Implements the client-only residual-batch feature end-to-end:
- src/shared/batch.{c,h}: self-contained single-file batch codec using the
existing chunk_serialize/chunk_deserialize codec (byte-identical by
construction). Magic+format-version header (metadata mode is persisted into
the header so a batch is self-describing across machines), length-prefixed
chunk records, bounded reads that reject malformed/truncated/oversized
records cleanly.
- src/client/client_send.c: write_batch_from_source (deterministic separate
scan pass, loads every chunk's file images, emits header+records) and
apply_batch_to_dest (local apply to a destination root via
file_save_to_disk_full). No wire change, no server involved.
- src/client/client_validation.c: --write-batch XOR --only-write-batch;
--read-batch exclusive with both; --read-batch needs only a DEST,
--only-write-batch only a SOURCE.
- src/client/client_cli.c: main() drives the three batch modes without
connecting/transferring for read/only-write; --write-batch runs the live
transfer (single-threaded so the config survives) then emits the batch.
- tests/test_batch.{c,h} (unit: byte-identical roundtrip with and without
metadata; bad-magic/truncated/oversized rejection) + tests/integration/
test_batch.py (only-write no-server, read-batch no-source roundtrip,
--write-batch with a live transfer, conflict rejections).
- clang-format: realign PART-1 config.h comment block.
No PROTOCOL_VERSION bump, no config-frame field, no server flag.
Capture+transmit source atime (pre-read stat; O_NOATIME sender guard) and birth
time (statx STATX_BTIME); receiver restores atime with mtime (crtime not settable
portably -> transmitted, explicitly not applied). --open-noatime is client-only.
-O/-J documented as accepted no-ops (FastSync never preserves dir/symlink times).
Wire: metadata frame gains atime/crtime val+sec+nsec; PROTOCOL_VERSION
2.11.0->2.12.0. Review fixes: gate atime capture to Linux (no epoch clobber on
non-Linux), close fd on fdopen failure, honest -O/-J status (Compat no-op).
Source files sharing (st_dev,st_ino) are recreated as hard links on the
destination; only the first member's data crosses the wire (siblings ride a
payload-less STATUS_HARDLINK frame). Ordering requires the single-FIFO-writer
receiver + forced sequential scan (documented). link()-failure falls back to a
byte-identical local copy. Rejects -s/--append. PROTOCOL_VERSION 2.11.0->2.12.0.
Review fixes: delete the dead HardLinkRegistry (ordering holds by FIFO writer),
and --existing no longer aborts when the first member is absent but the sibling
exists (leaves the sibling in place).
Receiver allocates the destination file's full size before streaming data
(posix_fallocate preferred, ftruncate fallback on EOPNOTSUPP/ENOSYS) so an
out-of-space transfer fails fast instead of partway. Additive config bool
crossing the wire; PROTOCOL_VERSION 2.10.0 -> 2.11.0. Threaded through all
store paths (atomic, inplace, partial/delay-updates staging, link-dest copy
fallback). Review hardening: explicit lseek(0) before the data write so
correctness does not depend on posix_fallocate leaving the fd offset unchanged.
Receiver-side ownership application, opt-in and privilege-gated:
- OFF for every existing transfer (plain -M/--preserve still never applies
ownership); only triggers on an explicit identity flag + receiver permission.
- EPERM/EACCES warn-and-continue (never aborts); other fchown errors escalate.
- fd-relative fchown after the file is written (symlink-safe, confined).
- New src/shared/identity.{c,h}; config fields numeric_ids / chown uid/gid /
usermap + groupmap id-pair tables cross the wire; PROTOCOL_VERSION 2.10.0
-> 2.11.0. CLI in client_cli.c; per-connection snapshot in server.c.
- Review fixes: EPERM/EACCES-only warn-and-continue, prominent root-receiver
notice, identity_clear_active on early server error paths, --numeric-ids
kept inert standalone (removed from activation trigger set).
BLOCKER: an absent mirror whose PARENT directory does not exist on the
destination (a deeper --files-from missing entry, -R or full-mirror layout) was
treated as a hard failure because file_open_secure_parent returned -1 when the
parent was missing. That aborted the whole run, skipped the --delete extras
walk, and tore down an early --delete-before/during connection, contradicting
'missing mirror = no-op / all-missing succeeds'. A parent-open failure is now a
no-op when errno is ENOENT/ENOTDIR (matching file_remove_tree_secure); only a
genuine I/O error fails the run.
Also: an already-absent mirror reached via unlinkat-ENOENT no longer prints
'Deleted: <path>' (a no-op dressed as a deletion); the per-path 'Deleted:' line
is printed only when an entry was actually removed.
