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2021-03-13use CALLOC_ARRAYLibravatar René Scharfe1-2/+1
Add and apply a semantic patch for converting code that open-codes CALLOC_ARRAY to use it instead. It shortens the code and infers the element size automatically. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-15diffcore-rename: guide inexact rename detection based on basenamesLibravatar Elijah Newren1-5/+48
Make use of the new find_basename_matches() function added in the last two patches, to find renames more rapidly in cases where we can match up files based on basenames. As a quick reminder (see the last two commit messages for more details), this means for example that docs/extensions.txt and docs/config/extensions.txt are considered likely renames if there are no remaining 'extensions.txt' files elsewhere among the added and deleted files, and if a similarity check confirms they are similar, then they are marked as a rename without looking for a better similarity match among other files. This is a behavioral change, as covered in more detail in the previous commit message. We do not use this heuristic together with either break or copy detection. The point of break detection is to say that filename similarity does not imply file content similarity, and we only want to know about file content similarity. The point of copy detection is to use more resources to check for additional similarities, while this is an optimization that uses far less resources but which might also result in finding slightly fewer similarities. So the idea behind this optimization goes against both of those features, and will be turned off for both. For the testcases mentioned in commit 557ac0350d ("merge-ort: begin performance work; instrument with trace2_region_* calls", 2020-10-28), this change improves the performance as follows: Before After no-renames: 13.815 s ± 0.062 s 13.294 s ± 0.103 s mega-renames: 1799.937 s ± 0.493 s 187.248 s ± 0.882 s just-one-mega: 51.289 s ± 0.019 s 5.557 s ± 0.017 s Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-15diffcore-rename: complete find_basename_matches()Libravatar Elijah Newren1-3/+79
It is not uncommon in real world repositories for the majority of file renames to not change the basename of the file; i.e. most "renames" are just a move of files into different directories. We can make use of this to avoid comparing all rename source candidates with all rename destination candidates, by first comparing sources to destinations with the same basenames. If two files with the same basename are sufficiently similar, we record the rename; if not, we include those files in the more exhaustive matrix comparison. This means we are adding a set of preliminary additional comparisons, but for each file we only compare it with at most one other file. For example, if there was a include/media/device.h that was deleted and a src/module/media/device.h that was added, and there are no other device.h files in the remaining sets of added and deleted files after exact rename detection, then these two files would be compared in the preliminary step. This commit does not yet actually employ this new optimization, it merely adds a function which can be used for this purpose. The next commit will do the necessary plumbing to make use of it. Note that this optimization might give us different results than without the optimization, because it's possible that despite files with the same basename being sufficiently similar to be considered a rename, there's an even better match between files without the same basename. I think that is okay for four reasons: (1) it's easy to explain to the users what happened if it does ever occur (or even for them to intuitively figure out), (2) as the next patch will show it provides such a large performance boost that it's worth the tradeoff, and (3) it's somewhat unlikely that despite having unique matching basenames that other files serve as better matches. Reason (4) takes a full paragraph to explain... If the previous three reasons aren't enough, consider what rename detection already does. Break detection is not the default, meaning that if files have the same _fullname_, then they are considered related even if they are 0% similar. In fact, in such a case, we don't even bother comparing the files to see if they are similar let alone comparing them to all other files to see what they are most similar to. Basically, we override content similarity based on sufficient filename similarity. Without the filename similarity (currently implemented as an exact match of filename), we swing the pendulum the opposite direction and say that filename similarity is irrelevant and compare a full N x M matrix of sources and destinations to find out which have the most similar contents. This optimization just adds another form of filename similarity comparison, but augments it with a file content similarity check as well. Basically, if two files have the same basename and are sufficiently similar to be considered a rename, mark them as such without comparing the two to all other rename candidates. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-15diffcore-rename: compute basenames of source and dest candidatesLibravatar Elijah Newren1-0/+63
