The provider chain so far holds the diff-hunks store in front of the
terminal builtin computation. Open it to external processes: a pair on
a path whose driver configures diff.<driver>.process is answered by a
long-running process speaking a pkt-line protocol (following the filter
process protocol), registered at the head of the chain and consulted
before the store and before any blob is loaded.
The protocol starts with the smallest request that can carry an answer:
object names alone. A request is the pathname and the pair's
old-oid/new-oid, with no content. The process answers with hunk lines,
with a zero-hunk success that asserts the blobs equivalent (trailing
newlines included), or with status=need-content, on which the pair
falls through to the builtin answer. This serves the two shapes that
need no content pushed to them: a cache keyed on the blob pair, and a
process that fetches the blobs itself (for example over "git cat-file
--batch"). A pair whose side is not a stored blob carries a NULL id;
the provider sends no request and passes it. Because Git holds no
content for the exchange, the answer is used as sent: hunks are
validated for order, overlap, lockstep alignment, and magnitude, then
replayed without the normalization xdiff applies to diffs it computes
itself. The magnitude bound is the blobs' sizes, read from the object
database without loading content: a blob of N bytes holds at most N
lines.
Because the process's answer is authoritative, it outranks the store,
and its head-of-chain position says so. A pair the process answers
never reaches the store and is never recorded, so nothing it produces
enters the store, which holds the builtin answer only. A request it
does not answer, whether need-content, a missing capability, or a
missing id, passes down the chain to the builtin answer, which is what
the store serves, so the store may serve such a pair and a warming run
may record it. Entries recorded before a process was configured are
not purged; a pair the process answers ignores them, and "git diff-hunks
clear" discards them.
The provider gates itself per request. The driver is looked up by the
old-side path, so a renamed file resolves to the same driver, and by
the repository-relative path, so a diff.relative run from a
subdirectory names the pair the same way. Options the process is never
told about select no process: the whitespace-ignoring options, -I,
--anchored, and an algorithm forced by option or configuration (blame
routes its algorithm through xdl_opts, so --histogram is covered). The
request gains its last field, the path; the consumers change only by
filling it, and neither names the process.
The provider's state is its repository's pool of running processes,
keyed by the configured command, so drivers sharing a command share a
process, a submodule speaks to its own, and releasing the provider
(from repo_clear()) stops them. The pool owns a copy of each command
string, so an entry outlives a config re-read. A command that fails
stays as an entry that is not retried: its request and every later one
pass, so the store may serve the path for the rest of the command.
A protocol error in a response never kills the command. The response
is read through a packet reader gentle about framing, so an error takes
one path: a single warning, the process stopped and marked failed, and
the builtin diff for the rest of the command. That covers garbage
bytes, a truncated response, an empty packet, a bare status, and an
unrecognized status. Semantically invalid coordinates cost only their
pair: the response is drained, the pair is computed, and the process
stays alive. A path the protocol cannot carry (an embedded newline, or
one too long for a packet) falls back per path rather than costing the
command its process. The handshake keeps one fatal check: a process
that announces a capability Git did not request aborts the command, as
the long-running filter protocol does.
Consulting is allowed per command, following the allow_textconv
precedent. "git diff", "git log" and "git show", and "git blame" set
allow_diff_process; the plumbing diff commands and the interactive-patch
machinery never set it, so scripted and staging output stays builtin.
The options adjust the flag:
- --no-ext-diff clears it and --ext-diff sets it;
- --diff-process and --no-diff-process set and clear it alone, leaving
external diff drivers as they were;
- format-patch clears it unconditionally, so a generated patch applies
for recipients without the process;
- range-diff passes --no-ext-diff to the "git log" it compares.
git blame and the summary formats consult the process. For blame, a
pair reported equivalent emits no hunks, so the whole commit passes to
its parent. In the stat formats such a pair sums to a zero-count entry,
which the "nothing changed" rule omits, as under -w. The subprocess is
long-running: one startup cost across a traversal, one round-trip per
consulted pair. Answers travel in struct xdl_hunk, new in
xdiff-interface.h, holding xdiff's 1-based coordinates; nothing feeds
them back to xdiff, since only coordinate consumers consult.
