Update proof sync.WaitGroup scooped variables & Add time prints in cli proof generation

cli/cli.go

@@ -5,6 +5,7 @@ import (
 	"flag"
 	"fmt"
 	"io/ioutil"
+	"time"
 
 	"github.com/iden3/go-circom-prover-verifier/parsers"
 	"github.com/iden3/go-circom-prover-verifier/prover"
@@ -46,6 +47,8 @@ func main() {
 
 func cmdProve(provingKeyPath, witnessPath, proofPath, publicPath string) error {
 	fmt.Println("zkSNARK Groth16 prover")
+
+	fmt.Println("Reading proving key file:", provingKeyPath)
 	provingKeyJson, err := ioutil.ReadFile(provingKeyPath)
 	if err != nil {
 		return err
@@ -55,6 +58,7 @@ func cmdProve(provingKeyPath, witnessPath, proofPath, publicPath string) error {
 		return err
 	}
 
+	fmt.Println("Reading witness file:", witnessPath)
 	witnessJson, err := ioutil.ReadFile(witnessPath)
 	if err != nil {
 		return err
@@ -64,10 +68,13 @@ func cmdProve(provingKeyPath, witnessPath, proofPath, publicPath string) error {
 		return err
 	}
 
+	fmt.Println("Generating the proof")
+	beforeT := time.Now()
 	proof, pubSignals, err := prover.GenerateProof(pk, w)
 	if err != nil {
 		return err
 	}
+	fmt.Println("proof generation time elapsed:", time.Since(beforeT))
 
 	proofStr, err := parsers.ProofToJson(proof)
 	if err != nil {

prover/prover.go

@@ -73,39 +73,39 @@ func GenerateProof(pk *types.Pk, w types.Witness) (*types.Proof, []*big.Int, err
 	proof.C = new(bn256.G1).ScalarBaseMult(big.NewInt(0))
 	proofBG1 := new(bn256.G1).ScalarBaseMult(big.NewInt(0))
 
-	var waitGroup sync.WaitGroup
-	waitGroup.Add(4)
-	go func(wg *sync.WaitGroup) {
+	var wg sync.WaitGroup
+	wg.Add(4)
+	go func() {
 		for i := 0; i < pk.NVars; i++ {
 			proof.A = new(bn256.G1).Add(proof.A, new(bn256.G1).ScalarMult(pk.A[i], w[i]))
 		}
 		wg.Done()
-	}(&waitGroup)
-	go func(wg *sync.WaitGroup) {
+	}()
+	go func() {
 		for i := 0; i < pk.NVars; i++ {
 			proof.B = new(bn256.G2).Add(proof.B, new(bn256.G2).ScalarMult(pk.B2[i], w[i]))
 		}
 		wg.Done()
-	}(&waitGroup)
-	go func(wg *sync.WaitGroup) {
+	}()
+	go func() {
 		for i := 0; i < pk.NVars; i++ {
 			proofBG1 = new(bn256.G1).Add(proofBG1, new(bn256.G1).ScalarMult(pk.B1[i], w[i]))
 		}
 		wg.Done()
-	}(&waitGroup)
-	go func(wg *sync.WaitGroup) {
+	}()
+	go func() {
 		for i := pk.NPublic + 1; i < pk.NVars; i++ {
 			proof.C = new(bn256.G1).Add(proof.C, new(bn256.G1).ScalarMult(pk.C[i], w[i]))
 		}
 		wg.Done()
-	}(&waitGroup)
-	waitGroup.Wait()
+	}()
+	wg.Wait()
 
 	h := calculateH(pk, w)
 
-	var waitGroup2 sync.WaitGroup
-	waitGroup2.Add(2)
-	go func(wg *sync.WaitGroup) {
+	var wg2 sync.WaitGroup
+	wg2.Add(2)
+	go func() {
 		proof.A = new(bn256.G1).Add(proof.A, pk.VkAlpha1)
 		proof.A = new(bn256.G1).Add(proof.A, new(bn256.G1).ScalarMult(pk.VkDelta1, r))
 
@@ -114,15 +114,15 @@ func GenerateProof(pk *types.Pk, w types.Witness) (*types.Proof, []*big.Int, err
 
 		proofBG1 = new(bn256.G1).Add(proofBG1, pk.VkBeta1)
 		proofBG1 = new(bn256.G1).Add(proofBG1, new(bn256.G1).ScalarMult(pk.VkDelta1, s))
-		wg.Done()
-	}(&waitGroup2)
-	go func(wg *sync.WaitGroup) {
+		wg2.Done()
+	}()
+	go func() {
 		for i := 0; i < len(h); i++ {
 			proof.C = new(bn256.G1).Add(proof.C, new(bn256.G1).ScalarMult(pk.HExps[i], h[i]))
 		}
-		wg.Done()
-	}(&waitGroup2)
-	waitGroup2.Wait()
+		wg2.Done()
+	}()
+	wg2.Wait()
 
 	proof.C = new(bn256.G1).Add(proof.C, new(bn256.G1).ScalarMult(proof.A, s))
 	proof.C = new(bn256.G1).Add(proof.C, new(bn256.G1).ScalarMult(proofBG1, r))