feat: gnark/profile now filter frontend private method for clarity an…

…d return a tree as txt repr (Consensys#538)

go.sum

@@ -2,8 +2,6 @@ github.com/blang/semver/v4 v4.0.0 h1:1PFHFE6yCCTv8C1TeyNNarDzntLi7wMI5i/pzqYIsAM
 github.com/blang/semver/v4 v4.0.0/go.mod h1:IbckMUScFkM3pff0VJDNKRiT6TG/YpiHIM2yvyW5YoQ=
 github.com/consensys/bavard v0.1.13 h1:oLhMLOFGTLdlda/kma4VOJazblc7IM5y5QPd2A/YjhQ=
 github.com/consensys/bavard v0.1.13/go.mod h1:9ItSMtA/dXMAiL7BG6bqW2m3NdSEObYWoH223nGHukI=
-github.com/consensys/gnark-crypto v0.9.1 h1:mru55qKdWl3E035hAoh1jj9d7hVnYY5pfb6tmovSmII=
-github.com/consensys/gnark-crypto v0.9.1/go.mod h1:a2DQL4+5ywF6safEeZFEPGRiiGbjzGFRUN2sg06VuU4=
 github.com/consensys/gnark-crypto v0.9.2-0.20230222154459-49b5c6cfd875 h1:FTOvlE+90hvp+XHi8i89xCejJ0627wfbP0RSWzmVFks=
 github.com/consensys/gnark-crypto v0.9.2-0.20230222154459-49b5c6cfd875/go.mod h1:a2DQL4+5ywF6safEeZFEPGRiiGbjzGFRUN2sg06VuU4=
 github.com/coreos/go-systemd/v22 v22.3.3-0.20220203105225-a9a7ef127534/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=

profile/profile.go

@@ -92,7 +92,7 @@ func Start(options ...Option) *Profile {
 
 	log := logger.Logger()
 	if p.filePath == "" {
-		log.Warn().Msg("gnark profiling enabled [not writting to disk]")
+		log.Warn().Msg("gnark profiling enabled [not writing to disk]")
 	} else {
 		log.Info().Str("path", p.filePath).Msg("gnark profiling enabled")
 	}
@@ -131,7 +131,7 @@ func (p *Profile) Stop() {
 		f.Close()
 		log.Info().Str("path", p.filePath).Msg("gnark profiling disabled")
 	} else {
-		log.Warn().Msg("gnark profiling disabled [not writting to disk]")
+		log.Warn().Msg("gnark profiling disabled [not writing to disk]")
 	}
 
 }
@@ -144,7 +144,7 @@ func (p *Profile) NbConstraints() int {
 // Top return a similar output than pprof top command
 func (p *Profile) Top() string {
 	r := report.NewDefault(&p.pprof, report.Options{
-		OutputFormat:  report.Text,
+		OutputFormat:  report.Tree,
 		CompactLabels: true,
 		NodeFraction:  0.005,
 		EdgeFraction:  0.001,

profile/profile_test.go

@@ -4,11 +4,13 @@ package profile_test
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/consensys/gnark-crypto/ecc"
 	"github.com/consensys/gnark/frontend"
 	"github.com/consensys/gnark/frontend/cs/r1cs"
 	"github.com/consensys/gnark/profile"
+	"golang.org/x/exp/slices"
 )
 
 type Circuit struct {
@@ -29,12 +31,27 @@ func Example() {
 	_, _ = frontend.Compile(ecc.BN254.ScalarField(), r1cs.NewBuilder, &Circuit{})
 	p.Stop()
 
