Prototype of DirStore and some routes for working with buckets

database/database.go

@@ -1,3 +1,132 @@
 package database
 
-type Database interface{}
+import (
+	"encoding/json"
+	"log"
+	"os"
+
+	"git.phc.dm.unipi.it/phc/storage/store"
+)
+
+type Database interface {
+	Buckets() ([]string, error)
+	CreateBucket(bucket string, options ...any) error
+
+	Bucket(bucket string) (store.Store, error)
+}
+
+type bucketInfo struct {
+	Name string `json:"name"`
+	Path string `json:"path"`
+}
+
+type jsonDB struct {
+	file string
+
+	BucketsInfo map[string]bucketInfo `json:"buckets"`
+}
+
+func NewJSON(file string) Database {
+	db := &jsonDB{
+		file:        file,
+		BucketsInfo: map[string]bucketInfo{},
+	}
+
+	err := db.load()
+	if err != nil {
+		panic(err)
+	}
+
+	return db
+}
+
+func (db *jsonDB) setup() error {
+	if _, err := os.Stat(db.file); !os.IsNotExist(err) {
+		return nil
+	}
+
+	log.Printf("missing %q, creating empty database file", db.file)
+
+	f, err := os.Create(db.file)
+	defer f.Close()
+	if err != nil {
+		return err
+	}
+
+	enc := json.NewEncoder(f)
+	enc.SetIndent("", "    ")
+	if err := enc.Encode(&db); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (db *jsonDB) store() error {
+	f, err := os.Create(db.file)
+	defer f.Close()
+	if err != nil {
+		return err
+	}
+
+	enc := json.NewEncoder(f)
+	enc.SetIndent("", "    ")
+	if err := enc.Encode(&db); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (db *jsonDB) load() error {
+	if err := db.setup(); err != nil {
+		return err
+	}
+
+	f, err := os.Open(db.file)
+	defer f.Close()
+	if err != nil {
+		return err
+	}
+
+	if err := json.NewDecoder(f).Decode(&db); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (db *jsonDB) Buckets() ([]string, error) {
+	db.load()
+
+	buckets := make([]string, 0, len(db.BucketsInfo))
+
+	for _, b := range db.BucketsInfo {
+		buckets = append(buckets, b.Name)
+	}
+
+	return buckets, nil
+}
+
+func (db *jsonDB) CreateBucket(bucket string, options ...any) error {
+	db.load()
+	defer db.store()
+
+	bi := bucketInfo{Name: bucket, Path: bucket + "/"}
+	if len(options) > 0 {
+		bi.Path = options[0].(string)
+	}
+
+	db.BucketsInfo[bucket] = bi
+
+	return nil
+}
+
+func (db *jsonDB) Bucket(bucket string) (store.Store, error) {
+	b := db.BucketsInfo[bucket]
+
+	return &store.DirStore{
+		BaseDir: b.Path,
+		Prefix:  2,
+	}, nil
+}

database/mem.go

@@ -1,7 +0,0 @@
-package database
-
-type memDB struct {}
-
-func NewInMemoryDB() Database {
-	return &memDB{}
-}

database/sqlite.go

@@ -1,19 +0,0 @@
-package database
-
-import "database/sql"
-
-// Uncomment if actually using SQLite, the first build will be fairly slow
-// import _ "github.com/mattn/go-sqlite3"
-
-type sqliteDatabase struct {
-	Db *sql.DB
-}
-
-func NewSQLite(filename string) (Database, error) {
-	db, err := sql.Open("sqlite3", filename)
-	if err != nil {
-		return nil, err
-	}
-
-	return &sqliteDatabase{db}, nil
-}