteStreamRequest):
                The request object. Request message for invoking
                `FinalizeWriteStream`.
            name (str):
                Required. Name of the stream to finalize, in the form of
                ``projects/{project}/datasets/{dataset}/tables/{table}/streams/{stream}``.

                This corresponds to the ``name`` field
                on the ``request`` instance; if ``request`` is provided, this
                should not be set.
            retry (google.api_core.retry.Retry): Designation of what errors, if any,
                should be retried.
            timeout (float): The timeout for this request.
            metadata (Sequence[Tuple[str, str]]): Strings which should be
                sent along with the request as metadata.

        Returns:
            google.cloud.bigquery_storage_v1beta2.types.FinalizeWriteStreamResponse:
                Response message for FinalizeWriteStream.
        """
        # Create or coerce a protobuf request object.
        # Sanity check: If we got a request object, we should *not* have
        # gotten any keyword arguments that map to the request.
        has_flattened_params = any([name])
        if request is not None and has_flattened_params:
            raise ValueError(
                "If the `request` argument is set, then none of "
                "the individual field arguments should be set."
            )

        # Minor optimization to avoid making a copy if the user passes
        # in a storage.FinalizeWriteStreamRequest.
        # There's no risk of modifying the input as we've already verified
        # there are no flattened fields.
        if not isinstance(request, storage.FinalizeWriteStreamRequest):
            request = storage.FinalizeWriteStreamRequest(request)
            # If we have keyword arguments corresponding to fields on the
            # request, apply these.
            if name is not None:
                request.name = name

        # Wrap the RPC method; this adds retry and timeout information,
        # and friendly error handling.
        rpc = self._transport._wrapped_methods[self._transport.finalize_write_stream]

        # Certain fields should be provided within the metadata header;
        # add these here.
        metadata = tuple(metadata) + (
            gapic_v1.routing_header.to_grpc_metadata((("name", request.name),)),
        )

        # Send the request.
        response = rpc(request, retry=retry, timeout=timeout, metadata=metadata,)

        # Done; return the response.
        return response

    def batch_commit_write_streams(
        self,
        request: storage.BatchCommitWriteStreamsRequest = None,
        *,
        parent: str = None,
        retry: retries.Retry = gapic_v1.method.DEFAULT,
        timeout: float = None,
        metadata: Sequence[Tuple[str, str]] = (),
    ) -> storage.BatchCommitWriteStreamsResponse:
        r"""Atomically commits a group of ``PENDING`` streams that belong to
        the same ``parent`` table. Streams must be finalized before
        commit and cannot be committed multiple times. Once a stream is
        committed, data in the stream becomes available for read
        operations.

        Args:
            request (google.cloud.bigquery_storage_v1beta2.types.BatchCommitWriteStreamsRequest):
                The request object. Request message for
                `BatchCommitWriteStreams`.
            parent (str):
                Required. Parent table that all the streams should
                belong to, in the form of
                ``projects/{project}/datasets/{dataset}/tables/{table}``.

                This corresponds to the ``parent`` field
                on the ``request`` instance; if ``request`` is provided, this
                should not be set.
            retry (google.api_core.retry.Retry): Designation of what errors, if any,
                should be retried.
            timeout (float): The timeout for this request.
            metadata (Sequence[Tuple[str, str]]): Strings which should be
                sent along with the request as metadata.

        Returns:
            google.cloud.bigquery_storage_v1beta2.types.BatchCommitWriteStreamsResponse:
                Response message for BatchCommitWriteStreams.
        """
        # Create or coerce a protobuf request object.
        # Sanity check: If we got a request object, we should *not* have
        # gotten any keyword arguments that map to the request.
        has_flattened_params = any([parent])
        if request is not None and has_flattened_params:
            raise ValueError(
                "If the `request` argument is set, then none of "
                "the individual field arguments should be set."
            )