We want to make use of unique basenames among remaining source and destination files to help inform rename detection, so that more likely pairings can be checked first. (src/moduleA/foo.txt and source/module/A/foo.txt are likely related if there are no other 'foo.txt' files among the remaining deleted and added files.) Add a new function, not yet used, which creates a map of the unique basenames within rename_src and another within rename_dst, together with the indices within rename_src/rename_dst where those basenames show up. Non-unique basenames still show up in the map, but have an invalid index (-1). This function was inspired by the fact that in real world repositories, files are often moved across directories without changing names. Here are some sample repositories and the percentage of their historical renames (as of early 2020) that preserved basenames: * linux: 76% * gcc: 64% * gecko: 79% * webkit: 89% These statistics alone don't prove that an optimization in this area will help or how much it will help, since there are also unpaired adds and deletes, restrictions on which basenames we consider, etc., but it certainly motivated the idea to try something in this area. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-15diffcore-rename: filter rename_src list when possibleLibravatar Elijah Newren1-8/+51
We have to look at each entry in rename_src a total of rename_dst_nr times. When we're not detecting copies, any exact renames or ignorable rename paths will just be skipped over. While checking that these can be skipped over is a relatively cheap check, it's still a waste of time to do that check more than once, let alone rename_dst_nr times. When rename_src_nr is a few thousand times bigger than the number of relevant sources (such as when cherry-picking a commit that only touched a handful of files, but from a side of history that has different names for some high level directories), this time can add up. First make an initial pass over the rename_src array and move all the relevant entries to the front, so that we can iterate over just those relevant entries. For the testcases mentioned in commit 557ac0350d ("merge-ort: begin performance work; instrument with trace2_region_* calls", 2020-10-28), this change improves the performance as follows: Before After no-renames: 14.119 s ± 0.101 s 13.815 s ± 0.062 s mega-renames: 1802.044 s ± 0.828 s 1799.937 s ± 0.493 s just-one-mega: 51.391 s ± 0.028 s 51.289 s ± 0.019 s Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-12diffcore-rename: no point trying to find a match better than exactLibravatar Elijah Newren1-6/+14
diffcore_rename() had some code to avoid having destination paths that already had an exact rename detected from being re-checked for other renames. Source paths, however, were re-checked because we wanted to allow the possibility of detecting copies. But if copy detection isn't turned on, then this merely amounts to attempting to find a better-than-exact match, which naturally ends up being an expensive no-op. In particular, copy detection is never turned on by the merge machinery. For the testcases mentioned in commit 557ac0350d ("merge-ort: begin performance work; instrument with trace2_region_* calls", 2020-10-28), this change improves the performance as follows: Before After no-renames: 14.263 s ± 0.053 s 14.119 s ± 0.101 s mega-renames: 5504.231 s ± 5.150 s 1802.044 s ± 0.828 s just-one-mega: 158.534 s ± 0.498 s 51.391 s ± 0.028 s Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-23merge-ort: begin performance work; instrument with trace2_region_* callsLibravatar Elijah Newren1-0/+8
Add some timing instrumentation for both merge-ort and diffcore-rename; I used these to measure and optimize performance in both, and several future patch series will build on these to reduce the timings of some select testcases. === Setup === The primary testcase I used involved rebasing a random topic in the linux kernel (consisting of 35 patches) against an older version. I added two variants, one where I rename a toplevel directory, and another where I only rebase one patch instead of the whole topic. The setup is as follows: $ git clone git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git $ git branch hwmon-updates fd8bdb23b91876ac1e624337bb88dc1dcc21d67e $ git branch hwmon-just-one fd8bdb23b91876ac1e624337bb88dc1dcc21d67e~34 $ git branch base 4703d9119972bf586d2cca76ec6438f819ffa30e $ git switch -c 5.4-renames v5.4 $ git mv drivers pilots # Introduce over 26,000 renames $ git commit -m "Rename drivers/ to pilots/" $ git config merge.renameLimit 30000 $ git config merge.directoryRenames true === Testcases === Now with REBASE standing for either "git rebase [--merge]" (using merge-recursive) or "test-tool fast-rebase" (using merge-ort), the testcases are: Testcase #1: no-renames $ git checkout v5.4^0 $ REBASE --onto HEAD base hwmon-updates Note: technically the name is misleading; there are some renames, but very few. Rename detection only takes about half the overall time. Testcase #2: mega-renames $ git checkout 5.4-renames^0 $ REBASE --onto HEAD base hwmon-updates Testcase #3: just-one-mega $ git checkout 5.4-renames^0 $ REBASE --onto HEAD base hwmon-just-one === Timing results === Overall timings, using hyperfine (1 warmup run, 3 runs for mega-renames, 10 runs for the other two cases): merge-recursive merge-ort no-renames: 18.912 s ± 0.174 s 14.263 s ± 0.053 s mega-renames: 5964.031 s ± 10.459 s 5504.231 s ± 5.150 s just-one-mega: 149.583 s ± 0.751 s 158.534 s ± 0.498 s A single re-run of each with some breakdowns: --- no-renames --- merge-recursive merge-ort overall runtime: 19.302 s 14.257 s inexact rename detection: 7.603 s 7.906 s everything else: 11.699 s 6.351 s --- mega-renames --- merge-recursive merge-ort overall runtime: 5950.195 s 5499.672 s inexact rename detection: 5746.309 s 5487.120 s everything else: 203.886 s 17.552 s --- just-one-mega --- merge-recursive merge-ort overall runtime: 151.001 s 158.582 s inexact rename detection: 143.448 s 157.835 s everything else: 7.553 s 0.747 s === Timing observations === 0) Maximum speedup The "everything else" row represents the maximum speedup we could achieve if we were to somehow infinitely parallelize inexact rename detection, but leave everything else alone. The fact that this is so much smaller than the real runtime (even in the case with virtually no renames) makes it clear just how overwhelmingly large the time spent on rename detection can be. 1) no-renames 1a) merge-ort is faster than merge-recursive, which is nice. However, this still should not be considered good enough. Although the "merge" backend to rebase (merge-recursive) is sometimes faster than the "apply" backend, this is one of those cases where it is not. In fact, even merge-ort is slower. The "apply" backend can complete this testcase in 6.940 s ± 0.485 s which is about 2x faster than merge-ort and 3x faster than merge-recursive. One goal of the merge-ort performance work will be to make it faster than git-am on this (and similar) testcases. 