internal/app/state: use absolute pathnames

This is less error-prone and fits better into internal/app which already uses check.Absolute for all pathnames.

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

cmd/hakurei/command.go

@@ -321,7 +321,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 		c.NewCommand("ps", "List active instances", func(args []string) error {
 			var sc hst.Paths
 			app.CopyPaths().Copy(&sc, new(app.Hsu).MustID(nil))
-			printPs(os.Stdout, time.Now().UTC(), state.NewMulti(msg, sc.RunDirPath.String()), flagShort, flagJSON)
+			printPs(os.Stdout, time.Now().UTC(), state.NewMulti(msg, sc.RunDirPath), flagShort, flagJSON)
 			return errSuccess
 		}).Flag(&flagShort, "short", command.BoolFlag(false), "Print instance id")
 	}

cmd/hakurei/parse.go

@@ -84,7 +84,7 @@ func tryIdentifier(msg message.Msg, name string) (config *hst.Config, entry *hst
 	return tryIdentifierEntries(msg, name, func() map[hst.ID]*hst.State {
 		var sc hst.Paths
 		app.CopyPaths().Copy(&sc, new(app.Hsu).MustID(nil))
-		s := state.NewMulti(msg, sc.RunDirPath.String())
+		s := state.NewMulti(msg, sc.RunDirPath)
 		if entries, err := state.Join(s); err != nil {
 			msg.GetLogger().Printf("cannot join store: %v", err) // not fatal
 			return nil

internal/app/process.go

@@ -221,7 +221,7 @@ func (k *outcome) main(msg message.Msg) {
 		ms.fatal("cannot commit system setup:", err)
 	}
 	ms.uintptr |= mainNeedsRevert
-	ms.store = state.NewMulti(msg, k.state.sc.RunDirPath.String())
+	ms.store = state.NewMulti(msg, k.state.sc.RunDirPath)
 
 	ctx, cancel := context.WithCancel(k.ctx)
 	defer cancel()

internal/app/state/multi.go

@@ -5,10 +5,10 @@ import (
 	"fmt"
 	"io/fs"
 	"os"
-	"path"
 	"strconv"
 	"sync"
 
+	"hakurei.app/container/check"
 	"hakurei.app/hst"
 	"hakurei.app/internal/lockedfile"
 	"hakurei.app/message"
@@ -19,7 +19,8 @@ const multiLockFileName = "lock"
 
 // fine-grained locking and access
 type multiStore struct {
-	base string
+	// Pathname of directory that the store is rooted in.
+	base *check.Absolute
 
 	// All currently known instances of multiHandle, keyed by their identity.
 	handles sync.Map
@@ -39,7 +40,7 @@ type multiStore struct {
 // bigLock acquires fileMu on multiStore.
 // Must be called while holding a read lock on multiStore.
 func (s *multiStore) bigLock() (unlock func(), err error) {
-	s.mkdirOnce.Do(func() { s.mkdirErr = os.MkdirAll(s.base, 0700) })
+	s.mkdirOnce.Do(func() { s.mkdirErr = os.MkdirAll(s.base.String(), 0700) })
 	if s.mkdirErr != nil {
 		return nil, &hst.AppError{Step: "create state store directory", Err: s.mkdirErr}
 	}
@@ -66,10 +67,10 @@ func (s *multiStore) identityHandle(identity int) (*multiHandle, error) {
 			defer unlock()
 		}
 
-		b.path = path.Join(s.base, strconv.Itoa(identity))
+		b.path = s.base.Append(strconv.Itoa(identity))
-		b.fileMu = lockedfile.MutexAt(path.Join(b.path, multiLockFileName))
+		b.fileMu = lockedfile.MutexAt(b.path.Append(multiLockFileName).String())
 
-		if err := os.MkdirAll(b.path, 0700); err != nil && !errors.Is(err, fs.ErrExist) {
+		if err := os.MkdirAll(b.path.String(), 0700); err != nil && !errors.Is(err, fs.ErrExist) {
 			s.handles.CompareAndDelete(identity, b)
 			return nil, &hst.AppError{Step: "create store segment directory", Err: err}
 		}
@@ -114,7 +115,7 @@ func (s *multiStore) List() ([]int, error) {
 	if unlock, err := s.bigLock(); err != nil {
 		return nil, err
 	} else {
-		entries, err = os.ReadDir(s.base)
+		entries, err = os.ReadDir(s.base.String())
 		s.mu.RUnlock()
 		unlock()
 
