Add xts-config replacement

This saves about half a second in run-time when running remotely
(presumably due to all the extra round-trips of xset and xdpyinfo).

The savings locally are less impressive (about 0.06s by saving a bunch of
fork/exec pairs, and reducing the amount of output parsing going on).

2 files changed, 193 insertions, 3 deletions

diff --git a/config.go b/config.go
new file mode 100644
index 0000000..8e6cbca
--- /dev/null
+++ b/config.go
@@ -0,0 +1,182 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/BurntSushi/xgb"
+	"github.com/BurntSushi/xgb/xproto"
+)
+
+func createConfig(outdir string) error {
+	c, err := xgb.NewConn()
+	if err != nil {
+		return err
+	}
+	defer c.Close()
+	gfpCookie := xproto.GetFontPath(c)
+
+	set := make(map[string]string)
+	s := xproto.Setup(c)
+
+	set["XT_PROTOCOL_VERSION"] = strconv.Itoa(int(s.ProtocolMajorVersion))
+	set["XT_PROTOCOL_REVISION"] = strconv.Itoa(int(s.ProtocolMinorVersion))
+	set["XT_SERVER_VENDOR"] = s.Vendor
+	set["XT_VENDOR_RELEASE"] = strconv.FormatUint(uint64(s.ReleaseNumber), 10)
+	set["XT_DISPLAYMOTIONBUFFERSIZE"] = strconv.FormatUint(uint64(s.MotionBufferSize), 10)
+	set["XT_SCREEN_COUNT"] = strconv.Itoa(len(s.Roots))
+	if c.DefaultScreen >= len(s.Roots) {
+		return fmt.Errorf("screen %d does not exist (only %d screens)", c.DefaultScreen, len(s.Roots))
+	}
+	set["XT_ALT_SCREEN"] = "UNSUPPORTED"
+	if len(s.Roots) > 1 {
+		if c.DefaultScreen == 0 {
+			set["XT_ALT_SCREEN"] = "1"
+		} else {
+			set["XT_ALT_SCREEN"] = "0"
+		}
+	}
+
+	r := s.Roots[c.DefaultScreen]
+	set["XT_WIDTH_MM"] = strconv.Itoa(int(r.WidthInMillimeters))
+	set["XT_HEIGHT_MM"] = strconv.Itoa(int(r.HeightInMillimeters))
+	set["XT_BLACK_PIXEL"] = strconv.FormatUint(uint64(r.BlackPixel), 10)
+	set["XT_WHITE_PIXEL"] = strconv.FormatUint(uint64(r.WhitePixel), 10)
+	set["XT_DOES_BACKING_STORE"] = strconv.Itoa(int(r.BackingStores))
+	set["XT_DOES_SAVE_UNDERS"] = "No"
+	if r.SaveUnders {
+		set["XT_DOES_SAVE_UNDERS"] = "Yes"
+	}
+	var list []string
+	visuals := make(map[string]struct{})
+	visType := map[byte]string{
+		xproto.VisualClassStaticGray:  "StaticGray",
+		xproto.VisualClassGrayScale:   "GrayScale",
+		xproto.VisualClassStaticColor: "StaticColor",
+		xproto.VisualClassPseudoColor: "PseudoColor",
+		xproto.VisualClassTrueColor:   "TrueColor",
+		xproto.VisualClassDirectColor: "DirectColor",
+	}
+	for _, v := range r.AllowedDepths {
+		list = append(list, strconv.Itoa(int(v.Depth)))
+		for _, vis := range v.Visuals {
+			if class, ok := visType[vis.Class]; ok {
+				visuals[fmt.Sprintf("%s(%d)", class, v.Depth)] = struct{}{}
+			} else {
+				return fmt.Errorf("visual type %d invalid", vis.Class)
+			}
+		}
+	}
+	set["XT_PIXMAP_DEPTHS"] = strings.Join(list, " ")
+	list = list[:0]
+	for k, _ := range visuals {
+		list = append(list, k)
+	}
+	set["XT_VISUAL_CLASSES"] = strings.Join(list, " ")
+
+	// DISPLAY := os.Getenv("DISPLAY") or ":0"
+	tetRoot := env("TET_ROOT", "/usr/local/share")
+
+	gfp, err := gfpCookie.Reply()
+	if err != nil {
+		return err
+	}
+	list = list[:0]
+	for _, v := range gfp.Path {
+		list = append(list, v.Name)
+	}
+	fontPath := strings.Join(list, ",")
+	set["XT_FONTPATH_GOOD"] = fontPath
+	set["XT_FONTPATH"] = filepath.Join(tetRoot, "xts5", "fonts") + "," + fontPath
+
+	localDisplay := regexp.MustCompile(`^:\d+(\.\d+)?$`)
+	display := env("DISPLAY", ":0")
+	if localDisplay.MatchString(display) {
+		set["XT_LOCAL"] = "Yes"
+		set["XT_TCP"] = "No"
+		set["XT_DISPLAYHOST"] = ""
+		if hostname, err := os.Hostname(); err == nil {
+			// try connecting to the same display via TCP
+			tcpConn, err := xgb.NewConnDisplay(hostname + display)
+			if err == nil {
+				tcpConn.Close()
+				set["XT_TCP"] = "Yes"
+				set["XT_DISPLAYHOST"] = hostname
+			}
+		}
+	} else {
+		// Remote display
+		set["XT_TCP"] = "Yes"
+		hostname := ""
+		offset := strings.LastIndex(display, ":")
+		if offset >= 0 {
+			hostname = display[:offset]
+		}
+		set["XT_DISPLAYHOST"] = hostname
+
+		// Not a local display; admin is responsible for placing
+		// xtest fonts on the font path before running xts-config.
+		set["XT_FONTPATH"] = fontPath
+		list = list[:0]
+		for _, v := range gfp.Path {
+			// Remove xtest directory
+			if !strings.Contains(strings.ToLower(v.Name), "xtest") {
+				list = append(list, v.Name)
+			}
+		}
+		fpg := strings.Join(list, ",")
+		// If xtest directory is not called "xtest", remove the
+		// last directory in the path (as it's less likely to
+		// be the path containing "default"/"cursor" than the
+		// first directory in the path).
+		if fpg == fontPath && len(list) > 0 {
+			fpg = strings.Join(list[:len(list)-1], ",")
+		}
+		set["XT_FONTPATH_GOOD"] = fpg
+	}
+
+	config_in := filepath.Join(tetRoot, "xts5", "tetexec.cfg.in")
+
+	in, err := os.Open(config_in)
+	if err != nil {
+		return err
+	}
+	defer in.Close()
+	o, err := os.Create(*config)
+	if err != nil {
+		return err
+	}
+	defer o.Close()
+	out := bufio.NewWriter(o)
+	defer out.Flush()
+
+	scan := bufio.NewScanner(in)
+	for scan.Scan() {
+		text := scan.Text()
+		thing := strings.SplitN(text, "=", 2)
+		if len(thing) == 2 {
+			leftThing := strings.TrimSpace(thing[0])
+			if rep, ok := set[leftThing]; ok {
+				text = thing[0] + "=" + rep
+				delete(set, leftThing)
+			}
+		}
+		fmt.Fprintln(out, text)
+	}
+	if err := scan.Err(); err != nil {
+		return err
+	}
+	if len(set) == 0 {
+		return nil
+	}
+	fmt.Fprintln(out, "\n# Undocumented variables:\n\n")
+	for k, v := range set {
+		fmt.Fprintln(out, k+"="+v)
+	}
+	return nil
+}
diff --git a/run.go b/run.go
index 9a103fe..ddb03ad 100644
--- a/run.go
+++ b/run.go
@@ -8,6 +8,8 @@
 // - Creates config file in results directory (instead of $TMPDIR)
 //
 // - Adds ability to run a single (or multiple) sub-test(s) (similar to run_assert)
+//
+// - Avoids shelling out to xts-config (and therefore xset/xdpyinfo) (faster remote startup)
 package main
 
