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2020-02-24packed_object_info(): use object_id for returning delta baseLibravatar Jeff King1-4/+4
If a caller sets the object_info.delta_base_sha1 to a non-NULL pointer, we'll write the oid of the object's delta base to it. But we can increase our type safety by switching this to a real object_id struct. All of our callers are just pointing into the hash member of an object_id anyway, so there's no inconvenience. Note that we do still keep it as a pointer-to-struct, because the NULL sentinel value tells us whether the caller is even interested in the information. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-14Merge branch 'mt/use-passed-repo-more-in-funcs'Libravatar Junio C Hamano1-24/+31
Some codepaths were given a repository instance as a parameter to work in the repository, but passed the_repository instance to its callees, which has been cleaned up (somewhat). * mt/use-passed-repo-more-in-funcs: sha1-file: allow check_object_signature() to handle any repo sha1-file: pass git_hash_algo to hash_object_file() sha1-file: pass git_hash_algo to write_object_file_prepare() streaming: allow open_istream() to handle any repo pack-check: use given repo's hash_algo at verify_packfile() cache-tree: use given repo's hash_algo at verify_one() diff: make diff_populate_filespec() honor its repo argument
2020-02-14Merge branch 'mt/threaded-grep-in-object-store'Libravatar Junio C Hamano1-5/+52
Traditionally, we avoided threaded grep while searching in objects (as opposed to files in the working tree) as accesses to the object layer is not thread-safe. This limitation is getting lifted. * mt/threaded-grep-in-object-store: grep: use no. of cores as the default no. of threads grep: move driver pre-load out of critical section grep: re-enable threads in non-worktree case grep: protect packed_git [re-]initialization grep: allow submodule functions to run in parallel submodule-config: add skip_if_read option to repo_read_gitmodules() grep: replace grep_read_mutex by internal obj read lock object-store: allow threaded access to object reading replace-object: make replace operations thread-safe grep: fix racy calls in grep_objects() grep: fix race conditions at grep_submodule() grep: fix race conditions on userdiff calls
2020-01-31sha1-file: allow check_object_signature() to handle any repoLibravatar Matheus Tavares1-10/+11
Some callers of check_object_signature() can work on arbitrary repositories, but the repo does not get passed to this function. Instead, the_repository is always used internally. To fix possible inconsistencies, allow the function to receive a struct repository and make those callers pass on the repo being handled. Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31sha1-file: pass git_hash_algo to hash_object_file()Libravatar Matheus Tavares1-9/+11
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>
2020-01-31sha1-file: pass git_hash_algo to write_object_file_prepare()Libravatar Matheus Tavares1-8/+12
Allow write_object_file_prepare() to receive arbitrary 'struct git_hash_algo's instead of always using the_hash_algo. The added parameter will be used in the next commit to make hash_object_file() be able to work with arbitrary git_hash_algo's, as well. Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31streaming: allow open_istream() to handle any repoLibravatar Matheus Tavares1-1/+1
Some callers of open_istream() at archive-tar.c and archive-zip.c are capable of working on arbitrary repositories but the repo struct is not passed down to open_istream(), which uses the_repository internally. For now, that's not a problem since the said callers are only being called with the_repository. But to be consistent and avoid future problems, let's allow open_istream() to receive a struct repository and use that instead of the_repository. This parameter addition will also be used in a future patch to make sha1-file.c:check_object_signature() be able to work on arbitrary repos. Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-17object-store: allow threaded access to object readingLibravatar Matheus Tavares1-5/+52
Allow object reading to be performed by multiple threads protecting it with an internal lock, the obj_read_mutex. The lock usage can be toggled with enable_obj_read_lock() and disable_obj_read_lock(). Currently, the functions which can be safely called in parallel are: read_object_file_extended(), repo_read_object_file(), read_object_file(), read_object_with_reference(), read_object(), oid_object_info() and oid_object_info_extended(). It's also possible to use obj_read_lock() and obj_read_unlock() to protect other sections that cannot execute in parallel with object reading. Probably there are many spots in the functions listed above that could be executed unlocked (and thus, in parallel). But, for now, we are most interested in allowing parallel