@@ -155,7 +156,8 @@ func (s *multiStore) List() ([]int, error) {
 
 // multiHandle is a handle on a multiStore segment.
 type multiHandle struct {
-	path string
+	// Pathname of directory that the segment referred to by multiHandle is rooted in.
+	path *check.Absolute
 
 	// created by prepare
 	fileMu *lockedfile.Mutex
@@ -163,7 +165,8 @@ type multiHandle struct {
 	mu sync.RWMutex
 }
 
-func (h *multiHandle) filename(id *hst.ID) string { return path.Join(h.path, id.String()) }
+// instance returns the absolute pathname of a state entry file.
+func (h *multiHandle) instance(id *hst.ID) *check.Absolute { return h.path.Append(id.String()) }
 
 // load iterates over all [hst.State] entries reachable via multiHandle,
 // decoding their contents if decode is true.
@@ -173,7 +176,7 @@ func (h *multiHandle) load(decode bool) (map[hst.ID]*hst.State, error) {
 
 	// read directory contents, should only contain files named after ids
 	var entries []os.DirEntry
-	if pl, err := os.ReadDir(h.path); err != nil {
+	if pl, err := os.ReadDir(h.path.String()); err != nil {
 		return nil, &hst.AppError{Step: "read store segment directory", Err: err}
 	} else {
 		entries = pl
@@ -201,7 +204,7 @@ func (h *multiHandle) load(decode bool) (map[hst.ID]*hst.State, error) {
 		// run in a function to better handle file closing
 		if err := func() error {
 			// open state file for reading
-			if f, err := os.Open(path.Join(h.path, e.Name())); err != nil {
+			if f, err := os.Open(h.path.Append(e.Name()).String()); err != nil {
 				return &hst.AppError{Step: "open state file", Err: err}
 			} else {
 				var s hst.State
@@ -240,8 +243,7 @@ func (h *multiHandle) Save(state *hst.State) error {
 		return err
 	}
 
-	statePath := h.filename(&state.ID)
+	if f, err := os.OpenFile(h.instance(&state.ID).String(), os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600); err != nil {
-	if f, err := os.OpenFile(statePath, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600); err != nil {
 		return &hst.AppError{Step: "create state file", Err: err}
 	} else if err = entryEncode(f, state); err != nil {
 		_ = f.Close()
@@ -256,7 +258,7 @@ func (h *multiHandle) Destroy(id hst.ID) error {
 	h.mu.Lock()
 	defer h.mu.Unlock()
 
-	if err := os.Remove(h.filename(&id)); err != nil {
+	if err := os.Remove(h.instance(&id).String()); err != nil {
 		return &hst.AppError{Step: "destroy state entry", Err: err}
 	}
 	return nil
@@ -274,8 +276,8 @@ func (h *multiHandle) Len() (int, error) {
 }
 
 // NewMulti returns an instance of the multi-file store.
-func NewMulti(msg message.Msg, runDir string) Store {
+func NewMulti(msg message.Msg, prefix *check.Absolute) Store {
-	store := &multiStore{msg: msg, base: path.Join(runDir, "state")}
+	store := &multiStore{msg: msg, base: prefix.Append("state")}
-	store.fileMu = lockedfile.MutexAt(path.Join(store.base, multiLockFileName))
+	store.fileMu = lockedfile.MutexAt(store.base.Append(multiLockFileName).String())
 	return store
 }

internal/app/state/multi_test.go

@@ -4,10 +4,11 @@ import (
 	"log"
 	"testing"
 
+	"hakurei.app/container/check"
 	"hakurei.app/internal/app/state"
 	"hakurei.app/message"
 )
 
 func TestMulti(t *testing.T) {
-	testStore(t, state.NewMulti(message.NewMsg(log.New(log.Writer(), "multi: ", 0)), t.TempDir()))
+	testStore(t, state.NewMulti(message.NewMsg(log.New(log.Writer(), "multi: ", 0)), check.MustAbs(t.TempDir())))
 }