 import (
@@ -23,6 +25,7 @@ import (
 var config = flag.String("config", "", "Location of xts configuration file")
 var output = flag.String("output", "xts-results", "Output directory to use")
 var version = flag.Bool("version", false, "Display version number and exit")
+var extconfig = flag.Bool("extconfig", false, "Use external xts-config")
 
 func env(evar string, def string) string {
 	rv := os.Getenv(evar)
@@ -32,8 +35,7 @@ func env(evar string, def string) string {
 	return rv
 }
 
-func createConfig(outdir string) error {
-	*config = filepath.Join(outdir, "tetexec.cfg")
+func createConfigExt(outdir string) error {
 	perl := env("PERL", "perl")
 	tetRoot := env("TET_ROOT", "/usr/local/share")
 	config_in := filepath.Join(tetRoot, "xts5", "tetexec.cfg.in")
@@ -104,7 +106,13 @@ func main() {
 
 	// Create the config file if necessary
 	if *config == "" {
-		err := createConfig(outdir)
+		*config = filepath.Join(outdir, "tetexec.cfg")
+		var err error
+		if *extconfig {
+			err = createConfigExt(outdir)
+		} else {
+			err = createConfig(outdir)
+		}
 		if err != nil {
 			fmt.Fprintln(os.Stdout, err)
 			os.Exit(1)