+	const expectedOutput = `Showing nodes accounting for 2, 100% of 2 total
+----------------------------------------------------------+-------------
+      flat  flat%   sum%        cum   cum%   calls calls% + context              
+----------------------------------------------------------+-------------
+                                                 1   100% |   profile_test.(*Circuit).Define profile/profile_test.go:21
+         1 50.00% 50.00%          1 50.00%                | r1cs.(*builder).AssertIsEqual frontend/cs/r1cs/api_assertions.go:37
+----------------------------------------------------------+-------------
+                                                 1   100% |   profile_test.(*Circuit).Define profile/profile_test.go:21
+         1 50.00%   100%          1 50.00%                | r1cs.(*builder).Mul frontend/cs/r1cs/api.go:221
+----------------------------------------------------------+-------------
+         0     0%   100%          2   100%                | profile_test.(*Circuit).Define profile/profile_test.go:21
+                                                 1 50.00% |   r1cs.(*builder).AssertIsEqual frontend/cs/r1cs/api_assertions.go:37
+                                                 1 50.00% |   r1cs.(*builder).Mul frontend/cs/r1cs/api.go:221
+----------------------------------------------------------+-------------`
+
+	a := strings.Fields(p.Top())
+	b := strings.Fields(expectedOutput)
+
 	fmt.Println(p.NbConstraints())
-	fmt.Println(p.Top())
+	fmt.Println(slices.Equal(a, b))
 	// Output:
 	// 2
-	// Showing nodes accounting for 2, 100% of 2 total
-	//       flat  flat%   sum%        cum   cum%
-	//          1 50.00% 50.00%          2   100%  profile_test.(*Circuit).Define profile/profile_test.go:19
-	//          1 50.00%   100%          1 50.00%  r1cs.(*builder).AssertIsEqual frontend/cs/r1cs/api_assertions.go:37
+	// true
 }

profile/profile_worker.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 	"sync"
 	"sync/atomic"
+	"unicode"
 
 	"github.com/google/pprof/profile"
 )
@@ -68,26 +69,8 @@ func collectSample(pc []uintptr) {
 			continue
 		}
 
-		// to avoid aving a location that concentrates 99% of the calls, we transfer the "addConstraint"
-		// occuring in Mul to the previous level in the stack
-		if strings.Contains(frame.Function, "github.com/consensys/gnark/frontend/cs/r1cs.(*builder).Mul") {
-			continue
-		}
-
-		if strings.HasPrefix(frame.Function, "github.com/consensys/gnark/frontend/cs/scs.(*scs).Mul") {
-			continue
-		}
-
-		if strings.HasPrefix(frame.Function, "github.com/consensys/gnark/frontend/cs/scs.(*scs).split") {
-			continue
-		}
-
-		// with scs.Builder (Plonk) Add and Sub always add a constraint --> we record the caller as the constraint adder
-		// but in the future we may record a different type of sample for these
-		if strings.HasPrefix(frame.Function, "github.com/consensys/gnark/frontend/cs/scs.(*scs).Add") {
-			continue
-		}
-		if strings.HasPrefix(frame.Function, "github.com/consensys/gnark/frontend/cs/scs.(*scs).Sub") {
+		// filter internal builder functions
+		if filterSCSPrivateFunc(frame.Function) || filterR1CSPrivateFunc(frame.Function) {
 			continue
 		}
 
@@ -123,3 +106,27 @@ func collectSample(pc []uintptr) {
 	}
 
 }
+
+func filterSCSPrivateFunc(f string) bool {
+	const scsPrefix = "github.com/consensys/gnark/frontend/cs/scs.(*builder)."
+	if strings.HasPrefix(f, scsPrefix) && len(f) > len(scsPrefix) {
+		// filter plonk frontend private APIs from the trace.
+		c := []rune(f)[len(scsPrefix)]
+		if unicode.IsLower(c) {
+			return true
+		}
+	}
+	return false
+}
+
+func filterR1CSPrivateFunc(f string) bool {
+	const r1csPrefix = "github.com/consensys/gnark/frontend/cs/r1cs.(*builder)."
+	if strings.HasPrefix(f, r1csPrefix) && len(f) > len(r1csPrefix) {
+		// filter r1cs frontend private APIs from the trace.
+		c := []rune(f)[len(r1csPrefix)]
+		if unicode.IsLower(c) {
+			return true
+		}
+	}
+	return false
+}