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2015-01-07Merge branch 'jc/merge-bases'Libravatar Junio C Hamano1-2/+5
The get_merge_bases*() API was easy to misuse by careless copy&paste coders, leaving object flags tainted in the commits that needed to be traversed. * jc/merge-bases: get_merge_bases(): always clean-up object flags bisect: clean flags after checking merge bases
2014-12-22Merge branch 'cc/interpret-trailers-more'Libravatar Junio C Hamano1-0/+3
"git interpret-trailers" learned to properly handle the "Conflicts:" block at the end. * cc/interpret-trailers-more: trailer: add test with an old style conflict block trailer: reuse ignore_non_trailer() to ignore conflict lines commit: make ignore_non_trailer() non static merge & sequencer: turn "Conflicts:" hint into a comment builtin/commit.c: extract ignore_non_trailer() helper function merge & sequencer: unify codepaths that write "Conflicts:" hint builtin/merge.c: drop a parameter that is never used
2014-11-10commit: make ignore_non_trailer() non staticLibravatar Christian Couder1-0/+3
Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-30get_merge_bases(): always clean-up object flagsLibravatar Junio C Hamano1-2/+5
The callers of get_merge_bases() can choose to leave object flags used during the merge-base traversal by passing cleanup=0 as a parameter, but in practice a very few callers can afford to do so (namely, "git merge-base"), as they need to compute merge base in preparation for other processing of their own and they need to see the object without contaminate flags. Change the function signature of get_merge_bases_many() and get_merge_bases() to drop the cleanup parameter, so that the majority of the callers do not have to say ", 1" at the end. Give a new get_merge_bases_many_dirty() API to support only a few callers that know they do not need to spend cycles cleaning up the object flags. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-09-19Merge branch 'da/styles'Libravatar Junio C Hamano1-1/+1
* da/styles: stylefix: asterisks stick to the variable, not the type
2014-09-19Merge branch 'jk/commit-author-parsing'Libravatar Junio C Hamano1-0/+11
Code clean-up. * jk/commit-author-parsing: determine_author_info(): copy getenv output determine_author_info(): reuse parsing functions date: use strbufs in date-formatting functions record_author_date(): use find_commit_header() record_author_date(): fix memory leak on malformed commit commit: provide a function to find a header in a buffer
2014-09-11Merge branch 'jk/name-decoration-alloc'Libravatar Junio C Hamano1-2/+14
The API to allocate the structure to keep track of commit decoration was cumbersome to use, inviting lazy code to overallocate memory. * jk/name-decoration-alloc: log-tree: use FLEX_ARRAY in name_decoration log-tree: make name_decoration hash static log-tree: make add_name_decoration a public function
2014-09-02stylefix: asterisks stick to the variable, not the typeLibravatar David Aguilar1-1/+1
Signed-off-by: David Aguilar <davvid@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-27commit: provide a function to find a header in a bufferLibravatar Jeff King1-0/+11
Usually when we parse a commit, we read it line by line and handle each individual line (e.g., parse_commit and parse_commit_header). Sometimes, however, we only care about extracting a single header. Code in this situation is stuck doing an ad-hoc parse of the commit buffer. Let's provide a reusable function to locate a header within the commit. The code is modeled after pretty.c's get_header, which is used to extract the encoding. Since some callers may not have the "struct commit" to go along with the buffer, we drop that parameter. The only thing lost is a warning for truncated commits, but that's OK. This shouldn't happen in practice, and even if it does, there's no particular reason that this function needs to complain about it. It either finds the header it was asked for, or it doesn't (and in the latter case, the caller will typically complain). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-27log-tree: use FLEX_ARRAY in name_decorationLibravatar Jeff King1-1/+1
We are already using the flex-array technique; let's annotate it with our usual FLEX_ARRAY macro. Besides being more readable, this is slightly more efficient on compilers that understand flex-arrays. Note that we need to bump the allocation in add_name_decoration, which did not explicitly add one byte for the NUL terminator of the string we are putting into the flex-array (it did not need to before, because the struct itself was over-allocated by one byte). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-26log-tree: make name_decoration hash staticLibravatar Jeff King1-1/+1
