The Lua gRPC binding.
gRPC-Lua depends on
All these libraries can be installed by conan C/C++ package manager.
- Install conan.
- Add conan repositories
conan remote add remote_bintray_conan-community https://api.bintray.com/conan/conan-community/conan
conan remote add remote_bintray_bincrafters https://api.bintray.com/conan/bincrafters/public-conan
conan remote add remote_bintray_inexorgame https://api.bintray.com/conan/inexorgame/inexor-conan
conan remote add remote_bintray_conan https://api.bintray.com/conan/conan/conan-transit
conan remote add remote_bintray_jinq0123 https://api.bintray.com/conan/jinq0123/test
conan create . user/channel --build missing
- The result
grpc_lua.dll
/grpc_lua.so
is in~/.conan/data/grpc-lua/0.1/user/channel/package/
...
- The result
See premake/README.md to use premake5 to generate VS solution.
Tutorial shows some codes in the route_guide example.
See examples/route_guide/route_guide.proto.
// Interface exported by the server.
service RouteGuide {
// A simple RPC.
rpc GetFeature(Point) returns (Feature) {}
// A server-to-client streaming RPC.
rpc ListFeatures(Rectangle) returns (stream Feature) {}
// A client-to-server streaming RPC.
rpc RecordRoute(stream Point) returns (RouteSummary) {}
// A Bidirectional streaming RPC.
rpc RouteChat(stream RouteNote) returns (stream RouteNote) {}
}
...
For both client and server codes:
local grpc = require("grpc_lua.grpc_lua")
grpc.import_proto_file("route_guide.proto")
No need to generate codes.
See examples/route_guide/route_guide_client.lua.
local c_channel = grpc.channel("localhost:50051")
local stub = grcp.service_stub(c_channel, "routeguide.RouteGuide")
-
Sync call
-
Simple RPC:
sync_get_feature()
local feature = stub.sync_request("GetFeature", point(409146138, -746188906))
-
Server-side streaming RPC:
sync_list_features()
local sync_reader = stub:sync_request_read("ListFeatures", rect) while true do local feature = sync_reader.read_one() if not feature then break end print("Found feature: "..inspect(feature)) end -- while
-
Client-side streaming RPC:
sync_record_route()
local sync_writer = stub.sync_request_write("RecordRoute") for i = 1, 10 do local feature = db.get_rand_feature() local loc = assert(feature.location) if not sync_writer.write(loc) then break end -- if end -- for -- Recv status and reponse. local summary, error_str, status_code = sync_writer.close() if summary then print_route_sumary(summary) end
-
Bidirectional streaming RPC:
sync_route_chat()
local sync_rdwr = stub.sync_request_rdwr("RouteChat") for _, note in ipairs(notes) do sync_rdwr.write(note) end sync_rdwr.close_writing() -- read remaining while true do local server_note = sync_rdwr.read_one() if not server_note then break end print("Got message: "..inspect(server_note)) end -- while
-
-
Async call
-
Simple RPC:
get_feature_async()
stub.async_request("GetFeature", point(409146138, -746188906), function(resp) print("Get feature: "..inspect(resp)) stub.shutdown() -- to return end) stub.run() -- run async requests until stub.shutdown()
-
Ignore response
stub.async_request("GetFeature", point()) -- ignore response
-
Set error callback
stub.set_error_cb(function(error_str, status_code) ... end)
beforeasync_request()
-
-
Run the stub
- Async calls need
run()
stub.run() -- run async requests until stub.shutdown()
stub.shutdown()
endsstub.run()
.