        # Minor optimization to avoid making a copy if the user passes
        # in a storage.BatchCommitWriteStreamsRequest.
        # There's no risk of modifying the input as we've already verified
        # there are no flattened fields.
        if not isinstance(request, storage.BatchCommitWriteStreamsRequest):
            request = storage.BatchCommitWriteStreamsRequest(request)
            # If we have keyword arguments corresponding to fields on the
            # request, apply these.
            if parent is not None:
                request.parent = parent

        # Wrap the RPC method; this adds retry and timeout information,
        # and friendly error handling.
        rpc = self._transport._wrapped_methods[
            self._transport.batch_commit_write_streams
        ]

        # Certain fields should be provided within the metadata header;
        # add these here.
        metadata = tuple(metadata) + (
            gapic_v1.routing_header.to_grpc_metadata((("parent", request.parent),)),
        )

        # Send the request.
        response = rpc(request, retry=retry, timeout=timeout, metadata=metadata,)

        # Done; return the response.
        return response

    def flush_rows(
        self,
        request: storage.FlushRowsRequest = None,
        *,
        write_stream: str = None,
        retry: retries.Retry = gapic_v1.method.DEFAULT,
        timeout: float = None,
        metadata: Sequence[Tuple[str, str]] = (),
    ) -> storage.FlushRowsResponse:
        r"""Flushes rows to a BUFFERED stream. If users are appending rows
        to BUFFERED stream, flush operation is required in order for the
        rows to become available for reading. A Flush operation flushes
        up to any previously flushed offset in a BUFFERED stream, to the
        offset specified in the request. Flush is not supported on the
        \_default stream, since it is not BUFFERED.

        Args:
            request (google.cloud.bigquery_storage_v1beta2.types.FlushRowsRequest):
                The request object. Request message for `FlushRows`.
            write_stream (str):
                Required. The stream that is the
                target of the flush operation.

                This corresponds to the ``write_stream`` field
                on the ``request`` instance; if ``request`` is provided, this
                should not be set.
            retry (google.api_core.retry.Retry): Designation of what errors, if any,
                should be retried.
            timeout (float): The timeout for this request.
            metadata (Sequence[Tuple[str, str]]): Strings which should be
                sent along with the request as metadata.

        Returns:
            google.cloud.bigquery_storage_v1beta2.types.FlushRowsResponse:
                Respond message for FlushRows.
        """
        # Create or coerce a protobuf request object.
        # Sanity check: If we got a request object, we should *not* have
        # gotten any keyword arguments that map to the request.
        has_flattened_params = any([write_stream])
        if request is not None and has_flattened_params:
            raise ValueError(
                "If the `request` argument is set, then none of "
                "the individual field arguments should be set."
            )

        # Minor optimization to avoid making a copy if the user passes
        # in a storage.FlushRowsRequest.
        # There's no risk of modifying the input as we've already verified
        # there are no flattened fields.
        if not isinstance(request, storage.FlushRowsRequest):
            request = storage.FlushRowsRequest(request)
            # If we have keyword arguments corresponding to fields on the
            # request, apply these.
            if write_stream is not None:
                request.write_stream = write_stream

        # Wrap the RPC method; this adds retry and timeout information,
        # and friendly error handling.
        rpc = self._transport._wrapped_methods[self._transport.flush_rows]

        # Certain fields should be provided within the metadata header;
        # add these here.
        metadata = tuple(metadata) + (
            gapic_v1.routing_header.to_grpc_metadata(
                (("write_stream", request.write_stream),)
            ),
        )

        # Send the request.
        response = rpc(request, retry=retry, timeout=timeout, metadata=metadata,)

        # Done; return the response.
        return response


try:
    DEFAULT_CLIENT_INFO = gapic_v1.client_info.ClientInfo(
        gapic_version=pkg_resources.get_distribution(
            "google-cloud-bigquery-storage",
        ).version,
    )
except pkg_resources.DistributionNotFound:
    DEFAULT_CLIENT_INFO = gapic_v1.client_info.ClientInfo()


__all__ = ("BigQueryWriteClient",)