2) mega-renames 2a) Obviously rename detection is a huge cost; it's where most the time is spent. We need to cut that down. If we could somehow infinitely parallelize it and drive its time to 0, the merge-recursive time would drop to about 204s, and the merge-ort time would drop to about 17s. I think this particular stat shows I've subtly baked a couple performance improvements into merge-ort and into fast-rebase already. 3) just-one-mega 3a) not much to say here, it just gives some flavor for how rebasing only one patch compares to rebasing 35. === Goals === This patch is obviously just the beginning. Here are some of my goals that this measurement will help us achieve: * Drive the cost of rename detection down considerably for merges * After the above has been achieved, see if there are other slowness factors (which would have previously been overshadowed by rename detection costs) which we can then focus on and also optimize. * Ensure our rebase testcase that requires little rename detection is noticeably faster with merge-ort than with apply-based rebase. Signed-off-by: Elijah Newren <newren@gmail.com> Acked-by: Taylor Blau <ttaylorr@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-04diffcore-rename: remove unnecessary duplicate entry checksLibravatar Elijah Newren1-23/+0
Commit 25d5ea410f ("[PATCH] Redo rename/copy detection logic.", 2005-05-24) added a duplicate entry check on rename_src in order to avoid segfaults; the code at the time was prone to double free()s and an easy way to avoid it was just to turn off rename detection for any duplicate entries. Note that the form of the check was modified two commits ago in this series. Similarly, commit 4d6be03b95 ("diffcore-rename: avoid processing duplicate destinations", 2015-02-26) added a duplicate entry check on rename_dst for the exact same reason -- the code was prone to double free()s, and an easy way to avoid it was just to turn off rename detection entirely. Note that the form of the check was modified in the commit just before this one. In the original code in both places, the code was dealing with individual diff_filespecs and trying to match things up, instead of just keeping the original diff_filepairs around as we do now. The intervening change in structure has fixed the accounting problems and the associated double free()s that used to occur, and thus we already have a better fix. As such, we can remove the band-aid checks for duplicate entries. Due to the last two patches, the diffcore_rename() setup is no longer a sizeable chunk of overall runtime. Thus, in a large rebase of many commits with lots of renames and several optimizations to inexact rename detection, this patch only speeds up the overall code by about half a percent or so and is pretty close to the run-to-run variability making it hard to get an exact measurement. However, with some trace2 regions around the setup code in diffcore_rename() so that I can focus on just it, I measure that this patch consistently saves almost a third of the remaining time spent in diffcore_rename() setup. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-14diffcore-rename: accelerate rename_dst setupLibravatar Elijah Newren1-83/+65
register_rename_src() simply references the passed pair inside rename_src. In contrast, add_rename_dst() did something entirely different for rename_dst. Instead of copying the passed pair, it made a copy of the second diff_filespec from the passed pair, referenced it, and then set the diff_rename_dst.pair field to NULL. Later, when a pairing is found, record_rename_pair() allocated a full diff_filepair via diff_queue() and pointed its src and dst fields at the appropriate diff_filespecs. This contrast between register_rename_src() for the rename_src data structure and add_rename_dst() for the rename_dst data structure is oddly inconsistent and requires more memory and work than necessary. Let's just reference the original diff_filepair in rename_dst as-is, just as we do with rename_src. Add a new rename_dst.is_rename field, since the rename_dst.p field is never NULL unlike the old rename_dst.pair field. Taking advantage of this change and the fact that same-named paths will be adjacent, we can get rid of the sorting of the array and most of the lookups on it, allowing us to instead just append as we go. However, there is one remaining reason to still keep locate_rename_dst(): handling broken pairs (i.e. when break detection is on). Those are somewhat rare, but we can set up a simple strintmap to get the map between the source and the index. Doing that allows us to still have a fast lookup without sorting the rename_dst array. Since the sorting had been done in a weakly quadratic manner, when many renames are involved this time could add up. There is still a strcmp() in add_rename_dst() that I have left in place to make it easier to verify that the algorithm has the same results. This strcmp() is there to check for duplicate destination entries (which was the easiest way at the time to avoid segfaults in the diffcore-rename code when trees had multiple entries at a given path). The underlying double free()s are no longer an issue with the new algorithm, but that can be addressed in a subsequent commit. This patch is being submitted in a different order than its original development, but in a large rebase of many commits with lots of renames and with several optimizations to inexact rename detection, both setup time and write back to output queue time from diffcore_rename() were sizeable chunks of overall runtime. This patch accelerated the setup time by about 65%, and final write back to the output queue time by about 50%, resulting in an overall drop of 3.5% on the execution time of rebasing a few dozen patches. