Class: GRPC::ClientStub
- Inherits:
-
Object
- Object
- GRPC::ClientStub
- Includes:
- Core::StatusCodes, GRPC::Core::TimeConsts
- Defined in:
- src/ruby/lib/grpc/generic/client_stub.rb
Overview
ClientStub represents a client connection to a gRPC server, and can be used to send requests.
Constant Summary collapse
- DEFAULT_TIMEOUT =
Default timeout is infinity.
INFINITE_FUTURE
Instance Attribute Summary collapse
-
#propagate_mask ⇒ Object
writeonly
Allows users of the stub to modify the propagate mask.
Class Method Summary collapse
-
.setup_channel(alt_chan, host, creds, channel_args = {}) ⇒ Object
setup_channel is used by #initialize to constuct a channel from its arguments.
Instance Method Summary collapse
-
#bidi_streamer(method, requests, marshal, unmarshal, deadline: nil, return_op: false, parent: nil, credentials: nil, metadata: {}, &blk) ⇒ Enumerator|nil|Operation
bidi_streamer sends a stream of requests to the GRPC server, and yields a stream of responses.
-
#client_streamer(method, requests, marshal, unmarshal, deadline: nil, return_op: false, parent: nil, credentials: nil, metadata: {}) ⇒ Object|Operation
client_streamer sends a stream of requests to a GRPC server, and returns a single response.
-
#initialize(host, creds, channel_override: nil, timeout: nil, propagate_mask: nil, channel_args: {}) ⇒ ClientStub
constructor
Creates a new ClientStub.
-
#request_response(method, req, marshal, unmarshal, deadline: nil, return_op: false, parent: nil, credentials: nil, metadata: {}) ⇒ Object
request_response sends a request to a GRPC server, and returns the response.
-
#server_streamer(method, req, marshal, unmarshal, deadline: nil, return_op: false, parent: nil, credentials: nil, metadata: {}, &blk) ⇒ Enumerator|Operation|nil
server_streamer sends one request to the GRPC server, which yields a stream of responses.
Methods included from GRPC::Core::TimeConsts
Constructor Details
#initialize(host, creds, channel_override: nil, timeout: nil, propagate_mask: nil, channel_args: {}) ⇒ ClientStub
Creates a new ClientStub.
Minimally, a stub is created with the just the host of the gRPC service it wishes to access, e.g.,
my_stub = ClientStub.new(example.host.com:50505,
:this_channel_is_insecure)
If a channel_override argument is passed, it will be used as the underlying channel. Otherwise, the channel_args argument will be used to construct a new underlying channel.
There are some specific keyword args that are not used to configure the channel:
-
:channel_override
when present, this must be a pre-created GRPC::Channel. If it’s present the host and arbitrary keyword arg areignored, and the RPC connection uses this channel.
-
:timeout
when present, this is the default timeout used for calls
107 108 109 110 111 112 113 114 115 116 117 118 |
# File 'src/ruby/lib/grpc/generic/client_stub.rb', line 107 def initialize(host, creds, channel_override: nil, timeout: nil, propagate_mask: nil, channel_args: {}) @ch = ClientStub.setup_channel(channel_override, host, creds, channel_args) alt_host = channel_args[Core::Channel::SSL_TARGET] @host = alt_host.nil? ? host : alt_host @propagate_mask = propagate_mask @timeout = timeout.nil? ? DEFAULT_TIMEOUT : timeout end |
Instance Attribute Details
#propagate_mask=(value) ⇒ Object (writeonly)
Allows users of the stub to modify the propagate mask.
This is an advanced feature for use when making calls to another gRPC server whilst running in the handler of an existing one.
69 70 71 |
# File 'src/ruby/lib/grpc/generic/client_stub.rb', line 69 def propagate_mask=(value) @propagate_mask = value end |
Class Method Details
.setup_channel(alt_chan, host, creds, channel_args = {}) ⇒ Object
setup_channel is used by #initialize to constuct a channel from its arguments.
