ownCloud Client 2.2.x

June 24, 2016 11 comments

A couple of weeks ago we released another significant milestone of the ownCloud Client, called version 2.2.0, followed by two small maintenance releases. (download). I’d like to highlight some of the new features and the changes that we have made to improve the user experience:

Overlay Icons

Overlay icons for the various file managers on our three platforms already exist for quite some time, but it has turned out that the performance was not up to the mark for big sync folders. The reason was mainly that too much communication between the file manager plugin and the client was happening. Once asked about the sync state of a single file, the client had to jump through quite some hoops in order to retrieve the required information. That involved not only database access to the sqlite-based sync journal, but also file system interaction to gather file information. Not a big deal if it’s only a few, but if the user syncs huge amounts, these efforts do sum up.

This becomes especially tricky for the propagation of changes upwards the file tree. Imagine there is a sync error happening in the foo/bar/baz/myfile. What should happen is that a warning icon appears on the icon for foo in the file manager, telling that within this directory, a problem exists. The complexity of the existing implementation was already high and adding this extra functionality would have reduced the reliability of the code lower than it already was.

Jocelyn was keen enough to do a refactoring of the underlying code which we call the SocketApi. Starting from the basic assumption that all files are in sync, and the code has just to care for these files that are new or changed, erroneous or ignored or similar, the amount of data to keep is very much reduced, which makes processing way faster.

Server Notifications

On the ownCloud server, there are situation where notifications are created which make the user aware of things that happened.

An example are federated shares:

If somebody shares a folder with you, you previously had to acknowledge it through the web interface. This explicit step is a safety net to avoid people sharing tons of Gigabytes of content, filling up your disk.


With 2.2.x, you can acknowledge the share right from the client, saving you the round trip to the web interface to check for new shares.

Keeping an Eye on Word & Friends

Microsoft Word and other office tools are rather hard to deal with in syncing, because they do very strict file locking of the files that are worked on. So strict that the subsequent sync app is not even allowed to open the file, not even for reading. That would be required to be able to sync the file.

As a result the sync client needs to wait until word unlocks the file, and then continue syncing.

For previous version of the client, this was hard to detect and worked only if other changes happened in the same directory where the file in question resides.

With 2.2.0 we added a special watcher that keeps an eye on the office docs Word and friends are blocking. And once the files are unlocked, the watcher starts a sync run to get the files to the server, or down from the server.

Advances on Desktop Sharing

The sharing has been further integrated and received several UX- and bugfixes. There is more feedback when performing actions so you know when your client is waiting for a response from the server. The client now also respect more data returned from the server if you have apps enabled on the server that for example
limit the expiration date.

Further more we better respect the share permissions granted. This means that if
somebody shared a folder without create permissions with you and you want to reshare
this folder in the client you won’t get the option to share with delete permissions. This avoids errors when sharing and is more in line with how the whole ownCloud platform handles re-sharing. We also adjusted the behavior for federated reshares with the server.

Please note to take full advantage of all improvements you will need to run at least
server version 9.0.

Have fun!

Volumio2 Release Candidate

April 15, 2016 1 comment

Last night I found time to finally install the first release candidate of Volumio 2, my preferred audio player software. This is more exciting than it sounds, because when I read the blogpost last summer that Volumio is going to be completely rewritten, with replacing the base technologies, I was a bit afraid that this will be one of the last bits that we heard from this project. Too many cool projects died after famous last announcements like that.

But not Volumio.


After quite some development time the project released RC1. While there were a few small bugs in a beta, my feelings about the RC1 are really positive. Volumio2 has a very nice and stylish GUI, a great improvement over Volumio1. Album-art is now nicely integrated in the playback pane and and everything is more shiny, even if the general concept is the same as in Volumio1.

I like it because it is only a music player. Very reduced on that, but also very thought through and focussed to fulfill that job perfectly. I just want to find and play music from my collection, quickly and comfortable and with good sound quality. No movies, series, images. Just sound.

