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2018-10-26Merge branch 'sg/split-index-racefix'Libravatar Junio C Hamano1-0/+2
The codepath to support the experimental split-index mode had remaining "racily clean" issues fixed. * sg/split-index-racefix: split-index: BUG() when cache entry refers to non-existing shared entry split-index: smudge and add racily clean cache entries to split index split-index: don't compare cached data of entries already marked for split index split-index: count the number of deleted entries t1700-split-index: date back files to avoid racy situations split-index: add tests to demonstrate the racy split index problem t1700-split-index: document why FSMONITOR is disabled in this test script
2018-10-19Merge branch 'nd/status-refresh-progress'Libravatar Junio C Hamano1-2/+5
"git status" learns to show progress bar when refreshing the index takes a long time. * nd/status-refresh-progress: status: show progress bar if refreshing the index takes too long
2018-10-19Merge branch 'nd/the-index'Libravatar Junio C Hamano1-6/+8
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 ...
2018-10-12split-index: smudge and add racily clean cache entries to split indexLibravatar SZEDER Gábor1-0/+2
Ever since the split index feature was introduced [1], refreshing a split index is prone to a variant of the classic racy git problem. Consider the following sequence of commands updating the split index when the shared index contains a racily clean cache entry, i.e. an entry whose cached stat data matches with the corresponding file in the worktree and the cached mtime matches that of the index: echo "cached content" >file git update-index --split-index --add file echo "dirty worktree" >file # size stays the same! # ... wait ... git update-index --add other-file Normally, when a non-split index is updated, then do_write_index() (the function responsible for writing all kinds of indexes, "regular", split, and shared) recognizes racily clean cache entries, and writes them with smudged stat data, i.e. with file size set to 0. When subsequent git commands read the index, they will notice that the smudged stat data doesn't match with the file in the worktree, and then go on to check the file's content and notice its dirtiness. In the above example, however, in the second 'git update-index' prepare_to_write_split_index() decides which cache entries stored only in the shared index should be replaced in the new split index. Alas, this function never looks out for racily clean cache entries, and since the file's stat data in the worktree hasn't changed since the shared index was written, it won't be replaced in the new split index. Consequently, do_write_index() doesn't even get this racily clean cache entry, and can't smudge its stat data. Subsequent git commands will then see that the index has more recent mtime than the file and that the (not smudged) cached stat data still matches with the file in the worktree, and, ultimately, will erroneously consider the file clean. Modify prepare_to_write_split_index() to recognize racily clean cache entries, and mark them to be added to the split index. Note that there are two places where it should check raciness: first those cache entries that are only stored in the shared index, and then those that have been copied by unpack_trees() from the shared index while it constructed a new index. This way do_write_index() will get these racily clean cache entries as well, and will then write them with smudged stat data to the new split index. This change makes all tests in 't1701-racy-split-index.sh' pass, so flip the two 'test_expect_failure' tests to success. Also add the '#' (as in nr. of trial) to those tests' description that were omitted when the tests expected failure. Note that after this change if the index is split when it contains a racily clean cache entry, then a smudged cache entry will be written both to the new shared and to the new split indexes. This doesn't affect regular git commands: as far as they are concerned this is just an entry in the split index replacing an outdated entry in the shared index. It did affect a few tests in 't1700-split-index.sh', though, because they actually check which entries are stored in the split index; a previous patch in this series has already made the necessary adjustments in 't1700'. And racily clean cache entries and index splitting are rare enough to not worry about the resulting duplicated smudged cache entries, and the additional complexity required to prevent them is not worth it. Several tests failed occasionally when the test suite was run with 'GIT_TEST_SPLIT_INDEX=yes'. Here are those that I managed to trace back to this racy split index problem, starting with those failing more frequently, with a link to a failing Travis CI build job for each. The highlighted line [2] shows when the racy file was written, which is not always in the failing test but in a preceeding setup test. t3903-stash.sh: https://travis-ci.org/git/git/jobs/385542084#L5858 t4024-diff-optimize-common.sh: https://travis-ci.org/git/git/jobs/386531969#L3174 t4015-diff-whitespace.sh: https://travis-ci.org/git/git/jobs/360797600#L8215 t2200-add-update.sh: https://travis-ci.org/git/git/jobs/382543426#L3051 t0090-cache-tree.sh: https://travis-ci.org/git/git/jobs/416583010#L3679 There might be others, e.g. perhaps 't1000-read-tree-m-3way.sh' and others using 'lib-read-tree-m-3way.sh', but I couldn't confirm yet. [1] In the branch leading to the merge commit v2.1.0-rc0~45 (Merge branch 'nd/split-index', 2014-07-16). [2] Note that those highlighted lines are in the 'after failure' fold, and your browser might unhelpfully fold it up before you could take a good look. Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21ws.c: remove implicit dependency on the_indexLibravatar Nguyễn Thái Ngọc Duy1-1/+1