access to zlib inflation. This is one of the sections where object reading spends most of the time in (e.g. up to one-third of git-grep's execution time in the chromium repo corresponds to inflation) and it's already thread-safe. So, to take advantage of that, the obj_read_mutex is released when calling git_inflate() and re-acquired right after, for every calling spot in oid_object_info_extended()'s call chain. We may refine this lock to also exploit other possible parallel spots in the future, but for now, threaded zlib inflation should already give great speedups for threaded object reading callers. Note that add_delta_base_cache() was also modified to skip adding already present entries to the cache. This wasn't possible before, but it would be now, with the parallel inflation. Take for example the following situation, where two threads - A and B - are executing the code at unpack_entry(): 1. Thread A is performing the decompression of a base O (which is not yet in the cache) at PHASE II. Thread B is simultaneously trying to unpack O, but just starting at PHASE I. 2. Since O is not yet in the cache, B will go to PHASE II to also perform the decompression. 3. When they finish decompressing, one of them will get the object reading mutex and go to PHASE III while the other waits for the mutex. Let’s say A got the mutex first. 4. Thread A will add O to the cache, go throughout the rest of PHASE III and return. 5. Thread B gets the mutex, also add O to the cache (if the check wasn't there) and returns. Finally, it is also important to highlight that the object reading lock can only ensure thread-safety in the mentioned functions thanks to two complementary mechanisms: the use of 'struct raw_object_store's replace_mutex, which guards sections in the object reading machinery that would otherwise be thread-unsafe; and the 'struct pack_window's inuse_cnt, which protects window reading operations (such as the one performed during the inflation of a packed object), allowing them to execute without the acquisition of the obj_read_mutex. Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-02sha1-file: remove OBJECT_INFO_SKIP_CACHEDLibravatar Jonathan Tan1-20/+18
In a partial clone, if a user provides the hash of the empty tree ("git mktree </dev/null" - for SHA-1, this is 4b825d...) to a command which requires that that object be parsed, for example: git diff-tree 4b825d <a non-empty tree> then Git will lazily fetch the empty tree, unnecessarily, because parsing of that object invokes repo_has_object_file(), which does not special-case the empty tree. Instead, teach repo_has_object_file() to consult find_cached_object() (which handles the empty tree), thus bringing it in line with the rest of the object-store-accessing functions. A cost is that repo_has_object_file() will now need to oideq upon each invocation, but that is trivial compared to the filesystem lookup or the pack index search required anyway. (And if find_cached_object() needs to do more because of previous invocations to pretend_object_file(), all the more reason to be consistent in whether we present cached objects.) As a historical note, the function now known as repo_read_object_file() was taught the empty tree in 346245a1bb ("hard-code the empty tree object", 2008-02-13), and the function now known as oid_object_info() was taught the empty tree in c4d9986f5f ("sha1_object_info: examine cached_object store too", 2011-02-07). repo_has_object_file() was never updated, perhaps due to oversight. The flag OBJECT_INFO_SKIP_CACHED, introduced later in dfdd4afcf9 ("sha1_file: teach sha1_object_info_extended more flags", 2017-06-26) and used in e83e71c5e1 ("sha1_file: refactor has_sha1_file_with_flags", 2017-06-26), was introduced to preserve this difference in empty-tree handling, but now it can be removed. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-11Merge branch 'bc/object-id-part17'Libravatar Junio C Hamano1-1/+0
Preparation for SHA-256 upgrade continues. * bc/object-id-part17: (26 commits) midx: switch to using the_hash_algo builtin/show-index: replace sha1_to_hex rerere: replace sha1_to_hex builtin/receive-pack: replace sha1_to_hex builtin/index-pack: replace sha1_to_hex packfile: replace sha1_to_hex wt-status: convert struct wt_status to object_id cache: remove null_sha1 builtin/worktree: switch null_sha1 to null_oid builtin/repack: write object IDs of the proper length pack-write: use hash_to_hex when writing checksums sequencer: convert to use the_hash_algo bisect: switch to using the_hash_algo sha1-lookup: switch hard-coded constants to the_hash_algo config: use the_hash_algo in abbrev comparison combine-diff: replace GIT_SHA1_HEXSZ with the_hash_algo bundle: switch to use the_hash_algo connected: switch GIT_SHA1_HEXSZ to the_hash_algo show-index: switch hard-coded constants to the_hash_algo blame: remove needless comparison with GIT_SHA1_HEXSZ ...
