fichier: 1fichier support - fixes #2908

This was started by Fionera, finished off by Laura with fixes and more
docs from Nick.

Co-authored-by: Fionera <fionera@fionera.de>
Co-authored-by: Nick Craig-Wood <nick@craig-wood.com>

backend/fichier/object.go

@@ -0,0 +1,158 @@
+package fichier
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/ncw/rclone/fs"
+	"github.com/ncw/rclone/fs/hash"
+	"github.com/ncw/rclone/lib/rest"
+	"github.com/pkg/errors"
+)
+
+// Object is a filesystem like object provided by an Fs
+type Object struct {
+	fs     *Fs
+	remote string
+	file   File
+}
+
+// String returns a description of the Object
+func (o *Object) String() string {
+	return o.file.Filename
+}
+
+// Remote returns the remote path
+func (o *Object) Remote() string {
+	return o.remote
+}
+
+// ModTime returns the modification date of the file
+// It should return a best guess if one isn't available
+func (o *Object) ModTime(ctx context.Context) time.Time {
+	modTime, err := time.Parse("2006-01-02 15:04:05", o.file.Date)
+
+	if err != nil {
+		return time.Now()
+	}
+
+	return modTime
+}
+
+// Size returns the size of the file
+func (o *Object) Size() int64 {
+	return int64(o.file.Size)
+}
+
+// Fs returns read only access to the Fs that this object is part of
+func (o *Object) Fs() fs.Info {
+	return o.fs
+}
+
+// Hash returns the selected checksum of the file
+// If no checksum is available it returns ""
+func (o *Object) Hash(ctx context.Context, t hash.Type) (string, error) {
+	if t != hash.Whirlpool {
+		return "", hash.ErrUnsupported
+	}
+
+	return o.file.Checksum, nil
+}
+
+// Storable says whether this object can be stored
+func (o *Object) Storable() bool {
+	return true
+}
+
+// SetModTime sets the metadata on the object to set the modification date
+func (o *Object) SetModTime(context.Context, time.Time) error {
+	return fs.ErrorCantSetModTime
+	//return errors.New("setting modtime is not supported for 1fichier remotes")
+}
+
+// Open opens the file for read.  Call Close() on the returned io.ReadCloser
+func (o *Object) Open(ctx context.Context, options ...fs.OpenOption) (io.ReadCloser, error) {
+	fs.FixRangeOption(options, int64(o.file.Size))
+	downloadToken, err := o.fs.getDownloadToken(o.file.URL)
+
+	if err != nil {
+		return nil, err
+	}
+
+	var resp *http.Response
+	opts := rest.Opts{
+		Method:  "GET",
+		RootURL: downloadToken.URL,
+		Options: options,
+	}
+
+	err = o.fs.pacer.Call(func() (bool, error) {
+		resp, err = o.fs.rest.Call(&opts)
+		return shouldRetry(resp, err)
+	})
+
+	if err != nil {
+		return nil, err
+	}
+	return resp.Body, err
+}
+
+// Update in to the object with the modTime given of the given size
+//
+// When called from outside a Fs by rclone, src.Size() will always be >= 0.
+// But for unknown-sized objects (indicated by src.Size() == -1), Upload should either
+// return an error or update the object properly (rather than e.g. calling panic).
+func (o *Object) Update(ctx context.Context, in io.Reader, src fs.ObjectInfo, options ...fs.OpenOption) error {
+	if src.Size() < 0 {
+		return errors.New("refusing to update with unknown size")
+	}
+
+	// upload with new size but old name
+	info, err := o.fs.putUnchecked(ctx, in, o.Remote(), src.Size(), options...)
+	if err != nil {
+		return err
+	}
+
+	// Delete duplicate after successful upload
+	err = o.Remove(ctx)
+	if err != nil {
+		return errors.Wrap(err, "failed to remove old version")
+	}
+
+	// Replace guts of old object with new one
+	*o = *info.(*Object)
+
+	return nil
+}
+
+// Remove removes this object
+func (o *Object) Remove(ctx context.Context) error {
+	// fs.Debugf(f, "Removing file `%s` with url `%s`", o.file.Filename, o.file.URL)
+
+	_, err := o.fs.deleteFile(o.file.URL)
+
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// MimeType of an Object if known, "" otherwise
+func (o *Object) MimeType(ctx context.Context) string {
+	return o.file.ContentType
+}
+
+// ID returns the ID of the Object if known, or "" if not
+func (o *Object) ID() string {
+	return o.file.URL
+}
+
+// Check the interfaces are satisfied
+var (
+	_ fs.Object    = (*Object)(nil)
+	_ fs.MimeTyper = (*Object)(nil)
+	_ fs.IDer      = (*Object)(nil)
+)