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2026-08-13delta: widen `create_delta()` and `diff_delta()` to `size_t`Johannes Schindelin1-5/+5
Last stop in the delta-encoding API widening for >4 GiB blobs on Windows: with `create_delta_index()` done in the prior commit and `create_delta()`/`diff_delta()` finished here, every byte count that crosses delta.h is now `size_t`. The struct fields they store into have been `size_t` since the diff-delta struct widening. The API change must move with all callers in the same commit (the build only passes when every `&delta_size` matches the new `size_t*`). Caller updates are kept minimal: * builtin/pack-objects.c `get_delta()` and `try_delta()`: widen only the local `delta_size` variable; the surrounding unsigned-long locals and their `cast_size_t_to_ulong()` shims are out of scope here and will be cleaned up in their own commits. * builtin/fast-import.c, diff.c, t/helper/test-pack-deltas.c: keep the local unsigned-long delta size (each feeds a still- unsigned-long downstream consumer: zlib's `avail_in`, `deflate_it()`, the test helper's own `do_compress()`), and bridge via a temporary `size_t` plus `cast_size_t_to_ulong()`. The new casts are paid back in later topics that widen those consumers. * t/helper/test-delta.c: widen the local outright (no downstream consumer beyond the test's own `out_size`, which is already `size_t`). Note that GCC struggles a bit to figure out that `deltalen` is always initialized before it is used; To help it along, we initialize it to 0. This work-around will go away in a later patch series when `deltalen` can be widened to `size_t`. Assisted-by: Opus 4.7 Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-08-13delta: widen `create_delta_index()` parameter to `size_t`Johannes Schindelin1-1/+1
The sole caller (`try_delta()` in builtin/pack-objects.c) passes an `unsigned long`, which promotes safely, so no caller fixups are needed. Splitting it out keeps the `diff_delta()`/`create_delta()` widening, which does ripple to several callers, in its own commit. Assisted-by: Opus 4.7 Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-08-13diff-delta: widen `struct delta_index`' size fields to `size_t`Johannes Schindelin1-1/+1
Preparation for widening the delta-encoding API to `size_t` in subsequent commits, which is what lets pack-objects drop the `cast_size_t_to_ulong()` shims that 606c192380 (odb, packfile: use size_t for streaming object sizes, 2026-05-08) had to leave behind in `get_delta()` and `try_delta()` because their downstream consumers were still narrow. The struct is private to diff-delta.c, so widening its fields in isolation is a no-op at runtime: the values stored continue to fit in 32 bits on Windows because the public API around it still truncates. Splitting it out keeps the API-change commit focused on caller updates. Since the `memsize` attribute is returned by the `sizeof_delta_index()` function verbatim, that function's return type is adjusted, too. Assisted-by: Opus 4.7 Helped-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-15packfile,delta: drop the `cast_size_t_to_ulong()` wrappersJohannes Schindelin1-12/+2
When I started the transition from `unsigned long` to `size_t`, in the interest of keeping the patches reviewable, I introduced these calls to prevent data type narrowing from silently failing to handle large object sizes. I also introduced `*_sz()` variants that would allow most of the callers to keep using that `unsigned long` that the 90s kindly asked to be returned. After the preceding commits, the only places that called the narrow wrappers either no longer exist or already use the `_sz` form internally, so the wrappers just narrow values back through `cast_size_t_to_ulong()` for no reason. Drop them and rename the `_sz` variants back to the natural names. Assisted-by: Opus 4.7 Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-15patch-delta: use size_t for sizesJohannes Schindelin1-3/+3
`patch_delta()` takes the source and delta sizes by value and writes back the reconstructed target size through an `unsigned long *`. That datatype cannot represent a value that exceeds 4 GiB on systems where `unsigned long` is 32-bit (notably 64-bit Windows builds), though, even though the delta encoding itself, the on-disk layout, and the in-memory buffers happily carry such sizes. A `size_t` companion to `get_delta_hdr_size()`, `get_delta_hdr_size_sz()`, was introduced in 17fa077596 (delta, packfile: use size_t for delta header sizes, 2026-05-08) precisely so that `patch_delta()` could be widened without changing the on-the-wire decoding helper's signature. Widen `patch_delta()`'s three size parameters to `size_t` and switch its internal use of `get_delta_hdr_size()` to the `_sz` variant. Then propagate the wider type through the callers. Assisted-by: Opus 4.7 Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-05-09delta, packfile: use size_t for delta header sizesJohannes Schindelin1-2/+12
The delta header decoding functions return unsigned long, which truncates on Windows for objects larger than 4GB. Introduce size_t variants get_delta_hdr_size_sz() and get_size_from_delta_sz() that preserve the full 64-bit size, and use them in packed_object_info() where the size is needed for streaming decisions. This was originally authored by LordKiRon <https://github.com/LordKiRon>, who preferred not to reveal their real name and therefore agreed that I take over authorship. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-03odb: guard against data loss checking out a huge fileMatt Cooper1-3/+3
This introduces an additional guard for platforms where `unsigned long` and `size_t` are not of the same size. If the size of an object in the database would overflow `unsigned long`, instead we now exit with an error. A complete fix will have to update _many_ other functions throughout the codebase to use `size_t` instead of `unsigned long`. It will have to be implemented at some stage. This commit puts in a stop-gap for the time being. Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Matt Cooper <vtbassmatt@gmail.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-05*.[ch]: manually align parameter listsDenton Liu1-2/+2
In previous patches, extern was mechanically removed from function declarations without care to formatting, causing parameter lists to be misaligned. Manually format changed sections such that the parameter lists should be realigned. Viewing this patch with 'git diff -w' should produce no output. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-05*.[ch]: remove extern from function declarations using spatchDenton Liu1-5/+5
