Stream
Open source
RSS
Stream
Using a gRPC client creates a stream. The client should be connected to the server (client.connect
called) before creating a stream.
Class/Method | Description |
---|---|
Stream(client, url, [,params]) | Using a connected gRPC client and the method’s URL creates a stream. Optionally, you can pass params for additional configuration options like tags, metadata, etc. |
Stream.write(message) | Writes a message to the stream. |
Stream.on(event, handler) | Sets up handler functions for various events on the gRPC stream. |
Stream.end() | Signals to the server that the client has finished sending. |
EventHandler | The handler function for various events on the gRPC stream. |
Metadata | The metadata of a gRPC stream’s message. |
Examples
A k6 script that sends several randomly chosen points from the pre-generated feature database with a variable delay in between. Prints the statistics when they are sent from the server.
JavaScript
import { Client, Stream } from 'k6/net/grpc';
import { sleep } from 'k6';
const COORD_FACTOR = 1e7;
const GRPC_ADDR = __ENV.GRPC_ADDR || '127.0.0.1:10000';
const GRPC_PROTO_PATH = __ENV.GRPC_PROTO_PATH || '../../grpc_server/route_guide.proto';
const client = new Client();
client.load([], GRPC_PROTO_PATH);
// a sample DB of points
const DB = [
{
location: { latitude: 407838351, longitude: -746143763 },
name: 'Patriots Path, Mendham, NJ 07945, USA',
},
{
location: { latitude: 408122808, longitude: -743999179 },
name: '101 New Jersey 10, Whippany, NJ 07981, USA',
},
{
location: { latitude: 413628156, longitude: -749015468 },
name: 'U.S. 6, Shohola, PA 18458, USA',
},
{
location: { latitude: 419999544, longitude: -740371136 },
name: '5 Conners Road, Kingston, NY 12401, USA',
},
{
location: { latitude: 414008389, longitude: -743951297 },
name: 'Mid Hudson Psychiatric Center, New Hampton, NY 10958, USA',
},
{
location: { latitude: 419611318, longitude: -746524769 },
name: '287 Flugertown Road, Livingston Manor, NY 12758, USA',
},
{
location: { latitude: 406109563, longitude: -742186778 },
name: '4001 Tremley Point Road, Linden, NJ 07036, USA',
},
{
location: { latitude: 416802456, longitude: -742370183 },
name: '352 South Mountain Road, Wallkill, NY 12589, USA',
},
{
location: { latitude: 412950425, longitude: -741077389 },
name: 'Bailey Turn Road, Harriman, NY 10926, USA',
},
{
location: { latitude: 412144655, longitude: -743949739 },
name: '193-199 Wawayanda Road, Hewitt, NJ 07421, USA',
},
];
export default () => {
if (__ITER == 0) {
client.connect(GRPC_ADDR, { plaintext: true });
}
const stream = new Stream(client, 'main.RouteGuide/RecordRoute');
stream.on('data', (stats) => {
console.log('Finished trip with', stats.pointCount, 'points');
console.log('Passed', stats.featureCount, 'features');
console.log('Travelled', stats.distance, 'meters');
console.log('It took', stats.elapsedTime, 'seconds');
});
stream.on('error', (err) => {
console.log('Stream Error: ' + JSON.stringify(err));
});
stream.on('end', () => {
client.close();
console.log('All done');
});
// send 5 random items
for (let i = 0; i < 5; i++) {
const point = DB[Math.floor(Math.random() * DB.length)];
pointSender(stream, point);
}
// close the client stream
stream.end();
sleep(1);
};
const pointSender = (stream, point) => {
console.log(
'Visiting point ' +
point.name +
' ' +
point.location.latitude / COORD_FACTOR +
', ' +
point.location.longitude / COORD_FACTOR
);
// send the location to the server
stream.write(point.location);
sleep(0.5);
};
A k6 script that sends a rectangle message and results (features) are streamed back to the client.
JavaScript
import { Client, Stream } from 'k6/net/grpc';
import { sleep } from 'k6';
const COORD_FACTOR = 1e7;
const GRPC_ADDR = __ENV.GRPC_ADDR || '127.0.0.1:10000';
const GRPC_PROTO_PATH = __ENV.GRPC_PROTO_PATH || '../../grpc_server/route_guide.proto';
const client = new Client();
client.load([], GRPC_PROTO_PATH);
export default () => {
client.connect(GRPC_ADDR, { plaintext: true });
const stream = new Stream(client, 'main.FeatureExplorer/ListFeatures', null);
stream.on('data', function (feature) {
console.log(
'Found feature called "' +
feature.name +
'" at ' +
feature.location.latitude / COORD_FACTOR +
', ' +
feature.location.longitude / COORD_FACTOR
);
});
stream.on('end', function () {
// The server has finished sending
client.close();
console.log('All done');
});
stream.on('error', function (e) {
// An error has occurred and the stream has been closed.
console.log('Error: ' + JSON.stringify(e));
});
// send a message to the server
stream.write({
lo: {
latitude: 400000000,
longitude: -750000000,
},
hi: {
latitude: 420000000,
longitude: -730000000,
},
});
sleep(0.5);
};
The preceding examples use a demo server, which you can run with the following command (Golang should be installed) in k6 repository’s root:
bash
$ go run -mod=mod examples/grpc_server/*.go
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