A content-carrying request is the natural extension: it would serve
sides that are not stored blobs and processes that want content pushed
to them, and bring patch output and log -L's range tracking to the same
answer. As it stands, a process's answers show in blame and the summary
formats while patch output stays builtin.
t4080 exercises the protocol, the per-command gate, and the error paths:
- each adversarial response shape warns and falls back to builtin, the
request log proving which failures disable the process and which keep
it alive (a malformed hunk line, coordinates past the blob size, a
count overflowing strtol(), overlapping or misaligned hunks, an
unrecognized status, a bare status, an empty packet, a mid-response
crash, and raw garbage);
- a capability-less process and status=abort degrade without noise, and
a failed start warns once and returns the path to the store;
- a trailing token on a hunk line is ignored, pinning field
appendability;
- positive consults for git diff, git show, and diff-tree under
--ext-diff and --diff-process; textconv output and gitlink sides are
never identified; a diff.relative run consults by the repo-relative
path;
- the equivalence answer is pinned from both consumers, and a warming
run past a deferring process records the pair for a later read.
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add the process field to struct userdiff_driver and teach the
config parser to populate it from diff.<driver>.process.
The field names a long-running hunk provider process. Nothing
reads it yet: the consult, the protocol, and the documentation
arrive with the next commit, which starts and pools processes keyed
by this field's command string.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
subprocess_read_status() reads "status=<key>" packets up to a flush with
packet_read_line_gently(), which is gentle only about EOF. A malformed
length header still dies inside pkt-line, and an empty packet is
indistinguishable from the flush that ends the section. A protocol
violation in a status section therefore either kills the whole command
or silently truncates the section. That posture fits the filter
protocol's callers, which treat their process as required
infrastructure; the diff process consult added later in this series
treats its process as optional, and any protocol error must degrade to
the builtin diff rather than abort the command.
Add subprocess_read_status_gently(): the same status loop, reading
through packet_read_with_status() with the gentle options, returning
-1 on a truncated or malformed packet and on an empty packet where a
status line or the terminating flush belongs. subprocess_read_status()
and its callers are unchanged.
The handshake has its gentle counterpart in 061a68e443 (sub-process:
use gentle handshake to avoid die() on startup failure, 2026-06-01),
which turned truncated handshake reads into error returns for every
caller. This series' base includes that commit, so a process that
dies during the handshake feeds the same non-fatal fallback as a
status failure here, and an optional diff process degrades to the
builtin diff on either kind of protocol error.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
subprocess_start() and subprocess_stop() couple two concerns: managing a
child process (setup, handshake, teardown) and managing a hashmap that
indexes running processes by command string. The hashmap suits callers
like convert.c where many files may share one filter process looked up
by name, but callers that manage process membership under their own
rules do not need the coupled operations.
Extract subprocess_start_command() and subprocess_stop_command() so
callers can reuse the child process setup and handshake machinery
without the map operations. subprocess_start() and subprocess_stop()
become thin wrappers that add hashmap operations on top.
The diff process support added later in this series keeps its processes
in a pool owned by a per-repository provider object, and an entry for a
failed command must stay behind there so the command is not retried.
That membership follows rules subprocess_start() and subprocess_stop()
do not know. The pool therefore uses the _command variants for process
lifecycle and manages its own map.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before diffing a target blob against a parent, offer the pair's identity
to the hunk provider interface. Blame's requests have gone through
diff_provider_emit_hunks() since the interface arrived, but carried no
identity, so nothing could answer them. Now blame fills in the pair's
blob object ids and its diff options, and the chain serves the pair from
the store, keyed by the ids and the request's xdiff flags, before the
terminal provider falls back to fill-and-compute. Blame diffs at zero
context, which is not part of the key. An answer replays the recorded
hunks through blame_chunk_cb without loading either blob; a request
carrying -I patterns or anchors is outside the key and always computes.
Blame withholds the identity where its diff is not the plain blob-pair
diff the key describes: reverse blame, ignored revisions, textconv
paths, and the working-tree or --contents pseudo-commit, whose blob is
not a stored object. Those requests always compute. Whitespace and
algorithm options such as -w instead change blame's xdl_opts, so the
consult keys a different entry and misses a store warmed without them.
Blame's default xdl_opts now come from DIFF_HUNKS_DEFAULT_XDL_OPTS, new
here, which records the key-relevant defaults a diff_options-based
consumer already carries (today the indent heuristic), so a default
blame run and a default "log --stat" warming run share keys by
construction.