In the previous commit, we made add_name_decoration global so that adders would not have to access the hash directly. We now make the hash itself static so that callers _have_ to add through our function, making sure that all additions go through a single point. To do this, we have to add one more accessor function: a way to lookup entries in the hash. Since the only caller doesn't actually look at the returned value, but rather only asks whether there is a decoration or not, we could provide only a boolean "has_name_decoration". That would allow us to make "struct name_decoration" local to log-tree, as well. However, it's unlikely to cause any maintainability harm making the actual data public, and this interface is more flexible if we need to look at decorations from other parts of the code in the future. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-26log-tree: make add_name_decoration a public functionLibravatar Jeff King1-0/+12
The log-tree code keeps a "struct decoration" hash to show text decorations for each commit during log traversals. It makes this available to other files by providing global access to the hash. This can result in other code adding entries that do not conform to what log-tree expects. For example, the bisect code adds its own "dist" decorations to be shown. Originally the bisect code was correct, but when the name_decoration code grew a new field in eb3005e (commit.h: add 'type' to struct name_decoration, 2010-06-19), the bisect code was not updated. As a result, the log-tree code can access uninitialized memory and even segfault. We can fix this by making name_decoration's adding function public. If all callers use it, then any changes to struct initialization only need to happen in one place (and because the members come in as parameters, the compiler can notice a caller who does not supply enough information). As a bonus, this also means that the decoration hashes created by the bisect code will use less memory (previously we over-allocated space for the distance integer, but now we format it into a temporary buffer and copy it to the final flex-array). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-30pretty: make empty userformats truly emptyLibravatar Jeff King1-0/+1
If the user provides an empty format with "--format=", we end up putting in extra whitespace that the user cannot prevent. This comes from two places: 1. If the format is missing a terminating newline, we add one automatically. This makes sense for --format=%h, but not for a truly empty format. 2. We add an extra newline between the pretty-printed format and a diff or diffstat. If the format is empty, there's no point in doing so if there's nothing to separate. With this patch, one can get a diff with no other cruft out of "diff-tree --format= $commit". Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-27Merge branch 'cc/replace-graft'Libravatar Junio C Hamano1-0/+2
"git replace" learned a "--graft" option to rewrite parents of a commit. * cc/replace-graft: replace: add test for --graft with a mergetag replace: check mergetags when using --graft replace: add test for --graft with signed commit replace: remove signature when using --graft contrib: add convert-grafts-to-replace-refs.sh Documentation: replace: add --graft option replace: add test for --graft replace: add --graft option replace: cleanup redirection style in tests
2014-07-22Merge branch 'kb/perf-trace'Libravatar Junio C Hamano1-0/+1
* kb/perf-trace: api-trace.txt: add trace API documentation progress: simplify performance measurement by using getnanotime() wt-status: simplify performance measurement by using getnanotime() git: add performance tracing for git's main() function to debug scripts trace: add trace_performance facility to debug performance issues trace: add high resolution timer function to debug performance issues trace: add 'file:line' to all trace output trace: move code around, in preparation to file:line output trace: add current timestamp to all trace output trace: disable additional trace output for unit tests trace: add infrastructure to augment trace output with additional info sha1_file: change GIT_TRACE_PACK_ACCESS logging to use trace API Documentation/git.txt: improve documentation of 'GIT_TRACE*' variables trace: improve trace performance trace: remove redundant printf format attribute trace: consistently name the format parameter trace: move trace declarations from cache.h to new trace.h
2014-07-21replace: remove signature when using --graftLibravatar Christian Couder1-0/+2
It could be misleading to keep a signature in a replacement commit, so let's remove it. Note that there should probably be a way to sign the replacement commit created when using --graft, but this can be dealt with in another commit or patch series. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-13trace: improve trace performanceLibravatar Karsten Blees1-0/+1
