fileservice

type DirEntry struct {
	// file name, not full path
	Name  string
	IsDir bool
	Size  int
}

type FileService interface {
	// Write writes a new file
	// returns ErrFileExisted if file already existed
	// returns ErrSizeNotMatch if provided size does not match data
	// entries in vector should be written atomically. if write failed, following reads must not succeed.
	Write(ctx context.Context, vector IOVector) error

	// Read reads a file to fill IOEntries
	// returns ErrFileNotFound if requested file not found
	// returns ErrUnexpectedEOF if less data is read than requested size
	// returns ErrEmptyRange if no data at specified offset and size
	Read(ctx context.Context, vector *IOVector) error

	// List lists sub-entries in a dir
	List(ctx context.Context, dirPath string) ([]DirEntry, error)

	// Delete deletes a file
	// returns ErrFileNotFound if requested file not found
	Delete(ctx context.Context, filePath string) error
}

type IOEntry struct {
	// offset in file, [0, len(file) - 1]
	Offset int

	// number of bytes to be read of written, [1, len(file)]
	Size int

	// raw content
	// when reading, if len(Data) < Size, a new Size-lengthed byte slice will be allocated
	Data []byte

	// when reading, if Writer is not nil, write data to it instead of setting Data field
	WriterForRead io.Writer

	// when reading, if ReadCloser is not nil, set an io.ReadCloser instead of setting Data field
	ReadCloserForRead *io.ReadCloser

	// when writing, if Reader is not nil, read data from it instead of reading Data field
	ReaderForWrite io.Reader
}

type IOVector struct {
	// path to file, '/' separated
	FilePath string
	// io entries
	// empty entry not allowed
	Entries []IOEntry
}

type LocalFS struct {
	sync.RWMutex
	// contains filtered or unexported fields
}

type MemoryFS struct {
	sync.RWMutex
	// contains filtered or unexported fields
}

type MutableFileService interface {
	FileService

	// Mutate mutates file contents
	Mutate(ctx context.Context, vector IOVector) error
}

type S3Config struct {
	Endpoint  string
	Region    string
	APIKey    string
	APISecret string
	Bucket    string
	// KeyPrefix enables multiple fs instances in one bucket
	KeyPrefix string
}

type S3FS struct {
	// contains filtered or unexported fields
}

type S3FSMinio struct {
	// contains filtered or unexported fields
}