Adds real algorithm selection (xxh64 default, plus md5 via OpenSSL EVP) and a
64-bit seed for the per-file whole-file digest used by the --incremental/
--checksum handshake and basis-dir content verification. The seed also feeds
the delta path's per-block xxHash32 strong checksum (low 32 bits) so an
explicit seed deterministically changes those digests too. Sender and receiver
hash identically: the algorithm id and seed cross the config wire frame and the
STATUS_CHECK handshake now carries a length-prefixed, bounded digest instead of
a fixed 64-bit value. Unsupported algorithm names are rejected at parse time
(never a silent no-op). PROTOCOL_VERSION bumped 2.9.0 -> 2.10.0; defaults
(xxh64, seed 0) preserve prior byte-for-byte behavior.
Implement rsync's append modes: when an existing destination file is SHORTER
than the source, the receiver negotiates a resume offset and only the tail is
transferred; the full file (retained prefix + tail) is rebuilt and installed
through the normal atomic store path, so the result is byte-identical to the
source whenever the prefix matches.
- --append: sends the tail without content-verifying the retained prefix
(rsync parity; the documented prefix-trust risk).
- --append-verify: verifies the retained prefix against the source's prefix
xxHash64 before appending and, on a mismatch, falls back to a clean full
transfer (never a corrupt prefix+tail blend).
New wire frames STATUS_APPEND / STATUS_APPEND_SIG / STATUS_APPEND_OK /
STATUS_APPEND_DATA; PROTOCOL_VERSION bumped 2.9.0 -> 2.10.0 (peers must match).
Both flags imply --incremental and are incompatible with -s (chunk
serialization) and --whole-file (rejected up front). Respects --inplace,
--partial/--partial-dir and --delay-updates via the shared store engine.
New flags parse onto the config; --delete-missing-args implies
--ignore-missing-args (order-independent) and does NOT imply --delete (rsync:
independent of other delete processing). The files-from preflight now classifies
listed-but-missing entries instead of hard-failing: under the flags each is
skipped (logged + counted, never silent) and the run succeeds for the rest,
including the all-missing case; an empty list stays a hard error. Under
--delete-missing-args the missing entries' destination mirrors (bare relative
path with -R, full source mirror otherwise) ride the manifest's third section in
both the single-threaded and -m senders; --dirs listed-but-missing entries are
skipped in the scanner.
scan_directory_multithreaded read directory_scanner_had_io_error() /
parallel_scanner_had_io_error() AFTER destroying the scanner object (a
heap-use-after-free on every successful -m run that recorded an io_error); the
flag is now captured before the destroy. As a second line of defense against
an empty-keep-set wipe, all four manifest send sites (sequential and -m, early
pre-scan and commit data pass) now refuse to transmit a keep-set manifest when
the scan that built it recorded an io_error and produced no keep entries: a
source that merely LOOKS empty because part of it was unreadable must never
delete the whole destination. A genuinely empty source (no io_error) still
sends its empty keep-set and prunes extras.
A sequential scanner records an opendir failure of its seed/root directory as a
skippable io_error and would complete an EMPTY scan, whose keep-set manifest
would then delete every destination entry. The seed directory that maps to the
transfer root (relative path "") is now fatal regardless of --ignore-errors;
only subdirectories discovered during an otherwise-successful root scan are
skippable. The -m path never had this hole (its root open failure aborts
scanner creation), so sequential and -m now agree.
The --fuzzy implication previously forced use_incremental back on even when
the user passed --no-incremental, while --no-delta and -W were honored.
Track a --no-incremental latch (like the no_delta latch): with it set, do not
force the handshake on, and because delta needs the handshake, also suppress
the delta implication so no invalid '--delta requires --incremental' config
results. A --fuzzy --no-incremental run is therefore a plain default-mode
transfer (fuzzy inert), consistent with -W/--no-delta. Documented in the
usage text (this deliberately differs from the basis-dir options, which still
force incremental unconditionally).
The scanners now record every entry pruned by user-selection rules
(--filter/-C/per-dir, --exclude/--include, --max-size/--min-size) as a
destination-relative protected path on a caller-supplied sink (thread-safe in
the parallel scanner); --files-from subset pruning and -R relative wire paths
are never recorded. The sender transmits these as manifest protected prefixes,
giving rsync's default --delete behavior (excluded mirrors survive) with
--delete-excluded opting back into deleting them. --ignore-errors makes an
unreadable source directory a recorded, non-fatal scan error: the run continues,
the deletion still runs, and the exit code reports the ignored error.
--prune-empty-dirs omits an empty source directory's explicit --dirs entry.
Empty directories were never transferred by recursive scans (rsync -m parity).
Adds ignore_errors (client-only) and force_delete (wire) booleans, makes
max_delete default -1 (no client limit), and parses --delete-excluded,
--max-delete=NUM, --ignore-errors, --force, --prune-empty-dirs. Bumps
PROTOCOL_VERSION 2.8.0 -> 2.9.0 for the new on-the-wire force_delete field.