"--show-stats" reports how many pairs the store served and how many
consultations it could not, read from diff_hunks_read_stats(); the store
counts its own consultations, so blame keeps no tally.
Extend t4220 with the blame side:
- parity for plain, --porcelain, and --incremental output, and hit and
miss accounting across warming runs;
- the blame inputs that must bypass or miss the store: -w, indent
heuristics, --reverse, textconv, -M/-C, and the --ignore-rev pass;
- rename and merge handling, and --contents;
- reading a truncated or corrupt store as absent, and a crafted
zero-hunk record as a miss that verify flags.
Add p4218, measuring the cost of a warming run and the read speedups.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach builtin_diffstat() to consult the hunk provider interface through
diff_provider_consult(), new here: the consult-only entry that answers
without loading content or computing, so it never returns
DIFF_PROVIDER_ERROR. On an answer, the summing callback accumulates the
provided counts directly into the diffstat entry; the blobs were already
loaded for the binary check, so an answer saves the diff run, not the
content load (blame, taught next, skips its loads too). On an
unanswered outcome it computes as before and, with a writer attached,
records what it computed; on unanswered-no-record it computes without
recording.
The provider behind the consult is the diff-hunks store, registered in
front of the terminal builtin computation. Its consult serves a
recorded pair through diff_hunks_replay(), which validates the sequence
before any hunk reaches the callback, so direct accumulation is safe.
The request gains the pair's object ids and the diff options read by the
exclusions below. A side whose bytes are not a stored blob, such as a
working-tree file or a gitlink, has a NULL id; the store passes it by and
the terminal provider computes it. diff_provider_emit_hunks() walks the
same chain, so blame's requests follow these rules the moment blame
supplies identity. The walk also insists, as a BUG check, that a
request's diff options belong to the repository whose chain it walks.
Each exclusion lives with the provider whose key cannot express it. -I
patterns and --anchored shape the diff outside the store key, and break
detection (-B) rescores the pair outside it; the store's consult maps
all three to stop-no-record, so such a request is neither served nor
recorded for any consumer. The consumer-side guard the recording commit
carried for those three comes out here. The compile-time assert on
xpparam_t's layout sits next to that decision, forcing an explicit
keying decision whenever a diff parameter is added. The stat consumer
keeps only the exclusion that is not about the key: --ignore-blank-lines
is part of the key but coalesces hunks differently between the
text-emitting and coordinate-callback paths, so the consumer returns
before consulting. A "log -L" range-scoped stat neither reads nor
records; the line-range filter computes it as before.
"git diff", "git log", "git show", and "git diff-tree" with the --stat,
--numstat, and --shortstat formats consult the interface. Reading is
controlled by core.diffHunks.
An answer is invisible in the output, so the store counts the pairs it
serves and the consultations it cannot, and diff_hunks_read_stats()
reports both; the stat path emits the hits as a trace2 "read-hits" datum
for tests and tuning. The counters live on the store because only the
store knows whether a consultation reached it, and none of its exclusion
legs reaches the replay, so none counts as a miss.
Extend t4220 with the read half:
- output parity with and without the store, at several context lengths
and both directions, and reversed pairs keying apart;
- the consultation made visible through the read-hits datum, and the
trim-divergent pair correct at every context;
- the settings that must bypass the store doing so in both directions
(-I, -B, --anchored, --ignore-blank-lines), asserted through the trace
rather than output parity alone, which a coincidentally equal count
could satisfy;
- a driver-forced algorithm keying apart rather than bypassing: it is
part of the key, so a read under it misses the default entries and a
warm records under its own.
A "log -L" range-scoped stat neither reads nor records.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The diff-hunks store has a writer, but nothing fills it. Teach
builtin_diffstat() to do so: on a warming run (a writer is attached), a
modified pair's stat is produced by collecting the pair's hunk
coordinates instead of emitting text, the counts are summed from those
hunks, and the pair is recorded. A run without a writer is unchanged,
and nothing reads the store yet; the read side arrives next.
