TreeWalker walks one or more roots in a stable segment-wise order with
exclusions and resumes after a cursor; ParentCursor merge-joins the
previous snapshot in the same order. BackupRun no longer keeps a file
list or the parent's entries in memory or in its state.
- migration: ngb_targets, ngb_runs, ngb_snapshots
- KeyService: master key stored encrypted with the instance secret
(unattended backups), passphrase-wrapped copy in every repository and
in the recovery kit, recorded admin confirmation per key fingerprint
- TargetService: locations built from files_external backends without a
mount; files_external is loaded through IAppManager::loadApp() and its
enabled state is left alone; credentials encrypted with ICrypto;
existing repositories are adopted only if made with this key, and a
repository cannot be registered twice
- Repository: initWithKey/openWithKey with an encrypted key check
- occ: backup:key:init|kit|confirm, backup:target:backends|add|list|remove
Dev tooling via composer (phpunit, psalm, nextcloud/ocp); vendor/ is
mounted from outside the repository by a helper script. 28 unit tests
ported from the phase-0 spikes (round trips, corruption, wrong keys,
dedup, incremental runs, partial restore, tampering, object binding,
time-boxed steps, file changed between steps).
- detect files changing during reading or between resumable steps and
re-read them (size/mtime/ctime/inode), spike F overwrites mid-run
- drop pending blob ids when a pack or index upload fails
- dump and restore PostgreSQL sequence state exactly, bound parameters,
validated catalog names; spike C checks all sequences exactly
- keep invalid UTF-8 byte-exact (tagged base64)
- refuse large tables without a primary key
- StorageBackend: check write/flush/close results, validate base path
- user_migration import/export: root paths, intermediate folders,
partial writes, read errors
- spikes: never touch an existing account, own fixtures, 512M note
BackupRun is a resumable state machine: each step works until a deadline,
uploads its pack and tree segment, and returns the state; large files are
resumed at the next blob. Snapshot is written last.
Spike F: 200 MiB file resumed across steps in separate processes; with 6
random kill -9 the run completes and restores bit-identically.
spikes/RESULTS.md summarises phase 0 and the findings for the plan.
RepositoryExportDestination / RepositoryImportSource implement the
public OCP\UserMigration interfaces on top of the repository, so
user_migration's migrators (calendar, contacts, trashbin, account,
files) export straight into the encrypted repository.
Spike E (NC34): export 0.8s, unchanged second export stores nothing;
after deleting the user, import restores account, files (bit-identical),
calendar event and contact. Findings: calendars/address books come back
as 'migrated-*' with new object URIs; importing over an existing user
duplicates contacts and adds a migrated birthday calendar; creating the
user on import needs >128 MB (password_policy word list).
ExternalStorageFactory builds storages with files_external's own
backends and auth mechanisms from an unsaved StorageConfig (as its
ConfigAdapter does), and StorageBackend adapts any IStorage to IBackend
(writeStream, seekable range reads, temp name + rename except on S3).
IBackend::put() now owns and always closes the stream, because
files_external's S3 writeStream closes it.
Spike D (NC34): S3 (SeaweedFS) and SFTP: 120 MiB backup ~6s, unchanged
run uploads nothing, restore bit-identical, no files_external mount
created, no temp files (max 12 KiB in /tmp). Works with files_external
disabled when its classes are loaded. Backup peak memory 85-89 MiB on
these targets (to investigate).
DbDumper reads every prefixed table through the Nextcloud connection in
one REPEATABLE READ (read-only) transaction, with keyset pagination on
the primary key, and streams each table as JSON lines into its own blob
stream (BlobWriter), so unchanged tables are deduplicated. Restore
replaces table contents in one transaction and resets PostgreSQL
sequences.
Spike C (NC34, PostgreSQL, standard image without pg_dump/pgsql ext):
300k-row table with bytea: dump 6.3s / 50 MiB peak, 94 MiB JSON -> 20 MiB
stored; unchanged second dump stores nothing; restore makes every table
checksum-identical and all 110 sequences continue above the maximum.
Content-addressed repository on an IBackend (local implementation):
4 MiB blobs, deflate when it helps, each blob encrypted with its id as
associated data, ~32 MiB packs with an encrypted header, one index file
per pack, snapshots as encrypted JSON lines written last.
Spike B: 390 MiB tree, peak 54 MiB; unchanged run reads nothing; a 1 MiB
change in a 300 MiB file uploads one blob; full and partial restore are
bit-identical; tampering is detected.
dillard