Commit Graph
12 Commits
Author SHA1 Message Date
Emma Thorpe f324b1b720 feat: convert Rockbox's playback log on the laptop, skipping the plugin
Build and publish container / build (pull_request) Successful in 5m6s
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.
2026-08-26 18:24:12 +01:00
Emma Thorpe 19ac9e5d92 fix: stop counting by default; the pass costs more than the transfer
Build and publish container / build (pull_request) Successful in 3m32s
The counting pass was added so the progress line could show a percentage and an
estimate, and on a real card it turned out to dominate the run. Measured
against the device: reading a track from the SMB mirror ran at 35 MB/s and
writing to the card at 21 MB/s, while the sync itself managed tens of kilobytes
per second. Neither end was slow. The cost was traversing fifty thousand files
across six thousand directories on FAT, and the counting pass does that a
second time, comparing both trees in full exactly as the transfer does.

Counting is now opt-in behind -P. Without it the progress line still shows the
running count, the transfer rate and the album in flight; the percentage and
the estimate are what needed the extra walk, and they were the least useful
part of the display.

That the fix for "it looks hung" was itself making it slow is the sort of thing
only measuring catches. The line still answers the question it was added for --
whether anything is happening -- without paying for the part that merely made
it prettier.
2026-08-26 13:57:49 +01:00
Emma Thorpe c99b423b72 feat: rebuild the Rockbox database during the sync, off the mirror
Build and publish container / build (pull_request) Successful in 6m36s
The on-device database commit does not work at this library size. It sorts the
whole index in whatever memory core_alloc_maximum() can scrape together, and on
fifty thousand tracks it runs for hours or aborts with a data abort -- observed
across several builds including stable.

Rockbox ships a host-side builder for exactly this, and the sync is the moment
the library changes, so it belongs here. MUSIC_MIRROR_DATABASE_TOOL points at
it; the step is skipped with a note when unset, as the scrobbler step is.

The scan runs against a scratch root -- a real .rockbox beside a symlink
standing in for wherever the music lands on the device -- so the paths recorded
are the ones Rockbox will look up, while the bytes are read from the mirror
rather than over USB. Only the dozen .tcd files cross to the card. Verified:
scanning through the symlink records /Music/... paths while reading from
somewhere else entirely.

The scratch root is kept between runs because the builder is incremental. A
second pass over unchanged files performs no metadata reads and finishes in a
fraction of a second, so only the first build pays the full cost.

That cost, measured rather than guessed: about 49 reads and 43 seeks per file,
the parser probing the head for ID3v2 and the tail for ID3v1. Two thousand
files in half a second on local disk. Over SMB the opens and the head/tail
split are real round trips, making a first full scan minutes rather than
seconds -- still preferable to an on-device commit that does not finish. There
is nothing to parallelise: the tool is single-threaded and two instances cannot
produce one database.
2026-08-26 13:20:20 +01:00
Emma Thorpe 8228c81b5c fix: flush and unmount even when the sync is interrupted
Build and publish container / build (pull_request) Canceled after 2m10s
rsync itself is safe under interruption. It writes to a hidden temporary file
and renames it into place only once complete, and by default deletes any
partial file when interrupted -- verified both in the manual and by killing a
transfer and inspecting what was left, which was nothing. --partial is
deliberately absent and there is now a test asserting it stays that way. An
unclean kill can leave a hidden .track.mp3.XXXXXX behind; it is unplayable, it
is not in the source, and the next run's --delete removes it.

The script was not safe. Ctrl-C killed it before the sync and the unmount,
leaving a journal-less FAT filesystem holding dirty buffers -- which is the
exact corruption the script exists to prevent, arrived at by the most likely
route a person would take.

INT and TERM are now trapped. Both the normal path and the interrupt path call
the same finish function, so the flush and the unmount cannot drift apart, and
an interrupted run exits 130 rather than pretending to have succeeded.

The test is structural rather than timed. Reproducing a mid-transfer signal
needs a payload large enough to be slow, and a test that depends on winning a
race is a test that fails in CI for reasons that have nothing to do with the
code. The behaviour was verified by hand: SIGTERM mid-transfer gave exit 130,
the flush ran, and the destination held no short files and no leftover
temporaries.
2026-08-25 12:51:42 +01:00
Emma Thorpe d6ef70922c perf: cut round trips over a network mount, and allow skipping the count
Build and publish container / build (pull_request) Successful in 2m39s
The transfer is metadata-bound rather than throughput-bound. Fifty thousand
files is fifty thousand round trips, and the counting pass added for the
percentage doubles that.

