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2014-03-21Merge branch 'nd/upload-pack-shallow'Libravatar Junio C Hamano1-3/+12
Serving objects from a shallow repository needs to write a temporary file to be used, but the serving upload-pack may not have write access to the repository which is meant to be read-only. Instead feed these temporary shallow bounds from the standard input of pack-objects so that we do not have to use a temporary file. * nd/upload-pack-shallow: upload-pack: send shallow info over stdin to pack-objects
2014-03-21Merge branch 'jk/shallow-update-fix'Libravatar Junio C Hamano1-6/+1
Serving objects from a shallow repository needs to write a new file to hold the temporary shallow boundaries but it was not cleaned when we exit due to die() or a signal. * jk/shallow-update-fix: shallow: verify shallow file after taking lock shallow: automatically clean up shallow tempfiles shallow: use stat_validity to check for up-to-date file
2014-03-11upload-pack: send shallow info over stdin to pack-objectsLibravatar Nguyễn Thái Ngọc Duy1-9/+12
Before cdab485 (upload-pack: delegate rev walking in shallow fetch to pack-objects - 2013-08-16) upload-pack does not write to the source repository. cdab485 starts to write $GIT_DIR/shallow_XXXXXX if it's a shallow fetch, so the source repo must be writable. git:// servers do not need write access to repos and usually don't have it, which means cdab485 breaks shallow clone over git:// Instead of using a temporary file as the media for shallow points, we can send them over stdin to pack-objects as well. Prepend shallow SHA-1 with --shallow so pack-objects knows what is what. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-02-27shallow: automatically clean up shallow tempfilesLibravatar Jeff King1-6/+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>
2014-02-20rename read_replace_refs to check_replace_refsLibravatar Michael Haggerty1-1/+1
The semantics of this flag was changed in commit e1111cef23 inline lookup_replace_object() calls but wasn't renamed at the time to minimize code churn. Rename it now, and add a comment explaining its use. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-01-17Merge branch 'nd/shallow-clone'Libravatar Junio C Hamano1-4/+4
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 ...
2013-12-17Merge branch 'cc/starts-n-ends-with'Libravatar Junio C Hamano1-5/+5
Remove a few duplicate implementations of prefix/suffix comparison functions, and rename them to starts_with and ends_with. * cc/starts-n-ends-with: replace {pre,suf}fixcmp() with {starts,ends}_with() strbuf: introduce starts_with() and ends_with() builtin/remote: remove postfixcmp() and use suffixcmp() instead environment: normalize use of prefixcmp() by removing " != 0"
2013-12-10smart-http: support shallow fetch/cloneLibravatar Nguyễn Thái Ngọc Duy1-2/+0
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/+1
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: extend setup_*_shallow() to accept extra shallow commitsLibravatar Nguyễn Thái Ngọc Duy1-1/+1
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10make the sender advertise shallow commits to the receiverLibravatar Nguyễn Thái Ngọc Duy1-2/+4
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>
2013-12-05replace {pre,suf}fixcmp() with {starts,ends}_with()Libravatar Christian Couder1-5/+5
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>
2013-12-05Merge 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
2013-11-18Merge branch 'maint'Libravatar Junio C Hamano1-1/+0
Hotfix for recent regression while talking to upload-pack in a repository with many symbolic refs. * maint: Revert "upload-pack: send non-HEAD symbolic refs"
2013-11-18Revert "upload-pack: send non-HEAD symbolic refs"Libravatar Junio C Hamano1-1/+0
This reverts commit 5e7dcad771cb873e278a0571b46910d7c32e2f6c; there may be unbounded number of symbolic refs in the repository, but the capability header line in the on-wire protocol has a rather low length limit.