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-14diffcore-rename: simplify and accelerate register_rename_src()Libravatar Elijah Newren1-26/+13
register_rename_src() took pains to create an array in rename_src which was sorted by pathname of the contained diff_filepair. The sorting was entirely unnecessary since callers pass filepairs to us in sorted order. We can simply append to the end of the rename_src array, speeding up diffcore_rename() setup time. Also, note that I dropped the return type on the function since it was unconditionally discarded anyway. This patch is being submitted in a different order than its original development, but in a large rebase of many commits with lots of renames and with several optimizations to inexact rename detection, diffcore_rename() setup time was a sizeable chunk of overall runtime. This patch dropped execution time of rebasing 35 commits with lots of renames by 2% overall. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-14diffcore-rename: reduce jumpiness in progress countersLibravatar Elijah Newren1-2/+3
Inexact rename detection works by comparing all sources to all destinations, computing similarities, and then finding the best matches among those that are sufficiently similar. However, it is preceded by exact rename detection that works by checking if there are files with identical hashes. If exact renames are found, we can exclude some files from inexact rename detection. The inexact rename detection loops over the full set of files, but immediately skips those for which rename_dst[i].is_rename is true and thus doesn't compare any sources to that destination. As such, these paths shouldn't be included in the progress counter. For the eagle eyed, this change hints at an actual optimization -- the first one I presented at Git Merge 2020. I'll be submitting that optimization later, once the basic merge-ort algorithm has merged. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-14diffcore-rename: simplify limit checkLibravatar Elijah Newren1-6/+9
diffcore-rename had two different checks of the form if ((a < limit || b < limit) && a * b <= limit * limit) This can be simplified to if (st_mult(a, b) <= st_mult(limit, limit)) which makes it clearer how we are checking for overflow, and makes it much easier to parse given the drop from 8 to 4 variable appearances. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-14diffcore-rename: avoid usage of global in too_many_rename_candidates()Libravatar Elijah Newren1-12/+12
too_many_rename_candidates() got the number of rename destinations via an argument to the function, but the number of rename sources via a global variable. That felt rather inconsistent. Pass in the number of rename sources as an argument as well. While we are at it... We had a local variable, num_src, that served two purposes. Initially it was set to the global value, but later was used for counting a subset of the number of sources. Since we now have a function argument for the former usage, introduce a clearer variable name for the latter usage. This patch has no behavioral changes; it's just renaming and passing an argument instead of grabbing it from the global namespace. (You may find it easier to view the patch using git diff's --color-words option.) Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-14diffcore-rename: rename num_create to num_destinationsLibravatar Elijah Newren1-12/+13
Our main data structures are rename_src and rename_dst. For counters of these data structures, num_sources and num_destinations seem natural; definitely more so than using num_create for the latter. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-02hashmap: provide deallocation function namesLibravatar Elijah Newren1-1/+1
hashmap_free(), hashmap_free_entries(), and hashmap_free_() have existed for a while, but aren't necessarily the clearest names, especially with hashmap_partial_clear() being added to the mix and lazy-initialization now being supported. Peff suggested we adopt the following names[1]: - hashmap_clear() - remove all entries and de-allocate any hashmap-specific data, but be ready for reuse - hashmap_clear_and_free() - ditto, but free the entries themselves - hashmap_partial_clear() - remove all entries but don't deallocate table - hashmap_partial_clear_and_free() - ditto, but free the entries This patch provides the new names and converts all existing callers over to the new naming scheme. [1] https://lore.kernel.org/git/20201030125059.GA3277724@coredump.intra.peff.net/ Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-07diff: restrict when prefetching occursLibravatar Jonathan Tan1-4/+51
