feat: add new File abstraction primarily to handle partial content/range requests

storage/file.go

@@ -0,0 +1,142 @@
+package storage
+
+import (
+	"encoding/hex"
+	"errors"
+	"git.lumeweb.com/LumeWeb/portal/db/models"
+	"git.lumeweb.com/LumeWeb/portal/interfaces"
+	"io"
+	"time"
+)
+
+var (
+	_ io.ReadSeekCloser = (*File)(nil)
+)
+
+type File struct {
+	reader  io.ReadCloser
+	hash    []byte
+	storage interfaces.StorageService
+	record  *models.Upload
+}
+
+func NewFile(hash []byte, storage interfaces.StorageService) *File {
+	return &File{hash: hash, storage: storage}
+}
+
+func (f *File) Exists() bool {
+	exists, _ := f.storage.FileExists(f.hash)
+
+	return exists
+}
+
+func (f *File) Read(p []byte) (n int, err error) {
+	err = f.init(0)
+	if err != nil {
+		return 0, err
+	}
+
+	return f.reader.Read(p)
+}
+
+func (f *File) Seek(offset int64, whence int) (int64, error) {
+	switch whence {
+	case io.SeekStart:
+		if f.reader != nil {
+			err := f.reader.Close()
+			if err != nil {
+				return 0, err
+			}
+			f.reader = nil
+		}
+		err := f.init(offset)
+		if err != nil {
+			return 0, err
+		}
+	case io.SeekCurrent, io.SeekEnd:
+		return 0, errors.New("not supported")
+	default:
+		return 0, errors.New("invalid whence")
+	}
+
+	return 0, nil
+}
+
+func (f *File) Close() error {
+	if f.reader != nil {
+		r := f.reader
+		f.reader = nil
+		return r.Close()
+	}
+
+	return nil
+}
+
+func (f *File) init(offset int64) error {
+	if f.reader == nil {
+		reader, _, err := f.storage.GetFile(f.hash, offset)
+		if err != nil {
+			return err
+		}
+
+		f.reader = reader
+	}
+
+	return nil
+}
+
+func (f *File) Record() (*models.Upload, error) {
+	if f.record == nil {
+		exists, record := f.storage.FileExists(f.hash)
+
+		if !exists {
+			return nil, errors.New("file does not exist")
+		}
+
+		f.record = &record
+	}
+
+	return f.record, nil
+}
+
+func (f *File) Hash() []byte {
+	hashStr := f.HashString()
+
+	if hashStr == "" {
+		return nil
+	}
+
+	str, err := hex.DecodeString(hashStr)
+	if err != nil {
+		return nil
+	}
+
+	return str
+}
+
+func (f *File) HashString() string {
+	record, err := f.Record()
+	if err != nil {
+		return ""
+	}
+
+	return record.Hash
+}
+
+func (f *File) Name() time.Time {
+	record, err := f.Record()
+	if err != nil {
+		return time.Unix(0, 0)
+	}
+
+	return record.CreatedAt
+}
+
+func (f *File) Modtime() time.Time {
+	record, err := f.Record()
+	if err != nil {
+		return time.Unix(0, 0)
+	}
+
+	return record.CreatedAt
+}