2013-11-08Merge branch 'jc/upload-pack-send-symref' into maintLibravatar Junio C Hamano1-6/+45
One long-standing flaw in the pack transfer protocol used by "git clone" was that there was no way to tell the other end which branch "HEAD" points at, and the receiving end needed to guess. A new capability has been defined in the pack protocol to convey this information so that cloning from a repository with more than one branches pointing at the same commit where the HEAD is at now reliably sets the initial branch in the resulting repository. * jc/upload-pack-send-symref: t5570: Update for clone-progress-to-stderr branch t5570: Update for symref capability clone: test the new HEAD detection logic connect: annotate refs with their symref information in get_remote_head() connect.c: make parse_feature_value() static upload-pack: send non-HEAD symbolic refs upload-pack: send symbolic ref information as capability upload-pack.c: do not pass confusing cb_data to mark_our_ref() t5505: fix "set-head --auto with ambiguous HEAD" test
2013-10-30Merge branch 'jc/upload-pack-send-symref'Libravatar Junio C Hamano1-6/+45
One long-standing flaw in the pack transfer protocol used by "git clone" was that there was no way to tell the other end which branch "HEAD" points at, and the receiving end needed to guess. A new capability has been defined in the pack protocol to convey this information so that cloning from a repository with more than one branches pointing at the same commit where the HEAD is at now reliably sets the initial branch in the resulting repository. * jc/upload-pack-send-symref: t5570: Update for clone-progress-to-stderr branch t5570: Update for symref capability clone: test the new HEAD detection logic connect: annotate refs with their symref information in get_remote_head() connect.c: make parse_feature_value() static upload-pack: send non-HEAD symbolic refs upload-pack: send symbolic ref information as capability upload-pack.c: do not pass confusing cb_data to mark_our_ref() t5505: fix "set-head --auto with ambiguous HEAD" test
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>
2013-10-23Merge branch 'nd/fetch-into-shallow' into maintLibravatar Junio C Hamano1-96/+32
When there is no sufficient overlap between old and new history during a "git fetch" into a shallow repository, objects that the sending side knows the receiving end has were unnecessarily sent. * 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
2013-10-17Merge branch 'jk/upload-pack-keepalive' into maintLibravatar Junio C Hamano1-1/+24
* jk/upload-pack-keepalive: upload-pack: bump keepalive default to 5 seconds upload-pack: send keepalive packets during pack computation
2013-09-20Merge branch 'jk/upload-pack-keepalive'Libravatar Junio C Hamano1-1/+24
When running "fetch -q", a long silence while the sender side computes the set of objects to send can be mistaken by proxies as dropped connection. The server side has been taught to send a small empty messages to keep the connection alive. * jk/upload-pack-keepalive: upload-pack: bump keepalive default to 5 seconds upload-pack: send keepalive packets during pack computation
2013-09-20Merge branch 'nd/fetch-into-shallow'Libravatar Junio C Hamano1-96/+32
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
2013-09-17upload-pack: send non-HEAD symbolic refsLibravatar Junio C Hamano1-0/+1
With the same mechanism as used to tell where "HEAD" points at to the other end, we can tell the target of other symbolic refs as well. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-09-17upload-pack: send symbolic ref information as capabilityLibravatar Junio C Hamano1-5/+43
One long-standing flaw in the pack transfer protocol was that there was no way to tell the other end which branch "HEAD" points at. With a capability "symref=HEAD:refs/heads/master", let the sender to tell the receiver what symbolic ref points at what ref. This capability can be repeated more than once to represent symbolic refs other than HEAD, such as "refs/remotes/origin/HEAD"). Add an infrastructure to collect symbolic refs, format them as extra capabilities and put it on the wire. For now, just send information on the "HEAD" and nothing else. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-09-17upload-pack.c: do not pass confusing cb_data to mark_our_ref()Libravatar Junio C Hamano1-1/+1
The callee does not use cb_data, and the caller is an intermediate function in a callchain that later wants to use the cb_data for its own use. Clarify the code by breaking the dataflow explicitly by not passing cb_data down to mark_our_ref(). Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-09-09upload-pack: bump keepalive default to 5 secondsLibravatar Jeff King1-1/+1