Commit 7fbbcb21b1 ("diff: batch fetching of missing blobs", 2019-04-08) optimized "diff" by prefetching blobs in a partial clone, but there are some cases wherein blobs do not need to be prefetched. In these cases, any command that uses the diff machinery will unnecessarily fetch blobs. diffcore_std() may read blobs when it calls the following functions: (1) diffcore_skip_stat_unmatch() (controlled by the config variable diff.autorefreshindex) (2) diffcore_break() and diffcore_merge_broken() (for break-rewrite detection) (3) diffcore_rename() (for rename detection) (4) diffcore_pickaxe() (for detecting addition/deletion of specified string) Instead of always prefetching blobs, teach diffcore_skip_stat_unmatch(), diffcore_break(), and diffcore_rename() to prefetch blobs upon the first read of a missing object. This covers (1), (2), and (3): to cover the rest, teach diffcore_std() to prefetch if the output type is one that includes blob data (and hence blob data will be required later anyway), or if it knows that (4) will be run. Helped-by: Jeff King <peff@peff.net> Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-07diff: make diff_populate_filespec_options structLibravatar Jonathan Tan1-5/+8
The behavior of diff_populate_filespec() currently can be customized through a bitflag, but a subsequent patch requires it to support a non-boolean option. Replace the bitflag with an options struct. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31sha1-file: pass git_hash_algo to hash_object_file()Libravatar Matheus Tavares1-2/+2
Allow hash_object_file() to work on arbitrary repos by introducing a git_hash_algo parameter. Change callers which have a struct repository pointer in their scope to pass on the git_hash_algo from the said repo. For all other callers, pass on the_hash_algo, which was already being used internally at hash_object_file(). This functionality will be used in the following patch to make check_object_signature() be able to work on arbitrary repos (which, in turn, will be used to fix an inconsistency at object.c:parse_object()). Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-15Merge branch 'ew/hashmap'Libravatar Junio C Hamano1-8/+7
Code clean-up of the hashmap API, both users and implementation. * ew/hashmap: hashmap_entry: remove first member requirement from docs hashmap: remove type arg from hashmap_{get,put,remove}_entry OFFSETOF_VAR macro to simplify hashmap iterators hashmap: introduce hashmap_free_entries hashmap: hashmap_{put,remove} return hashmap_entry * hashmap: use *_entry APIs for iteration hashmap_cmp_fn takes hashmap_entry params hashmap_get{,_from_hash} return "struct hashmap_entry *" hashmap: use *_entry APIs to wrap container_of hashmap_get_next returns "struct hashmap_entry *" introduce container_of macro hashmap_put takes "struct hashmap_entry *" hashmap_remove takes "const struct hashmap_entry *" hashmap_get takes "const struct hashmap_entry *" hashmap_add takes "struct hashmap_entry *" hashmap_get_next takes "const struct hashmap_entry *" hashmap_entry_init takes "struct hashmap_entry *" packfile: use hashmap_entry in delta_base_cache_entry coccicheck: detect hashmap_entry.hash assignment diff: use hashmap_entry_init on moved_entry.ent
2019-10-07OFFSETOF_VAR macro to simplify hashmap iteratorsLibravatar Eric Wong1-1/+1
While we cannot rely on a `__typeof__' operator being portable to use with `offsetof'; we can calculate the pointer offset using an existing pointer and the address of a member using pointer arithmetic for compilers without `__typeof__'. This allows us to simplify usage of hashmap iterator macros by not having to specify a type when a pointer of that type is already given. In the future, list iterator macros (e.g. list_for_each_entry) may also be implemented using OFFSETOF_VAR to save hackers the trouble of using container_of/list_entry macros and without relying on non-portable `__typeof__'. v3: use `__typeof__' to avoid clang warnings Signed-off-by: Eric Wong <e@80x24.org> Reviewed-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07hashmap: introduce hashmap_free_entriesLibravatar Eric Wong1-1/+1
`hashmap_free_entries' behaves like `container_of' and passes the offset of the hashmap_entry struct to the internal `hashmap_free_' function, allowing the function to free any struct pointer regardless of where the hashmap_entry field is located. `hashmap_free' no longer takes any arguments aside from the hashmap itself. Signed-off-by: Eric Wong <e@80x24.org> Reviewed-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07hashmap: use *_entry APIs to wrap container_ofLibravatar Eric Wong1-9/+5
Using `container_of' can be verbose and choosing names for intermediate "struct hashmap_entry" pointers is a hard problem. So introduce "*_entry" APIs inspired by similar linked-list APIs in the Linux kernel. Unfortunately, `__typeof__' is not portable C, so we need an extra parameter to specify the type. Signed-off-by: Eric Wong <e@80x24.org> Reviewed-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07hashmap_get_next returns "struct hashmap_entry *"Libravatar Eric Wong1-4/+7
This is a step towards removing the requirement for hashmap_entry being the first field of a struct. Signed-off-by: Eric Wong <e@80x24.org> Reviewed-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07hashmap_add takes "struct hashmap_entry *"Libravatar Eric Wong1-1/+1
This is less error-prone than "void *" as the compiler now detects invalid types being passed. Signed-off-by: Eric Wong <e@80x24.org> Reviewed-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07hashmap_get_next takes "const struct hashmap_entry *"Libravatar Eric Wong1-1/+1
This is less error-prone than "const void *" as the compiler now detects invalid types being passed. Signed-off-by: Eric Wong <e@80x24.org> Reviewed-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07hashmap_entry_init takes "struct hashmap_entry *"Libravatar Eric Wong1-1/+1
