cmd/mbf: command handling

This tool is a frontend for bootstrapping hakurei via internal/pkg. Named mbf for now for "maiden's best friend" as a tribute to the DOOM source port.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/mbf/main.go

@@ -0,0 +1,113 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"runtime"
+	"syscall"
+
+	"hakurei.app/command"
+	"hakurei.app/container"
+	"hakurei.app/container/check"
+	"hakurei.app/internal/pkg"
+	"hakurei.app/message"
+)
+
+func main() {
+	container.TryArgv0(nil)
+
+	log.SetFlags(0)
+	log.SetPrefix("mbf: ")
+	msg := message.New(log.Default())
+
+	if os.Geteuid() == 0 {
+		log.Fatal("this program must not run as root")
+	}
+
+	var cache *pkg.Cache
+	ctx, stop := signal.NotifyContext(context.Background(),
+		syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
+	defer stop()
+	defer func() {
+		if cache != nil {
+			cache.Close()
+		}
+
+		if r := recover(); r != nil {
+			fmt.Println(r)
+			log.Fatal("consider scrubbing the on-disk cache")
+		}
+	}()
+
+	var (
+		flagVerbose bool
+		flagCures   int
+		flagBase    string
+		flagTShift  int
+	)
+	c := command.New(os.Stderr, log.Printf, "mbf", func([]string) (err error) {
+		msg.SwapVerbose(flagVerbose)
+
+		var base *check.Absolute
+		if flagBase, err = filepath.Abs(flagBase); err != nil {
+			return
+		} else if base, err = check.NewAbs(flagBase); err != nil {
+			return
+		}
+		if cache, err = pkg.Open(ctx, msg, flagCures, base); err == nil {
+			if flagTShift < 0 || flagTShift > 31 {
+				flagTShift = 31
+			}
+			cache.SetThreshold(1 << flagTShift)
+		}
+		return
+	}).Flag(
+		&flagVerbose,
+		"v", command.BoolFlag(false),
+		"Print cure messages to the console",
+	).Flag(
+		&flagCures,
+		"cures", command.IntFlag(0),
+		"Maximum number of dependencies to cure at any given time",
+	).Flag(
+		&flagBase,
+		"d", command.StringFlag("cache"),
+		"Directory to store cured artifacts",
+	).Flag(
+		&flagTShift,
+		"tshift", command.IntFlag(31),
+		"Dependency graph size exponent, to the power of 2",
+	)
+
+	{
+		var flagShifts int
+		c.NewCommand(
+			"scrub", "Examine the on-disk cache for errors",
+			func(args []string) error {
+				if len(args) > 0 {
+					return errors.New("scrub expects no arguments")
+				}
+				if flagShifts < 0 || flagShifts > 31 {
+					flagShifts = 12
+				}
+				return cache.Scrub(runtime.NumCPU() << flagShifts)
+			},
+		).Flag(
+			&flagShifts,
+			"shift", command.IntFlag(12),
+			"Scrub parallelism size exponent, to the power of 2",
+		)
+	}
+
+	c.MustParse(os.Args[1:], func(err error) {
+		if cache != nil {
+			cache.Close()
+		}
+		log.Fatal(err)
+	})
+}