About speed: While the scanning of my not too big music collection on a NAS was a bit of a time consuming task in the past, this feels now much faster (maybe thats only because of a faster network between the Raspberry and the NAS?). Searching, browsing and everything works quite fluid on an Raspberry2. And with the Hifiberry DAC for output, the sound quality is more than ok.

This is an release candidate of the first release of the rewritten project, and the quality is already very good. Nevertheless I found a few things that did not work for me or could be improved. That the volume control is not working is probably because of the Hifiberry DAC driver, I remember there was something, but haven’t investigated yet.

There are some things in the GUI that could be looked at again: For example on the Browse page, there is the very well working search field. After entering the search term and Enter, the search result is displayed as a list of songs to select from. I wished that the songs were additionally grouped by albums, which should also be selectable to be pushed to the play queue.

Also it would be great if the Queue would somehow indicate which entry is currently played. I could not spot that.

But these are only minor findings which can easily be addressed later after enhancement requests were posted:-)

I think Volumio2 is already a great success, even before it was released! You should not hesitate to try it if you love to listen to music!

Thanks for the hard work Volumio-Team!

Categories: FOSS, KDE, Release, Volumio Tags: , , ,

ownCloud Chunking NG Part 3: Incremental Syncing

November 13, 2015 2 comments

This is the third and final part of a little blog series about a new chunking algorithm that we discussed in ownCloud. You might be interested to read the first two parts ownCloud Chunking NG and Announcing an Upload as well.

This part makes a couple of ideas how the new chunking could be useful with a future feature of incremental sync (also called delta sync) in ownCloud.

In preparartion of delta sync the server could provide another new WebDAV route: remote.php/dav/blocks.

For each file, remote.php/dav/blocks/file-id exists as long as the server has valid checksums for blocks of the file which is identified by its unique file id.

A successful reply to remote.php/dav/blocks/file-id returns an JSON formatted data block with byte ranges and the respective checksums (and the checksum type) over the data blocks for the file. The client can use that information to calculate the blocks of data that has changed and thus needs to be uploaded.

If a file was changed on the server and as a result the checksums are not longer valid, access to remote.php/blocks/file-id is returning the 404 "not found" return code. The client needs to be able to handle missing checksum information at any time.

The server gets the checksums of file blocks along the upload of the chunks from the client. There is no obligation of the server to calculate the checksums of data blocks that came in other than through the clients, yet it can if there is capacity.

To implement incremental sync, the following high level processing could be implemented:

  1. The client downloads the blocklist of the file: GET remote.php/dav/blocks/file-id
  2. If GET succeeded: Client computes the local blocklist and computes changes
  3. If GET failed: All blocks of the file have to be uploaded.
  4. Client sends request MKCOL /uploads/transfer-id as described in an earlier part of the blog.
  5. For blocks that have changed: PUT data to /uploads/transfer-id/part-no
  6. For blocks that have NOT changed: COPY /blocks/file-id/block-no /uploads/transfer-id/part-no
  7. If all blocks are handled by either being uploaded or copied: Client sends MOVE /uploads/transfer-id /path/to/target-file to finalize the upload.

This would be an extension to the previously described upload of complete files. The PROPFIND semantic on /uploads/transfer-id remains valid.

Depending on the amount of not changed blocks, this could be a dramatic cut for the data that have to be uploaded. More information has to be collected to find out how much that is.

Note that this is still in the idea- and to-be-discussed state, and not yet an agreed specification for a new chunking algorithm.

Please, as usual, share your feedback with us!

DIY Net Player

July 12, 2015 10 comments

Something I wanted to share is a device I recently built. It is a complete net player for music files, served by a NAS. It’s now finished and “in production” now, so here is my report.

The cherry ear net player, based on raspberry pi and HifiBerry Amp+.

The cherry ear net player, based on raspberry pi and HifiBerry Amp+.


The device is based on a Raspberry Model B+ with a HifiBerry Amp+.

