Fixed (beta) libraries for iOS 8 + Windows + Marvin

[Zebedi]

If it is any help regarding the number of books in Marvin, I unfortunately reset my ipad just before the IOS 8 problem started so had no books on it. After copying the new dll's I transferred 1189 books no problem. When I tried to transfer a further 29 I then got the message about not comunicating with the device and the malformed database. The further 29 did copy but that was as far as it went. Hope this helps.

[AndrewG]

Originally Posted by AndrewG

However in both cases I now get the malformed database message (attached). I first saw this message (on my Mac machine) with the fix to IOSRA for the change from Qt4 to Qt5 and I suspect that it is related to this. I do not get the malformed database message when running Calibre 64 bit 2.8 on my Win 7 machine when I use the standard Calibre dlls (rather than your latest versions) and the iPad running IOS7.

Just for completeness I would like to point out that Calibre 1.48 running on Mac OS X 10.10 still connects to Marvin 2.8 running on an iPad2 with IOS 7.1.2 with no malformed data base issue at all.

[Josieb1]

I don't want to play around with Calibre until the changes are official so will the plugin be changed or will this be part of a future Calibre release?

Thanks

[ShellShock]

Originally Posted by AndrewG

Good morning @ShellShock.

I found the solution to the connection problem - I needed to update the Apple software on my windows machine. Having done that I can connect either my iPhone 4s, running IOS8, or my iPad2, running IOS7. However in both cases I now get the malformed database message (attached). I first saw this message (on my Mac machine) with the fix to IOSRA for the change from Qt4 to Qt5 and I suspect that it is related to this. I do not get the malformed database message when running Calibre 64 bit 2.8 on my Win 7 machine when I use the standard Calibre dlls (rather than your latest versions) and the iPad running IOS7.

All the best.

Very interesting. If I can repro the bug, and if it only happens with the new dlls and not the old dlls, everything else being equal, then I may have a chance of fixing it.

[fkuehner]

Originally Posted by ShellShock

This is now fixed and tested with 32 bit Calibre on 64 bit Windows.

Great !!!! Now also works for my setup, thanx alot ShellShock !!! Your support is highly apprecited

[ShellShock]

Originally Posted by Josieb1

I don't want to play around with Calibre until the changes are official so will the plugin be changed or will this be part of a future Calibre release?

Thanks

One of two things need to happen first: either we confirm the "malformed database" error is not caused by the new dlls, or we confirm it is (and the old ones are OK) and I managed to fix it.

[AndrewG]

@ShellShock, if your new dlls could be transformed into dylibs, then perhaps we would also have a working solution for Mac users (using Calibre 1.48)

[ShellShock]

Any fix will be to the source code, which is (mostly) common to both Windows and Linux, so yes a fix should also work on Macs.

[Montana Harper]

Many many thanks for all your hard work on this!

[ShellShock]

Well thank you too!

[ShellShock]

I have not been able to repro the "database disk image is malformed" error. I have tried both ios 7 and 8; but I only have 300 books in my Calibre library and the error seems to be related to the number of books (more than I have).

I have created a new Calibre library, and I am going to load 1000s of copies of the same epub into it. I think this may take some time...

[AndrewG]

Originally Posted by ShellShock

I have not been able to repro the "database disk image is malformed" error. I have tried both ios 7 and 8; but I only have 300 books in my Calibre library and the error seems to be related to the number of books (more than I have).

I have created a new Calibre library, and I am going to load 1000s of copies of the same epub into it. I think this may take some time...

I have been using my iPhone to experiment with the "database disk image is malformed" error. I have some 8000 books to play with and my experience is that the error arises when the process of transfers from Calibre to Marvin glitches in some way and Calibre stops responding for a long time - it seems most easily triggered by marking a large number of books on Calibre for transfer to Marvin as one batch, particularly if the books are large. I think the batch size that triggers the problem may be related to the amount of RAM available to Calibre.

[ShellShock]

Or it could be a thread-safety problem. I don't know if send to device is single threaded or not; if not, then the bug could be due to lack of synchronisation across threads.

[comox]

I am not seeing the database problem but have a comment that may or may not be relevant.

AndrewG says problem is related to transfer glitch. I believe iOS 8.0 has a reliability problem with WiFi. I personally experienced it as an occasional broken sync using a different app. Solution was to disconnect and reconnect WiFi via iOS settings. I read that Apple fixed the problem in 8.1. I do not know if this is true but I have not seen the problem again since updating to 8.1.

[kovidgoyal]

Originally Posted by ShellShock

Or it could be a thread-safety problem. I don't know if send to device is single threaded or not; if not, then the bug could be due to lack of synchronisation across threads.

The device driver system in calibre is single threaded -- all device driver entry points are called on the same, dedicated thread. There are a few minor exceptions to this, which are documented in devices/interface.py, just search for thread.

Individual drivers are free to use multiple threads internally if they like.