There is no reason not to turn on keepalives by default. They take very little bandwidth, and significantly less than the progress reporting they are replacing. And in the case that progress reporting is on, we should never need to send a keepalive anyway, as we will constantly be showing progress and resetting the keepalive timer. We do not necessarily know what the client's idea of a reasonable timeout is, so let's keep this on the low side of 5 seconds. That is high enough that we will always prefer our normal 1-second progress reports to sending a keepalive packet, but low enough that no sane client should consider the connection hung. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-09-09upload-pack: send keepalive packets during pack computationLibravatar Jeff King1-1/+24
When upload-pack has started pack-objects, there may be a quiet period while pack-objects prepares the pack (i.e., counting objects and delta compression). Normally we would see (and send to the client) progress information, but if "--quiet" is in effect, pack-objects will produce nothing at all until the pack data is ready. On a large repository, this can take tens of seconds (or even minutes if the system is loaded or the repository is badly packed). Clients or intermediate proxies can sometimes give up in this situation, assuming that the server or connection has hung. This patch introduces a "keepalive" option; if upload-pack sees no data from pack-objects for a certain number of seconds, it will send an empty sideband data packet to let the other side know that we are still working on it. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-08-28upload-pack: delegate rev walking in shallow fetch to pack-objectsLibravatar Nguyễn Thái Ngọc Duy1-96/+32
upload-pack has a special revision walking code for shallow recipients. It works almost like the similar code in pack-objects except: 1. in upload-pack, graft points could be added for deepening; 2. also when the repository is deepened, the shallow point will be moved further away from the tip, but the old shallow point will be marked as edge to produce more efficient packs. See 6523078 (make shallow repository deepening more network efficient - 2009-09-03). Pass the file to pack-objects via --shallow-file. This will override $GIT_DIR/shallow and give pack-objects the exact repository shape that upload-pack has. mark edge commits by revision command arguments. Even if old shallow points are passed as "--not" revisions as in this patch, they will not be picked up by mark_edges_uninteresting() because this function looks up to parents for edges, while in this case the edge is the children, in the opposite direction. This will be fixed in an later patch when all given uninteresting commits are marked as edges. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-08cache.h: move remote/connect API out of itLibravatar Junio C Hamano1-0/+1
The definition of "struct ref" in "cache.h", a header file so central to the system, always confused me. This structure is not about the local ref used by sha1-name API to name local objects. It is what refspecs are expanded into, after finding out what refs the other side has, to define what refs are updated after object transfer succeeds to what values. It belongs to "remote.h" together with "struct refspec". While we are at it, also move the types and functions related to the Git transport connection to a new header file connect.h Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-28upload-pack: ignore 'shallow' lines with unknown obj-idsLibravatar Michael Heemskerk1-1/+1
When the client sends a 'shallow' line for an object that the server does not have, the server currently dies with the error: "did not find object for shallow <obj-id>". The client may have truncated the history at the commit by fetching shallowly from a different server, or the commit may have been garbage collected by the server. In either case, this unknown commit is not relevant for calculating the pack that is to be sent and can be safely ignored, and it is not used when recomputing where the updated history of the client is cauterised. The documentation in technical/pack-protocol.txt has been updated to remove the restriction that "Clients MUST NOT mention an obj-id which it does not know exists on the server". This requirement is not realistic because clients cannot know whether an object has been garbage collected by the server. Signed-off-by: Michael Heemskerk <mheemskerk@atlassian.com> Reviewed-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-04-01Merge branch 'jk/pkt-line-cleanup'Libravatar Junio C Hamano1-28/+12