--whole-file is already implied when both ends are local paths, which an SMB or
FAT mount is, but stating it records that the delta algorithm is deliberately
unwanted here: it would read every destination file back over USB to checksum
it, in order to avoid resending an MP3 that has changed in its entirety anyway.

--omit-dir-times drops one setattr per directory. Across six thousand album
folders on a FAT card that is six thousand operations spent on timestamps
nothing reads.

-Q skips the counting pass. The percentage and the estimate are worth a second
walk of a local tree and frequently are not worth one of a network mount, so
that is now a choice rather than a fixed cost.

The README covers the part that is not an rsync flag at all: SMB defaults to a
one second attribute cache, so nearly every stat goes to the wire, twice. An
actimeo of sixty on the mount does more than any of the above, and closes most
of the gap that would otherwise argue for moving to NFS.
2026-08-25 12:44:53 +01:00
Emma Thorpe 131c80f5de feat: estimate the time remaining from bytes and observed rate
Build and publish container / build (pull_request) Successful in 2m13s
rsync reports each file's size with %l as it completes, which is all an
estimate needs: bytes done over time elapsed is the same arithmetic rsync would
do internally, and requires nothing it does not already print. The scan pass now
sums those sizes as well as counting files, so both a percentage and an estimate
have a real denominator.

The rate is measured over a trailing thirty seconds rather than the whole run,
so it follows a device that slows down instead of averaging the slowdown away --
which for a card reader that thermally throttles, or a USB link that renegotiates
after an hour, is the difference between a useful estimate and a reassuring one.

Below two seconds no rate is reported at all. The first handful of files arrive
microseconds apart, and dividing by that window produces a rate in the gigabytes
per second and an estimate of zero, which is worse than showing nothing.

Directory entries are excluded from the byte total as well as the file count.
rsync reports them with a 4096 inode size, which across six thousand album
directories is several megabytes of transfer that never happens.
2026-08-25 12:40:32 +01:00
Emma Thorpe 37b841f009 feat: show which album is copying, and how far through
Build and publish container / build (pull_request) Successful in 2m33s
The transfer looked hung. rsync prints nothing while it builds its file list,
which on fifty thousand files over USB is several minutes of silence, and
--info=progress2 does not help: with incremental recursion its percentage is
computed against a list rsync has not finished discovering, so it moves
backwards as often as forwards.

The script now counts what needs copying first and says so, then renders its
own single line that rewrites in place, showing the album currently going
across and a percentage against a total that is actually known. Counting costs
a second pass over the tree. That is the price of a percentage meaning
something, and it is cheaper than staring at a blank terminal wondering whether
the thing has died.

Directories are excluded from the count. rsync reports those too, and including
them puts the figure past a hundred per cent.

Piped to a log the line becomes a plain one every thirty seconds, because a log
full of carriage returns and escape codes is not a log anybody reads.
2026-08-25 12:31:13 +01:00
Emma Thorpe d5dce9c769 fix: accept a destination inside the device, and say so in --help
Build and publish container / build (pull_request) Successful in 2m27s
The script required the destination to be its own mount point, while the
documentation and its own usage text both told the user to pass
/media/IPOD/Music. The documented invocation was rejected.

A subdirectory is the better target, so the guard was what was wrong. --delete
is confined to it, and the device path budget is now derived from it -- the
part of the destination below its mount point -- rather than configured, so the
budget cannot disagree with where the files are actually going. The check that
matters is that the destination sits on a FAT filesystem, which is also what
catches an unmounted device: /media/IPOD/Music then resolves to the host's own
root filesystem, and emptying that is the outcome all of these guards exist to
prevent.

Three further faults found by testing the guards rather than reasoning about
them:

Stripping the trailing slash from "/" left an empty string, so the guard
refusing the host root never fired and the user got "destination is not a
directory" instead.

die() printed only its first argument, so the second half of the non-FAT
message -- the half saying to check whether the device is mounted -- was
silently dropped.

--help was not handled at all. Only -h reached the usage text, and it exited 2
to stderr, which is right for misuse and wrong for someone asking a question.
Help now goes to stdout and exits zero, and carries the guidance rather than
leaving it to the README, since the question it answers is asked at a terminal.

