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2018-07-03fetch-pack: write shallow, then check connectivityJonathan Tan
When fetching, connectivity is checked after the shallow file is updated. There are 2 issues with this: (1) the connectivity check is only performed up to ancestors of existing refs (which is not thorough enough if we were deepening an existing ref in the first place), and (2) there is no rollback of the shallow file if the connectivity check fails. To solve (1), update the connectivity check to check the ancestry chain completely in the case of a deepening fetch by refraining from passing "--not --all" when invoking rev-list in connected.c. To solve (2), have fetch_pack() perform its own connectivity check before updating the shallow file. To support existing use cases in which "git fetch-pack" is used to download objects without much regard as to the connectivity of the resulting objects with respect to the existing repository, the connectivity check is only done if necessary (that is, the fetch is not a clone, and the fetch involves shallow/deepen functionality). "git fetch" still performs its own connectivity check, preserving correctness but sometimes performing redundant work. This redundancy is mitigated by the fact that fetch_pack() reports if it has performed a connectivity check itself, and if the transport supports connect or stateless-connect, it will bubble up that report so that "git fetch" knows not to perform the connectivity check in such a case. This was noticed when a user tried to deepen an existing repository by fetching with --no-shallow from a server that did not send all necessary objects - the connectivity check as run by "git fetch" succeeded, but a subsequent "git fsck" failed. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-13Merge branch 'jh/partial-clone'Junio C Hamano
The machinery to clone & fetch, which in turn involves packing and unpacking objects, have been told how to omit certain objects using the filtering mechanism introduced by the jh/object-filtering topic, and also mark the resulting pack as a promisor pack to tolerate missing objects, taking advantage of the mechanism introduced by the jh/fsck-promisors topic. * jh/partial-clone: t5616: test bulk prefetch after partial fetch fetch: inherit filter-spec from partial clone t5616: end-to-end tests for partial clone fetch-pack: restore save_commit_buffer after use unpack-trees: batch fetching of missing blobs clone: partial clone partial-clone: define partial clone settings in config fetch: support filters fetch: refactor calculation of remote list fetch-pack: test support excluding large blobs fetch-pack: add --no-filter fetch-pack, index-pack, transport: partial clone upload-pack: add object filtering for partial clone
2017-12-08fetch: support filtersJeff Hostetler
Teach fetch to support filters. This is only allowed for the remote configured in extensions.partialcloneremote. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-16Convert check_connected to use struct object_idbrian m. carlson
Convert check_connected and the callbacks it takes to use struct object_id. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-23pack: move {,re}prepare_packed_git and approximate_object_countJonathan Tan
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-23pack: move add_packed_git()Jonathan Tan
Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-10check_connected: accept an env argumentJeff King
This lets callers influence the environment seen by rev-list, which will be useful when we start providing quarantined objects. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-20check_connected: add progress flagJeff King
Connectivity checks have to traverse the entire object graph in the worst case (e.g., a full clone or a full push). For large repositories like linux.git, this can take 30-60 seconds, during which time git may produce little or no output. Let's add the option of showing progress, which is taken care of by rev-list. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-20check_connected: relay errors to alternate descriptorJeff King
Unless the "quiet" flag is given, check_connected sends any errors to the stderr of the caller (because the child rev-list inherits that descriptor). However, server-side callers may want to send these over a sideband channel instead. Let's make that possible. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-20check_everything_connected: use a struct with named optionsJeff King
