feat: tlsping and tcpping using step-by-step (#815)

## Checklist

- [x] I have read the [contribution guidelines](https://github.com/ooni/probe-cli/blob/master/CONTRIBUTING.md)
- [x] reference issue for this pull request: https://github.com/ooni/probe/issues/2158
- [x] if you changed anything related how experiments work and you need to reflect these changes in the ooni/spec repository, please link to the related ooni/spec pull request: https://github.com/ooni/spec/pull/250

## Description

This diff refactors the codebase to reimplement tlsping and tcpping
to use the step-by-step measurements style.

See docs/design/dd-003-step-by-step.md for more information on the
step-by-step measurement style.

internal/engine/experiment/tcpping/tcpping.go

@@ -10,13 +10,13 @@ import (
 	"net/url"
 	"time"
 
-	"github.com/ooni/probe-cli/v3/internal/measurex"
+	"github.com/ooni/probe-cli/v3/internal/measurexlite"
 	"github.com/ooni/probe-cli/v3/internal/model"
 )
 
 const (
 	testName    = "tcpping"
-	testVersion = "0.1.0"
+	testVersion = "0.2.0"
 )
 
 // Config contains the experiment configuration.
@@ -49,7 +49,7 @@ type TestKeys struct {
 
 // SinglePing contains the results of a single ping.
 type SinglePing struct {
-	TCPConnect []*measurex.ArchivalTCPConnect `json:"tcp_connect"`
+	TCPConnect *model.ArchivalTCPConnectResult `json:"tcp_connect"`
 }
 
 // Measurer performs the measurement.
@@ -103,42 +103,47 @@ func (m *Measurer) Run(
 	}
 	tk := new(TestKeys)
 	measurement.TestKeys = tk
-	out := make(chan *measurex.EndpointMeasurement)
-	mxmx := measurex.NewMeasurerWithDefaultSettings()
-	go m.tcpPingLoop(ctx, mxmx, parsed.Host, out)
+	out := make(chan *SinglePing)
+	go m.tcpPingLoop(ctx, measurement.MeasurementStartTimeSaved, sess.Logger(), parsed.Host, out)
 	for len(tk.Pings) < int(m.config.repetitions()) {
-		meas := <-out
-		tk.Pings = append(tk.Pings, &SinglePing{
-			TCPConnect: measurex.NewArchivalTCPConnectList(meas.Connect),
-		})
+		tk.Pings = append(tk.Pings, <-out)
 	}
 	return nil // return nil so we always submit the measurement
 }
 
 // tcpPingLoop sends all the ping requests and emits the results onto the out channel.
-func (m *Measurer) tcpPingLoop(ctx context.Context, mxmx *measurex.Measurer,
-	address string, out chan<- *measurex.EndpointMeasurement) {
+func (m *Measurer) tcpPingLoop(ctx context.Context, zeroTime time.Time,
+	logger model.Logger, address string, out chan<- *SinglePing) {
 	ticker := time.NewTicker(m.config.delay())
 	defer ticker.Stop()
 	for i := int64(0); i < m.config.repetitions(); i++ {
-		go m.tcpPingAsync(ctx, mxmx, address, out)
+		go m.tcpPingAsync(ctx, i, zeroTime, logger, address, out)
 		<-ticker.C
 	}
 }
 
 // tcpPingAsync performs a TCP ping and emits the result onto the out channel.
-func (m *Measurer) tcpPingAsync(ctx context.Context, mxmx *measurex.Measurer,
-	address string, out chan<- *measurex.EndpointMeasurement) {
-	out <- m.tcpConnect(ctx, mxmx, address)
+func (m *Measurer) tcpPingAsync(ctx context.Context, index int64,
+	zeroTime time.Time, logger model.Logger, address string, out chan<- *SinglePing) {
+	out <- m.tcpConnect(ctx, index, zeroTime, logger, address)
 }
 
 // tcpConnect performs a TCP connect and returns the result to the caller.
-func (m *Measurer) tcpConnect(ctx context.Context, mxmx *measurex.Measurer,
-	address string) *measurex.EndpointMeasurement {
+func (m *Measurer) tcpConnect(ctx context.Context, index int64,
+	zeroTime time.Time, logger model.Logger, address string) *SinglePing {
 	// TODO(bassosimone): make the timeout user-configurable
 	ctx, cancel := context.WithTimeout(ctx, 3*time.Second)
 	defer cancel()
-	return mxmx.TCPConnect(ctx, address)
+	trace := measurexlite.NewTrace(index, zeroTime)
+	dialer := trace.NewDialerWithoutResolver(logger)
+	ol := measurexlite.NewOperationLogger(logger, "TCPPing #%d %s", index, address)
+	conn, err := dialer.DialContext(ctx, "tcp", address)
+	ol.Stop(err)
+	measurexlite.MaybeClose(conn)
+	sp := &SinglePing{
+		TCPConnect: <-trace.TCPConnect,
+	}
+	return sp
 }
 
 // NewExperimentMeasurer creates a new ExperimentMeasurer.

internal/engine/experiment/tcpping/tcpping_test.go

@@ -40,14 +40,16 @@ func TestMeasurer_run(t *testing.T) {
 		if m.ExperimentName() != "tcpping" {
 			t.Fatal("invalid experiment name")
 		}
-		if m.ExperimentVersion() != "0.1.0" {
+		if m.ExperimentVersion() != "0.2.0" {
 			t.Fatal("invalid experiment version")
 		}
 		ctx := context.Background()
 		meas := &model.Measurement{
 			Input: model.MeasurementTarget(input),
 		}
-		sess := &mockable.Session{}
+		sess := &mockable.Session{
+			MockableLogger: model.DiscardLogger,
+		}
 		callbacks := model.NewPrinterCallbacks(model.DiscardLogger)
 		err := m.Run(ctx, sess, meas, callbacks)
 		return meas, m, err