add script for benchmarking git-media on a full git repo's working dir

.gitignore

@@ -1 +1,2 @@
-bin/
+bin/
+benchmark/

cmd/benchmark-git-media.git

@@ -0,0 +1,138 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+var (
+	ListFiles  = flag.Bool("list", false, "List files only")
+	SourcePath = flag.String("s", "/Users/rick/github/github", "Location of existing Git repository")
+	DestPath   = flag.String("d", "", "Location to setup benchmark repository")
+	Extensions = flag.String("ext", "", "Extensions to filter through git-media, separated by commas")
+	WorkingDir string
+)
+
+func main() {
+	flag.Parse()
+	wd, _ := os.Getwd()
+	WorkingDir = wd
+	if *DestPath == "" {
+		*DestPath = filepath.Join(WorkingDir, "benchmark")
+	}
+
+	os.Chdir(*SourcePath)
+
+	if *ListFiles {
+		list(findfiles())
+	} else {
+		bench(findfiles())
+	}
+}
+
+func list(files []string) {
+	for _, path := range files {
+		fmt.Println(path)
+	}
+}
+
+func bench(files []string) {
+	os.MkdirAll(*DestPath, 0777)
+	os.Chdir(*DestPath)
+
+	fmt.Println(safeExec("git", "init"))
+
+	if *Extensions != "" {
+		fmt.Printf("Filtering extensions: %s\n", *Extensions)
+		gitattr, err := os.Create(filepath.Join(*DestPath, ".gitattributes"))
+		if err != nil {
+			fmt.Println("Error opening .gitattributes")
+			panic(err)
+		}
+
+		for _, ext := range strings.Split(*Extensions, ",") {
+			gitattr.Write([]byte(fmt.Sprintf("*.%s\tfilter=media\n", ext)))
+		}
+		gitattr.Close()
+
+		fmt.Println(WorkingDir, filepath.Join(WorkingDir, "bin", "git-media-clean"))
+		safeExec("git", "config", "filter.media.clean", filepath.Join(WorkingDir, "bin", "git-media-clean"))
+		safeExec("git", "config", "filter.media.smudge", filepath.Join(WorkingDir, "bin", "git-media-smudge"))
+	}
+
+	fmt.Printf("Copying %d files...\n", len(files))
+
+	for _, path := range files {
+		copyFile(path)
+	}
+
+	fmt.Println("Adding to git...")
+
+	started := time.Now()
+	if _, err := simpleExec("git", "add", "."); err != nil {
+		fmt.Printf("Error with git add: %s\n", err)
+	}
+	cmd, err := simpleExec("git", "commit", "-a", "-m", "benchmark")
+	dur := time.Since(started)
+	if err != nil {
+		fmt.Printf("Error with git add: %s\n", err)
+	} else {
+		fmt.Println(cmd)
+	}
+	fmt.Printf("Added in %s\n", dur.String())
+}
+
+func copyFile(path string) {
+	sourcepath := filepath.Join(*SourcePath, path)
+	destpath := filepath.Join(*DestPath, path)
+
+	source, err := os.Open(sourcepath)
+	if err != nil {
+		return
+	}
+
+	os.MkdirAll(filepath.Dir(destpath), 0777)
+	dest, err := os.Create(destpath)
+	if err != nil {
+		fmt.Printf("Error opening destination: %s\n", destpath)
+		panic(err)
+	}
+
+	io.Copy(dest, source)
+	source.Close()
+	dest.Close()
+}
+
+func findfiles() []string {
+	cmd := safeExec("git", "ls-tree", "HEAD", "-r")
+	lines := strings.Split(cmd, "\n")
+	files := make([]string, len(lines)-1)
+
+	for i := range files {
+		pieces := strings.Split(lines[i], "\t")
+		files[i] = pieces[len(pieces)-1]
+	}
+	return files
+}
+
+func simpleExec(name string, args ...string) (string, error) {
+	cmd, err := exec.Command(name, args...).Output()
+	if err != nil {
+		return "", err
+	}
+	return string(cmd), nil
+}
+
+func safeExec(name string, args ...string) string {
+	str, err := simpleExec(name, args...)
+	if err != nil {
+		panic(err)
+	}
+	return str
+}