2019-09-18Merge branch 'cc/multi-promisor'Libravatar Junio C Hamano1-7/+8
Teach the lazy clone machinery that there can be more than one promisor remote and consult them in order when downloading missing objects on demand. * cc/multi-promisor: Move core_partial_clone_filter_default to promisor-remote.c Move repository_format_partial_clone to promisor-remote.c Remove fetch-object.{c,h} in favor of promisor-remote.{c,h} remote: add promisor and partial clone config to the doc partial-clone: add multiple remotes in the doc t0410: test fetching from many promisor remotes builtin/fetch: remove unique promisor remote limitation promisor-remote: parse remote.*.partialclonefilter Use promisor_remote_get_direct() and has_promisor_remote() promisor-remote: use repository_format_partial_clone promisor-remote: add promisor_remote_reinit() promisor-remote: implement promisor_remote_get_direct() Add initial support for many promisor remotes fetch-object: make functions return an error code t0410: remove pipes after git commands
2019-08-19cache: remove null_sha1Libravatar brian m. carlson1-1/+0
All of the existing uses of null_sha1 can be converted into uses of null_oid, so do so. Remove null_sha1 and is_null_sha1, and define is_null_oid in terms of null_oid. This also has the additional benefit of removing several uses of sha1_to_hex. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-13packfile: drop release_pack_memory()Libravatar Jeff King1-6/+2
Long ago, in 97bfeb34df (Release pack windows before reporting out of memory., 2006-12-24), we taught xmalloc() and friends to try unmapping pack windows when malloc() failed. It's unlikely that his helps a lot in practice, and it has some downsides. First, the downsides: 1. It makes xmalloc() not thread-safe. We've worked around this in pack-objects.c, which installs its own locking version of the try_to_free_routine(). But other threaded code doesn't. 2. It makes the system as a whole harder to reason about. Functions which allocate heap memory under the hood may have farther-reaching effects than expected. That might be worth the tradeoff if there's a benefit. But in practice, it seems unlikely. We're generally dealing with mmap'd files, so the OS is going to do a much better job at responding to memory pressure by dropping individual pages (the exception is systems with NO_MMAP, but even there the OS can probably respond just as well with swapping). So the only thing we're really freeing is address space. On 64-bit systems, we have plenty of that to go around. On 32-bit systems, it could possibly help. But around the same time we made two other changes: 77ccc5bbd1 (Introduce new config option for mmap limit., 2006-12-23) and 60bb8b1453 (Fully activate the sliding window pack access., 2006-12-23). Together that means that a 32-bit system should have no more than 256MB total of packed-git mmaps at one time, split between a few 32MB windows. It's unlikely we have any address space problems since then, but we don't have any data since the features were all added at the same time. Likewise, xmmap() will try to free memory. At first glance, it seems like we'd need this (when we try to mmap a new window, we might need to close an old one to save address space on a 32-bit system). But we're saved again by core.packedGitLimit: if we're going to exceed our 256MB limit, we'll close an existing window before we even call mmap(). So it seems unlikely that this feature is actually doing anything useful. And while we don't have reports of it harming anything (probably because it rarely if ever kicks in), it would be nice to simplify the system overall. This patch drops the whole try_to_free system from xmalloc(), as well as the manual pack memory release in xmmap(). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-07sha1-file: release strbuf after useLibravatar René Scharfe1-0/+1
Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-19Merge branch 'jk/check-connected-with-alternates'Libravatar Junio C Hamano1-0/+97
The tips of refs from the alternate object store can be used as starting point for reachability computation now. * jk/check-connected-with-alternates: check_everything_connected: assume alternate ref tips are valid object-store.h: move for_each_alternate_ref() from transport.h
2019-07-01object-store.h: move for_each_alternate_ref() from transport.hLibravatar Jeff King1-0/+97