The trace API currently rechecks the environment variable and reopens the trace file on every API call. This has the ugly side effect that errors (e.g. file cannot be opened, or the user specified a relative path) are also reported on every call. Performance can be improved by about factor three by remembering the environment state and keeping the file open. Replace the 'const char *key' parameter in the API with a pointer to a 'struct trace_key' that bundles the environment variable name with additional, trace-internal state. Change the call sites of these APIs to use a static 'struct trace_key' instead of a string constant. In trace.c::get_trace_fd(), save and reuse the file descriptor in 'struct trace_key'. Add a 'trace_disable()' API, so that packet_trace() can cleanly disable tracing when it encounters packed data (instead of using unsetenv()). Signed-off-by: Karsten Blees <blees@dcon.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-07commit: add for_each_mergetag()Libravatar Christian Couder1-0/+5
In the same way as there is for_each_ref() to iterate on refs, for_each_mergetag() allows the caller to iterate on the mergetags of a given commit. Use it to rewrite show_mergetag() used in "git log". Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-13reuse cached commit buffer when parsing signaturesLibravatar Jeff King1-1/+1
When we call show_signature or show_mergetag, we read the commit object fresh via read_sha1_file and reparse its headers. However, in most cases we already have the object data available, attached to the "struct commit". This is partially laziness in dealing with the memory allocation issues, but partially defensive programming, in that we would always want to verify a clean version of the buffer (not one that might have been munged by other users of the commit). However, we do not currently ever munge the commit buffer, and not using the already-available buffer carries a fairly big performance penalty when we are looking at a large number of commits. Here are timings on linux.git: [baseline, no signatures] $ time git log >/dev/null real 0m4.902s user 0m4.784s sys 0m0.120s [before] $ time git log --show-signature >/dev/null real 0m14.735s user 0m9.964s sys 0m0.944s [after] $ time git log --show-signature >/dev/null real 0m9.981s user 0m5.260s sys 0m0.936s Note that our user CPU time drops almost in half, close to the non-signature case, but we do still spend more wall-clock and system time, presumably from dealing with gpg. An alternative to this is to note that most commits do not have signatures (less than 1% in this repo), yet we pay the re-parsing cost for every commit just to find out if it has a mergetag or signature. If we checked that when parsing the commit initially, we could avoid re-examining most commits later on. Even if we did pursue that direction, however, this would still speed up the cases where we _do_ have signatures. So it's probably worth doing either way. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-13commit: record buffer length in cacheLibravatar Jeff King1-4/+4
Most callsites which use the commit buffer try to use the cached version attached to the commit, rather than re-reading from disk. Unfortunately, that interface provides only a pointer to the NUL-terminated buffer, with no indication of the original length. For the most part, this doesn't matter. People do not put NULs in their commit messages, and the log code is happy to treat it all as a NUL-terminated string. However, some code paths do care. For example, when checking signatures, we want to be very careful that we verify all the bytes to avoid malicious trickery. This patch just adds an optional "size" out-pointer to get_commit_buffer and friends. The existing callers all pass NULL (there did not seem to be any obvious sites where we could avoid an immediate strlen() call, though perhaps with some further refactoring we could). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-13commit: convert commit->buffer to a slabLibravatar Jeff King1-1/+0
This will make it easier to manage the buffer cache independently of the "struct commit" objects. It also shrinks "struct commit" by one pointer, which may be helpful. Unfortunately it does not reduce the max memory size of something like "rev-list", because rev-list uses get_cached_commit_buffer() to decide not to show each commit's output (and due to the design of slab_at, accessing the slab requires us to extend it, allocating exactly the same number of buffer pointers we dropped from the commit structs). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-13convert logmsg_reencode to get_commit_bufferLibravatar Jeff King1-1/+0