- Async calls need
-
Server-side streaming RPC:
list_features_async()
stub.async_request_read("ListFeatures", rect, function(f) assert("table" == type(f)) print(string.format("Got feature %s at %f,%f", f.name, f.location.latitude/kCoordFactor, f.location.longitude/kCoordFactor)) end, function(error_str, status_code) assert("number" == type(status_code)) stub.shutdown() -- To break Run(). end) stub.run() -- until stub.shutdown()
-
Client-side streaming RPC:
record_route_async()
local async_writer = stub.async_request_write("RecordRoute") for i = 1, 10 do local f = db.get_rand_feature() local loc = f.location if not async_writer:write(loc) do break end -- Broken stream. end -- for -- Recv reponse and status. async_writer.close( function(resp, error_str, status_code) if resp then print_route_summary(resp) end -- if stub.shutdown() -- to break run() end) stub.run() -- until stutdown()
-
Bidirectional streaming RPC:
route_chat_async()
local rdwr = stub.async_request_rdwr("RouteChat", function(error_str, status_code) stub.shutdown() -- to break run() end) for _, note in ipairs(notes) do rdwr.write(note) end rdwr.close_writing() -- Optional. rdwr.read_each(function(server_note) assert("table" == type(server_note)) print("Got message: "..inspect(server_note)) end) stub.run() -- until shutdown()
-
See examples/route_guide/route_guide_server.lua.
local svr = grpc.server()
svr:add_listening_port("0.0.0.0:50051")
-- Service implementation is a table.
local service = require("route_guide_service")
svr:register_service("routeguide.RouteGuide", service)
svr:run()
Service is a table with the service functions defined in the proto file. The function name must be the same as in the proto file. The function parameters are different for different RPC method types.
-
Simple RPC:
GetFeature()
--- Simple RPC method. -- @tab request -- @tparam Replier replier function M.GetFeature(request, replier) assert("table" == type(request)) assert("table" == type(replier)) local name = get_feature_name(request) local response = { name = name, location = request } replier:reply(response); end -- GetFeature()
replier
can be copied andreply()
later. -
Server-side streaming RPC:
ListFeatures()
--- Server-to-client streaming method. -- @table rectangle -- @tparam Writer writer function M.ListFeatures(rectangle, writer) assert("table" == type(rectangle)) assert("table" == type(writer)) ... for _, f in ipairs(db.features) do local l = f.location if l... then if not writer.write(f) then print("Failed to write.") break end -- if not writer.write() end -- if l end -- for _, f writer.close() end -- ListFeatures()
-
Client-side streaming RPC:
RecordRoute()
-
Should return a reader table:
--- Client-to-server streaming method. -- @tab replier `Replier` object -- @treturn table server reader object function M.RecordRoute(replier) assert("table" == type(replier)) return require("server_reader.RecordRouteReader"):new(replier, db) end -- RecordRoute()
-
the reader table should optionally have these methods
function Reader:on_msg(msg)
function Reader:on_error(error_str, status_code)
function Reader:on_end()
-
-
Bidirectional streaming RPC:
RouteChat()
-
Should return a reader table.
--- Bi-directional streaming method. -- @table writer `Writer` object -- @treturn table server reader object function M.RouteChat(writer) assert("table" == type(writer)) return require("server_reader.RouteChatReader"):new(writer, db) end -- RouteChat()
-
The reader table should optionally have methods as client-side streaming reader.
-
-
Install dependencies into
~/.conan/data
usingconan install
- Rename examples/conan_install.bat.example
to
conan_install.bat
- Run it.
- Rename examples/conan_install.bat.example
to
-
Copy required exe and dll.
- Rename examples/copy_from_conan.bat.example
to
copy_from_conan.bat
- Change variables in
copy_from_conan.bat
conandata
, conan data dir, default~/.conan/data
- package names, conan package names for dependencies
lua_cpp_package
luapbintf_package
grpc_lua_package
- Run it, which will copy exe and dlls from
~/.conan/data
- lua-cpp.exe
- lua-cpp.dll
- luapbintf.dll
- grpc_lua.dll
- Rename examples/copy_from_conan.bat.example
to
-
Start lua script
- helloworld
lua-cpp.exe greeter_server.lua
lua-cpp.exe greeter_client.lua
- route_guide
lua-cpp.exe route_guide_server.lua
lua-cpp.exe route_guide_client.lua
- helloworld
I think it is easy to integrate grpc-lua into Unity, but I have no time to do this. Work is:
- Use C version of Lua
- Support Lua5.1 and LuaJIT
- Build for iOS and Android
Unity uses Lua library compiled as C. If use lua.exe and lua.lib compiled as C, C++ objects on stack must be destructed correctly on error. See LuaIntf error handling.
Building with Lua51 or LuaJIT library should succeed. LuaPbIntf, which is used to encode and decode protobuf messages, need to be recompiled with Lua51 or LuaJIT.