Cherry Ear backside with connectors and power supply

Cherry Ear backside with connectors and power supply

The Amp+ is a high-quality power amplifier that is mounted on the Raspberry mini computer, shortcutting the sub optimal audio system of the raspy. Only loudspeakers need to be connected, and this little combination is a very capable stereo audio system.

Software: Volumio

On the Raspberry runs a specialised linux distribution with a web based audio player for audio files and web radio. The name of this project is Volumio and it is one of my most favorite projects currently. What I like with it is that it is only a music player, and not a project that tries to manage all kind of media. Volumios user interface is accessible via web browser, and it is very user friendly, modern, pretty and clean.

It works on all size factors (from mobile phone to desktop) and is very easy to handle. Its a web interface to mpd which runs on the raspi for the actual music indexing and playing.

Volumio User Interface Example

Volumio User Interface

The distribution all is running on is an optimized raspbian, with a variety of kernel drivers for audio output devices. Everything is pre configured. Once the volumio image is written to SD-Card, the Raspberry boots up and the device starts to play nicely basically after network and media source was configured through the web interface.

It is impressive how the Volumio project aims for absolute simplicity in use, but also allows to play around with a whole lot of interesting settings. A lot can be, but very little has to be configured.

Bottomline: Volumio is really a interesting project which you wanna try if you’re interested in these things.

The Housing

I built the housing out of cherry tree from the region here. I got it from friends growing cherries, and they gave a few very nice shelfs. It was sliced and planed to 10mm thickness. The dark inlay is teak which I got from 70’s furniture that was found on bulky waste years ago.

After having everything cut, the cherry wood was glued together, with some internal help construction from plywood. After the sanding and polishing, the box was done.


Sizes [cm]

The Raspberry and Hifiberry are mounted on a little construction attached to the metal back cover, together with the speaker connector. The metal cover is tightend with one screw, and the whole electronics can be taken off the wood box by unscrewing it.

At the bottom of the device there is a switching power supply that provides the energy for the player.

How to Operate?

The player is comletely operated from the web interface. The make all additional knobs and stuff superflous, the user even uses the tablet or notebook to adjust the volume. And since the device is never switched off, it does not even have a power button.

I combined it with Denon SC-M39 speakers. The music files come from a consumer NAS in the home network. The Raspberry is very well powerful enough for the software, and the Hifiberry device is surprisingly powerful and clean. The sound is very nice. Clear and fresh in the mid and heights, but still enough base, which never is annoying blurry or drones.

I am very happy about the result of this little project. Hope you like it:-)

Categories: DIY, FOSS, Volumio Tags: , ,

ownCloud Chunking NG Part 2: Announcing an Upload

July 10, 2015 5 comments

The first part of this little blog series explained the basic operations of chunk file upload as we set it up for discussion. This part goes a bit beyond and talks about an addition to that, called announcing the upload.

With the processing described in the first part of the blog, the upload is done savely and with a clean approach, but it also has some drawbacks.

Most notably the server does not know the target filename of the uploaded file upfront. Also it does not know the final size or mimetype of the target file. That is not a problem in general, but imagine the following situation: A big file should be uploaded, which would exceed the users quota. That would only become an error for the user once all uploads happened, and the final upload directory is going to be moved on the final file name.

To avoid useless file transfers like that or to implement features like a file firewall, it would be good if the server would know these data at start of the upload and stop the upload in case it can not be accepted.

To achieve that, the client creates a file called _meta in /uploads/ before the upload of the chunks starts. The file contains information such as overall size, target file name and other meta information.

The server’s reply to the PUT of the _meta file can be a fail result code and error description to indicate that the upload will not be accepted due to certain server conditions. The client should check the result codes in order to avoid not necessary upload of data volume of which the final MOVE would fail anyway.

This is just a collection of ideas for an improved big file chunking protocol, nothing is decided yet. But now is the time to discuss. We’re looking forward to hearing your input.

The third and last part will describe how this plays into delta sync, which is especially interesting for big files, which are usually chunked.

ownCloud Chunking NG

June 22, 2015 15 comments

Recently Thomas and me met in person and thought about an alternative approach to bring our big file chunking to the next level. “Big file chunking” is ownClouds algorithm to upload huge files to ownCloud with clients.