The number of variants of check_everything_connected has grown over the years, so that the "real" function takes several possibly-zero, possibly-NULL arguments. We hid the complexity behind some wrapper functions, but this doesn't scale well when we want to add new options. If we add more wrapper variants to handle the new options, then we can get a combinatorial explosion when those options might be used together (right now nobody wants to use both "shallow" and "transport" together, so we get by with just a few wrappers). If instead we add new parameters to each function, each of which can have a default value, then callers who want the defaults end up with confusing invocations like: check_everything_connected(fn, 0, data, -1, 0, NULL); where it is unclear which parameter is which (and every caller needs updated when we add new options). Instead, let's add a struct to hold all of the optional parameters. This is a little more verbose for the callers (who have to declare the struct and fill it in), but it makes their code much easier to follow, because every option is named as it is set (and unused options do not have to be mentioned at all). Note that we could also stick the iteration function and its callback data into the option struct, too. But since those are required for each call, by avoiding doing so, we can let very simple callers just pass "NULL" for the options and not worry about the struct at all. While we're touching each site, let's also rename the function to check_connected(). The existing name was quite long, and not all of the wrappers even used the full name. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-20check_everything_connected: convert to argv_arrayJeff King
This avoids the magic "9" array-size which we must avoid overflowing, making further patches simpler. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-20check_everything_connected: always pass --quiet to rev-listJeff King
The check_everything_connected function takes a "quiet" parameter which does two things if non-zero: 1. redirect rev-list's stderr to /dev/null to avoid showing errors to the user 2. pass "--quiet" to rev-list Item (1) is obviously useful. But item (2) is surprisingly not. For rev-list, "--quiet" does not have anything to do with chattiness on stderr; it tells rev-list not to bother writing the list of traversed objects to stdout, for efficiency. And since we always redirect rev-list's stdout to /dev/null in this function, there is no point in asking it to ever write anything to stdout. The efficiency gains are modest; a best-of-five run of "git rev-list --objects --all" on linux.git dropped from 32.013s to 30.502s when adding "--quiet". That's only about 5%, but given how easy it is, it's worth doing. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-05-09connected.c: use error_errno()Nguyễn Thái Ngọc Duy
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-20run-command: introduce CHILD_PROCESS_INITRené Scharfe
Most struct child_process variables are cleared using memset first after declaration. Provide a macro, CHILD_PROCESS_INIT, that can be used to initialize them statically instead. That's shorter, doesn't require a function call and is slightly more readable (especially given that we already have STRBUF_INIT, ARGV_ARRAY_INIT etc.). Helped-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-30use strip_suffix instead of ends_with in simple casesJeff King
When stripping a suffix like: if (ends_with(str, "foo")) buf = xmemdupz(str, strlen(str) - 3); we can instead use strip_suffix to avoid the constant 3, which must match the literal "foo" (we sometimes use strlen("foo") instead, but that means we are repeating ourselves). The example above becomes: if (strip_suffix(str, "foo", &len)) buf = xmemdupz(str, len); This also saves a strlen(), since we calculate the string length when detecting the suffix. Note that in some cases we also switch from xstrndup to xmemdupz, which saves a further strlen call. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-01-17Merge branch 'nd/shallow-clone'Junio C Hamano
Fetching from a shallow-cloned repository used to be forbidden, primarily because the codepaths involved were not carefully vetted and we did not bother supporting such usage. This attempts to allow object transfer out of a shallow-cloned repository in a controlled way (i.e. the receiver become a shallow repository with truncated history). * nd/shallow-clone: (31 commits) t5537: fix incorrect expectation in test case 10 shallow: remove unused code send-pack.c: mark a file-local function static git-clone.txt: remove shallow clone limitations prune: clean .git/shallow after pruning objects clone: use git protocol for cloning shallow repo locally send-pack: support pushing from a shallow clone via http receive-pack: support pushing to a shallow clone via http smart-http: support shallow fetch/clone remote-curl: pass ref SHA-1 to fetch-pack as well send-pack: support pushing to a shallow clone receive-pack: allow pushes that update .git/shallow connected.c: add new variant that runs with --shallow-file add GIT_SHALLOW_FILE to propagate --shallow-file to subprocesses receive/send-pack: support pushing from a shallow clone receive-pack: reorder some code in unpack() fetch: add --update-shallow to accept refs that update .git/shallow upload-pack: make sure deepening preserves shallow roots fetch: support fetching from a shallow repository clone: support remote shallow repository ...
