gistfile1.txt

package main

import (
	"encoding/json"
	"fmt"
	"go/build"
	"os"
	"path/filepath"
	"strings"
)

func main() {
	processSequential() // 0.23s user 0.12s system 98% cpu 0.356 total
	//processParallel() // 0.29s user 0.20s system 112% cpu 0.432 total
}

func processParallel() {
	sem := make(chan bool, 1)
	count := 0

	for _, path := range packagePaths() {
		go func(path string) {
			processPackage(path)
			sem <- true
		}(path)

		count++
	}

	for i := 0; i < count; i++ {
		<-sem
	}
}

func processSequential() {
	for _, path := range packagePaths() {
		processPackage(path)
	}
}

func isPathDir(path string) bool {
	f, err := os.Open(path)
	defer f.Close()
	if err != nil {
		fmt.Printf("Error when opening path %v: %v\n", path, err)
		return false
	}
	info, err := f.Stat()
	if err != nil {
		fmt.Printf("Error when statting path %v: %v\n", path, err)
		return false
	}

	return info.IsDir()
}

func fullGlob(basePath string) []string {
	result := []string{}

	for {
		basePath = basePath + "/[^.]*"
		paths, err := filepath.Glob(basePath)
		if err != nil {
			fmt.Printf("Error when globbing path %v: %v\n", basePath, err)
			break
		}

		if len(paths) == 0 {
			break
		}

		for _, path := range paths {
			if isPathDir(path) {
				result = append(result, path)
			}
		}
	}

	return result
}

func packagePaths() []string {
	result := []string{}

	for _, srcDir := range build.Default.SrcDirs() {
		for _, path := range fullGlob(srcDir) {
			if isPathDir(path) {
				result = append(result, path)
			}
		}
	}

	return result
}

func packageInfo(path string) *build.Package {
	result, err := build.Default.ImportDir(path, 0)
	if err != nil {
		fmt.Printf("Failed to import package %v: %v\n", path, err)
		return nil
	}

	return result
}

func processPackage(packagePath string) {
	// fmt.Printf("processPackage(%v)\n", packagePath)
	info, err := build.Default.ImportDir(packagePath, 0)
	if err != nil {
		fmt.Printf("Failed to import package %v: %v\n", packagePath, err)
		return
	}

	targetPath := "out/" + strings.Replace(packagePath, "/", "-", -1) + ".txt"
	infoFile, err := os.Create(targetPath)
	if err != nil {
		fmt.Printf("Failed to open file for writing %v: %v\n", targetPath, err)
		return
	}

	data, _ := json.MarshalIndent(info, "", "  ")
	fmt.Fprint(infoFile, string(data))

	infoFile.Close()
}