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21sha1-file.c: remove implicit dependency on the_indexLibravatar Nguyễn Thái Ngọc Duy1-2/+2
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21merge.c: remove implicit dependency on the_indexLibravatar Nguyễn Thái Ngọc Duy1-2/+4
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21read-cache.c: remove 'const' from index_has_changes()Libravatar Nguyễn Thái Ngọc Duy1-1/+1
This function calls do_diff_cache() which eventually needs to set this "istate" to unpack_options->src_index [1]. This is an unfortunate fact that unpack_trees() _will_ update [2] src_index so we can't really pass a const index_state there. Just remove 'const'. [1] Right now diff_cache() in diff-lib.c assigns the_index to src_index. But the plan is to get rid of the_index, so it should be 'istate' from here that gets assigned to src_index. [2] Some transient bits in the source index are touched. Optional extensions can also be removed. But other than that the source tree should still be valid. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-17Merge branch 'jk/cocci'Libravatar Junio C Hamano1-6/+16
spatch transformation to replace boolean uses of !hashcmp() to newly introduced oideq() is added, and applied, to regain performance lost due to support of multiple hash algorithms. * jk/cocci: show_dirstat: simplify same-content check read-cache: use oideq() in ce_compare functions convert hashmap comparison functions to oideq() convert "hashcmp() != 0" to "!hasheq()" convert "oidcmp() != 0" to "!oideq()" convert "hashcmp() == 0" to hasheq() convert "oidcmp() == 0" to oideq() introduce hasheq() and oideq() coccinelle: use <...> for function exclusion
2018-09-17Merge branch 'nd/clone-case-smashing-warning'Libravatar Junio C Hamano1-0/+1
Running "git clone" against a project that contain two files with pathnames that differ only in cases on a case insensitive filesystem would result in one of the files lost because the underlying filesystem is incapable of holding both at the same time. An attempt is made to detect such a case and warn. * nd/clone-case-smashing-warning: clone: report duplicate entries on case-insensitive filesystems
2018-09-17status: show progress bar if refreshing the index takes too longLibravatar Nguyễn Thái Ngọc Duy1-2/+5
Refreshing the index is usually very fast, but it can still take a long time sometimes. Cold cache is one. Or copying a repo to a new place (*). It's good to show something to let the user know "git status" is not hanging, it's just busy doing something. (*) In this case, all stat info in the index becomes invalid and git falls back to rehashing all file content to see if there's any difference between updating stat info in the index. This is quite expensive. Even with a repo as small as git.git, it takes 3 seconds. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29convert "hashcmp() == 0" to hasheq()Libravatar Jeff King1-4/+4
This is the partner patch to the previous one, but covering the "hash" variants instead of "oid". Note that our coccinelle rule is slightly more complex to avoid triggering the call in hasheq(). I didn't bother to add a new rule to convert: - hasheq(E1->hash, E2->hash) + oideq(E1, E2) Since these are new functions, there won't be any such existing callers. And since most of the code is already using oideq, we're not likely to introduce new ones. We might still see "!hashcmp(E1->hash, E2->hash)" from topics in flight. But because our new rule comes after the existing ones, that should first get converted to "!oidcmp(E1, E2)" and then to "oideq(E1, E2)". Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29convert "oidcmp() == 0" to oideq()Libravatar Jeff King1-2/+2
Using the more restrictive oideq() should, in the long run, give the compiler more opportunities to optimize these callsites. For now, this conversion should be a complete noop with respect to the generated code. The result is also perhaps a little more readable, as it avoids the "zero is equal" idiom. Since it's so prevalent in C, I think seasoned programmers tend not to even notice it anymore, but it can sometimes make for awkward double negations (e.g., we can drop a few !!oidcmp() instances here). This patch was generated almost entirely by the included coccinelle patch. This mechanical conversion should be completely safe, because we check explicitly for cases where oidcmp() is compared to 0, which is what oideq() is doing under the hood. Note that we don't have to catch "!oidcmp()" separately; coccinelle's standard isomorphisms make sure the two are treated equivalently. I say "almost" because I did hand-edit the coccinelle output to fix up a few style violations (it mostly keeps the original formatting, but sometimes unwraps long lines). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29introduce hasheq() and oideq()Libravatar Jeff King1-0/+10