There's nothing inherently transport-related about enumerating the alternate ref tips. The code has lived in transport.[ch] because the only use so far had been advertising available tips during transport. But it could be used for more, and a future patch will teach rev-list to access these refs. Let's move it alongside the other alt-odb code, declaring it in object-store.h with the implementation in sha1-file.c. This lets us drop the inclusion of transport.h from receive-pack, which perhaps shows how it was misplaced (though receive-pack is about transporting objects, transport.h is mostly about the client side). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-27sha1-file.c: remove the_repo from read_object_with_reference()Libravatar Nguyễn Thái Ngọc Duy1-2/+3
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-25Use promisor_remote_get_direct() and has_promisor_remote()Libravatar Christian Couder1-7/+8
Instead of using the repository_format_partial_clone global and fetch_objects() directly, let's use has_promisor_remote() and promisor_remote_get_direct(). This way all the configured promisor remotes will be taken into account, not only the one specified by extensions.partialClone. Also when cloning or fetching using a partial clone filter, remote.origin.promisor will be set to "true" instead of setting extensions.partialClone to "origin". This makes it possible to use many promisor remote just by fetching from them. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-25fetch-object: make functions return an error codeLibravatar Christian Couder1-2/+2
The callers of the fetch_object() and fetch_objects() might be interested in knowing if these functions succeeded or not. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-17Merge branch 'ds/object-info-for-prefetch-fix'Libravatar Junio C Hamano1-1/+1
Code cleanup and futureproof. * ds/object-info-for-prefetch-fix: sha1-file: split OBJECT_INFO_FOR_PREFETCH
2019-05-28sha1-file: split OBJECT_INFO_FOR_PREFETCHLibravatar Derrick Stolee1-1/+1
The OBJECT_INFO_FOR_PREFETCH bitflag was added to sha1-file.c in 0f4a4fb1 (sha1-file: support OBJECT_INFO_FOR_PREFETCH, 2019-03-29) and is used to prevent the fetch_objects() method when enabled. However, there is a problem with the current use. The definition of OBJECT_INFO_FOR_PREFETCH is given by adding 32 to OBJECT_INFO_QUICK. This is clearly stated above the definition (in a comment) that this is so OBJECT_INFO_FOR_PREFETCH implies OBJECT_INFO_QUICK. The problem is that using "flag & OBJECT_INFO_FOR_PREFETCH" means that OBJECT_INFO_QUICK also implies OBJECT_INFO_FOR_PREFETCH. Split out the single bit from OBJECT_INFO_FOR_PREFETCH into a new OBJECT_INFO_SKIP_FETCH_OBJECT as the single bit and keep OBJECT_INFO_FOR_PREFETCH as the union of two flags. This allows a clearer use of flag checking while also keeping the implication of OBJECT_INFO_QUICK. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-25Merge branch 'jt/batch-fetch-blobs-in-diff'Libravatar Junio C Hamano1-1/+2
While running "git diff" in a lazy clone, we can upfront know which missing blobs we will need, instead of waiting for the on-demand machinery to discover them one by one. Aim to achieve better performance by batching the request for these promised blobs. * jt/batch-fetch-blobs-in-diff: diff: batch fetching of missing blobs sha1-file: support OBJECT_INFO_FOR_PREFETCH
2019-04-01sha1-file: support OBJECT_INFO_FOR_PREFETCHLibravatar Jonathan Tan1-1/+2
Teach oid_object_info_extended() to support a new flag that inhibits fetching of missing objects. This is equivalent to setting fetch_is_missing to 0, calling oid_object_info_extended(), then setting fetch_if_missing to whatever it was before. Update unpack-trees.c to use this new flag instead of repeatedly setting fetch_if_missing. This new flag complicates things slightly in that there are now 2 ways to do the same thing. But this eliminates the need to repeatedly set a global variable, and more importantly, allows prefetching to be done in parallel (in the future); hence, this patch. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01hash: add a function to lookup hash algorithm by lengthLibravatar brian m. carlson1-0/+8
There are some cases, such as the dumb HTTP transport and bundles, where we can only determine the hash algorithm in use by the length of the object IDs. Provide a function that looks up the algorithm by length. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-06Merge branch 'jk/loose-object-cache-oid'Libravatar Junio C Hamano1-116/+104
Code clean-up. * jk/loose-object-cache-oid: prefer "hash mismatch" to "sha1 mismatch" sha1-file: avoid "sha1 file" for generic use in messages sha1-file: prefer "loose object file" to "sha1 file" in messages sha1-file: drop has_sha1_file() convert has_sha1_file() callers to has_object_file() sha1-file: convert pass-through functions to object_id sha1-file: modernize loose header/stream functions sha1-file: modernize loose object file functions http: use struct object_id instead of bare sha1 update comment references to sha1_object_info() sha1-file: fix outdated sha1 comment references