Like the callsites in the previous commit, logmsg_reencode already falls back to read_sha1_file when necessary. However, I split its conversion out into its own commit because it's a bit more complex. We return either: 1. The original commit->buffer 2. A newly allocated buffer from read_sha1_file 3. A reencoded buffer (based on either 1 or 2 above). while trying to do as few extra reads/allocations as possible. Callers currently free the result with logmsg_free, but we can simplify this by pointing them straight to unuse_commit_buffer. This is a slight layering violation, in that we may be passing a buffer from (3). However, since the end result is to free() anything except (1), which is unlikely to change, and because this makes the interface much simpler, it's a reasonable bending of the rules. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-13provide helpers to access the commit bufferLibravatar Jeff King1-0/+21
Many sites look at commit->buffer to get more detailed information than what is in the parsed commit struct. However, we sometimes drop commit->buffer to save memory, in which case the caller would need to read the object afresh. Some callers do this (leading to duplicated code), and others do not (which opens the possibility of a segfault if somebody else frees the buffer). Let's provide a pair of helpers, "get" and "unuse", that let callers easily get the buffer. They will use the cached buffer when possible, and otherwise load from disk using read_sha1_file. Note that we also need to add a "get_cached" variant which returns NULL when we do not have a cached buffer. At first glance this seems to defeat the purpose of "get", which is to always provide a return value. However, some log code paths actually use the NULL-ness of commit->buffer as a boolean flag to decide whether to try printing the commit. At least for now, we want to continue supporting that use. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-13provide a helper to set the commit bufferLibravatar Jeff King1-0/+6
Right now this is just a one-liner, but abstracting it will make it easier to change later. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-13provide a helper to free commit bufferLibravatar Jeff King1-0/+11
This converts two lines into one at each caller. But more importantly, it abstracts the concept of freeing the buffer, which will make it easier to change later. Note that we also need to provide a "detach" mechanism for a tricky case in index-pack. We are passed a buffer for the object generated by processing the incoming pack. If we are not using --strict, we just calculate the sha1 on that buffer and return, leaving the caller to free it. But if we are using --strict, we actually attach that buffer to an object, pass the object to the fsck functions, and then detach the buffer from the object again (so that the caller can free it as usual). In this case, we don't want to free the buffer ourselves, but just make sure it is no longer associated with the commit. Note that we are making the assumption here that the attach/detach process does not impact the buffer at all (e.g., it is never reallocated or modified). That holds true now, and we have no plans to change that. However, as we abstract the commit_buffer code, this dependency becomes less obvious. So when we detach, let's also make sure that we get back the same buffer that we gave to the commit_buffer code. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-12logmsg_reencode: return const bufferLibravatar Jeff King1-4/+4
The return value from logmsg_reencode may be either a newly allocated buffer or a pointer to the existing commit->buffer. We would not want the caller to accidentally free() or modify the latter, so let's mark it as const. We can cast away the constness in logmsg_free, but only once we have determined that it is a free-able buffer. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-12commit_tree: take a pointer/len pair rather than a const strbufLibravatar Jeff King1-2/+4
While strbufs are pretty common throughout our code, it is more flexible for functions to take a pointer/len pair than a strbuf. It's easy to turn a strbuf into such a pair (by dereferencing its members), but less easy to go the other way (you can strbuf_attach, but that has implications about memory ownership). This patch teaches commit_tree (and its associated callers and sub-functions) to take such a pair for the commit message rather than a strbuf. This makes passing the buffer around slightly more verbose, but means we can get rid of some dangerous strbuf_attach calls in the next patch. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-08Merge branch 'bp/commit-p-editor' into maintLibravatar Junio C Hamano1-0/+3
* bp/commit-p-editor: run-command: mark run_hook_with_custom_index as deprecated merge hook tests: fix and update tests merge: fix GIT_EDITOR override for commit hook commit: fix patch hunk editing with "commit -p -m" test patch hunk editing with "commit -p -m" merge hook tests: use 'test_must_fail' instead of '!' merge hook tests: fix missing '&&' in test