C compilers do type checking to make life easier for us. So rely on that and update all hashmap_entry_init callers to take "struct hashmap_entry *" to avoid future bugs while improving safety and readability. Signed-off-by: Eric Wong <e@80x24.org> Reviewed-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-02diffcore_rename(): use a stable sortLibravatar Johannes Schindelin1-1/+1
During Git's rename detection, the file names are sorted. At the moment, this job is performed by `qsort()`. As that function is not guaranteed to implement a stable sort algorithm, this can lead to inconsistent and/or surprising behavior: a rename might be detected differently depending on the platform where Git was run. The `qsort()` in MS Visual C's runtime does _not_ implement a stable sort algorithm, and it even leads to an inconsistency leading to a test failure in t3030.35 "merge-recursive remembers the names of all base trees": a different code path than on Linux is taken in the rename detection of an ambiguous rename between either `e` to `a` or `a~Temporary merge branch 2_0` to `a` during a recursive merge, unexpectedly resulting in a clean merge. Let's use the stable sort provided by `git_stable_qsort()` to avoid this inconsistency. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-09Merge branch 'jk/oidhash'Libravatar Junio C Hamano1-1/+1
Code clean-up to remove hardcoded SHA-1 hash from many places. * jk/oidhash: hashmap: convert sha1hash() to oidhash() hash.h: move object_id definition from cache.h khash: rename oid helper functions khash: drop sha1-specific map types pack-bitmap: convert khash_sha1 maps into kh_oid_map delta-islands: convert island_marks khash to use oids khash: rename kh_oid_t to kh_oid_set khash: drop broken oid_map typedef object: convert create_object() to use object_id object: convert internal hash_obj() to object_id object: convert lookup_object() to use object_id object: convert lookup_unknown_object() to use object_id pack-objects: convert locate_object_entry_hash() to object_id pack-objects: convert packlist_find() to use object_id pack-bitmap-write: convert some helpers to use object_id upload-pack: rename a "sha1" variable to "oid" describe: fix accidental oid/hash type-punning
2019-06-20hashmap: convert sha1hash() to oidhash()Libravatar Jeff King1-1/+1
There are no callers left of sha1hash() that do not simply pass the "hash" member of a "struct object_id". Let's get rid of the outdated sha1-specific function and provide one that operates on the whole struct (even though the technique, taking the first few bytes of the hash, will remain the same). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-13cleanup: fix possible overflow errors in binary search, part 2Libravatar René Scharfe1-2/+2
Calculating the sum of two array indexes to find the midpoint between them can overflow, i.e. code like this is unsafe for big arrays: mid = (first + last) >> 1; Make sure the intermediate value stays within the boundaries instead, like this: mid = first + ((last - first) >> 1); The loop condition of the binary search makes sure that 'last' is always greater than 'first', so this is safe as long as 'first' is not negative. And that can be verified easily using the pre-context of each change, except for name-hash.c, so add an assertion to that effect there. The unsafe calculations were found with: git grep '(.*+.*) *>> *1' This is a continuation of 19716b21a4 (cleanup: fix possible overflow errors in binary search, 2017-10-08). Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-19Merge branch 'nd/the-index'Libravatar Junio C Hamano1-13/+22
Various codepaths in the core-ish part learn to work on an arbitrary in-core index structure, not necessarily the default instance "the_index". * nd/the-index: (23 commits) revision.c: reduce implicit dependency the_repository revision.c: remove implicit dependency on the_index ws.c: remove implicit dependency on the_index tree-diff.c: remove implicit dependency on the_index submodule.c: remove implicit dependency on the_index line-range.c: remove implicit dependency on the_index userdiff.c: remove implicit dependency on the_index rerere.c: remove implicit dependency on the_index sha1-file.c: remove implicit dependency on the_index patch-ids.c: remove implicit dependency on the_index merge.c: remove implicit dependency on the_index merge-blobs.c: remove implicit dependency on the_index ll-merge.c: remove implicit dependency on the_index diff-lib.c: remove implicit dependency on the_index read-cache.c: remove implicit dependency on the_index diff.c: remove implicit dependency on the_index grep.c: remove implicit dependency on the_index diff.c: remove the_index dependency in textconv() functions blame.c: rename "repo" argument to "r" combine-diff.c: remove implicit dependency on the_index ...
2018-09-21diff.c: reduce implicit dependency on the_indexLibravatar Nguyễn Thái Ngọc Duy1-13/+22
diff and textconv code has so widespread use that it's hard to simply update their api and all call sites at once because it would result in a big patch. For now reduce the_index references to two places: diff_setup() and fill_textconv(). Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29convert "oidcmp() != 0" to "!oideq()"Libravatar Jeff King1-1/+1
This is the flip side of the previous two patches: checking for a non-zero oidcmp() can be more strictly expressed as inequality. Like those patches, we write "!= 0" in the coccinelle transformation, which covers by isomorphism the more common: if (oidcmp(E1, E2)) As with the previous two patches, this patch can be achieved almost entirely by running "make coccicheck"; the only differences are manual line-wrap fixes to match the original code. There is one thing to note for anybody replicating this, though: coccinelle 1.0.4 seems to miss the case in builtin/tag.c, even though it's basically the same as all the others. Running with 1.0.7 does catch this, so presumably it's just a coccinelle bug that was fixed in the interim. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-16object-store: move object access functions to object-store.hLibravatar Stefan Beller1-0/+1