The main comparison functions we provide for comparing object ids are hashcmp() and oidcmp(). These are more flexible than a strict equality check, since they also express ordering. That makes them useful for sorting and binary searching. However, it also makes them potentially slower than a strict equality check. Consider this C code, which is traditionally what our hashcmp has looked like: #include <string.h> int hashcmp(const unsigned char *a, const unsigned char *b) { return memcmp(a, b, 20); } Compiling with "gcc -O2 -S -fverbose-asm", the generated assembly shows that we actually call memcmp(). But if we change this to a strict equality check: return !memcmp(a, b, 20); we get a faster inline version: movq (%rdi), %rax # MEM[(void *)a_4(D)], MEM[(void *)a_4(D)] movq 8(%rdi), %rdx # MEM[(void *)a_4(D)], tmp101 xorq (%rsi), %rax # MEM[(void *)b_5(D)], tmp94 xorq 8(%rsi), %rdx # MEM[(void *)b_5(D)], tmp93 orq %rax, %rdx # tmp94, tmp93 jne .L2 #, movl 16(%rsi), %eax # MEM[(void *)b_5(D)], tmp104 cmpl %eax, 16(%rdi) # tmp104, MEM[(void *)a_4(D)] je .L5 #, Obviously our hashcmp() doesn't include the "!". But because it's an inline function, optimizing compilers are able to see "!hashcmp(a,b)" in calling code and take advantage of this case. So there has been no value thus far in introducing a more restricted interface for doing strict equality checks. But as Git learns about more values for the_hash_algo, our hashcmp() will grow more complicated and may even delegate at runtime to functions optimized specifically for that hash size. That breaks the inline connection we have, and the compiler will have to assume that the caller really cares about the sign and magnitude of the memcmp() result, even though the vast majority don't. We can solve that by introducing a hasheq() function (and matching oideq() wrapper), which callers can use to make it clear that they only care about equality. For now, the implementation will literally be "!hashcmp()", but it frees us up later to introduce code optimized specifically for the equality check. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-23hashcmp: assert constant hash sizeLibravatar Jeff King1-0/+10
Prior to 509f6f62a4 (cache: update object ID functions for the_hash_algo, 2018-07-16), hashcmp() called memcmp() with a constant size of 20 bytes. Some compilers were able to turn that into a few quad-word comparisons, which is faster than actually calling memcmp(). In 509f6f62a4, we started using the_hash_algo->rawsz instead. Even though this will always be 20, the compiler doesn't know that while inlining hashcmp() and ends up just generating a call to memcmp(). Eventually we'll have to deal with multiple hash sizes, but for the upcoming v2.19, we can restore some of the original performance by asserting on the size. That gives the compiler enough information to know that the memcmp will always be called with a length of 20, and it performs the same optimization. Here are numbers for p0001.2 run against linux.git on a few versions. This is using -O2 with gcc 8.2.0. Test v2.18.0 v2.19.0-rc0 HEAD ------------------------------------------------------------------------------ 0001.2: 34.24(33.81+0.43) 34.83(34.42+0.40) +1.7% 33.90(33.47+0.42) -1.0% You can see that v2.19 is a little slower than v2.18. This commit ended up slightly faster than v2.18, but there's a fair bit of run-to-run noise (the generated code in the two cases is basically the same). This patch does seem to be consistently 1-2% faster than v2.19. I tried changing hashcpy(), which was also touched by 509f6f62a4, in the same way, but couldn't measure any speedup. Which makes sense, at least for this workload. A traversal of the whole commit graph requires looking up every entry of every tree via lookup_object(). That's many multiples of the numbers of objects in the repository (most of the lookups just return "yes, we already saw that object"). [jn: verified using "make object.s" that the memcmp call goes away.] Reported-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Jeff King <peff@peff.net Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-20Merge branch 'en/incl-forward-decl'Libravatar Junio C Hamano1-10/+0
Code hygiene improvement for the header files. * en/incl-forward-decl: Remove forward declaration of an enum compat/precompose_utf8.h: use more common include guard style urlmatch.h: fix include guard Move definition of enum branch_track from cache.h to branch.h alloc: make allocate_alloc_state and clear_alloc_state more consistent Add missing includes and forward declarations
2018-08-20Merge branch 'jk/for-each-object-iteration'Libravatar Junio C Hamano1-56/+0
The API to iterate over all objects learned to optionally list objects in the order they appear in packfiles, which helps locality of access if the caller accesses these objects while as objects are enumerated. * jk/for-each-object-iteration: for_each_*_object: move declarations to object-store.h cat-file: use a single strbuf for all output cat-file: split batch "buf" into two variables cat-file: use oidset check-and-insert cat-file: support "unordered" output for --batch-all-objects cat-file: rename batch_{loose,packed}_object callbacks t1006: test cat-file --batch-all-objects with duplicates for_each_packed_object: support iterating in pack-order for_each_*_object: give more comprehensive docstrings for_each_*_object: take flag arguments as enum for_each_*_object: store flag definitions in a single location
2018-08-17clone: report duplicate entries on case-insensitive filesystemsLibravatar Duy Nguyen1-0/+1
Paths that only differ in case work fine in a case-sensitive filesystems, but if those repos are cloned in a case-insensitive one, you'll get problems. The first thing to notice is "git status" will never be clean with no indication what exactly is "dirty". This patch helps the situation a bit by pointing out the problem at clone time. Even though this patch talks about case sensitivity, the patch makes no assumption about folding rules by the filesystem. It simply observes that if an entry has been already checked out at clone time when we're about to write a new path, some folding rules are behind this. In the case that we can't rely on filesystem (via inode number) to do this check, fall back to fspathcmp() which is not perfect but should not give false positives. This patch is tested with vim-colorschemes and Sublime-Gitignore repositories on a JFS partition with case insensitive support on Linux. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-15Merge branch 'js/vscode'Libravatar Junio C Hamano1-11/+13