2014-03-28Merge branch 'bp/commit-p-editor'Libravatar Junio C Hamano1-0/+3
When it is not necessary to edit a commit log message (e.g. "git commit -m" is given a message without specifying "-e"), we used to disable the spawning of the editor by overriding GIT_EDITOR, but this means all the uses of the editor, other than to edit the commit log message, are also affected. * bp/commit-p-editor: run-command: mark run_hook_with_custom_index as deprecated merge hook tests: fix and update tests merge: fix GIT_EDITOR override for commit hook commit: fix patch hunk editing with "commit -p -m" test patch hunk editing with "commit -p -m" merge hook tests: use 'test_must_fail' instead of '!' merge hook tests: fix missing '&&' in test
2014-03-18commit: fix patch hunk editing with "commit -p -m"Libravatar Benoit Pierre1-0/+3
Don't change git environment: move the GIT_EDITOR=":" override to the hook command subprocess, like it's already done for GIT_INDEX_FILE. Signed-off-by: Benoit Pierre <benoit.pierre@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-02-27shallow: automatically clean up shallow tempfilesLibravatar Jeff King1-1/+1
We sometimes write tempfiles of the form "shallow_XXXXXX" during fetch/push operations with shallow repositories. Under normal circumstances, we clean up the result when we are done. However, we do no take steps to clean up after ourselves when we exit due to die() or signal death. This patch teaches the tempfile creation code to register handlers to clean up after ourselves. To handle this, we change the ownership semantics of the filename returned by setup_temporary_shallow. It now keeps a copy of the filename itself, and returns only a const pointer to it. We can also do away with explicit tempfile removal in the callers. They all exit not long after finishing with the file, so they can rely on the auto-cleanup, simplifying the code. Note that we keep things simple and maintain only a single filename to be cleaned. This is sufficient for the current caller, but we future-proof it with a die("BUG"). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-01-17Merge branch 'nd/shallow-clone'Libravatar Junio C Hamano1-4/+33
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 ...
2014-01-10Merge branch 'nd/commit-tree-constness'Libravatar Junio C Hamano1-2/+2
Code clean-up. * nd/commit-tree-constness: commit.c: make "tree" a const pointer in commit_tree*()
2014-01-06shallow: remove unused codeLibravatar Ramsay Jones1-2/+0
Commit 58babfff ("shallow.c: the 8 steps to select new commits for .git/shallow", 05-12-2013) added a function to implement step 5 of the quoted eight steps, namely 'remove_nonexistent_ours_in_pack()'. This function implements an optional optimization step in the new shallow commit selection algorithm. However, this function has no callers. (The commented out call sites would need to change, in order to provide information required by the function.) Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Acked-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-26commit.c: make "tree" a const pointer in commit_tree*()Libravatar 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>
2013-12-10prune: clean .git/shallow after pruning objectsLibravatar Nguyễn Thái Ngọc Duy1-0/+1
This patch teaches "prune" to remove shallow roots that are no longer reachable from any refs (e.g. when the relevant refs are removed). Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10receive-pack: allow pushes that update .git/shallowLibravatar Nguyễn Thái Ngọc Duy1-0/+9
The basic 8 steps to update .git/shallow does not fully apply here because the user may choose to accept just a few refs (while fetch always accepts all refs). The steps are modified a bit. 1-6. same as before. After calling assign_shallow_commits_to_refs at step 6, each shallow commit has a bitmap that marks all refs that require it. 7. mark all "ours" shallow commits that are reachable from any refs. We will need to do the original step 7 on them later. 8. go over all shallow commit bitmaps, mark refs that require new shallow commits. 9. setup a strict temporary shallow file to plug all the holes, even if it may cut some of our history short. This file is used by all hooks. The hooks could use --shallow-file=$GIT_DIR/shallow to overcome this and reach everything in current repo. 10. go over the new refs one by one. For each ref, do the reachability test if it needs a shallow commit on the list from step 7. Remove it if it's reachable from our refs. Gather all required shallow commits, run check_everything_connected() with the new ref, then install them to .git/shallow. This mode is disabled by default and can be turned on with receive.shallowupdate Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10add GIT_SHALLOW_FILE to propagate --shallow-file to subprocessesLibravatar Nguyễn Thái Ngọc Duy1-1/+1