The test stage installs bash, rsync and findmnt, none of which are in the base
image, and the tests skip rather than fail where they are absent -- a machine
without rsync is not a machine that would run this script.
2026-08-25 12:23:52 +01:00
Emma Thorpe ece79515c0 fix: cost the device prefix exactly rather than approximately
Build and publish container / build (pull_request) Successful in 3m54s
The budget subtracted the prefix length plus two, on the assumption of a
leading and a trailing slash. That is right for /Music and wrong for an empty
prefix, where there is only one slash -- losing a character at the card root,
which is exactly where the longest paths sit.

Computed from the prefix as it will actually appear instead: /Music/ costs
seven characters and gives a mirror-relative budget of 253, the root costs one
and gives 259.

Worth being exact about because the reverse error is worse. A checker
comparing mirror-relative paths against the flat 260 passes everything between
253 and 260, and those are precisely the paths closest to the edge.
2026-08-25 11:52:03 +01:00
Emma Thorpe d5f67c6de5 feat: shorten paths that exceed the device's limit
Build and publish container / build (pull_request) Successful in 2m16s
Rockbox's MAX_PATH is 260, defined in firmware/include/fs_defines.h and used to
size the directory entry buffer in dir.h. It bounds the path as the device sees
it, so the directory the mirror is copied into spends part of the same budget;
--device-prefix accounts for that and defaults to /Music.

Over-budget paths are shortened from the deepest component outward. The track
name carries the least navigational value and the artist directory the most, so
the filename is cut first and the artist only if nothing else will serve. A
shortened component keeps its extension and gains four hex digits of the
original name: two long titles sharing a prefix cut to the same string
otherwise, and a silent collision between two tracks is a worse outcome than an
ugly filename.

The result is stable. The same source always yields the same shortened name, so
one pass does not rename what the last one wrote -- an unstable scheme would
churn the whole mirror every six hours. A path too deeply nested to fit without
reducing every component to nonsense is left alone and reported rather than
mangled.

Migration now tries more than one previous naming, because there is more than
one. A mirror already running with --fat32-safe holds sanitised but unshortened
paths, and matching only the original unsanitised name would have re-encoded
every one of them instead of moving it.

The checker gains the same two options, since it was measuring the
mirror-relative path against a limit that applies to the device-absolute one,
and so under-reported by the length of the destination directory.
2026-08-25 11:46:26 +01:00
Emma Thorpe 802d91490f feat: a sync script that submits scrobbles, copies, and unmounts cleanly
Build and publish container / build (pull_request) Canceled after 3m8s
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.
2026-08-25 11:05:00 +01:00
Emma Thorpe 3141f7ca87 feat: name the mirror so a FAT32 device will take it, and copy album art
Build and publish container / build (pull_request) Successful in 2m18s
Two changes for playing the mirror on a Rockbox iPod, where the device is FAT32
and Rockbox reads a plain directory tree rather than a database.

--fat32-safe names mirror files acceptably: the reserved characters and control
characters become underscores, trailing dots and spaces are stripped because
FAT eats them silently and the name then round-trips as a different one, and a
component left empty becomes an underscore. Names differing only in case are
detected as collisions, since two files here are one file there and the second
would silently overwrite the first. "Kick Out the Epic Motherf**ker" is a real
example from a real library, and without this it simply never arrives.

Off by default. It renames files, and that should be a decision rather than a
surprise on somebody's next pass.

Turning it on does not re-encode anything. Every track whose name held a
reserved character changes path, and encoding those again would be hours of
work producing files that already exist byte for byte, so the run moves them
instead and logs each one. Prune then finds nothing left behind.

Album art is now also copied into the mirror as cover.jpg beside the tracks.
Rockbox searches the filesystem for art -- cover.jpg, folder.jpg and the rest,
in the track's directory or its parent -- and that search never looks at the
picture embedded in the tag, so a mirror that only embeds art displays none of
it on the device. Embedding continues for the Apple firmware; both are now
satisfied. A cover whose tracks have all been pruned is removed too, or its
directory would never look empty and never go.

Adds tools/check_fat32.py, which reports unacceptable paths before a copy
rather than during one: rsync reports them too, but scattered through fifty
thousand files where they are easy to lose. It exits non-zero so it can gate a
script.

The README documents the rsync invocation, including why --modify-window=2 is
required against FAT and why Rhythmbox must be kept out of the transfer --
rb_ipod_helpers_is_ipod() reads access-protocols from media-player-info and
returns true on the USB id alone, without looking at the filesystem, so
removing iPod_Control changes nothing.
2026-08-25 10:29:55 +01:00