Clean up pkt-line API, implementation and its callers to make them more robust. * jk/pkt-line-cleanup: do not use GIT_TRACE_PACKET=3 in tests remote-curl: always parse incoming refs remote-curl: move ref-parsing code up in file remote-curl: pass buffer straight to get_remote_heads teach get_remote_heads to read from a memory buffer pkt-line: share buffer/descriptor reading implementation pkt-line: provide a LARGE_PACKET_MAX static buffer pkt-line: move LARGE_PACKET_MAX definition from sideband pkt-line: teach packet_read_line to chomp newlines pkt-line: provide a generic reading function with options pkt-line: drop safe_write function pkt-line: move a misplaced comment write_or_die: raise SIGPIPE when we get EPIPE upload-archive: use argv_array to store client arguments upload-archive: do not copy repo name send-pack: prefer prefixcmp over memcmp in receive_status fetch-pack: fix out-of-bounds buffer offset in get_ack upload-pack: remove packet debugging harness upload-pack: do not add duplicate objects to shallow list upload-pack: use get_sha1_hex to parse "shallow" lines
2013-03-25Merge branch 'jk/peel-ref'Libravatar Junio C Hamano1-4/+2
Recent optimization broke shallow clones. * jk/peel-ref: upload-pack: load non-tip "want" objects from disk upload-pack: make sure "want" objects are parsed upload-pack: drop lookup-before-parse optimization
2013-03-21Merge branch 'jc/fetch-raw-sha1'Libravatar Junio C Hamano1-6/+19
Allows requests to fetch objects at any tip of refs (including hidden ones). It seems that there may be use cases even outside Gerrit (e.g. $gmane/215701). * jc/fetch-raw-sha1: fetch: fetch objects by their exact SHA-1 object names upload-pack: optionally allow fetching from the tips of hidden refs fetch: use struct ref to represent refs to be fetched parse_fetch_refspec(): clarify the codeflow a bit
2013-03-16upload-pack: load non-tip "want" objects from diskLibravatar Jeff King1-2/+2
It is a long-time security feature that upload-pack will not serve any "want" lines that do not correspond to the tip of one of our refs. Traditionally, this was enforced by checking the objects in the in-memory hash; they should have been loaded and received the OUR_REF flag during the advertisement. The stateless-rpc mode, however, has a race condition here: one process advertises, and another receives the want lines, so the refs may have changed in the interim. To address this, commit 051e400 added a new verification mode; if the object is not OUR_REF, we set a "has_non_tip" flag, and then later verify that the requested objects are reachable from our current tips. However, we still die immediately when the object is not in our in-memory hash, and at this point we should only have loaded our tip objects. So the check_non_tip code path does not ever actually trigger, as any non-tip objects would have already caused us to die. We can fix that by using parse_object instead of lookup_object, which will load the object from disk if it has not already been loaded. We still need to check that parse_object does not return NULL, though, as it is possible we do not have the object at all. A more appropriate error message would be "no such object" rather than "not our ref"; however, we do not want to leak information about what objects are or are not in the object database, so we continue to use the same "not our ref" message that would be produced by an unreachable object. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-16upload-pack: make sure "want" objects are parsedLibravatar Jeff King1-1/+1
When upload-pack receives a "want" line from the client, it adds it to an object array. We call lookup_object to find the actual object, which will only check for objects already in memory. This works because we are expecting to find objects that we already loaded during the ref advertisement. We use the resulting object structs for a variety of purposes. Some of them care only about the object flags, but others care about the type of the object (e.g., ok_to_give_up), or even feed them to the revision parser (when --depth is used), which assumes that objects it receives are fully parsed. Once upon a time, this was OK; any object we loaded into memory would also have been parsed. But since 435c833 (upload-pack: use peel_ref for ref advertisements, 2012-10-04), we try to avoid parsing objects during the ref advertisement. This means that lookup_object may return an object with a type of OBJ_NONE. The resulting mess depends on the exact set of objects, but can include the revision parser barfing, or the shallow code sending the wrong set of objects. This patch teaches upload-pack to parse each "want" object as we receive it. We do not replace the lookup_object call with parse_object, as the current code is careful not to let just any object appear on a "want" line, but rather only one we have previously advertised (whereas parse_object would actually load any arbitrary object from disk). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-16upload-pack: drop lookup-before-parse optimizationLibravatar Jeff King1-3/+1
