Render images with Go library instead of Graphviz's dot (#70)

README.md

@@ -21,10 +21,11 @@ the code much higher or when you are just simply trying to understand code of so
 ### Features
 
 - 🆕 **support for Go modules!** :boom:
-- interactive view allowing quick switching between focused packages in web browser
 - focus specific package in the program
+- click on package to quickly switch the focus using [interactive viewer](#interactive-viewer)
 - group functions by package and/or methods by type
 - filter packages to specific import path prefixes
+- ignore funcs from standard library
 - omit various types of function calls
 
 ### Output preview
@@ -74,8 +75,8 @@ Here you can find descriptions for various types of output.
 
 #### Requirements
 
-- [Go](https://golang.org/dl/) 1.12+
-- [Graphviz](http://www.graphviz.org/download/)
+- [Go](https://golang.org/dl/) 1.13+
+- [Graphviz](http://www.graphviz.org/download/) (optional, required only with `-graphviz` flag)
 
 ### Installation
 
@@ -88,13 +89,19 @@ cd go-callvis && make install
 
 ### Usage
 
+#### Interactive viewer
+
 To use the interactive view provided by a web server that serves SVG images of focused packages, you can simply run:
 
-`go-callvis [OPTIONS] <main package>`
+`go-callvis <target package>` 
+
+HTTP server is listening on [http://localhost:7878/](http://localhost:7878/) by default, use option `-http="ADDR:PORT"` to change HTTP server address.
+
+#### Render static output
 
-> HTTP server is listening on [http://localhost:7878/](http://localhost:7878/) by default.
+To generate a single output file use option `-file=<file path>` to choose output file destination.
 
-To generate a single output file use option `-file=<file path>` to choose output file destination. The output format defaults to `svg`, use option `-format=<svg|png|jpg|...>` to pick a different output format.
+The output format defaults to `svg`, use option `-format=<svg|png|jpg|...>` to pick a different output format.
 
 #### Options
 
@@ -108,8 +115,10 @@ Usage of go-callvis:
     	Focus specific package using name or import path. (default "main")
   -format string
     	output file format [svg | png | jpg | ...] (default "svg")
+  -graphviz
+    	Use Graphviz's dot program to render images.
   -group string
-    	Grouping functions by packages and/or types [pkg, type] (separated by comma)
+    	Grouping functions by packages and/or types [pkg, type] (separated by comma) (default "pkg")
   -http string
     	HTTP service address. (default ":7878")
   -ignore string

dot.go

@@ -10,6 +10,8 @@ import (
 	"path/filepath"
 	"strings"
 	"text/template"
+
+	"github.com/goccy/go-graphviz"
 )
 
 var (
@@ -21,8 +23,8 @@ var (
 // it's usually at: /usr/bin/dot
 var dotExe string
 
-// dotToImage generates a SVG using the 'dot' utility, returning the filepath
-func dotToImage(outfname string, format string, dot []byte) (string, error) {
+// dotToImageGraphviz generates a SVG using the 'dot' utility, returning the filepath
+func dotToImageGraphviz(outfname string, format string, dot []byte) (string, error) {
 	if dotExe == "" {
 		dot, err := exec.LookPath("dot")
 		if err != nil {
@@ -39,7 +41,37 @@ func dotToImage(outfname string, format string, dot []byte) (string, error) {
 	}
 	cmd := exec.Command(dotExe, fmt.Sprintf("-T%s", format), "-o", img)
 	cmd.Stdin = bytes.NewReader(dot)
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
 	if err := cmd.Run(); err != nil {
+		return "", fmt.Errorf("command '%v': %v\n%v", cmd, err, stderr.String())
+	}
+	return img, nil
+}
+
+func dotToImage(outfname string, format string, dot []byte) (string, error) {
+	if *graphvizFlag {
+		return dotToImageGraphviz(outfname, format, dot)
+	}
+
+	g := graphviz.New()
+	graph, err := graphviz.ParseBytes(dot)
+	if err != nil {
+		return "", err
+	}
+	defer func() {
+		if err := graph.Close(); err != nil {
+			log.Fatal(err)
+		}
+		g.Close()
+	}()
+	var img string
+	if outfname == "" {
+		img = filepath.Join(os.TempDir(), fmt.Sprintf("go-callvis_export.%s", format))
+	} else {
+		img = fmt.Sprintf("%s.%s", outfname, format)
+	}
+	if err := g.RenderFilename(graph, graphviz.Format(format), img); err != nil {
 		return "", err
 	}
 	return img, nil

go.mod

@@ -3,6 +3,7 @@ module github.com/ofabry/go-callvis
 go 1.12
 
 require (
+	github.com/goccy/go-graphviz v0.0.6
 	github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4
 	golang.org/x/tools v0.0.0-20200305224536-de023d59a5d1
 )