Add a script (in contrib/) to help users of VSCode work better with our codebase. * js/vscode: vscode: let cSpell work on commit messages, too vscode: add a dictionary for cSpell vscode: use 8-space tabs, no trailing ws, etc for Git's source code vscode: wrap commit messages at column 72 by default vscode: only overwrite C/C++ settings mingw: define WIN32 explicitly cache.h: extract enum declaration from inside a struct declaration vscode: hard-code a couple defines contrib: add a script to initialize VS Code configuration
2018-08-15Merge branch 'jk/core-use-replace-refs'Libravatar Junio C Hamano1-4/+2
A new configuration variable core.usereplacerefs has been added, primarily to help server installations that want to ignore the replace mechanism altogether. * jk/core-use-replace-refs: add core.usereplacerefs config option check_replace_refs: rename to read_replace_refs check_replace_refs: fix outdated comment
2018-08-15Move definition of enum branch_track from cache.h to branch.hLibravatar Elijah Newren1-10/+0
'branch_track' feels more closely related to branching, and it is needed later in branch.h; rather than #include'ing cache.h in branch.h for this small enum, just move the enum and the external declaration for git_branch_track to branch.h. Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-14for_each_*_object: move declarations to object-store.hLibravatar Jeff King1-75/+0
The for_each_loose_object() and for_each_packed_object() functions are meant to be part of a unified interface: they use the same set of for_each_object_flags, and it's not inconceivable that we might one day add a single for_each_object() wrapper around them. Let's put them together in a single file, so we can avoid awkwardness like saying "the flags for this function are over in cache.h". Moving the loose functions to packfile.h is silly. Moving the packed functions to cache.h works, but makes the "cache.h is a kitchen sink" problem worse. The best place is the recently-created object-store.h, since these are quite obviously related to object storage. The for_each_*_in_objdir() functions do not use the same flags, but they are logically part of the same interface as for_each_loose_object(), and share callback signatures. So we'll move those, as well, as they also make sense in object-store.h. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-13for_each_packed_object: support iterating in pack-orderLibravatar Jeff King1-0/+5
We currently iterate over objects within a pack in .idx order, which uses the object hashes. That means that it is effectively random with respect to the location of the object within the pack. If you're going to access the actual object data, there are two reasons to move linearly through the pack itself: 1. It improves the locality of access in the packfile. In the cold-cache case, this may mean fewer disk seeks, or better usage of disk cache. 2. We store related deltas together in the packfile. Which means that the delta base cache can operate much more efficiently if we visit all of those related deltas in sequence, as the earlier items are likely to still be in the cache. Whereas if we visit the objects in random order, our cache entries are much more likely to have been evicted by unrelated deltas in the meantime. So in general, if you're going to access the object contents pack order is generally going to end up more efficient. But if you're simply generating a list of object names, or if you're going to end up sorting the result anyway, you're better off just using the .idx order, as finding the pack order means generating the in-memory pack-revindex. According to the numbers in 8b8dfd5132 (pack-revindex: radix-sort the revindex, 2013-07-11), that takes about 200ms for linux.git, and 20ms for git.git (those numbers are a few years old but are still a good ballpark). That makes it a good optimization for some cases (we can save tens of seconds in git.git by having good locality of delta access, for a 20ms cost), but a bad one for others (e.g., right now "cat-file --batch-all-objects --batch-check="%(objectname)" is 170ms in git.git, so adding 20ms to that is noticeable). Hence this patch makes it an optional flag. You can't actually do any interesting timings yet, as it's not plumbed through to any user-facing tools like cat-file. That will come in a later patch. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-13for_each_*_object: give more comprehensive docstringsLibravatar Jeff King1-3/+5
We already mention the local/alternate behavior of these functions, but we can help clarify a few other behaviors: - there's no need to mention LOCAL_ONLY specifically, since we already reference the flags by type (and as we add more flags, we don't want to have to mention each) - clarify that reachability doesn't matter here; this is all accessible objects - what ordering/uniqueness guarantees we give - how pack-specific flags are handled for the loose case Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-13for_each_*_object: take flag arguments as enumLibravatar Jeff King1-1/+2
It's not wrong to pass our flags in an "unsigned", as we know it will be at least as large as the enum. However, using the enum in the declaration makes it more obvious where to find the list of flags. While we're here, let's also drop the "extern" noise-words from the declarations, per our modern coding style. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-13for_each_*_object: store flag definitions in a single locationLibravatar Jeff King1-1/+12