The store records one context-free entry per pair, and only for a
trim-stable pair: one whose zero-context trimmed diff (what blame will
read) and untrimmed diff (whose counts a nonzero-context stat matches)
are identical. The warming path computes both and hands them to
diff_hunks_writer_record_stable(), new here, which records only when
they agree; a divergent pair is never recorded and every consumer
computes it. The warming run displays the counts it shows a store-less
run: the trimmed ones, since xdi_diff trims at zero context, while the
untrimmed counts serve only the stability comparison.
Not everything the stat path computes may be recorded.
--ignore-blank-lines is part of the key, but it coalesces hunks
differently between the text-emitting and coordinate-callback paths, so
a recorded entry would not match a store-less run's --stat. -I
patterns, --anchored, and break detection (-B) shape the diff outside
the key entirely; the guard for those three sits in this consumer for
now and moves into the store's own provider when it registers, next. A
"log -L" range-scoped stat is not the whole-pair diff the key describes,
so it does not record. Recording also requires both sides to be valid
regular files whose blobs the key can name: a working-tree side,
textconv output, or a gitlink has no usable id.
"git diff", "git log", "git show", and "git diff-tree" with the --stat,
--numstat, and --shortstat formats attach a writer when writing is
enabled and flush it when the traversal finishes, so a warming run such
as
GIT_DIFF_HUNKS_WRITE=1 git log --all --stat >/dev/null
fills the cache as a side effect of the diff work the command already
does. Writing is controlled by diffHunks.write and GIT_DIFF_HUNKS_WRITE.
Add the write half of t4220:
- ordinary commands never create the store, and creation is gated off
by default, the environment overriding the config;
- a warming run builds a store that verifies, and a second refreshes it
in place;
- a warming run displays parity at zero context on a trim-divergent
pair, committed as a fixture (small synthetic pairs cannot diverge:
minimal diffs add and delete equal counts, and trimming preserves
that);
- binary and mode-only pairs do not break the writer;
- a corrupt store is discarded at seed;
- verify and clear run against the files a warming run builds.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Blame and "git log --stat" recover hunk coordinates by diffing blob
pairs, and recompute them on every run. Add a cache of those
coordinates at $GIT_DIR/objects/info/diff-hunks, beside the
commit-graph, so a later run can look them up instead of decompressing
the blobs and running xdiff again.
The store is a single chunk-format file (see gitformat-chunk(5)): an
8-byte header, a DHIX index of fixed-size entries sorted by key, a DHDT
segment of hunk records, and a trailing hash checksum. An entry is
keyed by the two blob object ids and the xdl_opts the pair was diffed
under, so a stored result is served only where that exact key recurs,
independent of path. A zero-context diff trims unchanged lines from
hunk edges and can pick a different but equally valid set of hunks than
an untrimmed diff, so a recording caller stores a pair only when its
trimmed and untrimmed diffs are identical; such an entry answers any
consumer at any context, and the rare divergent pair is always
computed. Identical hunk blocks are interned once and shared across
keys.
The library provides a reader (repo_diff_hunks_store and _replay, gated
by core.diffHunks), loaded once and cached on the object database as the
commit-graph is, and a writer that accumulates entries and flushes them
in one atomic pass. An absent, corrupt, or disabled store reads as all
misses. A record with no hunks is invalid too: replaying it would claim
the pair equivalent, which the store never asserts, so it reads as a
miss.
Ordinary reads are diagnostic-free. Loading parses the chunk table
through read_table_of_contents_quiet(), new in chunk-format, which
prints nothing on a malformed table and takes the repository's hash
algorithm rather than the_hash_algo, so the file is bounds-checked under
the algorithm it is keyed by.
The flush closes the repository's mmapped store and forgets that loading
was attempted before committing the lockfile. A warming run that also
reads may hold the file it is replacing mapped, and the rename must not
land on a live mapping, which Windows refuses; a read after the flush
then observes the committed file. commit-graph closes its graph before
committing for the same reason.
Writing is off by default, enabled per run by GIT_DIFF_HUNKS_WRITE or
persistently by diffHunks.write, the environment winning. A writer
seeds from the existing store, so a flush merges rather than replaces.
The seed's checksum is verified first: a corrupt store is discarded, not
rewritten with a fresh checksum verify could no longer catch. An entry
that fails the shared diff_provider_check_hunk() or names no blob is
dropped with a warning, since it would only ever read as a miss. A seed
that discarded or dropped anything forces the flush even when the
warming run computed nothing new. The writer fsyncs through a new
diff-hunks core.fsync component.
