Class: Gapic::ServiceStub::RpcCall

Inherits:
Object
  • Object
show all
Defined in:
lib/gapic/grpc/service_stub/rpc_call.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(stub_method, stub_logger: nil, method_name: nil) ⇒ RpcCall

Creates an API object for making a single RPC call.

In typical usage, stub_method will be a proc used to make an RPC request. This will mostly likely be a bound method from a request Stub used to make an RPC call.

The result is created by applying a series of function decorators defined in this module to stub_method.

The result is another proc which has the same signature as the original.

Parameters:

  • stub_method (Proc) —

    Used to make a bare rpc call.



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# File 'lib/gapic/grpc/service_stub/rpc_call.rb', line 36

def initialize stub_method, stub_logger: nil, method_name: nil
  @stub_method = stub_method
  @stub_logger = stub_logger
  @method_name = method_name
  @request_id = LoggingConcerns.random_uuid4
end

Instance Attribute Details

#stub_method ⇒ Object (readonly)

Returns the value of attribute stub_method.



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# File 'lib/gapic/grpc/service_stub/rpc_call.rb', line 22

def stub_method
  @stub_method
end

Instance Method Details

#call(request, options: nil) {|response, operation| ... } ⇒ Object

Invoke the RPC call.

Examples:

require "google/showcase/v1beta1/echo_pb"
require "google/showcase/v1beta1/echo_services_pb"
require "gapic"
require "gapic/grpc"

echo_channel = ::GRPC::Core::Channel.new(
  "localhost:7469", nil, :this_channel_is_insecure
)
echo_stub = Gapic::ServiceStub.new(
  Google::Showcase::V1beta1::Echo::Stub,
  endpoint: "localhost:7469", credentials: echo_channel
)
echo_call = Gapic::ServiceStub::RpcCall.new echo_stub.method :echo

request = Google::Showcase::V1beta1::EchoRequest.new
response = echo_call.call request

Using custom call options:

require "google/showcase/v1beta1/echo_pb"
require "google/showcase/v1beta1/echo_services_pb"
require "gapic"
require "gapic/grpc"

echo_channel = ::GRPC::Core::Channel.new(
  "localhost:7469", nil, :this_channel_is_insecure
)
echo_stub = Gapic::ServiceStub.new(
  Google::Showcase::V1beta1::Echo::Stub,
  endpoint: "localhost:7469", credentials: echo_channel
)
echo_call = Gapic::ServiceStub::RpcCall.new echo_stub.method :echo

request = Google::Showcase::V1beta1::EchoRequest.new
options = Gapic::CallOptions.new(
  retry_policy = {
    retry_codes: [::GRPC::Core::StatusCodes::UNAVAILABLE]
  }
)
response = echo_call.call request, options: options

Accessing the RPC operation using a block:

require "google/showcase/v1beta1/echo_pb"
require "google/showcase/v1beta1/echo_services_pb"
require "gapic"
require "gapic/grpc"

echo_channel = ::GRPC::Core::Channel.new(
  "localhost:7469", nil, :this_channel_is_insecure
)
echo_stub = Gapic::ServiceStub.new(
  Google::Showcase::V1beta1::Echo::Stub,
  endpoint: "localhost:7469", credentials: echo_channel
)
echo_call = Gapic::ServiceStub::RpcCall.new echo_stub.method :echo

request = Google::Showcase::V1beta1::EchoRequest.new
metadata = echo_call.call request do |_response, operation|
  throw :response, operation.trailing_metadata
end

Parameters:

  • request (Object) —

    The request object.

  • options (Gapic::CallOptions, Hash) (defaults to: nil) —

    The options for making the RPC call. A Hash can be provided to customize the options object, using keys that match the arguments for CallOptions.new. This object should only be used once.

Yields:

  • (response, operation) —

    Access the response along with the RPC operation. Additionally, throwing :response, obj within the block will change the return value to obj.

Yield Parameters:

  • response (Object) —

    The response object.

  • operation (::GRPC::ActiveCall::Operation) —

    The RPC operation for the response.

Returns:

  • (Object) —

    The response object.



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# File 'lib/gapic/grpc/service_stub/rpc_call.rb', line 119

def call request, options: nil
  # Converts hash and nil to an options object
  options = Gapic::CallOptions.new(**options.to_h) if options.respond_to? :to_h
  deadline = calculate_deadline options
  metadata = options.metadata

  try_number = 1
  retried_exception = nil
  begin
    request = log_request request, metadata, try_number
    operation = stub_method.call request, deadline: deadline, metadata: metadata, return_op: true
    response = operation.execute
    catch :response do
      response = log_response response, try_number
      yield response, operation if block_given?
      response
    end
  rescue ::GRPC::DeadlineExceeded => e
    log_response e, try_number
    raise Gapic::GRPC::DeadlineExceededError.new e.message, root_cause: retried_exception
  rescue StandardError => e
    e = normalize_exception e
    log_response e, try_number

    if check_retry?(deadline) && options.retry_policy.call(e)
      retried_exception = e
      try_number += 1
      retry
    end

    raise e
  end
end