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| | """Functions that obviate explicit stubs and explicit channels.""" |
| |
|
| | import collections |
| | import datetime |
| | import logging |
| | import os |
| | import threading |
| | from typing import (Any, AnyStr, Callable, Dict, Iterator, Optional, Sequence, |
| | Tuple, TypeVar, Union) |
| |
|
| | import grpc |
| | from grpc.experimental import experimental_api |
| |
|
| | RequestType = TypeVar('RequestType') |
| | ResponseType = TypeVar('ResponseType') |
| |
|
| | OptionsType = Sequence[Tuple[str, str]] |
| | CacheKey = Tuple[str, OptionsType, Optional[grpc.ChannelCredentials], |
| | Optional[grpc.Compression]] |
| |
|
| | _LOGGER = logging.getLogger(__name__) |
| |
|
| | _EVICTION_PERIOD_KEY = "GRPC_PYTHON_MANAGED_CHANNEL_EVICTION_SECONDS" |
| | if _EVICTION_PERIOD_KEY in os.environ: |
| | _EVICTION_PERIOD = datetime.timedelta( |
| | seconds=float(os.environ[_EVICTION_PERIOD_KEY])) |
| | _LOGGER.debug("Setting managed channel eviction period to %s", |
| | _EVICTION_PERIOD) |
| | else: |
| | _EVICTION_PERIOD = datetime.timedelta(minutes=10) |
| |
|
| | _MAXIMUM_CHANNELS_KEY = "GRPC_PYTHON_MANAGED_CHANNEL_MAXIMUM" |
| | if _MAXIMUM_CHANNELS_KEY in os.environ: |
| | _MAXIMUM_CHANNELS = int(os.environ[_MAXIMUM_CHANNELS_KEY]) |
| | _LOGGER.debug("Setting maximum managed channels to %d", _MAXIMUM_CHANNELS) |
| | else: |
| | _MAXIMUM_CHANNELS = 2**8 |
| |
|
| | _DEFAULT_TIMEOUT_KEY = "GRPC_PYTHON_DEFAULT_TIMEOUT_SECONDS" |
| | if _DEFAULT_TIMEOUT_KEY in os.environ: |
| | _DEFAULT_TIMEOUT = float(os.environ[_DEFAULT_TIMEOUT_KEY]) |
| | _LOGGER.debug("Setting default timeout seconds to %f", _DEFAULT_TIMEOUT) |
| | else: |
| | _DEFAULT_TIMEOUT = 60.0 |
| |
|
| |
|
| | def _create_channel(target: str, options: Sequence[Tuple[str, str]], |
| | channel_credentials: Optional[grpc.ChannelCredentials], |
| | compression: Optional[grpc.Compression]) -> grpc.Channel: |
| | _LOGGER.debug( |
| | f"Creating secure channel with credentials '{channel_credentials}', " + |
| | f"options '{options}' and compression '{compression}'") |
| | return grpc.secure_channel(target, |
| | credentials=channel_credentials, |
| | options=options, |
| | compression=compression) |
| |
|
| |
|
| | class ChannelCache: |
| | |
| | _singleton = None |
| | _lock: threading.RLock = threading.RLock() |
| | _condition: threading.Condition = threading.Condition(lock=_lock) |
| | _eviction_ready: threading.Event = threading.Event() |
| |
|
| | _mapping: Dict[CacheKey, Tuple[grpc.Channel, datetime.datetime]] |
| | _eviction_thread: threading.Thread |
| |
|
| | def __init__(self): |
| | self._mapping = collections.OrderedDict() |
| | self._eviction_thread = threading.Thread( |
| | target=ChannelCache._perform_evictions, daemon=True) |
| | self._eviction_thread.start() |
| |
|
| | @staticmethod |
| | def get(): |
| | with ChannelCache._lock: |
| | if ChannelCache._singleton is None: |
| | ChannelCache._singleton = ChannelCache() |
| | ChannelCache._eviction_ready.wait() |
| | return ChannelCache._singleton |
| |
|
| | def _evict_locked(self, key: CacheKey): |
| | channel, _ = self._mapping.pop(key) |
| | _LOGGER.debug("Evicting channel %s with configuration %s.", channel, |
| | key) |
| | channel.close() |
| | del channel |
| |
|
| | @staticmethod |
| | def _perform_evictions(): |
| | while True: |
| | with ChannelCache._lock: |
| | ChannelCache._eviction_ready.set() |
| | if not ChannelCache._singleton._mapping: |
| | ChannelCache._condition.wait() |
| | elif len(ChannelCache._singleton._mapping) > _MAXIMUM_CHANNELS: |
| | key = next(iter(ChannelCache._singleton._mapping.keys())) |
| | ChannelCache._singleton._evict_locked(key) |
| | |
| | else: |
| | key, (_, eviction_time) = next( |
| | iter(ChannelCache._singleton._mapping.items())) |
| | now = datetime.datetime.now() |
| | if eviction_time <= now: |
| | ChannelCache._singleton._evict_locked(key) |
| | continue |
| | else: |
| | time_to_eviction = (eviction_time - now).total_seconds() |
| | |
| | |
| | |
| | |
| | |
| | ChannelCache._condition.wait(timeout=time_to_eviction) |
| |
|
| | def get_channel(self, target: str, options: Sequence[Tuple[str, str]], |
| | channel_credentials: Optional[grpc.ChannelCredentials], |
| | insecure: bool, |
