Setting the logs aside after a successful submission threw away more than it
had submitted. A play of a track missing from the mirror -- not yet copied, or
its tags unreadable -- was counted as unresolved and then carried off with the
rest, with nothing to retry it. The play happened and was lost.
Two obligations now, kept separate. The original log is renamed rather than
deleted, so a mistake here cannot destroy the record. And every play that was
not submitted is written back into a live log, so the next run attempts it
again: the unmatched ones, and anything in a batch that failed.
Submission is recorded batch by batch as each is accepted, so a failure partway
through knows exactly what got through. The remainder is written back and
nothing is sent twice. When nothing at all is accepted the logs are left
untouched.
Skips and clockless entries are deliberately not retained. Neither can ever be
submitted, so keeping them would mean reprocessing them for ever, and the
untouched original holds them regardless.
Also fixes a way to lose the lot: read_tags caught OSError and ValueError, but
ffprobe failing raises CalledProcessError, which is neither. A single unreadable
file aborted the whole submission rather than costing one unidentified play.
Scrobbling previously needed the on-device Last.fm plugin run by hand before
each sync, to turn Rockbox's playback log into AUDIOSCROBBLER format. Forgetting
that step means the sync submits nothing and quietly appears not to work.
Core Rockbox writes ROCKBOX_DIR/playback.log whenever "play log" is enabled,
with no plugin running at all. Each line is timestamp:elapsed_ms:length_ms:path.
The only thing missing is tags, and that is exactly why the plugin exists:
reading them back off the player is slow. Off the mirror it is free, because the
same files are already there -- so the conversion belongs on the laptop, and the
plugin can be skipped entirely.
A play counts as listened at half the track's length, matching the plugin's
savepct default, so the two cannot disagree about what a play was. A short play
is a skip. An entry with no usable timestamp is refused rather than invented,
which is the clockless case again. A path that maps to nothing in the mirror is
counted and reported instead of guessed at.
Rotated logs are picked up too; Rockbox starts a new one past half a megabyte.
All of them are renamed aside together once Last.fm has accepted the batch.
A .scrobbler.log is still read when the plugin has been run and left one.
tools/sync-to-ipod.sh does the whole transfer to a Rockbox device, so the only
manual part left is the disk-mode button sequence.
The guards are the substance rather than decoration. rsync --delete is being
aimed at a whole filesystem, so the destination must exist, be its own mount
point, and be a FAT filesystem; the mirror must be non-empty and must not be
the destination. Emptying the wrong directory is not a mistake that announces
itself.
It also excludes /.rockbox, the scrobbler logs and the usual filesystem
metadata directories. The mirror does not contain them, so a sync to the card
root would otherwise have deleted the Rockbox installation -- which the first
draft of this script would have done.
The unmount is why this is a script at all. FAT32 has no journal, the device is
reached through the Apple firmware's disk mode because Rockbox's own mass
storage is unreliable on an iFlash, and an interrupted write is corruption that
needs fsck.vfat from another machine.
tools/submit_scrobbles.py sends the Rockbox scrobbler log to Last.fm and sets
it aside. Rockbox writes it in AUDIOSCROBBLER 1.1: tab-separated, one line per
track, rated L for listened or S for skipped, and only the listened ones are a
play. It runs before the copy, because the plays already happened and a failed
transfer is no reason to lose them as well.
Two things there differ from every other Last.fm call in these projects.
Scrobbling is a write method, so it needs the API secret and a session key
obtained once through the browser rather than the read-only key. And a target
with no real-time clock gets /.scrobbler-timeless.log with every timestamp set
to zero; those are counted and reported but never sent, since submitting them
would mean inventing when they happened.
Signature generation sorts parameter names by the ASCII table rather than
numerically, so artist[10] precedes artist[1]. Sorting them the obvious way
produces an invalid signature and no other symptom, so there is a test for it.
The log is renamed rather than deleted once accepted, so that if Last.fm
quietly dropped something the evidence is still on the device.
Emma Thorpe