"git diff-hunks" inspects and manages the file: "verify" checks the
checksum, chunk table, sort order, entry bounds, and every entry's hunk
sequence against that shared check, so a store whose entries could only
read as misses fails verify; "clear" removes the file. Later patches
wire the readers and the writer into the diff and blame paths.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To learn which line ranges changed between two blobs, every consumer in
the diff machinery loads both blobs and runs xdiff. There is no other
way to supply that answer, even when it is known elsewhere: a cache may
hold the ranges from the last time the pair was diffed, and a
format-aware process may have its own idea of which lines changed.
Either could answer from the blob object ids alone, but the loading and
computing are hard-wired into each consumer, so such an answer has no
place to enter.
Introduce the hunk provider interface, diff-provider.h, between asking
the question and computing the answer. A provider answers a request
made of the pair's identity, its blob object ids and the parameters
that determine the diff. A provider is either authoritative, so its
answer may deliberately differ from the builtin diff, or not, so its
answer must reproduce the builtin result exactly. Every answer served
from identity passes diff_provider_check_hunk() before a consumer sees
it: coordinates fit int32, hunks are ordered and non-overlapping, and
the unchanged runs between them match on both sides. A failing answer
is discarded and the pair falls through as unanswered.
Providers are repository-lifecycle objects. Each repository owns a
chain of them, built on first consultation and released from
repo_clear(), so a submodule gets its own providers and no provider
state outlives the repository it serves. The chain has a fixed
composition, and each provider gates itself per request, passing when
it does not apply. Chain order is the authority: the first answer
wins. A provider may instead refuse a pair whose request is shaped by
parameters its recording key cannot express. After a refusal, no later
provider answers the pair from identity, and the consumer must not
record what it computes for it. The last provider is the builtin
computation, the only one that computes rather than answering from
identity, so a walk given a fill callback always ends in an answer,
refusal or not.
The walk in diff-provider.c maps a provider's four dispositions
(answer, pass, fail, refuse) onto the consumer-facing outcomes, and
checks with BUG() that only the computing provider fails and that it
passes on a walk with no fill callback. The implementor contract, the
provider struct, its dispositions, and the shared check, lives in
diff-provider-internal.h, as refs/refs-internal.h is to refs.h;
consumers see only diff-provider.h.
The consumer surface is two types. struct diff_provider_request names
what is diffed and under which parameters; each later commit that
consults on more state adds the field it keys on (the object ids and
diff options, then the path). enum diff_provider_outcome flattens two
dependent axes into four points: the response state (answered,
unanswered, failed) and, only when unanswered, whether the caller may
record what it computes. The record rule rides in the outcome, not a
separate flag, so -Wswitch forces every consumer to place the no-record
arm. A provider added later maps onto these values inside the walk, so
consumer code is written once.
diff_provider_emit_hunks() is the consumer entry: the caller states the
request, a hunk callback, and a content-loading callback that reaches
the terminal provider only when the ranges are computed. Blame's
pass_blame_to_parent() is the first consumer, since it knows both blob
ids before reading either blob; its loads move into the fill callback.
With only the terminal provider registered, every request still
computes, so behavior is unchanged. (Blame's -C/-M split detection
diffs partial buffers with no blob identity and stays on xdi_diff().)
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "Defining an external diff driver" section explains how to
configure diff.<driver>.command but not how the driver relates to the
rest of Git's diff machinery. In particular, the command only
replaces the textual patch: word diff, function context, color, and
the like cannot apply to its output, while the summary formats, blame,
and git log -L do not run it at all and keep using the builtin diff.
Spell this out so the scope of an external diff driver is clear.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* mm/line-log-limited-ops:
diffcore-pickaxe: limit -G to the -L tracked range
diff: support --check with -L line ranges
diff: support stat formats with -L
diff: extract a line-range diff helper for reuse
diff: emit -L hunk headers via xdiff's formatter
diff: simplify the line-range filter by classifying removals immediately
diff: rename line-range filter struct and clarify fields
Teach -G to only search the line ranges specified by -L.
Teaching -S is left as future work, so it still matches the entire
file even if -L is specified.