When we receive a "have" line from the client, we want to load the object pointed to by the sha1. However, we are careful to do: o = lookup_object(sha1); if (!o || !o->parsed) o = parse_object(sha1); to avoid loading the object from disk if we have already seen it. However, since ccdc603 (parse_object: try internal cache before reading object db), parse_object already does this optimization internally. We can just call parse_object directly. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-20pkt-line: provide a LARGE_PACKET_MAX static bufferLibravatar Jeff King1-7/+5
Most of the callers of packet_read_line just read into a static 1000-byte buffer (callers which handle arbitrary binary data already use LARGE_PACKET_MAX). This works fine in practice, because: 1. The only variable-sized data in these lines is a ref name, and refs tend to be a lot shorter than 1000 characters. 2. When sending ref lines, git-core always limits itself to 1000 byte packets. However, the only limit given in the protocol specification in Documentation/technical/protocol-common.txt is LARGE_PACKET_MAX; the 1000 byte limit is mentioned only in pack-protocol.txt, and then only describing what we write, not as a specific limit for readers. This patch lets us bump the 1000-byte limit to LARGE_PACKET_MAX. Even though git-core will never write a packet where this makes a difference, there are two good reasons to do this: 1. Other git implementations may have followed protocol-common.txt and used a larger maximum size. We don't bump into it in practice because it would involve very long ref names. 2. We may want to increase the 1000-byte limit one day. Since packets are transferred before any capabilities, it's difficult to do this in a backwards-compatible way. But if we bump the size of buffer the readers can handle, eventually older versions of git will be obsolete enough that we can justify bumping the writers, as well. We don't have plans to do this anytime soon, but there is no reason not to start the clock ticking now. Just bumping all of the reading bufs to LARGE_PACKET_MAX would waste memory. Instead, since most readers just read into a temporary buffer anyway, let's provide a single static buffer that all callers can use. We can further wrap this detail away by having the packet_read_line wrapper just use the buffer transparently and return a pointer to the static storage. That covers most of the cases, and the remaining ones already read into their own LARGE_PACKET_MAX buffers. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-20pkt-line: teach packet_read_line to chomp newlinesLibravatar Jeff King1-8/+0
The packets sent during ref negotiation are all terminated by newline; even though the code to chomp these newlines is short, we end up doing it in a lot of places. This patch teaches packet_read_line to auto-chomp the trailing newline; this lets us get rid of a lot of inline chomping code. As a result, some call-sites which are not reading line-oriented data (e.g., when reading chunks of packfiles alongside sideband) transition away from packet_read_line to the generic packet_read interface. This patch converts all of the existing callsites. Since the function signature of packet_read_line does not change (but its behavior does), there is a possibility of new callsites being introduced in later commits, silently introducing an incompatibility. However, since a later patch in this series will change the signature, such a commit would have to be merged directly into this commit, not to the tip of the series; we can therefore ignore the issue. This is an internal cleanup and should produce no change of behavior in the normal case. However, there is one corner case to note. Callers of packet_read_line have never been able to tell the difference between a flush packet ("0000") and an empty packet ("0004"), as both cause packet_read_line to return a length of 0. Readers treat them identically, even though Documentation/technical/protocol-common.txt says we must not; it also says that implementations should not send an empty pkt-line. By stripping out the newline before the result gets to the caller, we will now treat the newline-only packet ("0005\n") the same as an empty packet, which in turn gets treated like a flush packet. In practice this doesn't matter, as neither empty nor newline-only packets are part of git's protocols (at least not for the line-oriented bits, and readers who are not expecting line-oriented packets will be calling packet_read directly, anyway). But even if we do decide to care about the distinction later, it is orthogonal to this patch. The right place to tighten would be to stop treating empty packets as flush packets, and this change does not make doing so any harder. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-20pkt-line: drop safe_write functionLibravatar Jeff King1-1/+2