Register --fuzzy (alias -y) as a boolean option and fuzzy as negatable so
--no-fuzzy works through the generic negation machinery. FastSync's delta
machinery is off by default (unlike rsync, where --fuzzy implies nothing
because delta is the default), so --fuzzy implies --incremental and --delta
unless --whole-file or an explicit --no-delta switched delta off (leaving
fuzzy inert, matching rsync where -W makes fuzzy irrelevant). Add help text.
Basis dirs imply the per-file incremental check, which (like every whole-file
payload path in FastSync) is bounded by MAX_RECEIVE_WHOLE_FILE_SIZE. A source
tree with a larger file used to abort the whole run mid-stream on the receiver
with no client-side diagnostic. With basis dirs configured the client now
preflights the scan (respecting filters/size rules) and fails up front with a
clear error naming the offending file before connecting, matching the
documented 256 MiB whole-file limit instead of aborting silently.
Usage help now gives --delete-during a complete description with --del on its
own line, and notes that timing flags imply --delete while timing+--no-delete
is rejected regardless of argument order. RSYNC_COMPAT.md documents: the
receiver's MAX_MANIFEST_ENTRIES/MAX_MANIFEST_BYTES caps now abort an early-mode
run before any data (previously only the deletion step failed), the extended
early-delete ACK deadline, and the order-independent flag-conflict policy.
The receiver performs the whole bounded deletion walk (up to
MAX_SERVER_DELETE_COUNT unlinks) before answering the delete-before/during
manifest, so its STATUS_OK reply can take far longer than the default 60 s
per-message receive window. Waiting with the default would make the sender
abort AFTER the deletion had already committed on the receiver. Add a timed
receive variant (receive_status_timed / protocol_receive_n_data_timed) and use
it for the early-manifest ACK with a 1 h explicit deadline; connection errors
and EOF still abort immediately.
Deletion timing is now real and selected by the four rsync flags plus the
plain --delete default. Wire protocol bumps to 2.8.0: two new config
booleans (delete_during, delete_delay) are serialized and validated, joining
the existing delete_before/delete_after.
- Early modes (--delete-before, --delete-during/--del): the sender pre-scans
the whole tree (paths only), transmits the keep-set manifest BEFORE any
file data, and the receiver removes extras and acks STATUS_OK; the sender
only streams data after the deletion committed. Deletion is thus performed
even if a later transfer phase fails (rsync delete-before/during are
destructive by definition). FastSync streams in a single scan so it cannot
interleave per-directory like rsync delete-during; --delete-during selects
the same engine mode as --delete-before (documented divergence).
- Late/commit modes (plain --delete, --delete-after, --delete-delay): the
manifest closes the data stream and deletion is committed only after
STATUS_FINISHED proves the whole transfer succeeded, preserving FastSync's
commit-style safety. --delete-delay converges with --delete-after because
FastSync never snapshots the destination during data flow (documented).
- The STATUS_MANIFEST frame is now self-delimiting and position-independent.
Single-threaded receivers delete before the success frame; the -m receiver
hands the keep-set to server.c, which commits the deletion only after the
disk writer thread has drained (fixes a delete-vs-in-flight-temp race).
- Every timing flag implies --delete; at most one timing flag is allowed.
- Each timing flag implies --delete, matching rsync; conflicts are rejected.
The receiver's per-file incremental check now consults the ordered basis-dir
list whenever the destination is not already up to date. An exact basis match
requires equal size, equal mtime (unless --size-only; --ignore-times disables
basis matching like rsync), and an equal content xxHash64 -- the sender sends
its xxHash for every file whenever basis dirs are configured (not only under
--checksum), so a hard link or local copy is only ever made from byte-identical
content.
On a match:
- compare-dest: reply STATUS_OK and skip data only when the destination does
not already hold the file (sparse, rsync parity). A destination that holds
a DIFFERENT version falls back to a normal transfer instead of rsync's
delete, keeping the mirror complete.
- copy-dest: reply STATUS_OK and hand a synthetic File (bytes read from the
basis file, basis metadata) to the normal store sink, so the file is
installed as a real local copy through the existing atomic temp+rename
engine and honors --existing/--ignore-existing/--update/--backup/
--delay-updates/--partial-dir unchanged.
- link-dest: same, but File.basis_link records the basis path and the store
engine calls the new file_to_disk_secure_link(): an atomic temp hard link +
rename. Cross-filesystem/refused links fall back to a byte-identical local
copy (never a corrupt or partial file); the copy fallback applies metadata,
while a successful link keeps the basis inode's own attributes so the basis
file is never mutated.
Basis-materialized files carry File.skip so they are not acknowledged to a
--remove-source-files sender (the sender already saw STATUS_OK and keeps the
source). The no-match path is byte-for-byte identical to the existing delta /
full-data transfer.
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