48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 |
# File 'src/ruby/lib/grpc/generic/client_stub.rb', line 48 def self.setup_channel(alt_chan, host, creds, channel_args = {}) unless alt_chan.nil? fail(TypeError, '!Channel') unless alt_chan.is_a?(Core::Channel) return alt_chan end if channel_args['grpc.primary_user_agent'].nil? channel_args['grpc.primary_user_agent'] = '' else channel_args['grpc.primary_user_agent'] += ' ' end channel_args['grpc.primary_user_agent'] += "grpc-ruby/#{VERSION}" unless creds.is_a?(Core::ChannelCredentials) || creds.is_a?(Symbol) fail(TypeError, '!ChannelCredentials or Symbol') end Core::Channel.new(host, channel_args, creds) end |
Instance Method Details
#bidi_streamer(method, requests, marshal, unmarshal, deadline: nil, return_op: false, parent: nil, credentials: nil, metadata: {}, &blk) ⇒ Enumerator|nil|Operation
bidi_streamer sends a stream of requests to the GRPC server, and yields a stream of responses.
This method takes an Enumerable of requests, and returns and enumerable of responses.
requests ==
requests provides an ‘iterable’ of Requests. I.e. it follows Ruby’s #each enumeration protocol. In the simplest case, requests will be an array of marshallable objects; in typical case it will be an Enumerable that allows dynamic construction of the marshallable objects.
responses ==
This is an enumerator of responses. I.e, its #next method blocks waiting for the next response. Also, if at any point the block needs to consume all the remaining responses, this can be done using #each or #collect. Calling #each or #collect should only be done if the_call#writes_done has been called, otherwise the block will loop forever.
Flow Control ==
This is a blocking call.
-
the call completes when the next call to provided block returns
- False
-
the execution block parameters are two objects for sending and receiving responses, each of which blocks waiting for flow control. E.g, calles to bidi_call#remote_send will wait until flow control allows another write before returning; and obviously calls to responses#next block until the next response is available.
Termination ==
As well as sending and receiving messages, the block passed to the function is also responsible for:
-
calling bidi_call#writes_done to indicate no further reqs will be sent.
-
returning false if once the bidi stream is functionally completed.
Note that response#next will indicate that there are no further responses by throwing StopIteration, but can only happen either if bidi_call#writes_done is called.
To terminate the RPC correctly the block:
-
must call bidi#writes_done and then
* either return false as soon as there is no need for other responses * loop on responses#next until no further responses are available
Errors ==
An RuntimeError is raised if
-
the server responds with a non-OK status when any response is
-
retrieved
-
the deadline is exceeded
Return Value ==
if the return_op is false, the return value is an Enumerator of the results, unless a block is provided, in which case the block is executed with each response.
if return_op is true, the function returns an Operation whose #execute method runs the Bidi call. Again, Operation#execute either calls a given block with each response or returns an Enumerator of the responses.
412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 |
# File 'src/ruby/lib/grpc/generic/client_stub.rb', line 412 def bidi_streamer(method, requests, marshal, unmarshal, deadline: nil, return_op: false, parent: nil, credentials: nil, metadata: {}, &blk) c = new_active_call(method, marshal, unmarshal, deadline: deadline, parent: parent, credentials: credentials) return c.bidi_streamer(requests, metadata: , &blk) unless return_op # return the operation view of the active_call; define #execute # as a new method for this instance that invokes #bidi_streamer c.() op = c.operation op.define_singleton_method(:execute) do c.bidi_streamer(requests, &blk) end op end |
#client_streamer(method, requests, marshal, unmarshal, deadline: nil, return_op: false, parent: nil, credentials: nil, metadata: {}) ⇒ Object|Operation
client_streamer sends a stream of requests to a GRPC server, and returns a single response.
requests provides an ‘iterable’ of Requests. I.e. it follows Ruby’s #each enumeration protocol. In the simplest case, requests will be an array of marshallable objects; in typical case it will be an Enumerable that allows dynamic construction of the marshallable objects.