Rather than being part of diff.c's builtin implementations, the
diffcore-pickaxe functionality interacts with xdiff-interface as a
separate component. Add a sibling to xdi_diff_outf(), called
diff_emit_line_ranges(), that limits emitted lines to the given line
ranges.
Use diff_emit_line_ranges() when searching text if line ranges have
been specified. If textconv is enabled, use normal diffing instead of
diff_emit_line_ranges() since line range tracking relies on the line
coordinates of the original, pre-textconv file.
Update documentation and add tests accordingly.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reuse the line_range_filter in builtin_checkdiff() so -L supports
the --check option.
Add orig_hunk_fn field similar to orig_line_fn that forwards
xdiff_emit_hunk_fn calls when we flush filtered hunks. This is necessary
because --check relies on receiving calls to its checkdiff_consume_hunk
function for managing state.
Document and ungate the newly enabled option, and add tests verifying
the new behavior.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reuse the line_range_filter in builtin_diffstat() so -L supports
the stat formats and add tests verifying the new behavior.
Ungate the newly enabled options and drop "yet" from the generic
-L rejection message ("does not yet support the requested diff
format"). Some rejected formats do not fit -L at all, so "yet"
wrongly implies they are all awaiting support.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extract logic for initializing the line-range filter and running a diff
for a specific line range. This logic is needed for any diff that
targets a line range independent of the current patch display path.
The subsequent commits use this logic to enable additional line range
targeted diff modes.
No logical behavior change.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, diff's line-range filter implements its own method for
emitting diff hunk headers. This mostly matches what xdiff itself
outputs, but there is a discrepancy for postimage or preimage sides
with 0 line changes. For a side with no lines (count 0), the begin is
the line before the change. The header omits the line count of 1.
Rather than fix this case in the line-range implementation, expose the
function xdiff uses to emit its headers. Reusing it keeps the header
format consistent with and without -L.
Update test scenarios and fixtures to reflect the now consistent header
format.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, the diff line-range filter buffers preimage removal lines
until a postimage line arrives. That line's number confirms whether the
preimage line falls in a relevant range. However, storing preimage
lines in a separate buffer is unnecessary. Worse, the logic has a bug:
a preimage line outside the target range is included when it
immediately follows an in-range postimage line.
Preimage lines will always precede their postimage counterpart both in
content line number and emission order from xdiff's line callback
function. So preimage lines can share the postimage buffer. The filter
flushes them based on whether the postimage lines fall within the
target range.
Remove logic related to storing preimage lines in a separate "removal"
buffer and prepending them to the accumulating_hunk's line buffer.
Instead, store those lines in the accumulating_hunk's line_buffer
immediately and flush everything as appropriate based on postimage
line numbers that arrive. This resolves the bug by construction.
Also, calculate the old and new line counts for the diff hunk header
when flushing rather than storing counters in line_range_filter to
simplify state management further.
Add a test to t/t4211-line-log.sh that verifies the preimage line
emission bug is fixed.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff's line-range filtering logic uses the line_range_callback
struct to represent filtering state. However, this name does not
clearly reflect the role it plays. This is especially relevant as
we expand diff's line-range filtering to work with more options,
including --stat and -G.
Also, line_range_callback's fields are terse, while the comment
explaining line_range_callback is verbose and out of place compared to
its surroundings.
Rename line_range_callback to line_range_filter, and replace the verbose
comment with a concise one, instead preferring descriptive field and
variable names that are self-explanatory over comments.
No logical behavior change. Some fields are grouped under a new struct
in the newly renamed line_range_filter. Everything else is just a
rename.
Signed-off-by: Michael Montalbo <mmontalbo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The global variable 'fetch_if_missing' has been moved to a member in
'struct repository', continuing the libification process and
allowing per-repository control (such as for submodules).
* ty/repository-fetch-if-missing:
repository: move fetch_if_missing into struct repository
The pack-objects command has been updated to record the total bytes
written to pack files in trace2 output, allowing performance
analysis of different compression settings by comparing the
resulting pack sizes.
* fr/pack-objects-trace-pack-bytes:
pack-objects: trace pack bytes written
The mechanism to generate a packfile corresponding to the result of
a fetch/push has been made pluggable through a set of object
database callback functions, removing hardcoded references to
'pack-objects' and enabling alternative ODBs to serve packfiles
themselves.