2019-02-05Merge branch 'sb/more-repo-in-api'Libravatar Junio C Hamano1-14/+20
The in-core repository instances are passed through more codepaths. * sb/more-repo-in-api: (23 commits) t/helper/test-repository: celebrate independence from the_repository path.h: make REPO_GIT_PATH_FUNC repository agnostic commit: prepare free_commit_buffer and release_commit_memory for any repo commit-graph: convert remaining functions to handle any repo submodule: don't add submodule as odb for push submodule: use submodule repos for object lookup pretty: prepare format_commit_message to handle arbitrary repositories commit: prepare logmsg_reencode to handle arbitrary repositories commit: prepare repo_unuse_commit_buffer to handle any repo commit: prepare get_commit_buffer to handle any repo commit-reach: prepare in_merge_bases[_many] to handle any repo commit-reach: prepare get_merge_bases to handle any repo commit-reach.c: allow get_merge_bases_many_0 to handle any repo commit-reach.c: allow remove_redundant to handle any repo commit-reach.c: allow merge_bases_many to handle any repo commit-reach.c: allow paint_down_to_common to handle any repo commit: allow parse_commit* to handle any repo object: parse_object to honor its repository argument object-store: prepare has_{sha1, object}_file to handle any repo object-store: prepare read_object_file to deal with any repo ...
2019-01-29Merge branch 'bc/sha-256'Libravatar Junio C Hamano1-1/+69
Add sha-256 hash and plug it through the code to allow building Git with the "NewHash". * bc/sha-256: hash: add an SHA-256 implementation using OpenSSL sha256: add an SHA-256 implementation using libgcrypt Add a base implementation of SHA-256 support commit-graph: convert to using the_hash_algo t/helper: add a test helper to compute hash speed sha1-file: add a constant for hash block size t: make the sha1 test-tool helper generic t: add basic tests for our SHA-1 implementation cache: make hashcmp and hasheq work with larger hashes hex: introduce functions to print arbitrary hashes sha1-file: provide functions to look up hash algorithms sha1-file: rename algorithm to "sha1"
2019-01-18Merge branch 'rs/sha1-file-close-mapped-file-on-error'Libravatar Junio C Hamano1-0/+1
Code clean-up. * rs/sha1-file-close-mapped-file-on-error: sha1-file: close fd of empty file in map_sha1_file_1()
2019-01-08prefer "hash mismatch" to "sha1 mismatch"Libravatar Jeff King1-2/+2
To future-proof ourselves against a change in the hash, let's use the more generic "hash mismatch" to refer to integrity problems. Note that we do advertise this exact string in git-fsck(1). However, the message itself is marked for translation, meaning we do not expect it to be machine-readable. While we're touching that documentation, let's also update it for grammar and clarity. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08sha1-file: avoid "sha1 file" for generic use in messagesLibravatar Jeff King1-2/+2
These error messages say "sha1 file", which is vague and not common in user-facing documentation. Unlike the conversions from the previous commit, these do not always refer to loose objects. In finalize_object_file() we could be dealing with a packfile. Let's just say "unable to write file" instead; since we include the filename, the nature of the file is clear from the rest of the message. In force_object_loose(), we're calling into read_object(), which could actually be _any_ type of object. Just say "object". Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08sha1-file: prefer "loose object file" to "sha1 file" in messagesLibravatar Jeff King1-3/+3
When we're reporting an error for a loose object, let's use that term. It's more consistent with other parts of Git, and it is future-proof against changes to the hash function. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08sha1-file: drop has_sha1_file()Libravatar Jeff King1-14/+2
There are no callers left of has_sha1_file() or its with_flags() variant. Let's drop them, and convert has_object_file() from a wrapper into the "real" function. Ironically, the sha1 variant was just copying into an object_id internally, so the resulting code is actually shorter! We can also drop the coccinelle rules for catching has_sha1_file() callers. Since the function no longer exists, the compiler will do that for us. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08convert has_sha1_file() callers to has_object_file()Libravatar Jeff King1-1/+1
The only remaining callers of has_sha1_file() actually have an object_id already. They can use the "object" variant, rather than dereferencing the hash themselves. The code changes here were completely generated by the included coccinelle patch. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08sha1-file: convert pass-through functions to object_idLibravatar Jeff King1-13/+7
