directory-cleaner/main.go

package main

import (
	"log"
	"os"
	"path/filepath"
	"regexp"
	"strconv"
	"strings"
	"time"

	"github.com/djherbis/times"
)

var timeUnits = map[string]int64{
	"ms": 1,
	"s":  1000,
	"m":  1000 * 60,
	"h":  1000 * 60 * 60,
	"d":  1000 * 60 * 60 * 24,
	"M":  1000 * 60 * 60 * 24 * 30,
	"y":  1000 * 60 * 60 * 24 * 365,
}

var valueRegex, _ = regexp.Compile(`\d+`)
var unitRegex, _ = regexp.Compile(`[a-zA-Z]+`)

func parseDuration(date string) int64 {
	var milliseconds int64 = 0

	date = strings.TrimSpace(date)
	var parts = strings.Split(date, "_")
	for _, part := range parts {
		part = strings.TrimSpace(part)
		log.Printf("Parsing date part: %s\n", part)
		var value = valueRegex.FindString(part)
		var unit = unitRegex.FindString(part)

		if value == "" || unit == "" {
			log.Println("Invalid date part: " + part)
			continue
		}

		if _, ok := timeUnits[unit]; !ok {
			log.Println("Invalid date unit: " + unit)
			continue
		}
		log.Printf("Part %s parsed as: Value: %s, Unit: %s\n", part, value, unit)

		var valueMs, _ = strconv.ParseInt(value, 10, 16)
		valueMs = valueMs * timeUnits[unit]
		milliseconds += valueMs
		log.Printf("Adding %dms to duration, now: %d\n", valueMs, milliseconds)
	}

	return milliseconds
}

func getEnv(key, def string) string {
	var value, exists = os.LookupEnv(key)
	if exists {
		return value
	}
	return def
}

func scanRoot() {
	log.Println("Scanning root directory...")
	filepath.Walk(constants.ROOT, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			log.Printf("Error scanning %s: %s\n", path, err)
			return nil
		}
		path = filepath.ToSlash(path)

		if path == constants.ROOT {
			log.Printf("Skipping root directory %s...\n", path)
			return nil
		}

		if info.IsDir() {
			log.Printf("Skipping directory %s...\n", path)
			return nil
		}

		// We hope that IGNORED_DIRECTORIES is a small list, so we can afford to iterate over it
		// In fact iteration should be faster for small lists rather than hashing
		for _, ignoredDir := range constants.IGNORED_DIRECTORIES {
			if strings.HasPrefix(path, ignoredDir) {
				log.Printf("Ignoring directory %s\n", path)
				return nil
			}
		}

		processFile(path, info)
		return nil
	})
}

func scanArchive() {
	log.Println("Scanning archive...")
	filepath.Walk(constants.ROOT_ARCHIVE, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			log.Printf("Error scanning %s: %s\n", path, err)
			return nil
		}
		path = filepath.ToSlash(path)

		if path == constants.ROOT_ARCHIVE {
			log.Printf("Skipping root directory %s...\n", path)
			return nil
		}

		processArchiveFile(path, info)
		return nil
	})
}

func processFile(path string, info os.FileInfo) {
	var now = time.Now().UnixMilli()

	var fileATime int64 = times.Get(info).AccessTime().UnixMilli()
	var accessTimeDelta = now - fileATime
	log.Printf("File %s last accessed at %d, %dms ago\n", path, fileATime, accessTimeDelta)
	if accessTimeDelta > constants.ARCHIVE_THRESHOLD {
		log.Printf("File %s was accessed more than %dms ago, archiving...\n", path, constants.ARCHIVE_THRESHOLD)
		archiveFile(path)
	}
}

func processArchiveFile(path string, info os.FileInfo) {
	var now = time.Now().UnixMilli()

	var fileATime int64 = times.Get(info).AccessTime().UnixMilli()
	var accessTimeDelta = now - fileATime
	log.Printf("File %s last accessed at %d, %dms ago\n", path, fileATime, accessTimeDelta)
	if accessTimeDelta > constants.DELETE_THRESHOLD {
		log.Printf("File %s was accessed more than %dms ago, deleting...\n", path, constants.DELETE_THRESHOLD)
		deleteFile(path)
	}
}

func archiveFile(path string) {
	// defer os.Exit(1)
	var newPath = constants.ROOT_ARCHIVE + strings.Replace(path, constants.ROOT, "", 1)
	log.Printf("Archiving file %s to %s...\n", path, newPath)

	os.MkdirAll(filepath.Dir(newPath), os.ModePerm)
	var err = os.Rename(path, newPath)
	if err != nil {
		log.Printf("Error archiving file %s: %s\n", path, err)
		return
	}
}

func deleteFile(path string) {
	// defer os.Exit(1)
	log.Printf("Deleting file %s...\n", path)
	var err = os.Remove(path)
	if err != nil {
		log.Printf("Error deleting file %s: %s\n", path, err)
		return
	}
}

type Constants struct {
	ROOT                string
	ROOT_ARCHIVE        string
	IGNORED_DIRECTORIES []string
	ARCHIVE_THRESHOLD   int64
	DELETE_THRESHOLD    int64
	SCAN_INTERVAL       time.Duration
}

var constants = Constants{}

func main() {
	log.SetFlags(0b111)

	var ROOT = filepath.ToSlash(strings.TrimSpace(getEnv("ROOT", "/tmp")))
	var ROOT_ARCHIVE = filepath.ToSlash(strings.TrimSpace(getEnv("ROOT_ARCHIVE", ROOT+"/archive")))
	os.Mkdir(ROOT_ARCHIVE, os.ModePerm)
	var IGNORED_DIRECTORIES = strings.Split(getEnv("IGNORED_DIRECTORIES", ""), ",")
	IGNORED_DIRECTORIES = append(IGNORED_DIRECTORIES, ROOT_ARCHIVE)
	for key, dir := range IGNORED_DIRECTORIES {
		IGNORED_DIRECTORIES[key] = filepath.ToSlash(strings.TrimSpace(dir))
	}
	var ARCHIVE_THRESHOLD = parseDuration(getEnv("ARCHIVE_THRESHOLD", "1d"))
	var DELETE_THRESHOLD = parseDuration(getEnv("DELETE_THRESHOLD", "12h"))
	var SCAN_INTERVAL = time.Duration(parseDuration(getEnv("SCAN_INTERVAL", "1m")) * 1e6)

	constants.ROOT = ROOT
	constants.ROOT_ARCHIVE = ROOT_ARCHIVE
	constants.IGNORED_DIRECTORIES = IGNORED_DIRECTORIES
	constants.ARCHIVE_THRESHOLD = ARCHIVE_THRESHOLD
	constants.DELETE_THRESHOLD = DELETE_THRESHOLD
	constants.SCAN_INTERVAL = SCAN_INTERVAL

	log.Println("Input args parsed as:")
	log.Printf("ROOT: %s\n", ROOT)
	log.Printf("ROOT_ARCHIVE: %s\n", ROOT_ARCHIVE)
	log.Printf("IGNORED_DIRECTORIES: %s\n", IGNORED_DIRECTORIES)
	log.Printf("ARCHIVE_THRESHOLD: %d\n", ARCHIVE_THRESHOLD)
	log.Printf("DELETE_THRESHOLD: %d\n", DELETE_THRESHOLD)
	log.Printf("SCAN_INTERVAL: %d\n", SCAN_INTERVAL.Milliseconds())

	// scanRoot()
	for {
		log.Printf("Running at %d", time.Now().UnixMilli())
		time.Sleep(SCAN_INTERVAL)
		scanRoot()
		scanArchive()
	}
}