| | compression: Optional[grpc.Compression]) -> grpc.Channel: |
| | if insecure and channel_credentials: |
| | raise ValueError("The insecure option is mutually exclusive with " + |
| | "the channel_credentials option. Please use one " + |
| | "or the other.") |
| | if insecure: |
| | channel_credentials = grpc.experimental.insecure_channel_credentials( |
| | ) |
| | elif channel_credentials is None: |
| | _LOGGER.debug("Defaulting to SSL channel credentials.") |
| | channel_credentials = grpc.ssl_channel_credentials() |
| | key = (target, options, channel_credentials, compression) |
| | with self._lock: |
| | channel_data = self._mapping.get(key, None) |
| | if channel_data is not None: |
| | channel = channel_data[0] |
| | self._mapping.pop(key) |
| | self._mapping[key] = (channel, datetime.datetime.now() + |
| | _EVICTION_PERIOD) |
| | return channel |
| | else: |
| | channel = _create_channel(target, options, channel_credentials, |
| | compression) |
| | self._mapping[key] = (channel, datetime.datetime.now() + |
| | _EVICTION_PERIOD) |
| | if len(self._mapping) == 1 or len( |
| | self._mapping) >= _MAXIMUM_CHANNELS: |
| | self._condition.notify() |
| | return channel |
| |
|
| | def _test_only_channel_count(self) -> int: |
| | with self._lock: |
| | return len(self._mapping) |
| |
|
| |
|
| | @experimental_api |
| | def unary_unary( |
| | request: RequestType, |
| | target: str, |
| | method: str, |
| | request_serializer: Optional[Callable[[Any], bytes]] = None, |
| | response_deserializer: Optional[Callable[[bytes], Any]] = None, |
| | options: Sequence[Tuple[AnyStr, AnyStr]] = (), |
| | channel_credentials: Optional[grpc.ChannelCredentials] = None, |
| | insecure: bool = False, |
| | call_credentials: Optional[grpc.CallCredentials] = None, |
| | compression: Optional[grpc.Compression] = None, |
| | wait_for_ready: Optional[bool] = None, |
| | timeout: Optional[float] = _DEFAULT_TIMEOUT, |
| | metadata: Optional[Sequence[Tuple[str, Union[str, bytes]]]] = None |
| | ) -> ResponseType: |
| | """Invokes a unary-unary RPC without an explicitly specified channel. |
| | |
| | THIS IS AN EXPERIMENTAL API. |
| | |
| | This is backed by a per-process cache of channels. Channels are evicted |
| | from the cache after a fixed period by a background. Channels will also be |
| | evicted if more than a configured maximum accumulate. |
| | |
| | The default eviction period is 10 minutes. One may set the environment |
| | variable "GRPC_PYTHON_MANAGED_CHANNEL_EVICTION_SECONDS" to configure this. |
| | |
| | The default maximum number of channels is 256. One may set the |
| | environment variable "GRPC_PYTHON_MANAGED_CHANNEL_MAXIMUM" to configure |
| | this. |
| | |
| | Args: |
| | request: An iterator that yields request values for the RPC. |
| | target: The server address. |
| | method: The name of the RPC method. |
| | request_serializer: Optional :term:`serializer` for serializing the request |
| | message. Request goes unserialized in case None is passed. |
| | response_deserializer: Optional :term:`deserializer` for deserializing the response |
| | message. Response goes undeserialized in case None is passed. |
| | options: An optional list of key-value pairs (:term:`channel_arguments` in gRPC Core |
| | runtime) to configure the channel. |
| | channel_credentials: A credential applied to the whole channel, e.g. the |
| | return value of grpc.ssl_channel_credentials() or |
| | grpc.insecure_channel_credentials(). |
| | insecure: If True, specifies channel_credentials as |
| | :term:`grpc.insecure_channel_credentials()`. This option is mutually |
| | exclusive with the `channel_credentials` option. |
| | call_credentials: A call credential applied to each call individually, |
| | e.g. the output of grpc.metadata_call_credentials() or |
| | grpc.access_token_call_credentials(). |
| | compression: An optional value indicating the compression method to be |
| | used over the lifetime of the channel, e.g. grpc.Compression.Gzip. |
| | wait_for_ready: An optional flag indicating whether the RPC should fail |
| | immediately if the connection is not ready at the time the RPC is |
| | invoked, or if it should wait until the connection to the server |
| | becomes ready. When using this option, the user will likely also want |
| | to set a timeout. Defaults to True. |