* ps/odb-pluggable-pack-generation:
bundle: generate packfiles via the object database
bundle: get (mostly) rid of `the_repository`
builtin/bundle: refactor option handling for progress meter
send-pack: generate packfiles via the object database
upload-pack: generate packfiles via the object database
odb: introduce interface to generate packfiles
The 'git receive-pack' command has been updated to use a new ODB
transaction interface for writing incoming packfiles, making it more
backend-agnostic.
* jt/receive-pack-pluggable-writes:
odb/transaction: add transaction interface to write packfiles
odb: return temporary ODB source when set
builtin/receive-pack: explicitly pass packfile fd
builtin/receive-pack: report unpack errors via strbuf
builtin/receive-pack: lift global state out of unpack()
builtin/receive-pack: read unpack limit config lazily
builtin/receive-pack: pass shallow file explicitly
odb/transaction: add transaction finalize interface
builtin/receive-pack: properly clean up keep files
The threshold for geometric repacking to trigger based on loose
object count has been adjusted to match that of 'git gc --auto',
preventing over-aggressive repacking during concurrent writes.
* ps/odb-geometric-repack-loose-threshold:
odb/files: be less aggressive with geometric repacking
The trailer parsing machinery has been updated to avoid mistaking
lines that begin with a URL (e.g., 'https://...') as trailer lines.
This prevents intended textual URLs from being mangled or mistakenly
treated as metadata keys.
* kh/trailers-no-urls:
trailers: stop recognizing URLs as trailers
The object database layer has been simplified by eagerly loading
alternate object directories upon initialization, instead of
deferring it to the first object lookup. This eliminates the need
for scattered lazy-loading calls throughout the codebase and paves
the way for integrating alternates with the pluggable backends.
* ps/odb-eagerly-load-alternates:
odb: drop `alternates_db` field
odb: drop `loaded_alternates` field
odb: eagerly initialize alternates
odb: decouple source path comparisons from `the_repository`
setup: create ref and object databases after config is written
The command line completion (in contrib/) has been taught to handle
the experimental 'git history' command.
* vm/complete-history:
completion: complete 'git history split' pathspecs
completion: complete 'git history --update-refs' values
completion: complete 'git history --empty' values
completion: add 'git history' subcommands
The object database (odb) API has been refactored to distinguish
between missing objects and corrupt ones by returning more
descriptive error statuses. Both the packed and loose backends now
faithfully propagate error details using a generic strbuf error
mechanism, removing backend-specific leakage from central lookup
paths.
* ps/odb-generic-corrupt-objects:
odb: handle `OBJECT_INFO_DIE_IF_CORRUPT` generically
odb/source: allow `read_object_info()` to bubble up error messages
odb/source: let callers discern missing and corrupt objects
odb/source: introduce error status when reading objects
odb/source-packed: flag known-bad objects as corrupt and not missing
The DWIM logic in 'git worktree add' sometimes tried to infer a
remote-tracking branch when an explicit '-b' or '-B' option was
given to create a new branch, causing the explicit branch name to
be ignored, which has been corrected.
* yn/worktree-add-no-dwim-with-b:
worktree add: shouldn't dwim if -b or -B is given
A heap-use-after-free bug in the object name parsing code when
reporting failures with a relative path to a sparse directory has
been corrected.
* sk/object-name-use-after-free:
object-name: avoid use-after-free in get_oid_with_context_1()
The documentation for 'git format-rev' has been updated to use the
[synopsis] block definition on code blocks to properly highlight
placeholders, and a quoting inconsistency in the running text has
been fixed.
* kh/format-rev-doc-synopsis:
doc: format-rev: use [synopsis] on code block
doc: format-rev: quote subject placeholder before and after
'git -C <dir> checkout fi<TAB>' did not complete, which has been
corrected.
* jc/complete-checkout:
completion: 'git checkout' completes untracked paths as a last resort
completion: complete tracked paths for "git checkout"
completion: no-op refactoring of checkout completion
'git -C <dir> diff fi<TAB>' did not complete 'file', which has been
corrected.
