I'm seeing quite bizarre behavior while taking pictures with the camera and watching dbus.log (Aquaris E5, OTA-10).
I have about 2000 songs without embedded artwork on the phone. The music app is sitting on the Artist tab, showing a bunch of images, as well as default artwork for some albums for which 7digital doesn't have artist art. The thumbnail cache is hot for the artists that are showing.
Now I change to the camera app and take a picture. About two seconds after I press the shutter button, I see the trace below in dbus.log. Every time I take a picture, something sends 59 (!) requests for album and artist art. Presumably, adding the picture, which wakes up mediascanner, causes the model for the music app to be updated, which then redraws everything even though it doesn't have a display surface.
It would be great to avoid this. Is there a way to not update the music app model when a picture is added?
Note that, to see hits as well as misses and errors, you need to run
gsettings set com.canonical.Unity.Thumbnailer log-level 2
thumbnailer-service: [05:04:43.195] Idle timeout reached.
thumbnailer-service: [05:04:43.211] Exiting
Activating service name='com.canonical.MediaScanner2.Extractor'
Successfully activated service 'com.canonical.MediaScanner2.Extractor'
Activating service name='com.canonical.Thumbnailer'
thumbnailer-service: [05:07:15.676] Initializing
thumbnailer-service: [05:07:15.981] DBusInterface(): adjusted max-extractions to 1 for Arm
Successfully activated service 'com.canonical.Thumbnailer'
thumbnailer-service: [05:07:16.000] image cache: 510 entries, 40916819 bytes, hit rate 0.01 (14/1833), avg hit run 1.27, avg miss run 152.75
thumbnailer-service: [05:07:16.001] thumbnail cache: 526 entries, 9587820 bytes, hit rate 0.74 (5215/1847), avg hit run 7.02, avg miss run 2.49
thumbnailer-service: [05:07:16.001] failure cache: 89 entries, 2206 bytes, hit rate 0.35 (649/1204), avg hit run 4.01, avg miss run 7.43
thumbnailer-service: [05:07:16.014] "album: Los Olimarenos/Olimareños (102,102): 0.008060 sec (HIT)"
thumbnailer-service: [05:07:16.015] "album: Los Rabanes/Rabanes (102,102): 0.007594 sec (HIT)"
thumbnailer-service: [05:07:16.020] "album: Loscil/Sea Island (102,102): 0.009945 sec (HIT)"
thumbnailer-service: [05:07:16.021] "album: Lostprophets/Liberation Transmission (102,102): 0.010446 sec (HIT)"
thumbnailer-service: [05:07:16.021] "album: Loscil/Plume (102,102): 0.011435 sec (HIT)"
thumbnailer-service: [05:07:16.022] "album: Lou Dalfin/Cavalier Faidit (102,102): 0.011045 sec (HIT)"
thumbnailer-service: [05:07:16.022] "album: Lou Doillon/Places (102,102): 0.011228 sec (HIT)"
thumbnailer-service: [05:07:16.022] "album: Los de Abajo/Latin SKA Force (102,102): 0.012802 sec (HIT)"
thumbnailer-service: [05:07:16.024] "album: Lostprophets/The Fake Sound of Progress (102,102): 0.013897 sec (HIT)"
thumbnailer-service: [05:07:16.028] "album: Los Suaves/¿Hay Alguien Ahí? (102,102): 0.018531 sec (HIT)"
thumbnailer-service: [05:07:16.127] Warning: "DBusInterface::GetAlbumArt(): Skrillex/: unity::InvalidArgumentException: Thumbnailer::get_album_art(): album is empty"
thumbnailer-service: [05:07:16.131] Warning: "DBusInterface::GetAlbumArt(): STONE Angus /: unity::InvalidArgumentException: Thumbnailer::get_album_art(): album is empty"
thumbnailer-service: [05:07:16.139] Warning: "DBusInterface::GetAlbumArt(): Prince/: unity::InvalidArgumentException: Thumbnailer::get_album_art(): album is empty"
thumbnailer-service: [05:07:16.142] Warning: "DBusInterface::GetAlbumArt(): Lehmber Hussainpuri/: unity::InvalidArgumentException: Thumbnailer::get_album_art(): album is empty"
thumbnailer-service: [05:07:16.147] Warning: "DBusInterface::GetAlbumArt(): Lazlo Bane/: unity::InvalidArgumentException: Thumbnailer::get_album_art(): album is empty"
thumbnailer-service: [05:07:16.153] Warning: "DBusInterface::GetAlbumArt(): Kumar Sanu, Anuradha Paudwal/: unity::InvalidArgumentException: Thumbnailer::get_album_art(): album is empty"
thumbnailer-service: [05:07:16.156] Warning: "DBusInterface::GetAlbumArt(): Faith No More /: unity::InvalidArgumentException: Thumbnailer::get_album_art(): album is empty"
thumbnailer-service: [05:07:16.160] Warning: "DBusInterface::GetAlbumArt(): Amy Winehouse /: unity::InvalidArgumentException: Thumbnailer::get_album_art(): album is empty"