These flags were split between cache.h and packfile.h, because some of the flags apply only to packs. However, they share a single numeric namespace, since both are respected for the packed variant. Let's make sure they're defined together so that nobody accidentally adds a new flag in one location that duplicates the other. While we're here, let's also put them in an enum (which helps debugger visibility) and use "(1<<n)" rather than counting powers of 2 manually. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-02Merge branch 'jt/commit-graph-per-object-store'Libravatar Junio C Hamano1-1/+0
The singleton commit-graph in-core instance is made per in-core repository instance. * jt/commit-graph-per-object-store: commit-graph: add repo arg to graph readers commit-graph: store graph in struct object_store commit-graph: add free_commit_graph commit-graph: add missing forward declaration object-store: add missing include commit-graph: refactor preparing commit graph
2018-08-02Merge branch 'en/dirty-merge-fixes'Libravatar Junio C Hamano1-6/+10
The recursive merge strategy did not properly ensure there was no change between HEAD and the index before performing its operation, which has been corrected. * en/dirty-merge-fixes: merge: fix misleading pre-merge check documentation merge-recursive: enforce rule that index matches head before merging t6044: add more testcases with staged changes before a merge is invoked merge-recursive: fix assumption that head tree being merged is HEAD merge-recursive: make sure when we say we abort that we actually abort t6044: add a testcase for index matching head, when head doesn't match HEAD t6044: verify that merges expected to abort actually abort index_has_changes(): avoid assuming operating on the_index read-cache.c: move index_has_changes() from merge.c
2018-08-02Merge branch 'jm/cache-entry-from-mem-pool'Libravatar Junio C Hamano1-2/+62
For a large tree, the index needs to hold many cache entries allocated on heap. These cache entries are now allocated out of a dedicated memory pool to amortize malloc(3) overhead. * jm/cache-entry-from-mem-pool: block alloc: add validations around cache_entry lifecyle block alloc: allocate cache entries from mem_pool mem-pool: fill out functionality mem-pool: add life cycle management functions mem-pool: only search head block for available space block alloc: add lifecycle APIs for cache_entry structs read-cache: teach make_cache_entry to take object_id read-cache: teach refresh_cache_entry to take istate
2018-08-02Merge branch 'bc/object-id'Libravatar Junio C Hamano1-3/+3
Conversion from uchar[40] to struct object_id continues. * bc/object-id: pretty: switch hard-coded constants to the_hash_algo sha1-file: convert constants to uses of the_hash_algo log-tree: switch GIT_SHA1_HEXSZ to the_hash_algo->hexsz diff: switch GIT_SHA1_HEXSZ to use the_hash_algo builtin/merge-recursive: make hash independent builtin/merge: switch to use the_hash_algo builtin/fmt-merge-msg: make hash independent builtin/update-index: simplify parsing of cacheinfo builtin/update-index: convert to using the_hash_algo refs/files-backend: use the_hash_algo for writing refs sha1-name: use the_hash_algo when parsing object names strbuf: allocate space with GIT_MAX_HEXSZ commit: express tree entry constants in terms of the_hash_algo hex: switch to using the_hash_algo tree-walk: replace hard-coded constants with the_hash_algo cache: update object ID functions for the_hash_algo
2018-07-30cache.h: extract enum declaration from inside a struct declarationLibravatar Johannes Schindelin1-11/+13
While it is technically possible, it is confusing. Not only the user, but also VS Code's intellisense. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-18check_replace_refs: rename to read_replace_refsLibravatar Jeff King1-1/+1
This was added as a NEEDSWORK in c3c36d7de2 (replace-object: check_replace_refs is safe in multi repo environment, 2018-04-11), waiting for a calmer period. Since doing so now doesn't conflict with anything in 'pu', it seems as good a time as any. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-18check_replace_refs: fix outdated commentLibravatar Jeff King1-3/+1
Commit afc711b8e1 (rename read_replace_refs to check_replace_refs, 2014-02-18) added a comment mentioning that check_replace_refs is set in two ways: - from user intent via --no-replace-objects, etc - after seeing there are no replace refs to respect Since c3c36d7de2 (replace-object: check_replace_refs is safe in multi repo environment, 2018-04-11) the second is no longer true. Let's drop that part of the comment. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-18Merge branch 'sb/object-store-grafts'Libravatar Junio C Hamano1-118/+1
The conversion to pass "the_repository" and then "a_repository" throughout the object access API continues. * sb/object-store-grafts: commit: allow lookup_commit_graft to handle arbitrary repositories commit: allow prepare_commit_graft to handle arbitrary repositories shallow: migrate shallow information into the object parser path.c: migrate global git_path_* to take a repository argument cache: convert get_graft_file to handle arbitrary repositories commit: convert read_graft_file to handle arbitrary repositories commit: convert register_commit_graft to handle arbitrary repositories commit: convert commit_graft_pos() to handle arbitrary repositories shallow: add repository argument to is_repository_shallow shallow: add repository argument to check_shallow_file_for_update shallow: add repository argument to register_shallow shallow: add repository argument to set_alternate_shallow_file commit: add repository argument to lookup_commit_graft commit: add repository argument to prepare_commit_graft commit: add repository argument to read_graft_file commit: add repository argument to register_commit_graft commit: add repository argument to commit_graft_pos object: move grafts to object parser object-store: move object access functions to object-store.h