| | timeout: An optional duration of time in seconds to allow for the RPC, |
| | after which an exception will be raised. If timeout is unspecified, |
| | defaults to a timeout controlled by the |
| | GRPC_PYTHON_DEFAULT_TIMEOUT_SECONDS environment variable. If that is |
| | unset, defaults to 60 seconds. Supply a value of None to indicate that |
| | no timeout should be enforced. |
| | metadata: Optional metadata to send to the server. |
| | |
| | Returns: |
| | The response to the RPC. |
| | """ |
| | channel = ChannelCache.get().get_channel(target, options, |
| | channel_credentials, insecure, |
| | compression) |
| | multicallable = channel.unary_unary(method, request_serializer, |
| | response_deserializer) |
| | wait_for_ready = wait_for_ready if wait_for_ready is not None else True |
| | return multicallable(request, |
| | metadata=metadata, |
| | wait_for_ready=wait_for_ready, |
| | credentials=call_credentials, |
| | timeout=timeout) |
| |
|
| |
|
| | @experimental_api |
| | def unary_stream( |
| | request: RequestType, |
| | target: str, |
| | method: str, |
| | request_serializer: Optional[Callable[[Any], bytes]] = None, |
| | response_deserializer: Optional[Callable[[bytes], Any]] = None, |
| | options: Sequence[Tuple[AnyStr, AnyStr]] = (), |
| | channel_credentials: Optional[grpc.ChannelCredentials] = None, |
| | insecure: bool = False, |
| | call_credentials: Optional[grpc.CallCredentials] = None, |
| | compression: Optional[grpc.Compression] = None, |
| | wait_for_ready: Optional[bool] = None, |
| | timeout: Optional[float] = _DEFAULT_TIMEOUT, |
| | metadata: Optional[Sequence[Tuple[str, Union[str, bytes]]]] = None |
| | ) -> Iterator[ResponseType]: |
| | """Invokes a unary-stream RPC without an explicitly specified channel. |
| | |
| | THIS IS AN EXPERIMENTAL API. |
| | |
| | This is backed by a per-process cache of channels. Channels are evicted |
| | from the cache after a fixed period by a background. Channels will also be |
| | evicted if more than a configured maximum accumulate. |
| | |
| | The default eviction period is 10 minutes. One may set the environment |
| | variable "GRPC_PYTHON_MANAGED_CHANNEL_EVICTION_SECONDS" to configure this. |
| | |
| | The default maximum number of channels is 256. One may set the |
| | environment variable "GRPC_PYTHON_MANAGED_CHANNEL_MAXIMUM" to configure |
| | this. |
| | |
| | Args: |
| | request: An iterator that yields request values for the RPC. |
| | target: The server address. |
| | method: The name of the RPC method. |
| | request_serializer: Optional :term:`serializer` for serializing the request |
| | message. Request goes unserialized in case None is passed. |
| | response_deserializer: Optional :term:`deserializer` for deserializing the response |
| | message. Response goes undeserialized in case None is passed. |
| | options: An optional list of key-value pairs (:term:`channel_arguments` in gRPC Core |
| | runtime) to configure the channel. |
| | channel_credentials: A credential applied to the whole channel, e.g. the |
| | return value of grpc.ssl_channel_credentials(). |
| | insecure: If True, specifies channel_credentials as |
| | :term:`grpc.insecure_channel_credentials()`. This option is mutually |
| | exclusive with the `channel_credentials` option. |
| | call_credentials: A call credential applied to each call individually, |
| | e.g. the output of grpc.metadata_call_credentials() or |
| | grpc.access_token_call_credentials(). |
| | compression: An optional value indicating the compression method to be |
| | used over the lifetime of the channel, e.g. grpc.Compression.Gzip. |
| | wait_for_ready: An optional flag indicating whether the RPC should fail |
| | immediately if the connection is not ready at the time the RPC is |
| | invoked, or if it should wait until the connection to the server |
| | becomes ready. When using this option, the user will likely also want |
| | to set a timeout. Defaults to True. |
| | timeout: An optional duration of time in seconds to allow for the RPC, |
| | after which an exception will be raised. If timeout is unspecified, |
| | defaults to a timeout controlled by the |
| | GRPC_PYTHON_DEFAULT_TIMEOUT_SECONDS environment variable. If that is |
| | unset, defaults to 60 seconds. Supply a value of None to indicate that |