go.sum

@@ -1,7 +1,23 @@
+github.com/corona10/goimagehash v1.0.2 h1:pUfB0LnsJASMPGEZLj7tGY251vF+qLGqOgEP4rUs6kA=
+github.com/corona10/goimagehash v1.0.2/go.mod h1:/l9umBhvcHQXVtQO1V6Gp1yD20STawkhRnnX0D1bvVI=
+github.com/fogleman/gg v1.3.0 h1:/7zJX8F6AaYQc57WQCyN9cAIz+4bCJGO9B+dyW29am8=
+github.com/fogleman/gg v1.3.0/go.mod h1:R/bRT+9gY/C5z7JzPU0zXsXHKM4/ayA+zqcVNZzPa1k=
+github.com/goccy/go-graphviz v0.0.6 h1:sCT69fmH2KKsObVfsozYyKXxrqmIfo3SyHZs72xkgxs=
+github.com/goccy/go-graphviz v0.0.6/go.mod h1:wXVsXxmyMQU6TN3zGRttjNn3h+iCAS7xQFC6TlNvLhk=
+github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF08vX0COfcOBJRhZ8lUbR+ZWIs0Y5g=
+github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
+github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
+github.com/nfnt/resize v0.0.0-20160724205520-891127d8d1b5 h1:BvoENQQU+fZ9uukda/RzCAL/191HHwJA5b13R6diVlY=
+github.com/nfnt/resize v0.0.0-20160724205520-891127d8d1b5/go.mod h1:jpp1/29i3P1S/RLdc7JQKbRpFeM1dOBd8T9ki5s+AY8=
 github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4 h1:49lOXmGaUpV9Fz3gd7TFZY106KVlPVa5jcYD1gaQf98=
 github.com/pkg/browser v0.0.0-20180916011732-0a3d74bf9ce4/go.mod h1:4OwLy04Bl9Ef3GJJCoec+30X3LQs/0/m4HFRt/2LUSA=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20200204104054-c9f3fb736b72/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/image v0.0.0-20200119044424-58c23975cae1 h1:5h3ngYt7+vXCDZCup/HkCQgW5XwmSvR/nA2JmJ0RErg=
+golang.org/x/image v0.0.0-20200119044424-58c23975cae1/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/mod v0.2.0 h1:KU7oHjnv3XNWfa5COkzUifxZmxp1TyI7ImMXqFxLwvQ=
 golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=

handler.go

@@ -106,7 +106,7 @@ func handler(w http.ResponseWriter, r *http.Request) {
 
 	// Convert list-style args to []string
 	if e := processListArgs(&opts); e != nil {
-		http.Error(w, "invalid group option", http.StatusInternalServerError)
+		http.Error(w, "invalid parameters", http.StatusBadRequest)
 		return
 	}
 
@@ -123,6 +123,7 @@ func handler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	log.Printf("converting dot to %s..\n", *outputFormat)
+
 	img, err := dotToImage("", *outputFormat, output)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)

main.go

@@ -20,19 +20,21 @@ import (
 
 var (
 	focusFlag    = flag.String("focus", "main", "Focus specific package using name or import path.")
-	groupFlag    = flag.String("group", "", "Grouping functions by packages and/or types [pkg, type] (separated by comma)")
+	groupFlag    = flag.String("group", "pkg", "Grouping functions by packages and/or types [pkg, type] (separated by comma)")
 	limitFlag    = flag.String("limit", "", "Limit package paths to given prefixes (separated by comma)")
 	ignoreFlag   = flag.String("ignore", "", "Ignore package paths containing given prefixes (separated by comma)")
 	includeFlag  = flag.String("include", "", "Include package paths with given prefixes (separated by comma)")
 	nostdFlag    = flag.Bool("nostd", false, "Omit calls to/from packages in standard library.")
 	nointerFlag  = flag.Bool("nointer", false, "Omit calls to unexported functions.")
 	testFlag     = flag.Bool("tests", false, "Include test code.")
-	debugFlag    = flag.Bool("debug", false, "Enable verbose log.")
-	versionFlag  = flag.Bool("version", false, "Show version and exit.")
+	graphvizFlag = flag.Bool("graphviz", false, "Use Graphviz's dot program to render images.")
 	httpFlag     = flag.String("http", ":7878", "HTTP service address.")
 	skipBrowser  = flag.Bool("skipbrowser", false, "Skip opening browser.")
 	outputFile   = flag.String("file", "", "output filename - omit to use server mode")
 	outputFormat = flag.String("format", "svg", "output file format [svg | png | jpg | ...]")
+
+	debugFlag   = flag.Bool("debug", false, "Enable verbose log.")
+	versionFlag = flag.Bool("version", false, "Show version and exit.")
 )
 
 func init() {

version.go

@@ -5,7 +5,7 @@ import (
 )
 
 var (
-	version = "v0.6.0"
+	version = "v0.6.1"
 	commit  = "(unknown)"
 )