2018-07-17commit-graph: add repo arg to graph readersLibravatar Jonathan Tan1-1/+0
Add a struct repository argument to the functions in commit-graph.h that read the commit graph. (This commit does not affect functions that write commit graphs.) Because the commit graph functions can now read the commit graph of any repository, the global variable core_commit_graph has been removed. Instead, the config option core.commitGraph is now read on the first time in a repository that a commit is attempted to be parsed using its commit graph. This commit includes a test that exercises the functionality on an arbitrary repository that is not the_repository. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-16cache: update object ID functions for the_hash_algoLibravatar brian m. carlson1-3/+3
Most of our code has been converted to use struct object_id for object IDs. However, there are some places that still have not, and there are a variety of places that compare equivalently sized hashes that are not object IDs. All of these hashes are artifacts of the internal hash algorithm in use, and when we switch to NewHash for object storage, all of these uses will also switch. Update the hashcpy, hashclr, and hashcmp functions to use the_hash_algo, since they are used in a variety of places to copy and manipulate buffers that need to move data into or out of struct object_id. This has the effect of making the corresponding oid* functions use the_hash_algo as well. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-11merge-recursive: fix assumption that head tree being merged is HEADLibravatar Elijah Newren1-4/+7
`git merge-recursive` does a three-way merge between user-specified trees base, head, and remote. Since the user is allowed to specify head, we can not necesarily assume that head == HEAD. Modify index_has_changes() to take an extra argument specifying the tree to compare against. If NULL, it will compare to HEAD. We then use this from merge-recursive to make sure we compare to the user-specified head. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03index_has_changes(): avoid assuming operating on the_indexLibravatar Elijah Newren1-5/+6
Modify index_has_changes() to take a struct istate* instead of just operating on the_index. This is only a partial conversion, though, because we call do_diff_cache() which implicitly assumes work is to be done on the_index. Ongoing work is being done elsewhere to do the remainder of the conversion, and thus is not duplicated here. Instead, a simple check is put in place until that work is complete. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03block alloc: add validations around cache_entry lifecyleLibravatar Jameson Miller1-0/+6
Add an option (controlled by an environment variable) perform extra validations on mem_pool allocated cache entries. When set: 1) Invalidate cache_entry memory when discarding cache_entry. 2) When discarding index_state struct, verify that all cache_entries were allocated from expected mem_pool. 3) When discarding mem_pools, invalidate mem_pool memory. This should provide extra checks that mem_pools and their allocated cache_entries are being used as expected. Signed-off-by: Jameson Miller <jamill@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03block alloc: allocate cache entries from mem_poolLibravatar Jameson Miller1-0/+21
When reading large indexes from disk, a portion of the time is dominated in malloc() calls. This can be mitigated by allocating a large block of memory and manage it ourselves via memory pools. This change moves the cache entry allocation to be on top of memory pools. Design: The index_state struct will gain a notion of an associated memory_pool from which cache_entries will be allocated from. When reading in the index from disk, we have information on the number of entries and their size, which can guide us in deciding how large our initial memory allocation should be. When an index is discarded, the associated memory_pool will be discarded as well - so the lifetime of a cache_entry is tied to the lifetime of the index_state that it was allocated for. In the case of a Split Index, the following rules are followed. 1st, some terminology is defined: Terminology: - 'the_index': represents the logical view of the index - 'split_index': represents the "base" cache entries. Read from the split index file. 