Flow Control ==
This is a blocking call.
-
it does not return until a response is received.
-
each requests is sent only when GRPC core’s flow control allows it to be sent.
Errors ==
An RuntimeError is raised if
-
the server responds with a non-OK status
-
the deadline is exceeded
Return Value ==
If return_op is false, the call consumes the requests and returns the response.
If return_op is true, the call returns the response.
221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 |
# File 'src/ruby/lib/grpc/generic/client_stub.rb', line 221 def client_streamer(method, requests, marshal, unmarshal, deadline: nil, return_op: false, parent: nil, credentials: nil, metadata: {}) c = new_active_call(method, marshal, unmarshal, deadline: deadline, parent: parent, credentials: credentials) return c.client_streamer(requests, metadata: ) unless return_op # return the operation view of the active_call; define #execute as a # new method for this instance that invokes #client_streamer. c.() op = c.operation op.define_singleton_method(:execute) do c.client_streamer(requests) end op end |
#request_response(method, req, marshal, unmarshal, deadline: nil, return_op: false, parent: nil, credentials: nil, metadata: {}) ⇒ Object
request_response sends a request to a GRPC server, and returns the response.
Flow Control ==
This is a blocking call.
-
it does not return until a response is received.
-
the requests is sent only when GRPC core’s flow control allows it to be sent.
Errors ==
An RuntimeError is raised if
-
the server responds with a non-OK status
-
the deadline is exceeded
Return Value ==
If return_op is false, the call returns the response
If return_op is true, the call returns an Operation, calling execute on the Operation returns the response.
157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 |
# File 'src/ruby/lib/grpc/generic/client_stub.rb', line 157 def request_response(method, req, marshal, unmarshal, deadline: nil, return_op: false, parent: nil, credentials: nil, metadata: {}) c = new_active_call(method, marshal, unmarshal, deadline: deadline, parent: parent, credentials: credentials) return c.request_response(req, metadata: ) unless return_op # return the operation view of the active_call; define #execute as a # new method for this instance that invokes #request_response. c.() op = c.operation op.define_singleton_method(:execute) do c.request_response(req, metadata: ) end op end |
#server_streamer(method, req, marshal, unmarshal, deadline: nil, return_op: false, parent: nil, credentials: nil, metadata: {}, &blk) ⇒ Enumerator|Operation|nil
server_streamer sends one request to the GRPC server, which yields a stream of responses.
responses provides an enumerator over the streamed responses, i.e. it follows Ruby’s #each iteration protocol. The enumerator blocks while waiting for each response, stops when the server signals that no further responses will be supplied. If the implicit block is provided, it is executed with each response as the argument and no result is returned.
Flow Control ==
This is a blocking call.
-
the request is sent only when GRPC core’s flow control allows it to be sent.
-
the request will not complete until the server sends the final response followed by a status message.
Errors ==
An RuntimeError is raised if
-
the server responds with a non-OK status when any response is
-
retrieved
-
the deadline is exceeded
Return Value ==
if the return_op is false, the return value is an Enumerator of the results, unless a block is provided, in which case the block is executed with each response.
if return_op is true, the function returns an Operation whose #execute method runs server streamer call. Again, Operation#execute either calls the given block with each response or returns an Enumerator of the responses.
Keyword Args ==
Unspecified keyword arguments are treated as metadata to be sent to the server.
299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 |
# File 'src/ruby/lib/grpc/generic/client_stub.rb', line 299 def server_streamer(method, req, marshal, unmarshal, deadline: nil, return_op: false, parent: nil, credentials: nil, metadata: {}, &blk) c = new_active_call(method, marshal, unmarshal, deadline: deadline, parent: parent, credentials: credentials) return c.server_streamer(req, metadata: , &blk) unless return_op # return the operation view of the active_call; define #execute # as a new method for this instance that invokes #server_streamer c.() op = c.operation op.define_singleton_method(:execute) do c.server_streamer(req, &blk) end op end |