| | no timeout should be enforced. |
| | metadata: Optional metadata to send to the server. |
| | |
| | Returns: |
| | An iterator of responses. |
| | """ |
| | channel = ChannelCache.get().get_channel(target, options, |
| | channel_credentials, insecure, |
| | compression) |
| | multicallable = channel.unary_stream(method, request_serializer, |
| | response_deserializer) |
| | wait_for_ready = wait_for_ready if wait_for_ready is not None else True |
| | return multicallable(request, |
| | metadata=metadata, |
| | wait_for_ready=wait_for_ready, |
| | credentials=call_credentials, |
| | timeout=timeout) |
| |
|
| |
|
| | @experimental_api |
| | def stream_unary( |
| | request_iterator: Iterator[RequestType], |
| | target: str, |
| | method: str, |
| | request_serializer: Optional[Callable[[Any], bytes]] = None, |
| | response_deserializer: Optional[Callable[[bytes], Any]] = None, |
| | options: Sequence[Tuple[AnyStr, AnyStr]] = (), |
| | channel_credentials: Optional[grpc.ChannelCredentials] = None, |
| | insecure: bool = False, |
| | call_credentials: Optional[grpc.CallCredentials] = None, |
| | compression: Optional[grpc.Compression] = None, |
| | wait_for_ready: Optional[bool] = None, |
| | timeout: Optional[float] = _DEFAULT_TIMEOUT, |
| | metadata: Optional[Sequence[Tuple[str, Union[str, bytes]]]] = None |
| | ) -> ResponseType: |
| | """Invokes a stream-unary RPC without an explicitly specified channel. |
| | |
| | THIS IS AN EXPERIMENTAL API. |
| | |
| | This is backed by a per-process cache of channels. Channels are evicted |
| | from the cache after a fixed period by a background. Channels will also be |
| | evicted if more than a configured maximum accumulate. |
| | |
| | The default eviction period is 10 minutes. One may set the environment |
| | variable "GRPC_PYTHON_MANAGED_CHANNEL_EVICTION_SECONDS" to configure this. |
| | |
| | The default maximum number of channels is 256. One may set the |
| | environment variable "GRPC_PYTHON_MANAGED_CHANNEL_MAXIMUM" to configure |
| | this. |
| | |
| | Args: |
| | request_iterator: An iterator that yields request values for the RPC. |
| | target: The server address. |
| | method: The name of the RPC method. |
| | request_serializer: Optional :term:`serializer` for serializing the request |
| | message. Request goes unserialized in case None is passed. |
| | response_deserializer: Optional :term:`deserializer` for deserializing the response |
| | message. Response goes undeserialized in case None is passed. |
| | options: An optional list of key-value pairs (:term:`channel_arguments` in gRPC Core |
| | runtime) to configure the channel. |
| | channel_credentials: A credential applied to the whole channel, e.g. the |
| | return value of grpc.ssl_channel_credentials(). |
| | call_credentials: A call credential applied to each call individually, |
| | e.g. the output of grpc.metadata_call_credentials() or |
| | grpc.access_token_call_credentials(). |
| | insecure: If True, specifies channel_credentials as |
| | :term:`grpc.insecure_channel_credentials()`. This option is mutually |
| | exclusive with the `channel_credentials` option. |
| | compression: An optional value indicating the compression method to be |
| | used over the lifetime of the channel, e.g. grpc.Compression.Gzip. |
| | wait_for_ready: An optional flag indicating whether the RPC should fail |
| | immediately if the connection is not ready at the time the RPC is |
| | invoked, or if it should wait until the connection to the server |
| | becomes ready. When using this option, the user will likely also want |
| | to set a timeout. Defaults to True. |
| | timeout: An optional duration of time in seconds to allow for the RPC, |
| | after which an exception will be raised. If timeout is unspecified, |
| | defaults to a timeout controlled by the |
| | GRPC_PYTHON_DEFAULT_TIMEOUT_SECONDS environment variable. If that is |
| | unset, defaults to 60 seconds. Supply a value of None to indicate that |
| | no timeout should be enforced. |
| | metadata: Optional metadata to send to the server. |
| | |
| | Returns: |
| | The response to the RPC. |
| | """ |
| | channel = ChannelCache.get().get_channel(target, options, |
| | channel_credentials, insecure, |
| | compression) |
| | multicallable = channel.stream_unary(method, request_serializer, |
