The batch budget counted JSON characters, but a Parcel carries strings
as UTF-16 plus a few hundred bytes per operation, so a full batch was
about 700 KB of a 1 MB Binder buffer the whole process shares. Batches
are now weighed at two bytes per character plus 300 bytes per op and
kept under 500 KB of that. The state op no longer joins a batch whose
last item already fills a provider yield window of 499 operations,
which ContactsProvider refused.
When a group's members change on the server, the download fetches the
contacts whose membership flipped in a chunk after the group's. The
group's chunk already stored its new version, so when the sync stopped
before the members' chunk, the next sync found no flip any more and
the phone kept the old members. Those contacts are now listed with the
group's rows, as objects to fetch first, until their own chunk ran.
A full reconcile that ran out of time resumes after the last object it
processed, in the sorted order of every listed id. It listed the
collections selected at the time it resumed and marked them all loaded
at its end, so a book turned on in between lost the objects that sorted
before that point, and was never loaded again. The reconcile now keeps
the collections it started with; one selected since is loaded after it
like any newly selected collection.
The SyncState's `selected` said which collections were on the device,
and changed only when a load or a removal had finished. A book turned
off and on again while the device was still removing it looked loaded,
so the contacts removed so far never came back; a calendar came back
empty. A book turned on and off again while it was still loading never
looked loaded, so the contacts loaded so far were never removed.
`selected` now names only collections whose rows are all on the device:
a collection leaves it before its first row is removed, and the
contacts SyncState lists collections that are loaded or removed only in
part, so the next run loads them again when they are selected, or
removes the rest when they are not. A book that still holds a change
waiting for its upload stays in that list instead of `selected`.
A provider that is busy may commit a batch up to a yield point and then
fail it. The engine retried every group of such a batch and relied on
the groups' asserts to refuse one that was already committed, but a
download into an unchanged event asserts only the event's own columns:
when it had only added a reminder or an attendee, the retry added it a
second time.
A download is now planned again from a new read after a failed batch
instead of being sent again, which turns a committed group into an echo.
The fake provider can commit a batch up to a yield point to test it.
When the server refused an edit made on the device (a book or calendar
that turned read-only, an event in a calendar where only one's own
events may be changed), the engine put the item back by deleting its
rows and inserting a fresh copy. A contact lost its star, ringtone and
the link to the contacts it was joined with; an event got a new row id.
The rows are now rewritten in place from the server's version, as after
an accepted upload. A refused deletion still brings the item back as a
new copy.
After an upload the stored state stays where the download left it, and
the engine relied on /changes to report its own creates back. /changes
leaves out an object that was created and destroyed after the state it
is asked from (Stalwart does, RFC 8620 allows it), so an event or
contact created on the device and deleted on the server before the next
download stayed on the device for good.
The SyncState now lists the objects our uploads created, written with
their identity, and the next run fetches them first: one that is gone
loses its rows, an unchanged one writes nothing. An upload-only sync
runs in full while the list is not empty.
A new contact is claimed for an address book before its create is
sent, so a retry after a lost response finds it again. When that book
was deleted on the server before the create went up, every attempt
failed and was retried after up to a day, forever. A book that is gone
can hold nothing of an earlier attempt, so the contact is now claimed
again for the book the settings choose.
An event cannot move on its own to another calendar: a create into a
calendar that is gone is no longer sent, and the report says why, until
the user moves the event in the calendar app.
A group whose latest server version the device could not store waits
on the stale list, and nothing uploads for it until it has been fetched
again. Membership edits bypassed that check: adding a contact to such a
group sent the whole member list as the device last knew it, which
removed members another client had added meanwhile. Membership edits
for a stale group now wait for that fetch, and the report lists them.
Whether a membership edit still has to go up is decided against the
group cards on the server, which the engine indexes from their shadows.
The index was only read before planning a download that held contacts,
so in a run that downloaded no contact, such as the upload sync after
an edit, it was empty: removing a contact from a group looked already
done on the server, the contact was marked clean and the removal was
never sent. The engine now reads the index before planning uploads too.
A contact stays marked as changed until the group cards on the server
show its membership edits. The engine uploaded those edits as patches
of the group cards after the contacts, but never looked at the contact
again in that run, so it stayed marked until the next sync. Turning
contacts sync off or signing out right after adding a contact to a
group therefore asked whether to drop one waiting change, although
nothing was waiting.
Once the membership patches are accepted, the contacts that have
nothing else to upload are now cleared in the same run, behind the
same version check as any other clean write.
The contacts SyncState lists the group rows on the device, so a group
an app hard-deleted (Fossify does) is found by its absence and deleted
on the server. The list changed only with a later state op, not with
the batch that inserted or deleted the rows. When a run stopped in
between (cancelled, out of time, a crash, or turning sync off while a
deselected book was being dropped), a group the engine had removed was
still listed, taken for a hard delete by the next run or by the
teardown's upload, and its card destroyed on the server; a group it had
inserted was never listed, so a later hard delete never went up.
A batch that inserts or deletes a group row now ends with a state op
holding that change, retries included, so the list and the rows never
disagree. A group a download finds unchanged is listed too, for rows
whose batch lost its state op at a provider yield point. And an absent
group whose card is no longer a group or is in no synced book is only
forgotten, never destroyed.
