webdav: add an ownCloud Infinite Scale vendor that enables tus chunked upload support

This change adds a new vendor called "infinitescale" to the webdav
backend. It enables the ownCloud Infinite Scale
https://github.com/owncloud/ocis project and implements its specific
chunked uploader following the tus protocol https://tus.io

Signed-off-by: Christian Richter <crichter@owncloud.com>
Co-authored-by: Klaas Freitag <klaas.freitag@kiteworks.com>
Co-authored-by: Christian Richter <crichter@owncloud.com>
Co-authored-by: Christian Richter <1058116+dragonchaser@users.noreply.github.com>
Co-authored-by: Ralf Haferkamp <r.haferkamp@opencloud.eu>

backend/webdav/tus-errors.go

@@ -0,0 +1,40 @@
+package webdav
+
+import (
+	"errors"
+	"fmt"
+)
+
+var (
+	// ErrChunkSize is returned when the chunk size is zero
+	ErrChunkSize = errors.New("tus chunk size must be greater than zero")
+	// ErrNilLogger is returned when the logger is nil
+	ErrNilLogger = errors.New("tus logger can't be nil")
+	// ErrNilStore is returned when the store is nil
+	ErrNilStore = errors.New("tus store can't be nil if resume is enable")
+	// ErrNilUpload is returned when the upload is nil
+	ErrNilUpload = errors.New("tus upload can't be nil")
+	// ErrLargeUpload is returned when the upload body is to large
+	ErrLargeUpload = errors.New("tus upload body is to large")
+	// ErrVersionMismatch is returned when the tus protocol version is mismatching
+	ErrVersionMismatch = errors.New("tus protocol version mismatch")
+	// ErrOffsetMismatch is returned when the tus upload offset is mismatching
+	ErrOffsetMismatch = errors.New("tus upload offset mismatch")
+	// ErrUploadNotFound is returned when the tus upload is not found
+	ErrUploadNotFound = errors.New("tus upload not found")
+	// ErrResumeNotEnabled is returned when the tus resuming is not enabled
+	ErrResumeNotEnabled = errors.New("tus resuming not enabled")
+	// ErrFingerprintNotSet is returned when the tus fingerprint is not set
+	ErrFingerprintNotSet = errors.New("tus fingerprint not set")
+)
+
+// ClientError represents an error state of a client
+type ClientError struct {
+	Code int
+	Body []byte
+}
+
+// Error returns an error string containing the client error code
+func (c ClientError) Error() string {
+	return fmt.Sprintf("unexpected status code: %d", c.Code)
+}