main.go

package main

import (
	"fmt"
	"os"
	"os/user"
	"path/filepath"
	"strconv"

	"time"

	"strings"

	"syscall"

	"os/signal"

	"runtime"

	"github.com/claudetech/loggo"
	. "github.com/claudetech/loggo/default"
	"github.com/dweidenfeld/plexdrive/chunk"
	"github.com/dweidenfeld/plexdrive/config"
	"github.com/dweidenfeld/plexdrive/drive"
	"github.com/dweidenfeld/plexdrive/mount"
	flag "github.com/ogier/pflag"
	"golang.org/x/sys/unix"
)

func main() {
	// get the users home dir
	user, err := user.Current()
	if nil != err {
		panic(fmt.Sprintf("Could not read users homedir %v\n", err))
	}

	// parse the command line arguments
	argLogLevel := flag.IntP("verbosity", "v", 0, "Set the log level (0 = error, 1 = warn, 2 = info, 3 = debug, 4 = trace)")
	argRootNodeID := flag.String("root-node-id", "root", "The ID of the root node to mount (use this for only mount a sub directory)")
	argConfigPath := flag.StringP("config", "c", filepath.Join(user.HomeDir, ".plexdrive"), "The path to the configuration directory")
	argCacheFile := flag.String("cache-file", filepath.Join(user.HomeDir, ".plexdrive", "cache.bolt"), "Path the the cache file")
	argChunkSize := flag.String("chunk-size", "10M", "The size of each chunk that is downloaded (units: B, K, M, G)")
	argChunkLoadThreads := flag.Int("chunk-load-threads", runtime.NumCPU()/2, "The number of threads to use for downloading chunks")
	argChunkCheckThreads := flag.Int("chunk-check-threads", runtime.NumCPU()/2, "The number of threads to use for checking chunk existence")
	argChunkLoadAhead := flag.Int("chunk-load-ahead", runtime.NumCPU()-1, "The number of chunks that should be read ahead")
	argMaxChunks := flag.Int("max-chunks", runtime.NumCPU()*2, "The maximum number of chunks to be stored on disk")
	argRefreshInterval := flag.Duration("refresh-interval", 1*time.Minute, "The time to wait till checking for changes")
	argMountOptions := flag.StringP("fuse-options", "o", "", "Fuse mount options (e.g. -fuse-options allow_other,...)")
	argVersion := flag.Bool("version", false, "Displays program's version information")
	argUID := flag.Int64("uid", -1, "Set the mounts UID (-1 = default permissions)")
	argGID := flag.Int64("gid", -1, "Set the mounts GID (-1 = default permissions)")
	argUmask := flag.Uint32("umask", 0, "Override the default file permissions")
	// argDownloadSpeedLimit := flag.String("speed-limit", "", "This value limits the download speed, e.g. 5M = 5MB/s per chunk (units: B, K, M, G)")
	flag.Parse()

	// display version information
	if *argVersion {
		fmt.Println("%VERSION%")
		return
	}

	argCommand := flag.Arg(0)

	if argCommand == "mount" {
		// check if mountpoint is specified
		argMountPoint := flag.Arg(1)
		if "" == argMountPoint {
			flag.Usage()
			fmt.Println()
			panic(fmt.Errorf("Mountpoint not specified"))
		}

		// calculate uid / gid
		uid := uint32(unix.Geteuid())
		gid := uint32(unix.Getegid())
		if *argUID > -1 {
			uid = uint32(*argUID)
		}
		if *argGID > -1 {
			gid = uint32(*argGID)
		}

		// parse filemode
		umask := os.FileMode(*argUmask)

		// parse the mount options
		var mountOptions []string
		if "" != *argMountOptions {
			mountOptions = strings.Split(*argMountOptions, ",")
		}

		// initialize the logger with the specific log level
		var logLevel loggo.Level
		switch *argLogLevel {
		case 0:
			logLevel = loggo.Error
		case 1:
			logLevel = loggo.Warning
		case 2:
			logLevel = loggo.Info
		case 3:
			logLevel = loggo.Debug
		case 4:
			logLevel = loggo.Trace
		default:
			logLevel = loggo.Warning
		}
		Log.SetLevel(logLevel)