This is just write_or_die by another name. The one distinction is that write_or_die will treat EPIPE specially by suppressing error messages. That's fine, as we die by SIGPIPE anyway (and in the off chance that it is disabled, write_or_die will simulate it). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-20upload-pack: remove packet debugging harnessLibravatar Jeff King1-9/+0
If you set the GIT_DEBUG_SEND_PACK environment variable, upload-pack will dump lines it receives in the receive_needs phase to a descriptor. This debugging harness is a strict subset of what GIT_TRACE_PACKET can do. Let's just drop it in favor of that. A few tests used GIT_DEBUG_SEND_PACK to confirm which objects get sent; we have to adapt them to the new output format. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-20upload-pack: do not add duplicate objects to shallow listLibravatar Jeff King1-2/+4
When the client tells us it has a shallow object via "shallow <sha1>", we make sure we have the object, mark it with a flag, then add it to a dynamic array of shallow objects. This means that a client can get us to allocate arbitrary amounts of memory just by flooding us with shallow lines (whether they have the objects or not). You can demonstrate it easily with: yes '0035shallow e83c5163316f89bfbde7d9ab23ca2e25604af290' | git-upload-pack git.git We already protect against duplicates in want lines by checking if our flag is already set; let's do the same thing here. Note that a client can still get us to allocate some amount of memory by marking every object in the repo as "shallow" (or "want"). But this at least bounds it with the number of objects in the repository, which is not under the control of an upload-pack client. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-20upload-pack: use get_sha1_hex to parse "shallow" linesLibravatar Jeff King1-1/+1
When we receive a line like "shallow <sha1>" from the client, we feed the <sha1> part to get_sha1. This is a mistake, as the argument on a shallow line is defined by Documentation/technical/pack-protocol.txt to contain an "obj-id". This is never defined in the BNF, but it is clear from the text and from the other uses that it is meant to be a hex sha1, not an arbitrary identifier (and that is what fetch-pack has always sent). We should be using get_sha1_hex instead, which doesn't allow the client to request arbitrary junk like "HEAD@{yesterday}". Because this is just marking shallow objects, the client couldn't actually do anything interesting (like fetching objects from unreachable reflog entries), but we should keep our parsing tight to be on the safe side. Because get_sha1 is for the most part a superset of get_sha1_hex, in theory the only behavior change should be disallowing non-hex object references. However, there is one interesting exception: get_sha1 will only parse a 40-character hex sha1 if the string has exactly 40 characters, whereas get_sha1_hex will just eat the first 40 characters, leaving the rest. That means that current versions of git-upload-pack will not accept a "shallow" packet that has a trailing newline, even though the protocol documentation is clear that newlines are allowed (even encouraged) in non-binary parts of the protocol. This never mattered in practice, though, because fetch-pack, contrary to the protocol documentation, does not include a newline in its shallow lines. JGit follows its lead (though it correctly is strict on the parsing end about wanting a hex object id). We do not adjust fetch-pack to send newlines here, as it would break communication with older versions of git (and there is no actual benefit to doing so, except for consistency with other parts of the protocol). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-17Merge branch 'jc/hidden-refs'Libravatar Junio C Hamano1-30/+33
Allow the server side to redact the refs/ namespace it shows to the client. Will merge to 'master'. * jc/hidden-refs: upload/receive-pack: allow hiding ref hierarchies upload-pack: simplify request validation upload-pack: share more code
2013-02-07upload-pack: optionally allow fetching from the tips of hidden refsLibravatar Junio C Hamano1-6/+19
With uploadpack.allowtipsha1inwant configuration option set, future versions of "git fetch" that allow an exact object name (likely to have been obtained out of band) on the LHS of the fetch refspec can make a request with a "want" line that names an object that may not have been advertised due to transfer.hiderefs configuration. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-07upload/receive-pack: allow hiding ref hierarchiesLibravatar Junio C Hamano1-1/+13