2013-12-11connected.c: add new variant that runs with --shallow-fileNguyễn Thái Ngọc Duy
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-05replace {pre,suf}fixcmp() with {starts,ends}_with()Christian Couder
Leaving only the function definitions and declarations so that any new topic in flight can still make use of the old functions, replace existing uses of the prefixcmp() and suffixcmp() with new API functions. The change can be recreated by mechanically applying this: $ git grep -l -e prefixcmp -e suffixcmp -- \*.c | grep -v strbuf\\.c | xargs perl -pi -e ' s|!prefixcmp\(|starts_with\(|g; s|prefixcmp\(|!starts_with\(|g; s|!suffixcmp\(|ends_with\(|g; s|suffixcmp\(|!ends_with\(|g; ' on the result of preparatory changes in this series. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-28clone: open a shortcut for connectivity checkNguyễn Thái Ngọc Duy
In order to make sure the cloned repository is good, we run "rev-list --objects --not --all $new_refs" on the repository. This is expensive on large repositories. This patch attempts to mitigate the impact in this special case. In the "good" clone case, we only have one pack. If all of the following are met, we can be sure that all objects reachable from the new refs exist, which is the intention of running "rev-list ...": - all refs point to an object in the pack - there are no dangling pointers in any object in the pack - no objects in the pack point to objects outside the pack The second and third checks can be done with the help of index-pack as a slight variation of --strict check (which introduces a new condition for the shortcut: pack transfer must be used and the number of objects large enough to call index-pack). The first is checked in check_everything_connected after we get an "ok" from index-pack. "index-pack + new checks" is still faster than the current "index-pack + rev-list", which is the whole point of this patch. If any of the conditions fail, we fall back to the good old but expensive "rev-list ..". In that case it's even more expensive because we have to pay for the new checks in index-pack. But that should only happen when the other side is either buggy or malicious. Cloning linux-2.6 over file:// before after real 3m25.693s 2m53.050s user 5m2.037s 4m42.396s sys 0m13.750s 0m16.574s A more realistic test with ssh:// over wireless before after real 11m26.629s 10m4.213s user 5m43.196s 5m19.444s sys 0m35.812s 0m37.630s This shortcut is not applied to shallow clones, partly because shallow clones should have no more objects than a usual fetch and the cost of rev-list is acceptable, partly to avoid dealing with corner cases when grafting is involved. This shortcut does not apply to unpack-objects code path either because the number of objects must be small in order to trigger that code path. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-03-15fetch/receive: remove over-pessimistic connectivity checkJunio C Hamano
Git 1.7.8 introduced an object and history re-validation step after "fetch" or "push" causes new history to be added to a receiving repository. This is to protect a malicious server or pushing client from corrupting the repository by taking advantage of an existing corrupt object that is unconnected to existing history. But this check is way over-pessimistic. During "fetch" or "receive-pack" (the server side of "push"), unpack-objects and index-pack already validate individual objects that are received, and the only thing we would want to catch are corrupted objects that already happen to exist in our repository but are not referenced from our refs. Such objects must have been written by an earlier run of our codepaths that write out loose objects or packfiles, and they must have done the validation of individual objects when they did so. The only thing left to worry about is the connectivity integrity, which can be checked with "rev-list --objects", which is much cheaper. We have been paying the 5x to 8x runtime overhead the --verify-objects often adds for no real gain. Revert check_everything_connected() not to use this over-pessimistic check. Credit goes to Nguyễn Thái Ngọc Duy, who originally identified the performance regression and endured multiple rounds of reviews to fix it. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-09-09check_everything_connected(): libifyJunio C Hamano
Extract the helper function and the type definition of the iterator function it uses out of builtin/fetch.c into a separate source and a header file. Signed-off-by: Junio C Hamano <gitster@pobox.com>