This may be needed when a hook is run after a new shallow pack is received, but .git/shallow is not settled yet. A temporary shallow file to plug all loose ends should be used instead. GIT_SHALLOW_FILE is overriden by --shallow-file. --shallow-file does not work in this case because the hook may spawn many git subprocesses and the launch commands do not have --shallow-file as it's a recent addition. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10shallow.c: steps 6 and 7 to select new commits for .git/shallowLibravatar Nguyễn Thái Ngọc Duy1-0/+3
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10shallow.c: the 8 steps to select new commits for .git/shallowLibravatar Nguyễn Thái Ngọc Duy1-0/+15
Suppose a fetch or push is requested between two shallow repositories (with no history deepening or shortening). A pack that contains necessary objects is transferred over together with .git/shallow of the sender. The receiver has to determine whether it needs to update .git/shallow if new refs needs new shallow comits. The rule here is avoid updating .git/shallow by default. But we don't want to waste the received pack. If the pack contains two refs, one needs new shallow commits installed in .git/shallow and one does not, we keep the latter and reject/warn about the former. Even if .git/shallow update is allowed, we only add shallow commits strictly necessary for the former ref (remember the sender can send more shallow commits than necessary) and pay attention not to accidentally cut the receiver history short (no history shortening is asked for) So the steps to figure out what ref need what new shallow commits are: 1. Split the sender shallow commit list into "ours" and "theirs" list by has_sha1_file. Those that exist in current repo in "ours", the remaining in "theirs". 2. Check the receiver .git/shallow, remove from "ours" the ones that also exist in .git/shallow. 3. Fetch the new pack. Either install or unpack it. 4. Do has_sha1_file on "theirs" list again. Drop the ones that fail has_sha1_file. Obviously the new pack does not need them. 5. If the pack is kept, remove from "ours" the ones that do not exist in the new pack. 6. Walk the new refs to answer the question "what shallow commits, both ours and theirs, are required in .git/shallow in order to add this ref?". Shallow commits not associated to any refs are removed from their respective list. 7. (*) Check reachability (from the current refs) of all remaining commits in "ours". Those reachable are removed. We do not want to cut any part of our (reachable) history. We only check up commits. True reachability test is done by check_everything_connected() at the end as usual. 8. Combine the final "ours" and "theirs" and add them all to .git/shallow. Install new refs. The case where some hook rejects some refs on a push is explained in more detail in the push patches. Of these steps, #6 and #7 are expensive. Both require walking through some commits, or in the worst case all commits. And we rather avoid them in at least common case, where the transferred pack does not contain any shallow commits that the sender advertises. Let's look at each scenario: 1) the sender has longer history than the receiver All shallow commits from the sender will be put into "theirs" list at step 1 because none of them exists in current repo. In the common case, "theirs" becomes empty at step 4 and exit early. 2) the sender has shorter history than the receiver All shallow commits from the sender are likely in "ours" list at step 1. In the common case, if the new pack is kept, we could empty "ours" and exit early at step 5. If the pack is not kept, we hit the expensive step 6 then exit after "ours" is emptied. There'll be only a handful of objects to walk in fast-forward case. If it's forced update, we may need to walk to the bottom. 3) the sender has same .git/shallow as the receiver This is similar to case 2 except that "ours" should be emptied at step 2 and exit early. A fetch after "clone --depth=X" is case 1. A fetch after "clone" (from a shallow repo) is case 3. Luckily they're cheap for the common case. A push from "clone --depth=X" falls into case 2, which is expensive. Some more work may be done at the sender/client side to avoid more work on the server side: if the transferred pack does not contain any shallow commits, send-pack should not send any shallow commits to the receive-pack, effectively turning it into a normal push and avoid all steps. This patch implements all steps except #3, already handled by fetch-pack and receive-pack, #6 and #7, which has their own patch due to their size. (*) in previous versions step 7 was put before step 3. I reorder it so that the common case that keeps the pack does not need to walk commits at all. In future if we implement faster commit reachability check (maybe with the help of pack bitmaps or commit cache), step 7 could become cheap and be moved up before 6 again. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10shallow.c: extend setup_*_shallow() to accept extra shallow commitsLibravatar Nguyễn Thái Ngọc Duy1-3/+5
