A compaction of reftables is just copying the results of a
MergedReftable into a ReftableWriter. Wrap this up into a utility.
Change-Id: I6f5677d923e9628993a2d8b4b007a9b8662c9045
MergedReftable combines multiple reference tables together in a stack,
allowing higher/later tables to shadow earlier/lower tables. This
forms the basis of a transaction system, where each transaction writes
a new reftable containing only the modified references, and readers
perform a merge on the fly to get the latest value.
Change-Id: Ic2cb750141e8c61a8b2726b2eb95195acb6ddc83
Add additional test cases for looking up entries within a namespace
such as refs/heads/ or refs/tags/, where the seek is passed a name
that ends with '/'.
Change-Id: I5f944de7518cd0090374bddba48d4dd3955a8d72
Add more test cases that cover larger collections of
references, verifying every reference is accessible
both by scan and by seek.
Change-Id: Icada59fdcfc92a4634f6df61baaebb1c37b75d98
This set of tests covers primitive storage of an empty
file, and each type of supported reference.
Change-Id: I3bdff35cae8ae27283051932f20608b3ac353559
ReftableReader provides sequential scanning support over all
references, a range of references within a subtree (such as
"refs/heads/"), and lookup of a single reference. Reads can be
accelerated by an index block, if it was created by the writer.
The BlockSource interface provides an abstraction to read from the
reftable's backing storage, supporting a future commit to connect
to JGit DFS and the DfsBlockCache.
Change-Id: Ib0dc5fa937d0c735f2a9ff4439d55c457fea7aa8
This is a simple writer to create reftable formatted files. Follow-up
commits will add support for reading from reftable, debugging
utilities, and tests.
Change-Id: I3d520c3515c580144490b0b45433ea175a3e6e11
Some repositories contain a lot of references (e.g. android at 866k,
rails at 31k). The reftable format provides:
- Near constant time lookup for any single reference, even when the
repository is cold and not in process or kernel cache.
- Near constant time verification a SHA-1 is referred to by at least
one reference (for allow-tip-sha1-in-want).
- Efficient lookup of an entire namespace, such as `refs/tags/`.
- Support atomic push `O(size_of_update)` operations.
- Combine reflog storage with ref storage.
Change-Id: I29d0ff1eee475845660ac9173413e1407adcfbf2
git-core follows HTTP redirects so JGit should also provide this.
Implement config setting http.followRedirects with possible values
"false" (= never), "true" (= always), and "initial" (only on GET, but
not on POST).[1]
We must do our own redirect handling and cannot rely on the support
that the underlying real connection may offer. At least the JDK's
HttpURLConnection has two features that get in the way:
* it does not allow cross-protocol redirects and thus fails on
http->https redirects (for instance, on Github).
* it translates a redirect after a POST to a GET unless the system
property "http.strictPostRedirect" is set to true. We don't want
to manipulate that system setting nor require it.
Additionally, git has its own rules about what redirects it accepts;[2]
for instance, it does not allow a redirect that adds query arguments.
We handle response codes 301, 302, 303, and 307 as per RFC 2616.[3]
On POST we do not handle 303, and we follow redirects only if
http.followRedirects == true.
Redirects are followed only a certain number of times. There are two
ways to control that limit:
* by default, the limit is given by the http.maxRedirects system
property that is also used by the JDK. If the system property is
not set, the default is 5. (This is much lower than the JDK default
of 20, but I don't see the value of following so many redirects.)
* this can be overwritten by a http.maxRedirects git config setting.
The JGit http.* git config settings are currently all global; JGit has
no support yet for URI-specific settings "http.<pattern>.name". Adding
support for that is well beyond the scope of this change.
Like git-core, we log every redirect attempt (LOG.info) so that users
may know about the redirection having occurred.
Extends the test framework to configure an AppServer with HTTPS support
so that we can test cloning via HTTPS and redirections involving HTTPS.
[1] https://git-scm.com/docs/git-config
[2] 6628eb41db
[3] https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
CQ: 13987
Bug: 465167
Change-Id: I86518cb76842f7d326b51f8715e3bbf8ada89859
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Currently there is no way to determine the precise changes done
to the working tree by a JGit command. Only the CheckoutCommand
actually provides access to the lists of modified, deleted, and
to-be-deleted files, but those lists may be inaccurate (since they
are determined up-front before the working tree is modified) if
the actual checkout then fails halfway through. Moreover, other
JGit commands that modify the working tree do not offer any way to
figure out which files were changed.
