working commit

app/storage/storage.go

@@ -1 +1,76 @@
 package storage
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"mstore/app/logger"
+	"mstore/pkg/auxuuid"
+)
+
+type Storage struct {
+	basepath string
+	logg     *logger.Logger
+}
+
+func NewStorage(basepath string) *Storage {
+	res := &Storage{
+		basepath: basepath,
+	}
+	res.logg = logger.NewLogger("storage")
+	return res
+}
+
+func (store *Storage) LinkFile(tmpname, collection, filename string) error {
+	var err error
+	dirname := filepath.Join(store.basepath, collection)
+	err = os.MkdirAll(dirname, 0750)
+	if err != nil {
+		return err
+	}
+
+	filename = filepath.Join(store.basepath, collection, filename)
+	os.Remove(filename)
+
+	err = os.Link(tmpname, filename)
+	if err != nil {
+		return err
+	}
+	err = os.Remove(tmpname)
+	if err != nil {
+		return err
+	}
+	return err
+}
+
+func (store *Storage) WriteTempFile(source io.Reader) (string, int64, string, error) {
+	var err error
+	var size int64
+	var digest string
+
+	tmpname := auxuuid.NewUUID()
+	tmpname = fmt.Sprintf("file-%s.tmp", tmpname)
+	tmppath := filepath.Join(store.basepath, tmpname)
+
+	file, err := os.OpenFile(tmppath, os.O_WRONLY|os.O_CREATE, 0640)
+	if err != nil {
+		return tmppath, size, digest, err
+	}
+	defer file.Close()
+
+	hasher := sha256.New()
+	writer := io.MultiWriter(file, hasher)
+
+	size, err = io.Copy(writer, source)
+	if err != nil {
+		return tmppath, size, digest, err
+	}
+	digest = hex.EncodeToString(hasher.Sum(nil))
+	digest = fmt.Sprintf("sha256:%s", digest)
+
+	return tmppath, size, digest, err
+}