| | response_deserializer) |
| | wait_for_ready = wait_for_ready if wait_for_ready is not None else True |
| | return multicallable(request_iterator, |
| | metadata=metadata, |
| | wait_for_ready=wait_for_ready, |
| | credentials=call_credentials, |
| | timeout=timeout) |
| |
|
| |
|
| | @experimental_api |
| | def stream_stream( |
| | request_iterator: Iterator[RequestType], |
| | target: str, |
| | method: str, |
| | request_serializer: Optional[Callable[[Any], bytes]] = None, |
| | response_deserializer: Optional[Callable[[bytes], Any]] = None, |
| | options: Sequence[Tuple[AnyStr, AnyStr]] = (), |
| | channel_credentials: Optional[grpc.ChannelCredentials] = None, |
| | insecure: bool = False, |
| | call_credentials: Optional[grpc.CallCredentials] = None, |
| | compression: Optional[grpc.Compression] = None, |
| | wait_for_ready: Optional[bool] = None, |
| | timeout: Optional[float] = _DEFAULT_TIMEOUT, |
| | metadata: Optional[Sequence[Tuple[str, Union[str, bytes]]]] = None |
| | ) -> Iterator[ResponseType]: |
| | """Invokes a stream-stream RPC without an explicitly specified channel. |
| | |
| | THIS IS AN EXPERIMENTAL API. |
| | |
| | This is backed by a per-process cache of channels. Channels are evicted |
| | from the cache after a fixed period by a background. Channels will also be |
| | evicted if more than a configured maximum accumulate. |
| | |
| | The default eviction period is 10 minutes. One may set the environment |
| | variable "GRPC_PYTHON_MANAGED_CHANNEL_EVICTION_SECONDS" to configure this. |
| | |
| | The default maximum number of channels is 256. One may set the |
| | environment variable "GRPC_PYTHON_MANAGED_CHANNEL_MAXIMUM" to configure |
| | this. |
| | |
| | Args: |
| | request_iterator: An iterator that yields request values for the RPC. |
| | target: The server address. |
| | method: The name of the RPC method. |
| | request_serializer: Optional :term:`serializer` for serializing the request |
| | message. Request goes unserialized in case None is passed. |
| | response_deserializer: Optional :term:`deserializer` for deserializing the response |
| | message. Response goes undeserialized in case None is passed. |
| | options: An optional list of key-value pairs (:term:`channel_arguments` in gRPC Core |
| | runtime) to configure the channel. |
| | channel_credentials: A credential applied to the whole channel, e.g. the |
| | return value of grpc.ssl_channel_credentials(). |
| | call_credentials: A call credential applied to each call individually, |
| | e.g. the output of grpc.metadata_call_credentials() or |
| | grpc.access_token_call_credentials(). |
| | insecure: If True, specifies channel_credentials as |
| | :term:`grpc.insecure_channel_credentials()`. This option is mutually |
| | exclusive with the `channel_credentials` option. |
| | compression: An optional value indicating the compression method to be |
| | used over the lifetime of the channel, e.g. grpc.Compression.Gzip. |
| | wait_for_ready: An optional flag indicating whether the RPC should fail |
| | immediately if the connection is not ready at the time the RPC is |
| | invoked, or if it should wait until the connection to the server |
| | becomes ready. When using this option, the user will likely also want |
| | to set a timeout. Defaults to True. |
| | timeout: An optional duration of time in seconds to allow for the RPC, |
| | after which an exception will be raised. If timeout is unspecified, |
| | defaults to a timeout controlled by the |
| | GRPC_PYTHON_DEFAULT_TIMEOUT_SECONDS environment variable. If that is |
| | unset, defaults to 60 seconds. Supply a value of None to indicate that |
| | no timeout should be enforced. |
| | metadata: Optional metadata to send to the server. |
| | |
| | Returns: |
| | An iterator of responses. |
| | """ |
| | channel = ChannelCache.get().get_channel(target, options, |
| | channel_credentials, insecure, |
| | compression) |
| | multicallable = channel.stream_stream(method, request_serializer, |
| | response_deserializer) |
| | wait_for_ready = wait_for_ready if wait_for_ready is not None else True |
| | return multicallable(request_iterator, |
| | metadata=metadata, |
| | wait_for_ready=wait_for_ready, |
| | credentials=call_credentials, |
| | timeout=timeout) |
| |
|