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10make the sender advertise shallow commits to the receiverLibravatar Nguyễn Thái Ngọc Duy1-0/+1
If either receive-pack or upload-pack is called on a shallow repository, shallow commits (*) will be sent after the ref advertisement (but before the packet flush), so that the receiver has the full "shape" of the sender's commit graph. This will be needed for the receiver to update its .git/shallow if necessary. This breaks the protocol for all clients trying to push to a shallow repo, or fetch from one. Which is basically the same end result as today's "is_repository_shallow() && die()" in receive-pack and upload-pack. New clients will be made aware of shallow upstream and can make use of this information. The sender must send all shallow commits that are sent in the following pack. It may send more shallow commits than necessary. upload-pack for example may choose to advertise no shallow commits if it knows in advance that the pack it's going to send contains no shallow commits. But upload-pack is the server, so we choose the cheaper way, send full .git/shallow and let the client deal with it. Smart HTTP is not affected by this patch. Shallow support on smart-http comes later separately. (*) A shallow commit is a commit that terminates the revision walker. It is usually put in .git/shallow in order to keep the revision walker from going out of bound because there is no guarantee that objects behind this commit is available. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-05Merge branch 'jk/robustify-parse-commit'Libravatar Junio C Hamano1-0/+1
* jk/robustify-parse-commit: checkout: do not die when leaving broken detached HEAD use parse_commit_or_die instead of custom message use parse_commit_or_die instead of segfaulting assume parse_commit checks for NULL commit assume parse_commit checks commit->object.parsed log_tree_diff: die when we fail to parse a commit
2013-10-24log_tree_diff: die when we fail to parse a commitLibravatar Jeff King1-0/+1
We currently call parse_commit and then assume we can dereference the resulting "tree" struct field. If parsing failed, however, that field is NULL and we end up segfaulting. Instead of a segfault, let's print an error message and die a little more gracefully. Note that this should never happen in practice, but may happen in a corrupt repository. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-09-20Merge branch 'nd/fetch-into-shallow'Libravatar Junio C Hamano1-0/+4
When there is no sufficient overlap between old and new history during a fetch into a shallow repository, we unnecessarily sent objects the sending side knows the receiving end has. * nd/fetch-into-shallow: Add testcase for needless objects during a shallow fetch list-objects: mark more commits as edges in mark_edges_uninteresting list-objects: reduce one argument in mark_edges_uninteresting upload-pack: delegate rev walking in shallow fetch to pack-objects shallow: add setup_temporary_shallow() shallow: only add shallow graft points to new shallow file move setup_alternate_shallow and write_shallow_commits to shallow.c
2013-09-09Merge branch 'jl/submodule-mv'Libravatar Junio C Hamano1-1/+1
"git mv A B" when moving a submodule A does "the right thing", inclusing relocating its working tree and adjusting the paths in the .gitmodules file. * jl/submodule-mv: (53 commits) rm: delete .gitmodules entry of submodules removed from the work tree mv: update the path entry in .gitmodules for moved submodules submodule.c: add .gitmodules staging helper functions mv: move submodules using a gitfile mv: move submodules together with their work trees rm: do not set a variable twice without intermediate reading. t6131 - skip tests if on case-insensitive file system parse_pathspec: accept :(icase)path syntax pathspec: support :(glob) syntax pathspec: make --literal-pathspecs disable pathspec magic pathspec: support :(literal) syntax for noglob pathspec kill limit_pathspec_to_literal() as it's only used by parse_pathspec() parse_pathspec: preserve prefix length via PATHSPEC_PREFIX_ORIGIN parse_pathspec: make sure the prefix part is wildcard-free rename field "raw" to "_raw" in struct pathspec tree-diff: remove the use of pathspec's raw[] in follow-rename codepath remove match_pathspec() in favor of match_pathspec_depth() remove init_pathspec() in favor of parse_pathspec() remove diff_tree_{setup,release}_paths convert common_prefix() to use struct pathspec ...
