This simplifies the implementation of remotes. The only required
interface is now `List` which is a simple one level directory list.
Optionally remotes may implement `ListR` if they have an efficient way
of doing a recursive list.
This makes directory listings much more efficient (one less
transaction needed) and also fixes#1439 (which was caused by having
to look up a directory name with quotes in which isn't dealt with well
by the list routine) by not doing a directory lookup at all.
* Add options to Put, PutUnchecked and Update for all Fses
* Use these to create HashOption
* Implement this in local
* Pass the option in fs.Copy
This has the effect that we only calculate hashes we need to in the
local Fs which speeds up transfers significantly.
Optional interfaces are becoming more important in rclone,
--track-renames and --backup-dir both rely on them.
Up to this point rclone has used interface upgrades to define optional
behaviour on Fs objects. However when one Fs object wraps another it
is very difficult for this scheme to work accurately. rclone has
relied on specific error messages being returned when the interface
isn't supported - this is unsatisfactory because it means you have to
call the interface to see whether it is supported.
This change enables accurate detection of optional interfaces by use
of a Features struct as returned by an obligatory Fs.Features()
method. The Features struct contains flags and function pointers
which can be tested against nil to see whether they can be used.
As a result crypt and hubic can accurately reflect the capabilities of
the underlying Fs they are wrapping.
This approach (ab)uses that trashed items can have naming conflicts
and that one can change their parents, even though direct replacing
("moving") is forbidden.
This means the feature can be disabled by setting the time to 0.
This also logs the HTTP status for analysis purposes.
Thanks Felix Bünemann for extensive testing and data collection.
When rclone is busy doing lots of very long uploads it doesn't refresh
the token. Amazon will fail uploads if they finish when the token is
more than 1 Hour past expiry.
Fix this by keeping track of the number of uploads and refreshing the
token when the token expires if there is an upload in progress.
Amazon Drive sometimes returns errors at the end of large uploads
* 408 REQUEST_TIMEOUT
* 504 GATEWAY_TIMEOUT
* 500 Internal error
The file may have been uploaded correctly though, so, on error, wait
for up to 2 minutes for it to appear if it was fully
uploaded (configure timeout with --acd-upload-wait-time).
Issues: #601#605#606
