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2014-01-17Merge branch 'nd/shallow-clone'Libravatar Junio C Hamano1-7/+462
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 ...
2014-01-06shallow: remove unused codeLibravatar Ramsay Jones1-16/+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>
2013-12-10prune: clean .git/shallow after pruning objectsLibravatar Nguyễn Thái Ngọc Duy1-2/+53
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/+23
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/+3
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>
2013-12-10upload-pack: make sure deepening preserves shallow rootsLibravatar Nguyễn Thái Ngọc Duy1-1/+5
When "fetch --depth=N" where N exceeds the longest chain of history in the source repo, usually we just send an "unshallow" line to the client so full history is obtained. When the source repo is shallow we need to make sure to "unshallow" the current shallow point _and_ "shallow" again when the commit reaches its shallow bottom in the source repo. This should fix both cases: large <N> and --unshallow. 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/+294
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/+72
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 Duy1-5/+15
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/+15
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 Hamano1-2/+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
2013-10-24use parse_commit_or_die instead of custom messageLibravatar Jeff King1-2/+1
Many calls to parse_commit detect errors and die. In some cases, the custom error messages are more useful than what parse_commit_or_die could produce, because they give some context, like which ref the commit came from. Some, however, just say "invalid commit". Let's convert the latter to use parse_commit_or_die; its message is slightly more informative, and it makes the error more consistent throughout git. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-08-28shallow: add setup_temporary_shallow()Libravatar Nguyễn Thái Ngọc Duy1-0/+23
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>
2013-08-28shallow: only add shallow graft points to new shallow fileLibravatar Nguyễn Thái Ngọc Duy1-0/+2
for_each_commit_graft() goes through all graft points, and shallow boundaries are just one special kind of grafting. If $GIT_DIR/shallow and $GIT_DIR/info/grafts are both present, write_shallow_commits() may catch both sets, accidentally turning some graft points to shallow boundaries. Don't do that. 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/+54
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-22Merge branch 'mk/upload-pack-off-by-one-dead-code-removal'Libravatar Junio C Hamano1-11/+6
* mk/upload-pack-off-by-one-dead-code-removal: upload-pack: remove a piece of dead code
2013-07-15upload-pack: remove a piece of dead codeLibravatar Matthijs Kooijman1-11/+6
Commit 682c7d2 (upload-pack: fix off-by-one depth calculation in shallow clone) introduced a new check in get_shallow_commits to decide when to stop traversing the history and mark the current commit as a shallow root. With this new check in place, the old check can no longer be true, since the first check always fires first. This commit removes that check, making the code a bit more simple again. Signed-off-by: Matthijs Kooijman <matthijs@stdin.nl> Acked-by: Duy Nguyen <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-28fetch-pack: prepare updated shallow file before fetching the packLibravatar Nguyễn Thái Ngọc Duy1-2/+40
index-pack --strict looks up and follows parent commits. If shallow information is not ready by the time index-pack is run, index-pack may be led to non-existent objects. Make fetch-pack save shallow file to disk before invoking index-pack. git learns new global option --shallow-file to pass on the alternate shallow file path. Undocumented (and not even support --shallow-file= syntax) because it's unlikely to be used again elsewhere. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-01-11upload-pack: fix off-by-one depth calculation in shallow cloneLibravatar Nguyễn Thái Ngọc Duy1-1/+7
get_shallow_commits() is used to determine the cut points at a given depth (i.e. the number of commits in a chain that the user likes to get). However we count current depth up to the commit "commit" but we do the cutting at its parents (i.e. current depth + 1). This makes upload-pack always return one commit more than requested. This patch fixes it. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-08-29object.h: Add OBJECT_ARRAY_INIT macro and make use of it.Libravatar Thiago Farina1-1/+1
Signed-off-by: Thiago Farina <tfransosi@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-18Merge branch 'mk/maint-parse-careful'Libravatar Junio C Hamano1-1/+2
* mk/maint-parse-careful: peel_onion: handle NULL check return value from parse_commit() in various functions parse_commit: don't fail, if object is NULL revision.c: handle tag->tagged == NULL reachable.c::process_tree/blob: check for NULL process_tag: handle tag->tagged == NULL check results of parse_commit in merge_bases list-objects.c::process_tree/blob: check for NULL reachable.c::add_one_tree: handle NULL from lookup_tree mark_blob/tree_uninteresting: check for NULL get_sha1_oneline: check return value of parse_object read_object_with_reference: don't read beyond the buffer
2008-02-18check return value from parse_commit() in various functionsLibravatar Martin Koegler1-1/+2
Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-17deref_tag: handle return value NULLLibravatar Martin Koegler1-1/+1
Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-07War on whitespaceLibravatar Junio C Hamano1-1/+0
This uses "git-apply --whitespace=strip" to fix whitespace errors that have crept in to our source files over time. There are a few files that need to have trailing whitespaces (most notably, test vectors). The results still passes the test, and build result in Documentation/ area is unchanged. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-01-21is_repository_shallow(): prototype fix.Libravatar Junio C Hamano1-1/+1
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-11-24get_shallow_commits: Avoid memory leak if a commit has been reached already.Libravatar Alexandre Julliard1-1/+3
Signed-off-by: Alexandre Julliard <julliard@winehq.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-11-24Shallow clone: do not ignore shallowness when following tagsLibravatar Alexandre Julliard1-1/+2
Tags should be considered when truncating the commit list. The patch below fixes it, and fetches the right number of commits for each tag. However the correct fix is probably to not fetch historical tags at all. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-11-24allow deepening of a shallow repositoryLibravatar Johannes Schindelin1-2/+6
Now, by saying "git fetch -depth <n> <repo>" you can deepen a shallow repository. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-11-24support fetching into a shallow repositoryLibravatar Johannes Schindelin1-0/+97
A shallow commit is a commit which has parents, which in turn are "grafted away", i.e. the commit appears as if it were a root. Since these shallow commits should not be edited by the user, but only by core git, they are recorded in the file $GIT_DIR/shallow. A repository containing shallow commits is called shallow. The advantage of a shallow repository is that even if the upstream contains lots of history, your local (shallow) repository needs not occupy much disk space. The disadvantage is that you might miss a merge base when pulling some remote branch. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <junkio@cox.net>