filestore.go

package filestore

import (
	"bufio"
	"io"
	"net/url"

	"github.com/dgraph-io/dgraph/x"
)

// FileStore represents a file or directory of files that are either stored
// locally or on minio/s3
type FileStore interface {
	// Similar to os.Open
	Open(path string) (io.ReadCloser, error)
	Exists(path string) bool
	FindDataFiles(str string, ext []string) []string
	ChunkReader(file string, key x.SensitiveByteSlice) (*bufio.Reader, func())
}

// NewFileStore returns a new file storage. If remote, it's backed by an x.MinioClient
func NewFileStore(path string) FileStore {
	url, err := url.Parse(path)
	x.Check(err)

	if url.Scheme == "minio" || url.Scheme == "s3" {
		mc, err := x.NewMinioClient(url, nil)
		x.Check(err)

		return &remoteFiles{mc}
	}

	return &localFiles{}
}

// Open takes a single path and returns a io.ReadCloser, similar to os.Open
func Open(path string) (io.ReadCloser, error) {
	return NewFileStore(path).Open(path)
}

// Exists returns false if the file doesn't exist. For remote storage, true does
// not guarantee existence
func Exists(path string) bool {
	return NewFileStore(path).Exists(path)
}