Add mock proof server

prover/prover.go

@@ -58,11 +58,28 @@ func (p *Proof) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
+// PublicInputs are the public inputs of the proof
+type PublicInputs []*big.Int
+
+// UnmarshalJSON unmarshals the JSON into the public inputs where the bigInts
+// are in decimal as quoted strings
+func (p *PublicInputs) UnmarshalJSON(data []byte) error {
+	pubInputs := []*bigInt{}
+	if err := json.Unmarshal(data, &pubInputs); err != nil {
+		return err
+	}
+	*p = make([]*big.Int, len(pubInputs))
+	for i, v := range pubInputs {
+		([]*big.Int)(*p)[i] = (*big.Int)(v)
+	}
+	return nil
+}
+
 // Client is the interface to a ServerProof that calculates zk proofs
 type Client interface {
 	// Non-blocking
 	CalculateProof(ctx context.Context, zkInputs *common.ZKInputs) error
-	// Blocking
+	// Blocking.  Returns the Proof and Public Data (public inputs)
 	GetProof(ctx context.Context) (*Proof, []*big.Int, error)
 	// Non-Blocking
 	Cancel(ctx context.Context) error
@@ -207,11 +224,11 @@ func (p *ProofServerClient) CalculateProof(ctx context.Context, zkInputs *common
 	return tracerr.Wrap(p.apiInput(ctx, zkInputs))
 }
 
-// GetProof retreives the Proof from the ServerProof, blocking until the proof
-// is ready.
+// GetProof retreives the Proof and Public Data (public inputs) from the
+// ServerProof, blocking until the proof is ready.
 func (p *ProofServerClient) GetProof(ctx context.Context) (*Proof, []*big.Int, error) {
 	if err := p.WaitReady(ctx); err != nil {
-		return nil, nil, err
+		return nil, nil, tracerr.Wrap(err)
 	}
 	status, err := p.apiStatus(ctx)
 	if err != nil {
@@ -219,11 +236,14 @@ func (p *ProofServerClient) GetProof(ctx context.Context) (*Proof, []*big.Int, e
 	}
 	if status.Status == StatusCodeSuccess {
 		var proof Proof
-		err := json.Unmarshal([]byte(status.Proof), &proof)
-		if err != nil {
+		if err := json.Unmarshal([]byte(status.Proof), &proof); err != nil {
+			return nil, nil, tracerr.Wrap(err)
+		}
+		var pubInputs PublicInputs
+		if err := json.Unmarshal([]byte(status.PubData), &pubInputs); err != nil {
 			return nil, nil, tracerr.Wrap(err)
 		}
-		return &proof, nil, nil
+		return &proof, pubInputs, nil
 	}
 	return nil, nil, fmt.Errorf("status != StatusCodeSuccess, status = %v", status.Status)
 }
@@ -269,7 +289,7 @@ func (p *MockClient) GetProof(ctx context.Context) (*Proof, []*big.Int, error) {
 	// Simulate a delay
 	select {
 	case <-time.After(500 * time.Millisecond): //nolint:gomnd
-		return &Proof{}, nil, nil
+		return &Proof{}, []*big.Int{big.NewInt(1234)}, nil //nolint:gomnd
 	case <-ctx.Done():
 		return nil, nil, tracerr.Wrap(common.ErrDone)
 	}

prover/prover_test.go

@@ -53,13 +53,16 @@ func testCalculateProof(t *testing.T) {
 }
 
 func testGetProof(t *testing.T) {
-	proof, _, err := proofServerClient.GetProof(context.Background())
+	proof, pubInputs, err := proofServerClient.GetProof(context.Background())
 	require.NoError(t, err)
-	require.NotNil(t, proof)
-	require.NotNil(t, proof.PiA)
-	require.NotNil(t, proof.PiB)
-	require.NotNil(t, proof.PiC)
-	require.NotNil(t, proof.Protocol)
+	assert.NotNil(t, proof.PiA)
+	assert.NotEqual(t, [2]*big.Int{}, proof.PiA)
+	assert.NotNil(t, proof.PiB)
+	assert.NotEqual(t, [3][2]*big.Int{}, proof.PiB)
+	assert.NotNil(t, proof.PiC)
+	assert.NotEqual(t, [2]*big.Int{}, proof.PiC)
+	assert.NotNil(t, proof.Protocol)
+	assert.NotEqual(t, 0, len(pubInputs))
 }
 
 func testCancel(t *testing.T) {

test/proofserver/cli/main.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"log"
+	"os"
+	"os/signal"
+	"sync"
+	"time"
+
+	"github.com/hermeznetwork/hermez-node/test/proofserver"
+)
+
+func main() {
+	var addr string
+	flag.StringVar(&addr, "a", "localhost:3000", "listen address")
+	var provingDuration time.Duration
+	flag.DurationVar(&provingDuration, "d", 2*time.Second, "proving time duration") //nolint:gomnd
+	flag.Parse()
+
+	mock := proofserver.NewMock(addr, provingDuration)
+	ctx, cancel := context.WithCancel(context.Background())
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		if err := mock.Run(ctx); err != nil {
+			log.Fatal(err)
+		}
+		wg.Done()
+	}()
+
+	stopCh := make(chan interface{})
+	// catch ^C to send the stop signal
+	ossig := make(chan os.Signal, 1)
+	signal.Notify(ossig, os.Interrupt)
+	go func() {
+		for sig := range ossig {
+			if sig == os.Interrupt {
+				stopCh <- nil
+			}
+		}
+	}()
+	<-stopCh
+	cancel()
+	wg.Wait()
+}

