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).
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.
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.
Replace the vestigial single compare_dest/copy_dest/link_dest Config fields with
an ordered BasisDest list (type + path per entry) that is serialized to the
receiver and interpreted relative to the destination root. Paths must be
relative with no '.'/'..' components (confined like --backup-dir); trailing
slashes are normalized. Wire layout changes, so PROTOCOL_VERSION -> 2.8.0.
CLI: each flag is parsed in both --flag=DIR and --flag DIR forms, is
repeatable, and keeps command-line order as basis priority. Supplying any
basis dir implies --incremental (and therefore metadata) on the sender because
the unchanged decision is receiver-side; combining basis dirs with -s chunk
serialization is rejected in validate_config. Usage text updated.
Review fixes for --delay-updates:
- --delete no longer deletes the staged files: the delete walker gains a
skip_root_child parameter and receive_manifest passes DELAY_UPDATES_STAGING_DIR
when delay_updates is active, so deletion removes genuine extras while the
staging dir (a direct child of the receive root) is left for publication in
both single and -m modes.
- --backup-dir is rejected when it collides with the reserved internal staging
name .fastsync-stage (trailing slash normalized), in client validation and in
the received-config wire validation, preventing old backups from being
silently installed as new files.
- Staging dir is now held under an exclusive advisory flock for the whole
transfer (context lifetime): two simultaneous delayed transfers to one
destination root no longer share/destroy each other's staged data - the
second fails cleanly. Cleanup only touches the staging dir when this context
owns the lock, so a lock-contention failure cannot wipe a live session.
- Post-publish staging cleanup now returns/logs instead of discarding failures
(warning when the staging dir cannot be fully removed).
- Reworked the publish-failure integration test to exercise real mid-publish
semantics (top-level file published, nested rename fails, no rollback,
sources retained under --remove-source-files) and added integration tests for
--delete + --delay-updates ordering and reserved --backup-dir rejection.
- RSYNC_COMPAT note documents delete ordering, the reserved-name hazard, and
the concurrency guard.
Stage every successfully written file under a private 0700 .fastsync-stage
directory inside the receive root and atomically publish all staged files
only after the whole protocol stream (manifest/delete handling included)
has completed, immediately before the success/outcome frame. On any
abort/error before publication nothing is installed and staging is removed;
a publish failure aborts the transfer with best-effort cleanup of the
remainder (already-published files are not rolled back). Crash leftovers
are wiped when the next delayed transfer starts.
Wire: new delay_updates config flag (selection-options block), protocol
version bumped to 2.6.0, client/server validation rejects --inplace.
CLI/usage/validation updated. Works in single-threaded and -m modes
(exactly one write_thread stages files; the staged-file registry is
mutex-protected; publication runs once after both threads join).
--existing/--ignore-existing/--update decide against the final destination
at stage time; --backup is deferred to publication. remove_source_files
outcomes are only sent after publication so skipped/unpublished sources are
never deleted. Default (no flag) behavior is unchanged.
Tests: config wire round-trip, CLI parse, --inplace rejection, new
test_delay_updates unit suite (27 suites total), and integration
TestDelayUpdates covering single/-m parity, incremental reruns, remove
source files, receiver-skip ordering, and a deterministic publish-failure
abort path.
Implement rsync-style itemized output backed by one shared change-event
engine (src/client/change_list.c):
- -i/--itemize-changes prints ">f+++++++++ <path>" for files actually sent
(single-threaded and -m); unchanged files print nothing.
- --list-only prints an ls-style listing of files that would be transferred
without contacting the server or writing anything.
- --out-format=FORMAT prints a printf-style template per changed file
(tokens %%f %%n %%l %%b %%M %%%%; unknown escapes preserved).
- --log-file-format=FMT logs each transferred file when --log-file is set.
Events are emitted from the per-file sender path shared by both transfer
modes, so the single sender thread is the only reporter (no races).
- file.c split layout retained; security-hardened secure-fs helpers
(open_secure_parent/to_disk_secure/rename_secure/stat_secure) now live in
file.c with file_ prefix and are shared with file_receive.c
- file_receive.c takes the security branch's bounded allocations
(receive_data_limited, data_decompress_limited, size checks) and
STATUS_ERROR signaling
- file_send.c gains the data consistency check on file->data
- client_validation.c: stricter --tls requiring --ca, log_message style
- utils.c: hardened openat/mkdirat mkdir_r from security branch
- Add log_perror() helper (context + strerror(errno)) to the log module
- Replace all bare perror() calls with log_perror() so errors are routed
through the unified logger (stderr sink + optional --log-file sink)
- Convert fprintf(stderr, "Error:/Warning: ...") in client code to
log_message(); raw fprintf kept only for progress/stats output
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