There has been a push to remove extern from function declarations. Remove some instances of "extern" for function declarations which are caught by Coccinelle. Note that Coccinelle has some difficulty with processing functions with `__attribute__` or varargs so some `extern` declarations are left behind to be dealt with in a future patch. This was the Coccinelle patch used: @@ type T; identifier f; @@ - extern T f(...); and it was run with: $ git ls-files \*.{c,h} | grep -v ^compat/ | xargs spatch --sp-file contrib/coccinelle/noextern.cocci --in-place Files under `compat/` are intentionally excluded as some are directly copied from external sources and we should avoid churning them as much as possible. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-03-31comments: fix misuses of "nor"Justin Lebar1-1/+1
Signed-off-by: Justin Lebar <jlebar@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-18Fix big left-shifts of unsigned charLinus Torvalds1-3/+2
Shifting 'unsigned char' or 'unsigned short' left can result in sign extension errors, since the C integer promotion rules means that the unsigned char/short will get implicitly promoted to a signed 'int' due to the shift (or due to other operations). This normally doesn't matter, but if you shift things up sufficiently, it will now set the sign bit in 'int', and a subsequent cast to a bigger type (eg 'long' or 'unsigned long') will now sign-extend the value despite the original expression being unsigned. One example of this would be something like unsigned long size; unsigned char c; size += c << 24; where despite all the variables being unsigned, 'c << 24' ends up being a signed entity, and will get sign-extended when then doing the addition in an 'unsigned long' type. Since git uses 'unsigned char' pointers extensively, we actually have this bug in a couple of places. I may have missed some, but this is the result of looking at git grep '[^0-9 ][ ]*<<[ ][a-z]' -- '*.c' '*.h' git grep '<<[ ]*24' which catches at least the common byte cases (shifting variables by a variable amount, and shifting by 24 bits). I also grepped for just 'unsigned char' variables in general, and converted the ones that most obviously ended up getting implicitly cast immediately anyway (eg hash_name(), encode_85()). In addition to just avoiding 'unsigned char', this patch also tries to use a common idiom for the delta header size thing. We had three different variations on it: "& 0x7fUL" in one place (getting the sign extension right), and "& ~0x80" and "& 0x7f" in two other places (not getting it right). Apart from making them all just avoid using "unsigned char" at all, I also unified them to then use a simple "& 0x7f". I considered making a sparse extension which warns about doing implicit casts from unsigned types to signed types, but it gets rather complex very quickly, so this is just a hack. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-07-12Support fetching the memory usage of a delta indexBrian Downing1-0/+7
Delta indices, at least on 64-bit platforms, tend to be larger than the actual uncompressed data. As such, keeping track of this storage is important if you want to successfully limit the memory size of your pack window. Squirrel away the total allocation size inside the delta_index struct, and add an accessor "sizeof_delta_index" to access it. Signed-off-by: Brian Downing <bdowning@lavos.net> Acked-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2006-05-15pack-object: slightly more efficientNicolas Pitre1-0/+2
Avoid creating a delta index for objects with maximum depth since they are not going to be used as delta base anyway. This also reduce peak memory usage slightly as the current object's delta index is not useful until the next object in the loop is considered for deltification. This saves a bit more than 1% on CPU usage. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-24split the diff-delta interfaceNicolas Pitre1-7/+68
This patch splits the diff-delta interface into index creation and delta generation. A wrapper is provided to preserve the diff-delta() call. This will allow for an optimization in pack-objects.c where the source object could be fixed and a full window of objects tentatively tried against that same source object without recomputing the source index each time. This patch only restructure things, plus a couple cleanups for good measure. There is no performance change yet. Signed-off-by: Nicolas Pitre <nico@cam.org>
2006-04-07check patch_delta bounds more carefullyNicolas Pitre1-2/+3
Let's avoid going south with invalid delta data. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-10delta micro optimizationNicolas Pitre1-5/+5
My kernel work habit made me look at the generated assembly for the delta code, and one obvious albeit small improvement is this patch. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-06-29[PATCH] assorted delta code cleanupNicolas Pitre1-0/+22
This is a wrap-up patch including all the cleanups I've done to the delta code and its usage. The most important change is the factorization of the delta header handling code. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-27[PATCH] Remove "delta" object representation.Junio C Hamano1-9/+0
Packed delta files created by git-pack-objects seems to be the way to go, and existing "delta" object handling code has exposed the object representation details to too many places. Remove it while we refactor code to come up with a proper interface in sha1_file.c. Signed-off-by: Junio C Hamano <junkio@cox.net> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25Add a "max_size" parameter to diff_delta()Linus Torvalds1-1/+1
Anything that generates a delta to see if two objects are close usually isn't interested in the delta ends up being bigger than some specified size, and this allows us to stop delta generation early when that happens.
2005-06-08[PATCH] Anal retentive 'const unsigned char *sha1'Jason McMullan1-1/+1
Make 'sha1' parameters const where possible Signed-off-by: Jason McMullan <jason.mcmullan@timesys.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-20[PATCH] delta checkNicolas Pitre1-0/+15
This adds knowledge of delta objects to fsck-cache and various object parsing code. A new switch to git-fsck-cache is provided to display the maximum delta depth found in a repository. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-19[PATCH] Deltification library work by Nicolas Pitre.Nicolas Pitre1-0/+6
This patch adds the basic library functions to create and replay delta information. Also included is a test-delta utility to validate the code. diff-delta was based on LibXDiff written by Davide Libenzi Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>