		// debug all given parameters
		Log.Debugf("verbosity            : %v", logLevel)
		Log.Debugf("root-node-id         : %v", *argRootNodeID)
		Log.Debugf("config               : %v", *argConfigPath)
		Log.Debugf("cache-file           : %v", *argCacheFile)
		Log.Debugf("chunk-size           : %v", *argChunkSize)
		Log.Debugf("chunk-load-threads   : %v", *argChunkLoadThreads)
		Log.Debugf("chunk-check-threads  : %v", *argChunkCheckThreads)
		Log.Debugf("chunk-load-ahead     : %v", *argChunkLoadAhead)
		Log.Debugf("max-chunks           : %v", *argMaxChunks)
		Log.Debugf("refresh-interval     : %v", *argRefreshInterval)
		Log.Debugf("fuse-options         : %v", *argMountOptions)
		Log.Debugf("UID                  : %v", uid)
		Log.Debugf("GID                  : %v", gid)
		Log.Debugf("umask                : %v", umask)
		// Log.Debugf("speed-limit          : %v", *argDownloadSpeedLimit)
		// version missing here

		// create all directories
		if err := os.MkdirAll(*argConfigPath, 0766); nil != err {
			Log.Errorf("Could not create configuration directory")
			Log.Debugf("%v", err)
			os.Exit(1)
		}
		if err := os.MkdirAll(filepath.Dir(*argCacheFile), 0766); nil != err {
			Log.Errorf("Could not create cache file directory")
			Log.Debugf("%v", err)
			os.Exit(1)
		}

		// set the global buffer configuration
		chunkSize, err := parseSizeArg(*argChunkSize)
		if nil != err {
			Log.Errorf("%v", err)
			os.Exit(2)
		}

		// read the configuration
		configPath := filepath.Join(*argConfigPath, "config.json")
		cfg, err := config.Read(configPath)
		if nil != err {
			cfg, err = config.Create(configPath)
			if nil != err {
				Log.Errorf("Could not read configuration")
				Log.Debugf("%v", err)
				os.Exit(3)
			}
		}

		cache, err := drive.NewCache(*argCacheFile, *argConfigPath, *argLogLevel > 3)
		if nil != err {
			Log.Errorf("%v", err)
			os.Exit(4)
		}
		defer cache.Close()

		client, err := drive.NewClient(cfg, cache, *argRefreshInterval, *argRootNodeID)
		if nil != err {
			Log.Errorf("%v", err)
			os.Exit(4)
		}

		chunkManager, err := chunk.NewManager(
			chunkSize,
			*argChunkLoadAhead,
			*argChunkCheckThreads,
			*argChunkLoadThreads,
			client,
			*argMaxChunks)
		if nil != err {
			Log.Errorf("%v", err)
			os.Exit(4)
		}

		// check os signals like SIGINT/TERM
		checkOsSignals(argMountPoint)
		if err := mount.Mount(client, chunkManager, argMountPoint, mountOptions, uid, gid, umask); nil != err {
			Log.Debugf("%v", err)
			os.Exit(5)
		}
	} else {
		Log.Errorf("Command %v not found", argCommand)
	}
}

func checkOsSignals(mountpoint string) {
	signals := make(chan os.Signal, 1)
	signal.Notify(signals, syscall.SIGINT)

	go func() {
		for sig := range signals {
			if sig == syscall.SIGINT {
				if err := mount.Unmount(mountpoint, false); nil != err {
					Log.Warningf("%v", err)
				}
			}
		}
	}()
}

func parseSizeArg(input string) (int64, error) {
	if "" == input {
		return 0, nil
	}

	suffix := input[len(input)-1]
	suffixLen := 1
	var multiplier float64
	switch suffix {
	case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.':
		suffixLen = 0
	case 'b', 'B':
		multiplier = 1
	case 'k', 'K':
		multiplier = 1024
	case 'm', 'M':
		multiplier = 1024 * 1024
	case 'g', 'G':
		multiplier = 1024 * 1024 * 1024
	default:
		return 0, fmt.Errorf("Invalid unit %v for %v", suffix, input)
	}
	input = input[:len(input)-suffixLen]
	value, err := strconv.ParseFloat(input, 64)
	if nil != err {
		Log.Debugf("%v", err)
		return 0, fmt.Errorf("Could not parse numeric value %v", input)
	}
	if value < 0 {
		return 0, fmt.Errorf("Numeric value must not be negative %v", input)
	}
	value *= multiplier
	return int64(value), nil
}