Checked with a crash at every checkpoint of a deselection, a teardown
and a deadline stop during one, a server-side move in a page of several
chunks, and a group written before an interruption and then deleted in
Fossify.
When another client moved a contact or an event out of every address
book or calendar the device syncs while the device had an unsent edit
of it, the download only noted it for dropping after the upload. Its
shadow stayed at the old version while the stored state moved past the
change, so the upload passed `ifInState` and resent whole maps built
from the old shadow: a number or an occurrence added on the server
meanwhile was lost. A full reconcile that found such an object did the
same.
The download now merges the new version into the dirty rows like any
other change, so the upload builds on it, and the rows still go once
it is accepted. A contact's collections are read from its shadow:
SYNC1 lists only the selected books and is empty for a card that left
them all, so such a contact was never dropped after its upload. The
calendar planner cannot merge an event that is in no synced calendar
yet; until it can, such an event waits on the device and is reported
instead of overwriting the server.
Checked with the real planners through `/changes` and through a full
reconcile.
Etar moves an event to another calendar, and turns a series into a
single event, by deleting the row and inserting a copy. The engine was
meant to pair the two rows and upload a patch of the existing event,
but it claimed every new row (a uid and a pending create) before it
asked the planner for pairs, and the planner pairs only unclaimed rows.
No pair ever formed: the event was destroyed and created again under a
new uid, which lost what the device cannot show (keywords, virtual
locations, links, the other attendees' answers, alerts relative to the
end) and sent every attendee a cancellation and a new invitation.
Pairs now upload before new rows are claimed, and a paired deletion no
longer counts toward the deletion threshold, since it is a move. When
an app changes the rows while the patch is on its way, they are read
and paired again; rows that no longer pair are left without the
identity instead of having the server's version written into the new
row, which overwrote the edit and left two rows with one identity.
Checked with the real planners: a move and a series turned single keep
their uid, keywords and attendee answers and send nothing; an edit made
during the upload is kept; an unchanged rewrite still pairs.
434c554 left an account that refuses to list its address books or
calendars out of the run, but reported it as an item error. The sync
settings then said "1 item could not be synced" after every run for an
account that merely shares a mailbox: nothing the user can fix, and no
item behind it. Such an account is now only logged.
Checked: the engine tests, `npm run typecheck` and `npm test` on this
commit, and the sync settings of usera on the API 32 emulator after a
new run.
Stalwart lists an account shared with the user for mail only with every
capability, and answers `forbidden` when the user asks for its address
books or calendars. The engine treated that like any failed request, so
on the local test server every sync of usera ended with an I/O error and
never reached the device, only because userb shares a mailbox.
An account that refuses to list its collections (`forbidden`,
`accountNotFound`, `accountNotSupportedByMethod`) is now left out of the
run and reported as an item error; the other accounts sync as before.
The rows written for such an account stay on the device: a refusal can
pass, and dropping the account's contacts and events for one refused
request would throw away device edits that are still waiting.
Checked: three new engine tests (a shared account that never listed,
one that stops listing its address books, one that stops listing its
calendars), which fail without the fix, `npm run typecheck` and
`npm test` on this commit, and a contacts sync of usera on the API 32
emulator, which now ends `ok` with one item error.
The sync adapters from ed2525e start a headless task for every sync, but
the task only reported "disabled". This adds the engine it runs
(`src/device-sync/engine`, `src/device-sync/jmap`): for one Android
account and authority it downloads the server's changes, uploads what
the device changed, and hands a report back to SyncManager.
- Downloads follow `/changes` from the state kept in the provider's
SyncState. Rows and the state they reach are written in one batch, so
a killed run resumes where it stopped. Without a state, after
`cannotCalculateChanges` or after the user discarded deletions, a full
reconcile compares ids instead.
- Uploads go in three phases across accounts (creates, updates,
deletions), so moving an item to another account never destroys it
before the copy exists. A create carries a uid written to the device
first, and the server is asked for that uid before creating, so a lost
response or a killed run never makes a duplicate. Updates are patches
guarded by `ifInState`; nothing is replaced whole.
- More than 50 deletions that are also more than a fifth of the synced
items hold every deletion back and report `tooManyDeletions`, so
Android asks the user; "undo" restores the items from the server.
- An item the server refuses is marked and not sent again until it
changes or its back-off (1 hour, doubling to a day) ends. Such
refusals and planner errors stay with their item; the rest of the run
goes on.
- Runs of one account and authority take a lock, stop at checkpoints
when cancelled or close to the deadline, and never throw: every
failure becomes an outcome, and a rejected sign-in posts one "Sign in
again" notification.
- The JMAP side uses a client of its own per app account, never the
UI's, since a run can share the JS runtime with the app.
Turning sync off or signing out runs the same upload first
(`teardownAuthority`) and deletes the rows only once nothing is waiting,
or when the user agreed to lose it.
The planners that map items to rows land in the next commits; until
then a run fails before it touches a row.
Checked: 94 engine tests against the fake provider and JMAP server
(sync flows, failures, crashes and retries, teardown), and `npm run
typecheck`, `npm test` and `npm run i18n:check` on this commit.
Linus Rath