thumbnailer-service: [05:07:16.162] "artist: Steve Aoki/ (512,512): 0.001151 sec (HIT)"
thumbnailer-service: [05:07:16.165] "artist: Skrillex/ (512,512): 0.001015 sec (HIT)"
thumbnailer-service: [05:07:16.171] "artist: Prince/ (512,512): 0.001234 sec (HIT)"
thumbnailer-service: [05:07:16.177] "artist: Lehmber Hussainpuri/ (512,512): 0.005300 sec (HIT)"
thumbnailer-service: [05:07:16.179] "artist: Lazlo Bane/ (512,512): 0.007401 sec (HIT)"
thumbnailer-service: [05:07:16.180] "artist: Kurt Weill/ (512,512): 0.008070 sec (HIT)"
thumbnailer-service: [05:07:16.182] "artist: Kumar Sanu, Anuradha Paudwal/ (512,512): 0.009481 sec (FAILED PREVIOUSLY)"
thumbnailer-service: [05:07:16.212] "artist: Feed Me / (512,512): 0.003607 sec (HIT)"
thumbnailer-service: [05:07:16.213] "artist: Faith No More / (512,512): 0.003531 sec (HIT)"
thumbnailer-service: [05:07:16.219] "artist: Eek a Mouse/ (512,512): 0.004071 sec (HIT)"
thumbnailer-service: [05:07:16.269] "artist: Easton Corbin/ (512,512): 0.002924 sec (HIT)"
thumbnailer-service: [05:07:16.277] "artist: David Guetta/ (512,512): 0.001401 sec (HIT)"
thumbnailer-service: [05:07:16.284] "artist: Amy Winehouse / (512,512): 0.001631 sec (HIT)"
thumbnailer-service: [05:07:16.291] "artist: / (512,512): 0.000862 sec (FAILED PREVIOUSLY)"
thumbnailer-service: [05:07:16.322] "album: Lynda Lemay/Lynda Lemay (102,102): 0.001968 sec (HIT)"
thumbnailer-service: [05:07:16.332] "album: Lykke Li/Youth Novel (102,102): 0.003788 sec (HIT)"
thumbnailer-service: [05:07:16.344] "album: Lykke Li/I Never Learn (102,102): 0.001581 sec (HIT)"
thumbnailer-service: [05:07:16.348] "album: Lygo/Sturzflug (102,102): 0.004530 sec (HIT)"
thumbnailer-service: [05:07:16.355] "album: Lustre/Welcome Winter (102,102): 0.001340 sec (HIT)"
thumbnailer-service: [05:07:16.364] "album: Luis Bacalov/Kill Bill Volume 2 (102,102): 0.001564 sec (HIT)"
thumbnailer-service: [05:07:16.372] "album: Ludovico Einaudi/In a Time Lapse (102,102): 0.003175 sec (HIT)"
thumbnailer-service: [05:07:16.376] "album: Lucrecia Dalt/Syzygy (102,102): 0.001422 sec (HIT)"
thumbnailer-service: [05:07:16.382] "album: Lucky Dube/House Of Exile (102,102): 0.001015 sec (HIT)"
thumbnailer-service: [05:07:16.396] "album: Lucius/Wildewoman (102,102): 0.001553 sec (HIT)"
thumbnailer-service: [05:07:16.399] "album: Louna/Сделай громче (102,102): 0.001407 sec (HIT)"
thumbnailer-service: [05:07:16.409] "album: Louise Attaque/Du Monde Tout Autour (102,102): 0.000865 sec (HIT)"
thumbnailer-service: [05:07:16.412] "album: Louise Attaque/Comme on a dit (102,102): 0.001603 sec (FAILED PREVIOUSLY)"
thumbnailer-service: [05:07:16.418] "album: Louise Attaque/Comme on a Dit (102,102): 0.002216 sec (FAILED PREVIOUSLY)"
thumbnailer-service: [05:07:16.423] "album: Louis Chédid/Botanique et Vieilles Charrues (102,102): 0.001317 sec (HIT)"
thumbnailer-service: [05:07:16.424] "album: Lou Reed/Walk on the Wild Side: The Best of Lou Reed (102,102): 0.001529 sec (HIT)"
thumbnailer-service: [05:07:19.308] "artist: Amy Winehouse / Back To Black (512,512): 0.001535 sec (HIT)"
thumbnailer-service: [05:07:19.329] "artist: David Guetta/German Top 100 Single Charts (512,512): 0.001468 sec (HIT)"
thumbnailer-service: [05:07:19.568] "artist: Easton Corbin/Billboard Hot 100 Singles Chart (512,512): 0.001506 sec (HIT)"
thumbnailer-service: [05:07:19.583] "artist: Faith No More /Judgment Night (512,512): 0.001538 sec (HIT)"
thumbnailer-service: [05:07:19.829] "artist: Eek a Mouse/Wa Do Dem (512,512): 0.001192 sec (HIT)"
thumbnailer-service: [05:07:19.846] "artist: Feed Me /Bravo Hits Vol. 80 (512,512): 0.002183 sec (HIT)"
thumbnailer-service: [05:07:20.104] "artist: Kurt Weill/DER JASAGER (Bert Brecht) - Sigfried Kohler (512,512): 0.001338 sec (HIT)"
thumbnailer-service: [05:07:20.132] "artist: Skrillex/Scary Monsters And Nice Sprites (512,512): 0.002168 sec (HIT)"
thumbnailer-service: [05:07:20.153] "artist: Lehmber Hussainpuri/Tanu Weds Manu - MyMp3Singer.com (512,512): 0.007430 sec (HIT)"
thumbnailer-service: [05:07:20.204] "artist: Prince/feat. Miles Davislive (512,512): 0.001222 sec (HIT)"
thumbnailer-service: [05:07:20.302] "artist: Steve Aoki/Music Top 100 Hits Flame (512,512): 0.002095 sec (HIT)"