2013-09-09Merge branch 'tr/log-full-diff-keep-true-parents'Libravatar Junio C Hamano1-0/+3
Output from "git log --full-diff -- <pathspec>" looked strange, because comparison was done with the previous ancestor that touched the specified <pathspec>, causing the patches for paths outside the pathspec to show more than the single commit has changed. Tweak "git reflog -p" for the same reason using the same mechanism. * tr/log-full-diff-keep-true-parents: log: use true parents for diff when walking reflogs log: use true parents for diff even when rewriting
2013-08-28shallow: add setup_temporary_shallow()Libravatar Nguyễn Thái Ngọc Duy1-0/+1
This function is like setup_alternate_shallow() except that it does not lock $GIT_DIR/shallow. It is supposed to be used when a program generates temporary shallow for use by another program, then throw the shallow file away. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-08-18move setup_alternate_shallow and write_shallow_commits to shallow.cLibravatar Nguyễn Thái Ngọc Duy1-0/+3
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-08-01log: use true parents for diff even when rewritingLibravatar Thomas Rast1-0/+3
When using pathspec filtering in combination with diff-based log output, parent simplification happens before the diff is computed. The diff is therefore against the *simplified* parents. This works okay, arguably by accident, in the normal case: simplification reduces to one parent as long as the commit is TREESAME to it. So the simplified parent of any given commit must have the same tree contents on the filtered paths as its true (unfiltered) parent. However, --full-diff breaks this guarantee, and indeed gives pretty spectacular results when comparing the output of git log --graph --stat ... git log --graph --full-diff --stat ... (--graph internally kicks in parent simplification, much like --parents). To fix it, store a copy of the parent list before simplification (in a slab) whenever --full-diff is in effect. Then use the stored parents instead of the simplified ones in the commit display code paths. The latter do not actually check for --full-diff to avoid duplicated code; they just grab the original parents if save_parents() has not been called for this revision walk. For ordinary commits it should be obvious that this is the right thing to do. Merge commits are a bit subtle. Observe that with default simplification, merge simplification is an all-or-nothing decision: either the merge is TREESAME to one parent and disappears, or it is different from all parents and the parent list remains intact. Redundant parents are not pruned, so the existing code also shows them as a merge. So if we do show a merge commit, the parent list just consists of the rewrite result on each parent. Running, e.g., --cc on this in --full-diff mode is not very useful: if any commits were skipped, some hunks will disagree with all sides of the merge (with one side, because commits were skipped; with the others, because they didn't have those changes in the first place). This triggers --cc showing these hunks spuriously. Therefore I believe that even for merge commits it is better to show the diffs wrt. the original parents. Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Helped-by: Junio C Hamano <gitster@pobox.com> Helped-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Thomas Rast <trast@inf.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>