These two static functions, read_object() and quick_has_loose(), both have to hashcpy() their bare-sha1 arguments into object_id structs to pass them along. Since all of their callers actually have object_id structs in the first place, we can eliminate the copying by adjusting their input parameters. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08object-store: retire odb_load_loose_cache()Libravatar René Scharfe1-7/+2
Inline odb_load_loose_cache() into its only remaining caller, odb_loose_cache(). The latter offers a nicer interface for loading the cache, as it doesn't require callers to deal with fanout directory numbers directly. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08sha1-file: modernize loose header/stream functionsLibravatar Jeff King1-41/+43
As with the open/map/close functions for loose objects that were recently converted, the functions for parsing the loose object stream use the name "sha1" and a bare "unsigned char *". Let's fix that so that unpack_sha1_header() becomes unpack_loose_header(), etc. These conversions are less clear-cut than the file access functions. You could argue that the they are parsing Git's canonical object format (i.e., "type size\0contents", over which we compute the hash), which is not strictly tied to loose storage. But in practice these functions are used only for loose objects, and using the term "loose_header" (instead of "object_header") distinguishes it from the object header found in packfiles (which contains the same information in a different format). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08object-store: use one oid_array per subdirectory for loose cacheLibravatar René Scharfe1-3/+6
The loose objects cache is filled one subdirectory at a time as needed. It is stored in an oid_array, which has to be resorted after each add operation. So when querying a wide range of objects, the partially filled array needs to be resorted up to 255 times, which takes over 100 times longer than sorting once. Use one oid_array for each subdirectory. This ensures that entries have to only be sorted a single time. It also avoids eight binary search steps for each cache lookup as a small bonus. The cache is used for collision checks for the log placeholders %h, %t and %p, and we can see the change speeding them up in a repository with ca. 100 objects per subdirectory: $ git count-objects 26733 objects, 68808 kilobytes Test HEAD^ HEAD -------------------------------------------------------------------- 4205.1: log with %H 0.51(0.47+0.04) 0.51(0.49+0.02) +0.0% 4205.2: log with %h 0.84(0.82+0.02) 0.60(0.57+0.03) -28.6% 4205.3: log with %T 0.53(0.49+0.04) 0.52(0.48+0.03) -1.9% 4205.4: log with %t 0.84(0.80+0.04) 0.60(0.59+0.01) -28.6% 4205.5: log with %P 0.52(0.48+0.03) 0.51(0.50+0.01) -1.9% 4205.6: log with %p 0.85(0.78+0.06) 0.61(0.56+0.05) -28.2% 4205.7: log with %h-%h-%h 0.96(0.92+0.03) 0.69(0.64+0.04) -28.1% Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08sha1-file: modernize loose object file functionsLibravatar Jeff King1-40/+41
The loose object access code in sha1-file.c is some of the oldest in Git, and could use some modernizing. It mostly uses "unsigned char *" for object ids, which these days should be "struct object_id". It also uses the term "sha1_file" in many functions, which is confusing. The term "loose_objects" is much better. It clearly distinguishes them from packed objects (which didn't even exist back when the name "sha1_file" came into being). And it also distinguishes it from the checksummed-file concept in csum-file.c (which until recently was actually called "struct sha1file"!). This patch converts the functions {open,close,map,stat}_sha1_file() into open_loose_object(), etc, and switches their sha1 arguments for object_id structs. Similarly, path functions like fill_sha1_path() become fill_loose_path() and use object_ids. The function sha1_loose_object_info() already says "loose", so we can just drop the "sha1" (and teach it to use object_id). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08object-store: factor out odb_clear_loose_cache()Libravatar René Scharfe1-0/+7
Add and use a function for emptying the loose object cache, so callers don't have to know any of its implementation details. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08object-store: factor out odb_loose_cache()Libravatar René Scharfe1-3/+9