test/proofserver/proofserver.go

@@ -0,0 +1,191 @@
+package proofserver
+
+import (
+	"context"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/gin-contrib/cors"
+	"github.com/gin-gonic/gin"
+	"github.com/hermeznetwork/hermez-node/log"
+	"github.com/hermeznetwork/hermez-node/prover"
+	"github.com/hermeznetwork/tracerr"
+)
+
+type msg struct {
+	value string
+	ackCh chan bool
+}
+
+func newMsg(value string) msg {
+	return msg{
+		value: value,
+		ackCh: make(chan bool),
+	}
+}
+
+// Mock proof server
+type Mock struct {
+	addr   string
+	status prover.StatusCode
+	sync.RWMutex
+	proof           string
+	pubData         string
+	counter         int
+	msgCh           chan msg
+	wg              sync.WaitGroup
+	provingDuration time.Duration
+}
+
+// NewMock creates a new mock server
+func NewMock(addr string, provingDuration time.Duration) *Mock {
+	return &Mock{
+		addr:            addr,
+		status:          prover.StatusCodeReady,
+		proof:           "",
+		pubData:         "",
+		counter:         0,
+		msgCh:           make(chan msg),
+		provingDuration: provingDuration,
+	}
+}
+
+func (s *Mock) err(c *gin.Context, err error) {
+	c.JSON(http.StatusInternalServerError, prover.ErrorServer{
+		Status:  "error",
+		Message: err.Error(),
+	})
+}
+
+func (s *Mock) handleCancel(c *gin.Context) {
+	msg := newMsg("cancel")
+	s.msgCh <- msg
+	<-msg.ackCh
+	c.JSON(http.StatusOK, "OK")
+}
+
+func (s *Mock) handleStatus(c *gin.Context) {
+	s.RLock()
+	c.JSON(http.StatusOK, prover.Status{
+		Status:  s.status,
+		Proof:   s.proof,
+		PubData: s.pubData,
+	})
+	s.RUnlock()
+}
+
+func (s *Mock) handleInput(c *gin.Context) {
+	s.RLock()
+	if !s.status.IsReady() {
+		s.err(c, fmt.Errorf("not ready"))
+		s.RUnlock()
+		return
+	}
+	s.RUnlock()
+	_, err := ioutil.ReadAll(c.Request.Body)
+	if err != nil {
+		s.err(c, err)
+		return
+	}
+	msg := newMsg("prove")
+	s.msgCh <- msg
+	<-msg.ackCh
+	c.JSON(http.StatusOK, "OK")
+}
+
+const longWaitDuration = 999 * time.Hour
+
+// const provingDuration = 2 * time.Second
+
+func (s *Mock) runProver(ctx context.Context) {
+	waitDuration := longWaitDuration
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case msg := <-s.msgCh:
+			switch msg.value {
+			case "cancel":
+				waitDuration = longWaitDuration
+				s.Lock()
+				if !s.status.IsReady() {
+					s.status = prover.StatusCodeAborted
+				}
+				s.Unlock()
+			case "prove":
+				waitDuration = s.provingDuration
+				s.Lock()
+				s.status = prover.StatusCodeBusy
+				s.Unlock()
+			}
+			msg.ackCh <- true
+		case <-time.After(waitDuration):
+			waitDuration = longWaitDuration
+			s.Lock()
+			if s.status != prover.StatusCodeBusy {
+				s.Unlock()
+				continue
+			}
+			i := s.counter * 100 //nolint:gomnd
+			s.counter++
+			// Mock data
+			s.proof = fmt.Sprintf(`{
+				"pi_a": ["%v", "%v"],
+				"pi_b": [["%v", "%v"],["%v", "%v"],["%v", "%v"]],
+				"pi_c": ["%v", "%v"],
+				"protocol": "groth16"
+			}`, i, i+1, i+2, i+3, i+4, i+5, i+6, i+7, i+8, i+9) //nolint:gomnd
+			s.pubData = fmt.Sprintf(`[
+				"%v"
+			]`, i+42) //nolint:gomnd
+			s.status = prover.StatusCodeSuccess
+			s.Unlock()
+		}
+	}
+}
+
+// Run the mock server.  Use ctx to stop it via cancel
+func (s *Mock) Run(ctx context.Context) error {
+	api := gin.Default()
+	api.Use(cors.Default())
+
+	apiGroup := api.Group("/api")
+	apiGroup.GET("/status", s.handleStatus)
+	apiGroup.POST("/input", s.handleInput)
+	apiGroup.POST("/cancel", s.handleCancel)
+
+	debugAPIServer := &http.Server{
+		Addr:    s.addr,
+		Handler: api,
+		// Use some hardcoded numberes that are suitable for testing
+		ReadTimeout:    30 * time.Second, //nolint:gomnd
+		WriteTimeout:   30 * time.Second, //nolint:gomnd
+		MaxHeaderBytes: 1 << 20,          //nolint:gomnd
+	}
+	go func() {
+		log.Infof("prover.MockServer is ready at %v", s.addr)
+		if err := debugAPIServer.ListenAndServe(); err != nil && tracerr.Unwrap(err) != http.ErrServerClosed {
+			log.Fatalf("Listen: %s\n", err)
+		}
+	}()
+	s.wg.Add(1)
+	go func() {
+		s.runProver(ctx)
+		s.wg.Done()
+	}()
+
+	<-ctx.Done()
+	log.Info("Stopping prover.MockServer...")
+
+	s.wg.Wait()
+	ctxTimeout, cancel := context.WithTimeout(context.Background(), 10*time.Second) //nolint:gomnd
+	defer cancel()
+	if err := debugAPIServer.Shutdown(ctxTimeout); err != nil {
+		return tracerr.Wrap(err)
+	}
+	log.Info("prover.MockServer done")
+	return nil
+}