* jc/complete-diff-tracked-paths:
completion: 'git diff' completes untracked paths as a last resort
completion: complete tracked paths for 'git diff'
completion: no-op refactoring of diff completion
The unused name parameter in 'struct chdir_notify_entry' has been
removed from chdir_notify_register(), chdir_notify_unregister(), and
related callback signatures across several subsystems, simplifying the
API now that trace output no longer uses it.
* ch/chdir-notify-drop-name:
chdir-notify.h: Removed unused param 'name'
The performance of adding numerous new packfiles has been improved
by introducing a fast path for known-new packfiles to skip an
unnecessary traversal in packfile_list_append(), avoiding a
quadratic complexity regression on load.
* js/packfile-fast-append:
packfile: fix perf regression with many packs
'git repack' has been taught '--drop-filtered' to delete local
promisor blobs exceeding a limit (currently 'blob:limit=') in partial
clones, reclaiming space. Guards prevent running during other
operations or if referenced by the index.
* ss/repack-drop-filtered:
builtin/repack: add guards for --drop-filtered
builtin/repack: actually drop filtered promisor blobs
builtin/repack: enumerate promisor blobs for --drop-filtered
repack-promisor: allow excluding objects from the rebuilt promisor pack
list-objects-filter: add list_objects_filter__filter_oidset()
builtin/repack: add --drop-filtered and --dry-run options
Various tests in 't7900-maintenance.sh' have been updated to use a
throwaway repository, and auto-detaching of maintenance tasks is now
disabled for these tests to fix flaky races with concurrent background
maintenance jobs.
* ps/t7900-deflake-maintenance:
t7900: fix flaky "maintenance.strategy" test
t7900: adapt some tests to use a throwaway repository
A client requesting the promisor-remote capability without a value
caused a null pointer dereference, which has been corrected by
rejecting a request without an argument.
* en/serve-promisor-remote-fix:
serve: reject valueless promisor-remote capability
The 'pack-objects' and delta-encoding code paths have been updated to
use 'size_t' instead of 'unsigned long' for object sizes and offset
limits, avoiding potential truncation issues on 64-bit Windows.
* js/pack-objects-delta-size-t:
packfile: widen `unpack_object_header_buffer()` to `size_t`
git-zlib: widen `git_deflate_bound()` to `size_t`
t/helper/test-pack-deltas: widen `do_compress()`'s maxsize local to `size_t`
http-push: widen `start_put()`'s size local from `ssize_t` to `size_t`
diff: widen `deflate_it()`'s bound local from int to `size_t`
archive-zip: widen `zlib_deflate_raw()`'s maxsize local to `size_t`
packfile, git-zlib: widen `use_pack()` and zstream avail fields to `size_t`
delta: widen `create_delta()` and `diff_delta()` to `size_t`
pack-objects: widen `mem_usage` and `try_delta()`'s out-param to `size_t`
pack-objects: widen `free_unpacked()` return to `size_t`
pack-objects: widen delta-cache accounting to `size_t`
delta: widen `create_delta_index()` parameter to `size_t`
diff-delta: widen `struct delta_index`' size fields to `size_t`
The '--shallow-file' option of 'git' command requires a value, but the
code did not check the presence of a value and instead segfaulted
without one, which has been corrected.
* cc/git-shallow-file-wo-value:
git: avoid segfault on "git --shallow-file" without a value
The setting of a now-unused member '.pretty_given' in the sequencer
machinery has been removed.
* en/sequencer-lose-pretty-given:
sequencer: remove unnecessary variable setting
A handful of code paths have been corrected to check return values
from functions like curl_easy_duphandle(), deflateInit(), lseek(),
dup(), and strbuf_getline_lf(), resolving several Coverity warnings
about unchecked returns.
* js/coverity-unchecked-returns-fix:
bisect: handle dup() failure when redirecting stdout
bisect: check get_terms return at all call sites
bisect: check strbuf_getline_lf return when reading terms
transport-helper: warn when export-marks file cannot be finalized
transport-helper: check dup() return in get_exporter
compat/pread: check initial lseek for errors
last-modified: handle repo_parse_commit() failures
reftable tests: check reftable_table_init_ref_iterator() return
reftable/block: check deflateInit() return value
reftable: handle block-writer initialization errors
config: propagate launch_editor() failure in show_editor()
http: die on curl_easy_duphandle failure in get_active_slot
Michael Montalbo