Add and use a function for loading the entries of a loose object subdirectory for a given object ID. It frees callers from deriving the fanout key; they can use the returned oid_array reference for lookups or forward range scans. Suggested-by: Jeff King <peff@peff.net> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-08sha1-file: fix outdated sha1 comment referencesLibravatar Jeff King1-3/+3
Commit 17e65451e3 (sha1_file: convert check_sha1_signature to struct object_id, 2018-03-12) switched to using the name "oid", but forgot to update the variable name in the comment. Likewise, b4f5aca40e (sha1_file: convert read_sha1_file to struct object_id, 2018-03-12) dropped the name read_sha1_file(), but missed a comment which mentions it. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-07sha1-file: close fd of empty file in map_sha1_file_1()Libravatar René Scharfe1-0/+1
map_sha1_file_1() checks if the file it is about to mmap() is empty and errors out in that case and explains the situation in an error message. It leaks the private handle to that empty file, though. Have the function clean up after itself and close the file descriptor before exiting early. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-04Merge branch 'jk/loose-object-cache'Libravatar Junio C Hamano1-106/+105
Code clean-up with optimization for the codepath that checks (non-)existence of loose objects. * jk/loose-object-cache: odb_load_loose_cache: fix strbuf leak fetch-pack: drop custom loose object cache sha1-file: use loose object cache for quick existence check object-store: provide helpers for loose_objects_cache sha1-file: use an object_directory for the main object dir handle alternates paths the same as the main object dir sha1_file_name(): overwrite buffer instead of appending rename "alternate_object_database" to "object_directory" submodule--helper: prefer strip_suffix() to ends_with() fsck: do not reuse child_process structs
2018-11-24odb_load_loose_cache: fix strbuf leakLibravatar Jeff King1-0/+1
Commit 3a2e0824 ("object-store: provide helpers for loose_objects_cache", 2018-11-12) moved the cache-loading code from find_short_object_filename(), but forgot the line that releases the path strbuf. Reported-by: René Scharfe <l.s.r@web.de> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-19Merge branch 'tb/print-size-t-with-uintmax-format'Libravatar Junio C Hamano1-3/+3
Code preparation to replace ulong vars with size_t vars where appropriate. * tb/print-size-t-with-uintmax-format: Upcast size_t variables to uintmax_t when printing
2018-11-14object-store: prepare has_{sha1, object}_file to handle any repoLibravatar Stefan Beller1-6/+9
Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14object-store: allow read_object_file_extended to read from any repoLibravatar Stefan Beller1-5/+6
read_object_file_extended is not widely used, so migrate it all at once. Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14Add a base implementation of SHA-256 supportLibravatar brian m. carlson1-0/+45
SHA-1 is weak and we need to transition to a new hash function. For some time, we have referred to this new function as NewHash. Recently, we decided to pick SHA-256 as NewHash. The reasons behind the choice of SHA-256 are outlined in the thread starting at [1] and in the commit history for the hash function transition document. Add a basic implementation of SHA-256 based off libtomcrypt, which is in the public domain. Optimize it and restructure it to meet our coding standards. Pull in the update and final functions from the SHA-1 block implementation, as we know these function correctly with all compilers. This implementation is slower than SHA-1, but more performant implementations will be introduced in future commits. Wire up SHA-256 in the list of hash algorithms, and add a test that the algorithm works correctly. Note that with this patch, it is still not possible to switch to using SHA-256 in Git. Additional patches are needed to prepare the code to handle a larger hash algorithm and further test fixes are needed. [1] https://public-inbox.org/git/20180609224913.GC38834@genre.crustytoothpaste.net/ Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14sha1-file: add a constant for hash block sizeLibravatar brian m. carlson1-0/+2
There is one place we need the hash algorithm block size: the HMAC code for push certs. Expose this constant in struct git_hash_algo and expose values for SHA-1 and for the largest value of any hash. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-13Merge branch 'jk/detect-truncated-zlib-input'Libravatar Junio C Hamano1-1/+2
A regression in Git 2.12 era made "git fsck" fall into an infinite loop while processing truncated loose objects. * jk/detect-truncated-zlib-input: cat-file: handle streaming failures consistently check_stream_sha1(): handle input underflow t1450: check large blob in trailing-garbage test