permission disk persistence

EsefexApi/main.go

@@ -47,6 +47,7 @@ func main() {
 	Must(err)
 
 	fpdb, err := filepermisssiondb.NewFilePermissionDB(cfg.Database.Permissiondblocation)
+	Must(err)
 
 	verT := time.Duration(cfg.VerificationExpiry * float32(time.Minute))
 	ldb := memorylinktokenstore.NewMemoryLinkTokenStore(verT)
@@ -76,6 +77,7 @@ func main() {
 		<-plr.Stop()
 
 		udb.Close()
+		fpdb.Close()
 
 		log.Println("All components stopped, exiting...")
 	}()

EsefexApi/permissiondb/filepermisssiondb/filepermisssiondb.go

@@ -4,6 +4,8 @@ import (
 	"encoding/json"
 	"esefexapi/permissiondb"
 	"esefexapi/permissions"
+	"esefexapi/util"
+	"log"
 	"os"
 	"sync"
 
@@ -13,49 +15,83 @@ import (
 var _ permissiondb.PermissionDB = &FilePermissionDB{}
 
 type FilePermissionDB struct {
-	filePath string
-	rw       *sync.RWMutex
-	stack    *permissions.PermissionStack
+	file  *os.File
+	rw    *sync.RWMutex
+	stack permissions.PermissionStack
 }
 
 func NewFilePermissionDB(path string) (*FilePermissionDB, error) {
+	log.Printf("Creating FileDB at %s", path)
+	file, err := util.EnsureFile(path)
+	if err != nil {
+		return nil, errors.Wrap(err, "Error ensuring file")
+	}
+
 	fpdb := &FilePermissionDB{
-		filePath: path,
-		rw:       &sync.RWMutex{},
-		stack:    permissions.NewPermissionStack(),
+		file:  file,
+		rw:    &sync.RWMutex{},
+		stack: permissions.NewPermissionStack(),
 	}
-	err := fpdb.load()
-	return fpdb, err
+	err = fpdb.load()
+	if err != nil {
+		return nil, errors.Wrap(err, "Error loading permission stack")
+	}
+
+	return fpdb, nil
 }
 
 // load loads the permission stack from the file.
 func (f *FilePermissionDB) load() error {
-	file, err := os.Open(f.filePath)
+	f.rw.Lock()
+	defer f.rw.Unlock()
+
+	// reset file
+	_, err := f.file.Seek(0, 0)
 	if err != nil {
-		return errors.Wrap(err, "Error opening file")
+		return errors.Wrap(err, "Error seeking to start of file")
 	}
-	defer file.Close()
 
-	err = json.NewDecoder(file).Decode(f.stack)
+	// read file
+	var perms permissions.PermissionStack
+	err = json.NewDecoder(f.file).Decode(&perms)
 	if err != nil {
-		return errors.Wrap(err, "Error decoding permission stack")
+		log.Printf("Error decoding file, creating empty permission stack: (%v)", err)
+		f.stack = permissions.NewPermissionStack()
+	} else {
+		f.stack = perms
 	}
 
 	return nil
 }
 
+func (f *FilePermissionDB) Close() error {
+	f.rw.Lock()
+	defer f.rw.Unlock()
+	log.Println("Closing file permissiondb")
+
+	err := f.save()
+	if err != nil {
+		return errors.Wrap(err, "Error saving permissiondb")
+	}
+	return f.file.Close()
+}
+
 // save saves the permission stack to the file.
-// TODO: Make this work
-func (f *FilePermissionDB) save() error {
-	file, err := os.OpenFile(f.filePath, os.O_RDWR|os.O_CREATE, os.ModePerm)
+// It assumes that the lock is already held.
+func (f FilePermissionDB) save() error {
+	// reset file
+	_, err := f.file.Seek(0, 0)
+	if err != nil {
+		return errors.Wrap(err, "Error seeking to start of file")
+	}
+	err = f.file.Truncate(0)
 	if err != nil {
-		return errors.Wrap(err, "Error opening file")
+		return errors.Wrap(err, "Error truncating file")
 	}
-	defer file.Close()
 
-	err = json.NewEncoder(file).Encode(f.stack)
+	err = json.NewEncoder(f.file).Encode(f.stack)
 	if err != nil {
-		return errors.Wrap(err, "Error encoding permission stack")
+		return errors.Wrap(err, "Error encoding file")
 	}
 
 	return nil

EsefexApi/permissions/stack.go

@@ -12,8 +12,8 @@ type PermissionStack struct {
 	Channel map[types.ChannelID]Permissions
 }
 
-func NewPermissionStack() *PermissionStack {
-	return &PermissionStack{
+func NewPermissionStack() PermissionStack {
+	return PermissionStack{
 		User:    make(map[types.UserID]Permissions),
 		Role:    make(map[types.RoleID]Permissions),
 		Channel: make(map[types.ChannelID]Permissions),

EsefexApi/userdb/fileuserdb/fileuserdb.go

@@ -64,17 +64,14 @@ func NewFileUserDB(filePath string) (*FileUserDB, error) {
 func (f *FileUserDB) Close() error {
 	log.Println("Closing userdb")
 
-	err := f.Save()
+	err := f.save()
 	if err != nil {
 		return errors.Wrap(err, "Error saving userdb")
 	}
 	return f.file.Close()
 }
 
-func (f *FileUserDB) Save() error {
-	f.fileLock.Lock()
-	defer f.fileLock.Unlock()
-
+func (f FileUserDB) save() error {
 	// reset file
 	_, err := f.file.Seek(0, 0)
 	if err != nil {

EsefexApi/userdb/fileuserdb/impluserdb.go

@@ -26,7 +26,7 @@ func (f *FileUserDB) SetUser(user userdb.User) error {
 	f.Users[user.ID] = user
 
 	go func() {
-		err := f.Save()
+		err := f.save()
 		if err != nil {
 			log.Printf("Error saving userdb: %+v", err)
 		}
@@ -40,7 +40,7 @@ func (f *FileUserDB) DeleteUser(userID types.UserID) error {
 	delete(f.Users, userID)
 
 	go func() {
-		err := f.Save()
+		err := f.save()
 		if err != nil {
 			log.Printf("Error saving userdb: %+v", err)
 		}
@@ -87,7 +87,7 @@ func (f *FileUserDB) NewToken(userID types.UserID) (userdb.Token, error) {
 	log.Printf("%v", f)
 
 	go func() {
-		err := f.Save()
+		err := f.save()
 		if err != nil {
 			log.Printf("Error saving userdb: %+v", err)
 		}

EsefexApi/util/util.go

@@ -4,10 +4,12 @@ import (
 	"fmt"
 	"math/rand"
 	"os"
+	"path"
 	"regexp"
 	"strings"
 
 	"github.com/bwmarrin/discordgo"
+	"github.com/pkg/errors"
 	"github.com/samber/lo"
 )
 
@@ -58,3 +60,17 @@ func RandomString(charset []rune, length int) string {
 
 	return string(str)
 }
+
+func EnsureFile(p string) (*os.File, error) {
+	err := os.MkdirAll(path.Dir(p), os.ModePerm)
+	if err != nil {
+		return nil, errors.Wrap(err, "Error creating directory")
+	}
+
+	file, err := os.OpenFile(p, os.O_RDWR|os.O_CREATE, os.ModePerm)
+	if err != nil {
+		return nil, errors.Wrap(err, "Error opening file")
+	}
+
+	return file, nil
+}