Add sub-prefix db wrapper

internal/storage/db.go

@@ -0,0 +1,43 @@
+package storage
+
+import (
+	"context"
+
+	"git.defalsify.org/vise.git/db"
+)
+
+const (
+	DATATYPE_USERSUB = 64
+)
+
+type SubPrefixDb struct {
+	store db.Db
+	pfx []byte
+}
+
+func NewSubPrefixDb(store db.Db, pfx []byte) *SubPrefixDb {
+	return &SubPrefixDb{
+		store: store,
+		pfx: pfx,
+	}
+}
+
+func(s *SubPrefixDb) toKey(k []byte) []byte {
+        return append(s.pfx, k...)
+}
+
+func(s *SubPrefixDb) Get(ctx context.Context, key []byte) ([]byte, error) {
+        s.store.SetPrefix(DATATYPE_USERSUB)
+	key = s.toKey(key)
+        v, err := s.store.Get(ctx, key)
+        if err != nil {
+                return nil, err
+        }
+        return v, nil
+}
+
+func(s *SubPrefixDb) Put(ctx context.Context, key []byte, val []byte) error {
+        s.store.SetPrefix(DATATYPE_USERSUB)
+	key = s.toKey(key)
+        return s.store.Put(ctx, key, val)
+}

internal/storage/db_test.go

@@ -0,0 +1,54 @@
+package storage
+
+import (
+	"bytes"
+	"context"
+	"testing"
+
+	memdb "git.defalsify.org/vise.git/db/mem"
+)
+
+func TestSubPrefix(t *testing.T) {
+	ctx := context.Background()
+	db := memdb.NewMemDb()
+	err := db.Connect(ctx, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	sdba := NewSubPrefixDb(db, []byte("tinkywinky"))
+	err = sdba.Put(ctx, []byte("foo"), []byte("dipsy"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	r, err := sdba.Get(ctx, []byte("foo"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(r, []byte("dipsy")) {
+		t.Fatalf("expected 'dipsy', got %s", r)
+	}
+
+	sdbb := NewSubPrefixDb(db, []byte("lala"))
+	r, err = sdbb.Get(ctx, []byte("foo"))
+	if err == nil {
+		t.Fatal("expected not found")
+	}
+
+	err = sdbb.Put(ctx, []byte("foo"), []byte("pu"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	r, err = sdbb.Get(ctx, []byte("foo"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(r, []byte("pu")) {
+		t.Fatalf("expected 'pu', got %s", r)
+	}
+
+	r, err = sdba.Get(ctx, []byte("foo"))
+	if !bytes.Equal(r, []byte("dipsy")) {
+		t.Fatalf("expected 'dipsy', got %s", r)
+	}
+}

internal/storage/storage.go

@@ -6,7 +6,7 @@ import (
 )
 
 const (
-	DATATYPE_CUSTOM = 128 
+	DATATYPE_EXTEND = 128 
 )
 
 type Storage struct {