This is the first of three little blog posts in which we want to present the idea and get your feedback. This is for open discussion, nothing is set in stone so far.

What is the downside of the current approach? Well, the current algorithm needs a lot of distributed knowledge between server and client to work: The naming scheme of the part files, semi secret headers, implicit knowledge. In addition to that, due to the character of the algorithm the server code is too much spread over the whole code base which makes maintaining difficult.

This situation could be improved with the following approach.

To handle chunked uploads, there will be a new WebDAV route, called remote.php/uploads.
All uploads of files larger than the chunk size will go through this route.

In a nutshell, an upload of a big file will happen as parts to a directory under that new route. The client creates it through the new route. This initiates a new upload. If the directory could be created successfully, the client starts to upload chunks of the original file into that directory. The sequence of the chunks is set by the names of the chunk files created in the directory. Once all chunks are uploaded, the client submits a MOVE request the renames the chunk upload directory to the target file.

Here is a pseudo code description of the sequence:

1. Client creates an upload directory with a self choosen name (ideally a numeric upload id):

MKCOL remote.php/uploads/upload-id

2. Client sends a chunk:

PUT remote.php/uploads/upload-id/chunk-id

3. Client repeats 2. until all chunks have successfully been uploaded
4. Client finalizes the upload:

MOVE remote.php/uploads/upload-id /path/to/target-file

5. The MOVE sends the ETag that is supposed to be overwritten in the request header to server. Server returns new ETag and FileID as reply headers of the MOVE.

During the upload, client can retrieve the current state of the upload by a PROPFIND request on the upload directory. The result will be a listing of all chunks that are already available on the server with metadata such as mtime, checksum and size.

If the server decides to remove an upload, ie. because it hasn’t been active for a time, it is free to remove the entire upload directory and return status 404 if a client tries to upload to. Also, a client is allowed to remove the entire upload directory to cancel an upload.

An upload is finalized by the MOVE request. Note that it’s a MOVE of a directory on a single file. This operation is not supported in normal file systems, but we think in this case, it has a nice well descriptive meaning. A MOVE is known as an atomic and fast operation, and that way it should be implemented by the server.

Also note that only with the final MOVE the upload operation is associated with the final destination file. We think that this approach already is a great improvement, because there is always a clear state of the upload with no secret knowledge hidden in the process.

In the next blog I will discuss an extension to this that adds more features to the process.

What do you think so far? Your feedback is appreciated, best on the ownCloud devel mailinglist!

ownCloud Client 1.8.0 Released

March 17, 2015 14 comments

Today, we’re happy to release the best ownCloud Desktop Client ever to our community and users! It is ownCloud Client 1.8.0 and it will push syncing with ownCloud to a new level of performance, stability and convenience.

The Share Dialog

The Share Dialog

This release brings a new integration into the operating system file manager. With 1.8.0, there is a new context menu that opens a dialog to allow the user to create a public link on a synced file. This link can be forwarded to other users who get access to the file via ownCloud.

Also the clients behavior when syncing files that are opened by other applications on Windows has greatly been improved. The problems with file locking some users saw for example with MS office apps were fixed.

Another area of improvements is again performance. With latest ownCloud servers, the client uses even more parallized requests, now for all kind of operations. Depending on the synced data structure, this can make a huge difference.

All the other changes, improvements and bug-fixes are too hard to count. Finally, this release received around 700 git commits compared to the previous release.

All this is only possible with the powerful and awesome community of ownClouders. We received a lot of very good contributions through the GitHub tracker, which helped us to nail down a lot of issues and improved the client tremendously.

But this time we’d like to specifically point out the code contributions of Alfie “Azelphur” Day and Roeland Jago Douma who contributed significant code bits to the sharing dialog on the client and also some server code.

A great thanks goes out to all of you who helped with this release. It was a great experience again and it is big fun working with you!

We hope you enjoy 1.8.0! Get it from https://owncloud.org/install/#desktop


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