This should make these functions easier to find and cache.h less overwhelming to read. In particular, this moves: - read_object_file - oid_object_info - write_object_file As a result, most of the codebase needs to #include object-store.h. In this patch the #include is only added to files that would fail to compile otherwise. It would be better to #include wherever identifiers from the header are used. That can happen later when we have better tooling for it. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-15Merge branch 'po/object-id'Libravatar Junio C Hamano1-2/+2
Conversion from uchar[20] to struct object_id continues. * po/object-id: sha1_file: rename hash_sha1_file_literally sha1_file: convert write_loose_object to object_id sha1_file: convert force_object_loose to object_id sha1_file: convert write_sha1_file to object_id notes: convert write_notes_tree to object_id notes: convert combine_notes_* to object_id commit: convert commit_tree* to object_id match-trees: convert splice_tree to object_id cache: clear whole hash buffer with oidclr sha1_file: convert hash_sha1_file to object_id dir: convert struct sha1_stat to use object_id sha1_file: convert pretend_sha1_file to object_id
2018-01-30sha1_file: convert hash_sha1_file to object_idLibravatar Patryk Obara1-2/+2
Convert the declaration and definition of hash_sha1_file to use struct object_id and adjust all function calls. Rename this function to hash_object_file. Signed-off-by: Patryk Obara <patryk.obara@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-22Use MOVE_ARRAYLibravatar SZEDER Gábor1-4/+4
Use the helper macro MOVE_ARRAY to move arrays. This is shorter and safer, as it automatically infers the size of elements. Patch generated by Coccinelle and contrib/coccinelle/array.cocci in Travis CI's static analysis build job. Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-02diffcore-rename: make diff-tree -l0 mean -l<large>Libravatar Jonathan Tan1-0/+2
In the documentation of diff-tree, it is stated that the -l option "prevents rename/copy detection from running if the number of rename/copy targets exceeds the specified number". The documentation does not mention any special handling for the number 0, but the implementation before commit 9f7e4bfa3b ("diff: remove silent clamp of renameLimit", 2017-11-13) treated 0 as a special value indicating that the rename limit is to be a very large number instead. The commit 9f7e4bfa3b changed that behavior, treating 0 as 0. Revert this behavior to what it was previously. This allows existing scripts and tools that use "-l0" to continue working. The alternative (to have "-l0" suppress rename detection) is probably much less useful, since users can just refrain from specifying -M and/or -C to have the same effect. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Reviewed-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-15diff: remove silent clamp of renameLimitLibravatar Elijah Newren1-7/+4
In commit 0024a5492 (Fix the rename detection limit checking; 2007-09-14), the renameLimit was clamped to 32767. This appears to have been to simply avoid integer overflow in the following computation: num_create * num_src <= rename_limit * rename_limit although it also could be viewed as a hardcoded bound on the amount of CPU time we're willing to allow users to tell git to spend on handling renames. An upper bound may make sense, but unfortunately this upper bound was neither communicated to the users, nor documented anywhere. Although large limits can make things slow, we have users who would be ecstatic to have a small five file change be correctly cherry picked even if they have to manually specify a large limit and wait ten minutes for the renames to be detected. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-15progress: fix progress meters when dealing with lots of workLibravatar Elijah Newren1-2/+2
The possibility of setting merge.renameLimit beyond 2^16 raises the possibility that the values passed to progress can exceed 2^32. Use uint64_t, because it "ought to be enough for anybody". :-) Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-01diff: make struct diff_flags members lowercaseLibravatar Brandon Williams1-3/+3
Now that the flags stored in struct diff_flags are being accessed directly and not through macros, change all struct members from being uppercase to lowercase. This conversion is done using the following semantic patch: @@ expression E; @@ - E.RECURSIVE + E.recursive @@ expression E; @@ - E.TREE_IN_RECURSIVE + E.tree_in_recursive @@ expression E; @@ - E.BINARY + E.binary @@ expression E; @@ - E.TEXT + E.text @@ expression E; @@ - E.FULL_INDEX + E.full_index @@ expression E; @@ - E.SILENT_ON_REMOVE + E.silent_on_remove @@ expression E; @@ - E.FIND_COPIES_HARDER + E.find_copies_harder @@ expression E; @@ - E.FOLLOW_RENAMES + E.follow_renames @@ expression E; @@ - E.RENAME_EMPTY + E.rename_empty @@ expression E; @@ - E.HAS_CHANGES + E.has_changes @@ expression E; @@ - E.QUICK + E.quick @@ expression E; @@ - E.NO_INDEX + E.no_index @@ expression E; @@ - E.ALLOW_EXTERNAL + E.allow_external @@ expression E; @@ - E.EXIT_WITH_STATUS + E.exit_with_status @@ expression E; @@ - E.REVERSE_DIFF + E.reverse_diff @@ expression E; @@ - E.CHECK_FAILED + E.check_failed @@ expression E; @@ - E.RELATIVE_NAME + E.relative_name @@ expression E; @@ - E.IGNORE_SUBMODULES + E.ignore_submodules @@ expression E; @@ - E.DIRSTAT_CUMULATIVE + E.dirstat_cumulative @@ expression E; @@ - E.DIRSTAT_BY_FILE + E.dirstat_by_file @@ expression E; @@ - E.ALLOW_TEXTCONV + E.allow_textconv @@ expression E; @@ - E.TEXTCONV_SET_VIA_CMDLINE + E.textconv_set_via_cmdline @@ expression E; @@ - E.DIFF_FROM_CONTENTS + E.diff_from_contents @@ expression E; @@ - E.DIRTY_SUBMODULES + E.dirty_submodules @@ expression E; @@ - E.IGNORE_UNTRACKED_IN_SUBMODULES + E.ignore_untracked_in_submodules @@ expression E; @@ - E.IGNORE_DIRTY_SUBMODULES + E.ignore_dirty_submodules @@ expression E; @@ - E.OVERRIDE_SUBMODULE_CONFIG + E.override_submodule_config @@ expression E; @@ - E.DIRSTAT_BY_LINE + E.dirstat_by_line @@ expression E; @@ - E.FUNCCONTEXT + E.funccontext @@ expression E; @@ - E.PICKAXE_IGNORE_CASE + E.pickaxe_ignore_case @@ expression E; @@ - E.DEFAULT_FOLLOW_RENAMES + E.default_follow_renames Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-01diff: remove DIFF_OPT_TST macroLibravatar Brandon Williams1-3/+3
Remove the `DIFF_OPT_TST` macro and instead access the flags directly. This conversion is done using the following semantic patch: @@ expression E; identifier fld; @@ - DIFF_OPT_TST(&E, fld) + E.flags.fld @@ type T; T *ptr; identifier fld; @@ - DIFF_OPT_TST(ptr, fld) + ptr->flags.fld Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-19progress: simplify "delayed" progress APILibravatar Junio C Hamano1-2/+2
We used to expose the full power of the delayed progress API to the callers, so that they can specify, not just the message to show and expected total amount of work that is used to compute the percentage of work performed so far, the percent-threshold parameter P and the delay-seconds parameter N. The progress meter starts to show at N seconds into the operation only if we have not yet completed P per-cent of the total work. Most callers used either (0%, 2s) or (50%, 1s) as (P, N), but there are oddballs that chose more random-looking values like 95%. For a smoother workload, (50%, 1s) would allow us to start showing the progress meter earlier than (0%, 2s), while keeping the chance of not showing progress meter for long running operation the same as the latter. For a task that would take 2s or more to complete, it is likely that less than half of it would complete within the first second, if the workload is smooth. But for a spiky workload whose earlier part is easier, such a setting is likely to fail to show the progress meter entirely and (0%, 2s) is more appropriate. But that is merely a theory. Realistically, it is of dubious value to ask each codepath to carefully consider smoothness of their workload and specify their own setting by passing two extra parameters. Let's simplify the API by dropping both parameters and have everybody use (0%, 2s). Oh, by the way, the percent-threshold parameter and the structure member were consistently misspelled, which also is now fixed ;-) Helped-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-30hashmap.h: compare function has access to a data fieldLibravatar Stefan Beller1-1/+1
When using the hashmap a common need is to have access to caller provided data in the compare function. A couple of times we abuse the keydata field to pass in the data needed. This happens for example in patch-ids.c. This patch changes the function signature of the compare function to have one more void pointer available. The pointer given for each invocation of the compare function must be defined in the init function of the hashmap and is just passed through. Documentation of this new feature is deferred to a later patch. This is a rather mechanical conversion, just adding the new pass-through parameter. However while at it improve the naming of the fields of all compare functions used by hashmaps by ensuring unused parameters are prefixed with 'unused_' and naming the parameters what they are (instead of 'unused' make it 'unused_keydata'). Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-24Merge branch 'ab/free-and-null'Libravatar Junio C Hamano1-4/+2
A common pattern to free a piece of memory and assign NULL to the pointer that used to point at it has been replaced with a new FREE_AND_NULL() macro. * ab/free-and-null: *.[ch] refactoring: make use of the FREE_AND_NULL() macro coccinelle: make use of the "expression" FREE_AND_NULL() rule coccinelle: add a rule to make "expression" code use FREE_AND_NULL() coccinelle: make use of the "type" FREE_AND_NULL() rule coccinelle: add a rule to make "type" code use FREE_AND_NULL() git-compat-util: add a FREE_AND_NULL() wrapper around free(ptr); ptr = NULL
2017-06-16coccinelle: make use of the "type" FREE_AND_NULL() ruleLibravatar Ævar Arnfjörð Bjarmason1-4/+2
Apply the result of the just-added coccinelle rule. This manually excludes a few occurrences, mostly things that resulted in many FREE_AND_NULL() on one line, that'll be manually fixed in a subsequent change. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-05diffcore-rename: use is_empty_blob_oidLibravatar Brandon Williams1-2/+2
Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-02diff: convert fill_filespec to struct object_idLibravatar Brandon Williams1-1/+1
Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-11-17Merge branch 'tk/diffcore-delta-remove-unused'Libravatar Junio C Hamano1-4/+0
Code cleanup. * tk/diffcore-delta-remove-unused: diffcore-delta: remove unused parameter to diffcore_count_changes()
2016-11-14diffcore-delta: remove unused parameter to diffcore_count_changes()Libravatar Tobias Klauser1-4/+0
The delta_limit parameter to diffcore_count_changes() has been unused since commit ba23bbc8e ("diffcore-delta: make change counter to byte oriented again.", 2006-03-04). Remove the parameter and adjust all callers. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>