A repository may have refs that are only used for its internal bookkeeping purposes that should not be exposed to the others that come over the network. Teach upload-pack to omit some refs from its initial advertisement by paying attention to the uploadpack.hiderefs multi-valued configuration variable. Do the same to receive-pack via the receive.hiderefs variable. As a convenient short-hand, allow using transfer.hiderefs to set the value to both of these variables. Any ref that is under the hierarchies listed on the value of these variable is excluded from responses to requests made by "ls-remote", "fetch", etc. (for upload-pack) and "push" (for receive-pack). Because these hidden refs do not count as OUR_REF, an attempt to fetch objects at the tip of them will be rejected, and because these refs do not get advertised, "git push :" will not see local branches that have the same name as them as "matching" ones to be sent. An attempt to update/delete these hidden refs with an explicit refspec, e.g. "git push origin :refs/hidden/22", is rejected. This is not a new restriction. To the pusher, it would appear that there is no such ref, so its push request will conclude with "Now that I sent you all the data, it is time for you to update the refs. I saw that the ref did not exist when I started pushing, and I want the result to point at this commit". The receiving end will apply the compare-and-swap rule to this request and rejects the push with "Well, your update request conflicts with somebody else; I see there is such a ref.", which is the right thing to do. Otherwise a push to a hidden ref will always be "the last one wins", which is not a good default. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-01Merge branch 'nd/fetch-depth-is-broken'Libravatar Junio C Hamano1-3/+10
"git fetch --depth" was broken in at least three ways. The resulting history was deeper than specified by one commit, it was unclear how to wipe the shallowness of the repository with the command, and documentation was misleading. * nd/fetch-depth-is-broken: fetch: elaborate --depth action upload-pack: fix off-by-one depth calculation in shallow clone fetch: add --unshallow for turning shallow repo into complete one
2013-01-28upload-pack: simplify request validationLibravatar Junio C Hamano1-17/+11
Long time ago, we used to punt on a large (read: asking for more than 256 refs) fetch request and instead sent a full pack, because we couldn't fit many refs on the command line of rev-list we run internally to enumerate the objects to be sent. To fix this, 565ebbf (upload-pack: tighten request validation., 2005-10-24), added a check to count the number of refs in the request and matched with the number of refs we advertised, and changed the invocation of rev-list to pass "--all" to it, still keeping us under the command line argument limit. However, these days we feed the list of objects requested and the list of objects the other end is known to have via standard input, so there is no longer a valid reason to special case a full clone request. Remove the code associated with "create_full_pack" to simplify the logic. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-01-18upload-pack: share more codeLibravatar Junio C Hamano1-17/+14
We mark the objects pointed at our refs with "OUR_REF" flag in two functions (mark_our_ref() and send_ref()), but we can just use the former as a helper for the latter. Update the way mark_our_ref() prepares in-core object to use lookup_unknown_object() to delay reading the actual object data, just like we did in 435c833 (upload-pack: use peel_ref for ref advertisements, 2012-10-04). Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-01-14Merge branch 'nd/upload-pack-shallow-must-be-commit'Libravatar Junio C Hamano1-0/+2
A minor consistency check patch that does not have much relevance to the real world. * nd/upload-pack-shallow-must-be-commit: upload-pack: only accept commits from "shallow" line
2013-01-11fetch: add --unshallow for turning shallow repo into complete oneLibravatar Nguyễn Thái Ngọc Duy1-3/+10
The user can do --depth=2147483647 (*) for restoring complete repo now. But it's hard to remember. Any other numbers larger than the longest commit chain in the repository would also do, but some guessing may be involved. Make easy-to-remember --unshallow an alias for --depth=2147483647. Make upload-pack recognize this special number as infinite depth. The effect is essentially the same as before, except that upload-pack is more efficient because it does not have to traverse to the bottom anymore. The chance of a user actually wanting exactly 2147483647 commits depth, not infinite, on a repository with a history that long, is probably too small to consider. The client can learn to add or subtract one commit to avoid the special treatment when that actually happens. (*) This is the largest positive number a 32-bit signed integer can contain. JGit and older C Git store depth as "int" so both are OK with this number. Dulwich does not support shallow clone. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>