Module: GRPC::GenericService::Dsl
- Defined in:
- src/ruby/lib/grpc/generic/service.rb
Overview
Provides a simple DSL to describe RPC services.
E.g, a Maths service that uses the serializable messages DivArgs, DivReply and Num might define its endpoint uses the following way:
rpc :div DivArgs, DivReply # single request, single response rpc :sum stream(Num), Num # streamed input, single response rpc :fib FibArgs, stream(Num) # single request, streamed response rpc :div_many stream(DivArgs), stream(DivReply)
# streamed req and resp
Each ‘rpc’ adds an RpcDesc to classes including this module, and #assert_rpc_descs_have_methods is used to ensure the including class provides methods with signatures that support all the descriptors.
Instance Attribute Summary collapse
-
#marshal_class_method ⇒ Object
the name of the instance method used to marshal events to a byte stream.
-
#service_name ⇒ Object
This allows configuration of the service name.
-
#unmarshal_class_method ⇒ Object
the name of the class method used to unmarshal from a byte stream.
Instance Method Summary collapse
- #assert_can_marshal(cls) ⇒ Object
- #inherited(subclass) ⇒ Object
-
#rpc(name, input, output) ⇒ Object
Adds an RPC spec.
-
#rpc_descs ⇒ Object
the RpcDescs defined for this GenericService, keyed by name.
-
#rpc_stub_class ⇒ Object
Creates a rpc client class with methods for accessing the methods currently in rpc_descs.
-
#stream(cls) ⇒ Object
Cls wrapped in a RpcDesc::Stream.
Instance Attribute Details
#marshal_class_method ⇒ Object
the name of the instance method used to marshal events to a byte stream.
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# File 'src/ruby/lib/grpc/generic/service.rb', line 128 def marshal_class_method @marshal_class_method ||= :marshal end |
#service_name ⇒ Object
This allows configuration of the service name.
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# File 'src/ruby/lib/grpc/generic/service.rb', line 92 def service_name @service_name end |
#unmarshal_class_method ⇒ Object
the name of the class method used to unmarshal from a byte stream.
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# File 'src/ruby/lib/grpc/generic/service.rb', line 133 def unmarshal_class_method @unmarshal_class_method ||= :unmarshal end |
Instance Method Details
#assert_can_marshal(cls) ⇒ Object
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# File 'src/ruby/lib/grpc/generic/service.rb', line 137 def assert_can_marshal(cls) cls = cls.type if cls.is_a? RpcDesc::Stream mth = unmarshal_class_method unless cls.methods.include? mth fail(ArgumentError, "#{cls} needs #{cls}.#{mth}") end mth = marshal_class_method return if cls.methods.include? mth fail(ArgumentError, "#{cls} needs #{cls}.#{mth}") end |
#inherited(subclass) ⇒ Object
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# File 'src/ruby/lib/grpc/generic/service.rb', line 119 def inherited(subclass) # Each subclass should have a distinct class variable with its own # rpc_descs subclass.rpc_descs.merge!(rpc_descs) subclass.service_name = service_name end |
#rpc(name, input, output) ⇒ Object
Adds an RPC spec.
Takes the RPC name and the classes representing the types to be serialized, and adds them to the including classes rpc_desc hash.
input and output should both have the methods #marshal and #unmarshal that are responsible for writing and reading an object instance from a byte buffer respectively.
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# File 'src/ruby/lib/grpc/generic/service.rb', line 106 def rpc(name, input, output) fail(DuplicateRpcName, name) if rpc_descs.key? name assert_can_marshal(input) assert_can_marshal(output) rpc_descs[name] = RpcDesc.new(name, input, output, marshal_class_method, unmarshal_class_method) define_method(GenericService.underscore(name.to_s).to_sym) do |_, _| fail GRPC::BadStatus.new_status_exception( GRPC::Core::StatusCodes::UNIMPLEMENTED) end end |
#rpc_descs ⇒ Object
the RpcDescs defined for this GenericService, keyed by name.
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# File 'src/ruby/lib/grpc/generic/service.rb', line 156 def rpc_descs @rpc_descs ||= {} end |
#rpc_stub_class ⇒ Object
Creates a rpc client class with methods for accessing the methods currently in rpc_descs.
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# File 'src/ruby/lib/grpc/generic/service.rb', line 162 def rpc_stub_class descs = rpc_descs route_prefix = service_name Class.new(ClientStub) do # @param host [String] the host the stub connects to # @param creds [Core::ChannelCredentials|Symbol] The channel # credentials to use, or :this_channel_is_insecure otherwise # @param kw [KeywordArgs] the channel arguments, plus any optional # args for configuring the client's channel def initialize(host, creds, **kw) super(host, creds, **kw) end # Used define_method to add a method for each rpc_desc. Each method # calls the base class method for the given descriptor. descs.each_pair do |name, desc| mth_name = GenericService.underscore(name.to_s).to_sym marshal = desc.marshal_proc unmarshal = desc.unmarshal_proc(:output) route = "/#{route_prefix}/#{name}" if desc.request_response? define_method(mth_name) do |req, = {}| GRPC.logger.debug("calling #{@host}:#{route}") request_response(route, req, marshal, unmarshal, ) end elsif desc.client_streamer? define_method(mth_name) do |reqs, = {}| GRPC.logger.debug("calling #{@host}:#{route}") client_streamer(route, reqs, marshal, unmarshal, ) end elsif desc.server_streamer? define_method(mth_name) do |req, = {}, &blk| GRPC.logger.debug("calling #{@host}:#{route}") server_streamer(route, req, marshal, unmarshal, , &blk) end else # is a bidi_stream define_method(mth_name) do |reqs, = {}, &blk| GRPC.logger.debug("calling #{@host}:#{route}") bidi_streamer(route, reqs, marshal, unmarshal, , &blk) end end end end end |