'the_index' can reference a single split_index, as well as cache_entries from the split_index. `the_index` will be discarded before the `split_index` is. This means that when we are allocating cache_entries in the presence of a split index, we need to allocate the entries from the `split_index`'s memory pool. This allows us to follow the pattern that `the_index` can reference cache_entries from the `split_index`, and that the cache_entries will not be freed while they are still being referenced. Managing transient cache_entry structs: Cache entries are usually allocated for an index, but this is not always the case. Cache entries are sometimes allocated because this is the type that the existing checkout_entry function works with. Because of this, the existing code needs to handle cache entries associated with an index / memory pool, and those that only exist transiently. Several strategies were contemplated around how to handle this: Chosen approach: An extra field was added to the cache_entry type to track whether the cache_entry was allocated from a memory pool or not. This is currently an int field, as there are no more available bits in the existing ce_flags bit field. If / when more bits are needed, this new field can be turned into a proper bit field. Alternatives: 1) Do not include any information about how the cache_entry was allocated. Calling code would be responsible for tracking whether the cache_entry needed to be freed or not. Pro: No extra memory overhead to track this state Con: Extra complexity in callers to handle this correctly. The extra complexity and burden to not regress this behavior in the future was more than we wanted. 2) cache_entry would gain knowledge about which mem_pool allocated it Pro: Could (potentially) do extra logic to know when a mem_pool no longer had references to any cache_entry Con: cache_entry would grow heavier by a pointer, instead of int We didn't see a tangible benefit to this approach 3) Do not add any extra information to a cache_entry, but when freeing a cache entry, check if the memory exists in a region managed by existing mem_pools. Pro: No extra memory overhead to track state Con: Extra computation is performed when freeing cache entries We decided tracking and iterating over known memory pool regions was less desirable than adding an extra field to track this stae. Signed-off-by: Jameson Miller <jamill@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03block alloc: add lifecycle APIs for cache_entry structsLibravatar Jameson Miller1-6/+34
It has been observed that the time spent loading an index with a large number of entries is partly dominated by malloc() calls. This change is in preparation for using memory pools to reduce the number of malloc() calls made to allocate cahce entries when loading an index. Add an API to allocate and discard cache entries, abstracting the details of managing the memory backing the cache entries. This commit does actually change how memory is managed - this will be done in a later commit in the series. This change makes the distinction between cache entries that are associated with an index and cache entries that are not associated with an index. A main use of cache entries is with an index, and we can optimize the memory management around this. We still have other cases where a cache entry is not persisted with an index, and so we need to handle the "transient" use case as well. To keep the congnitive overhead of managing the cache entries, there will only be a single discard function. This means there must be enough information kept with the cache entry so that we know how to discard them. A summary of the main functions in the API is: make_cache_entry: create cache entry for use in an index. Uses specified parameters to populate cache_entry fields. make_empty_cache_entry: Create an empty cache entry for use in an index. Returns cache entry with empty fields. make_transient_cache_entry: create cache entry that is not used in an index. Uses specified parameters to populate cache_entry fields. make_empty_transient_cache_entry: create cache entry that is not used in an index. Returns cache entry with empty fields. discard_cache_entry: A single function that knows how to discard a cache entry regardless of how it was allocated. Signed-off-by: Jameson Miller <jamill@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03read-cache: teach make_cache_entry to take object_idLibravatar Jameson Miller1-1/+6
Teach make_cache_entry function to take object_id instead of a SHA-1. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03read-cache: teach refresh_cache_entry to take istateLibravatar Jameson Miller1-1/+1
Refactor refresh_cache_entry() to work on a specific index, instead of implicitly using the_index. This is in preparation for making the make_cache_entry function apply to a specific index. Signed-off-by: Jameson Miller <jamill@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-29Merge branch 'sb/object-store-grafts' into sb/object-store-lookupLibravatar Junio C Hamano1-118/+1
* sb/object-store-grafts: commit: allow lookup_commit_graft to handle arbitrary repositories commit: allow prepare_commit_graft to handle arbitrary repositories shallow: migrate shallow information into the object parser path.c: migrate global git_path_* to take a repository argument cache: convert get_graft_file to handle arbitrary repositories commit: convert read_graft_file to handle arbitrary repositories commit: convert register_commit_graft to handle arbitrary repositories commit: convert commit_graft_pos() to handle arbitrary repositories shallow: add repository argument to is_repository_shallow shallow: add repository argument to check_shallow_file_for_update shallow: add repository argument to register_shallow shallow: add repository argument to set_alternate_shallow_file commit: add repository argument to lookup_commit_graft commit: add repository argument to prepare_commit_graft commit: add repository argument to read_graft_file commit: add repository argument to register_commit_graft commit: add repository argument to commit_graft_pos object: move grafts to object parser object-store: move object access functions to object-store.h
2018-06-25Merge branch 'sb/object-store-alloc'Libravatar Junio C Hamano1-9/+0
