refactor: move more commands to internal/cmd (#207)

* refactor: move more commands to internal/cmd

Part of https://github.com/ooni/probe/issues/1335.

We would like all commands to be at the same level of engine
rather than inside engine (now that we can do it).

* fix: update .gitignore

* refactor: also move jafar outside engine

* We should be good now?

internal/cmd/oohelperd/internal/measure.go

@@ -0,0 +1,88 @@
+package internal
+
+import (
+	"context"
+	"net"
+	"net/http"
+	"net/url"
+	"sync"
+
+	"github.com/ooni/probe-cli/v3/internal/engine/experiment/webconnectivity"
+	"github.com/ooni/probe-cli/v3/internal/engine/netx"
+)
+
+type (
+	// CtrlRequest is the request sent to the test helper
+	CtrlRequest = webconnectivity.ControlRequest
+
+	// CtrlResponse is the response from the test helper
+	CtrlResponse = webconnectivity.ControlResponse
+)
+
+// MeasureConfig contains configuration for Measure.
+type MeasureConfig struct {
+	Client            *http.Client
+	Dialer            netx.Dialer
+	MaxAcceptableBody int64
+	Resolver          netx.Resolver
+}
+
+// Measure performs the measurement described by the request and
+// returns the corresponding response or an error.
+func Measure(ctx context.Context, config MeasureConfig, creq *CtrlRequest) (*CtrlResponse, error) {
+	// parse input for correctness
+	URL, err := url.Parse(creq.HTTPRequest)
+	if err != nil {
+		return nil, err
+	}
+	// dns: start
+	wg := new(sync.WaitGroup)
+	dnsch := make(chan CtrlDNSResult, 1)
+	if net.ParseIP(URL.Hostname()) == nil {
+		wg.Add(1)
+		go DNSDo(ctx, &DNSConfig{
+			Domain:   URL.Hostname(),
+			Out:      dnsch,
+			Resolver: config.Resolver,
+			Wg:       wg,
+		})
+	}
+	// tcpconnect: start
+	tcpconnch := make(chan TCPResultPair, len(creq.TCPConnect))
+	for _, endpoint := range creq.TCPConnect {
+		wg.Add(1)
+		go TCPDo(ctx, &TCPConfig{
+			Dialer:   config.Dialer,
+			Endpoint: endpoint,
+			Out:      tcpconnch,
+			Wg:       wg,
+		})
+	}
+	// http: start
+	httpch := make(chan CtrlHTTPResponse, 1)
+	wg.Add(1)
+	go HTTPDo(ctx, &HTTPConfig{
+		Client:            config.Client,
+		Headers:           creq.HTTPRequestHeaders,
+		MaxAcceptableBody: config.MaxAcceptableBody,
+		Out:               httpch,
+		URL:               creq.HTTPRequest,
+		Wg:                wg,
+	})
+	// wait for measurement steps to complete
+	wg.Wait()
+	// assemble response
+	cresp := new(CtrlResponse)
+	select {
+	case cresp.DNS = <-dnsch:
+	default:
+		// we land here when there's no domain name
+	}
+	cresp.HTTPRequest = <-httpch
+	cresp.TCPConnect = make(map[string]CtrlTCPResult)
+	for len(cresp.TCPConnect) < len(creq.TCPConnect) {
+		tcpconn := <-tcpconnch
+		cresp.TCPConnect[tcpconn.Endpoint] = tcpconn.Result
+	}
+	return cresp, nil
+}