The conversion to pass "the_repository" and then "a_repository" throughout the object access API continues. * sb/object-store-alloc: alloc: allow arbitrary repositories for alloc functions object: allow create_object to handle arbitrary repositories object: allow grow_object_hash to handle arbitrary repositories alloc: add repository argument to alloc_commit_index alloc: add repository argument to alloc_report alloc: add repository argument to alloc_object_node alloc: add repository argument to alloc_tag_node alloc: add repository argument to alloc_commit_node alloc: add repository argument to alloc_tree_node alloc: add repository argument to alloc_blob_node object: add repository argument to grow_object_hash object: add repository argument to create_object repository: introduce parsed objects field
2018-06-01Merge branch 'nd/command-list'Libravatar Junio C Hamano1-5/+0
The list of commands with their various attributes were spread across a few places in the build procedure, but it now is getting a bit more consolidated to allow more automation. * nd/command-list: completion: allow to customize the completable command list completion: add and use --list-cmds=alias completion: add and use --list-cmds=nohelpers Move declaration for alias.c to alias.h completion: reduce completable command list completion: let git provide the completable command list command-list.txt: documentation and guide line help: use command-list.txt for the source of guides help: add "-a --verbose" to list all commands with synopsis git: support --list-cmds=list-<category> completion: implement and use --list-cmds=main,others git --list-cmds: collect command list in a string_list git.c: convert --list-* to --list-cmds=* Remove common-cmds.h help: use command-list.h for common command list generate-cmds.sh: export all commands to command-list.h generate-cmds.sh: factor out synopsis extract code
2018-05-30Merge branch 'bc/object-id'Libravatar Junio C Hamano1-19/+9
Conversion from uchar[20] to struct object_id continues. * bc/object-id: (42 commits) merge-one-file: compute empty blob object ID add--interactive: compute the empty tree value Update shell scripts to compute empty tree object ID sha1_file: only expose empty object constants through git_hash_algo dir: use the_hash_algo for empty blob object ID sequencer: use the_hash_algo for empty tree object ID cache-tree: use is_empty_tree_oid sha1_file: convert cached object code to struct object_id builtin/reset: convert use of EMPTY_TREE_SHA1_BIN builtin/receive-pack: convert one use of EMPTY_TREE_SHA1_HEX wt-status: convert two uses of EMPTY_TREE_SHA1_HEX submodule: convert several uses of EMPTY_TREE_SHA1_HEX sequencer: convert one use of EMPTY_TREE_SHA1_HEX merge: convert empty tree constant to the_hash_algo builtin/merge: switch tree functions to use object_id builtin/am: convert uses of EMPTY_TREE_SHA1_BIN to the_hash_algo sha1-file: add functions for hex empty tree and blob OIDs builtin/receive-pack: avoid hard-coded constants for push certs diff: specify abbreviation size in terms of the_hash_algo upload-pack: replace use of several hard-coded constants ...
2018-05-29Sync with Git 2.17.1Libravatar Junio C Hamano1-2/+10
* maint: (25 commits) Git 2.17.1 Git 2.16.4 Git 2.15.2 Git 2.14.4 Git 2.13.7 fsck: complain when .gitmodules is a symlink index-pack: check .gitmodules files with --strict unpack-objects: call fsck_finish() after fscking objects fsck: call fsck_finish() after fscking objects fsck: check .gitmodules content fsck: handle promisor objects in .gitmodules check fsck: detect gitmodules files fsck: actually fsck blob data fsck: simplify ".git" check index-pack: make fsck error message more specific verify_path: disallow symlinks in .gitmodules update-index: stat updated files earlier verify_dotfile: mention case-insensitivity in comment verify_path: drop clever fallthrough skip_prefix: add case-insensitive variant ...
2018-05-23Merge branch 'nd/pack-objects-pack-struct'Libravatar Junio C Hamano1-0/+2
"git pack-objects" needs to allocate tons of "struct object_entry" while doing its work, and shrinking its size helps the performance quite a bit. * nd/pack-objects-pack-struct: ci: exercise the whole test suite with uncommon code in pack-objects pack-objects: reorder members to shrink struct object_entry pack-objects: shrink delta_size field in struct object_entry pack-objects: shrink size field in struct object_entry pack-objects: clarify the use of object_entry::size pack-objects: don't check size when the object is bad pack-objects: shrink z_delta_size field in struct object_entry pack-objects: refer to delta objects by index instead of pointer pack-objects: move in_pack out of struct object_entry pack-objects: move in_pack_pos out of struct object_entry pack-objects: use bitfield for object_entry::depth pack-objects: use bitfield for object_entry::dfs_state pack-objects: turn type and in_pack_type to bitfields pack-objects: a bit of document about struct object_entry read-cache.c: make $GIT_TEST_SPLIT_INDEX boolean
2018-05-23Merge branch 'sb/oid-object-info'Libravatar Junio C Hamano1-2/+5
The codepath around object-info API has been taught to take the repository object (which in turn tells the API which object store the objects are to be located). * sb/oid-object-info: cache.h: allow oid_object_info to handle arbitrary repositories packfile: add repository argument to cache_or_unpack_entry packfile: add repository argument to unpack_entry packfile: add repository argument to read_object packfile: add repository argument to packed_object_info packfile: add repository argument to packed_to_object_type packfile: add repository argument to retry_bad_packed_offset cache.h: add repository argument to oid_object_info cache.h: add repository argument to oid_object_info_extended