This poses problems for EGit, which may need to refresh parts of the
Eclipse workspace when JGit has done java.io file operations.
Provide the foundations for better file change tracking: the working
tree is modified exclusively in DirCacheCheckout. Make it emit a new
type of RepositoryEvent that lists all files that were modified or
deleted, even if the checkout failed halfway through. We update the
'updated' and 'removed' lists determined up-front in case of file
system problems to reflect the actual state of changes made.
EGit thus can register a listener for these events and then knows
exactly which parts of the Eclipse workspace may need to be refreshed.
Two commands manage checking out individual DirCacheEntries themselves:
checkout specific paths, and applying a stash with untracked files.
Make those two also emit such a new WorkingTreeModifiedEvent.
Furthermore, merges may modify files, and clean, rm, and stash create
may delete files.
CQ: 13969
Bug: 500106
Change-Id: I7a100aee315791fa1201f43bbad61fbae60b35cb
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
When creating a new PackFile instance it is specified whether this pack
has an associated bitmap index file or not. This information is cached
and the public method getBitmapIndex() will always assume a bitmap index
file must exist if the cached data tells so. But it may happen that the
packfiles are repacked during a gc in a different process causing the
packfile, bitmap-index and index file to be deleted. Since JGit still
has an open FileHandle on the packfile this file is not really deleted
and can still be accessed. But index and bitmap index file are deleted.
Fix getBitmapIndex() to invalidate the cached packfile instance if such
a situation occurs.
This problem showed up when a gerrit server was serving repositories
which where garbage collected with native git regularly. Fetch and
clone commands for certain repositories failed permanently after a
native git gc had deleted old bitmap index files.
Change-Id: I8e620bec74dd3f310ba42024f9a657062f868f0e
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Per the git config documentation[1], pushInsteadOf is ignored when
a remote has explicit pushUris.
Implement this, and adapt tests.
Up to now JGit mistakenly applied pushInsteadOf also to existing
pushUris. If some repositories had relied on this mis-feature,
pushes may newly suddenly fail (the uncritical case; the config
just needs to be fixed) or even still succeed but push to unexpected
places, namely to the non-rewritten pushUrls (the critical case).
The release notes should point out this change.
[1] https://git-scm.com/docs/git-config
Bug: 393170
Change-Id: I38c83204d2ac74f88f3d22d0550bf5ff7ee86daf
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
According to [1], pushInsteadOf is
1. applied to the uris, not to the pushUris
2. ignored if a remote has an explicit pushUri
JGit applied it only to the pushUris. As a result, pushInsteadOf was
ignored for remotes having only a uri, but no pushUri.
This commit implements (1) if there are no pushUris. I did not dare
implement (2) because:
* there are explicit tests for it that expect that pushInsteadOf gets
applied to existing pushUrls, and
* people may actually use and rely on this JGit behavior.
[1] https://git-scm.com/docs/git-config
Bug: 393170
Change-Id: I6dacbf1768a105190c2a8c5272e7880c1c9c943a
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
This matches the proposal that has been discussed at length on
git-core mailing list and seems to be the accepted convention.
Change-Id: I9f6ab15144826893d1e2a4b48a2d657d6dd445ec
Otherwise fancy combinations of attributes (binary or -text in
combination with crlf or eol) may result in the corruption of binary
data.
Bug: 520910
Change-Id: I3ffc666c13d1b9d2ed987b69a67bfc7f42ccdbfc
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Attribute rules must match against the entry path relative to the
attribute node containing the rule. The global entry path is to be
used only for the init and the global node (and of course the root
node).
Bug: 520677
Change-Id: I80389a2dc272a72312729ccd5358d7c75e1ea20a
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Happily, most anonymous SectionParser implementations can be replaced
with FooConfig::new, as long as the constructor takes a single Config
arg. Many of these, the non-public ones, can in turn be inlined. A few
remaining SectionParsers can be lambdas.
Change-Id: I3f563e752dfd2007dd3a48d6d313d20e2685943a
This avoids executing mergeAlgorithm.merge on binary data, which is
unlikely to be useful.
Arguably, binary data should not make it to
ResolveMerger#contentMerge, but this approach has the following
advantages:
* binary detection is exact, since it doesn't only look at the start
of the blob.
* it is cheap, as we have to iterate over the bytes anyway to find
'\n'.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Change-Id: I424295df1dc60a719859d9d7c599067891b15792
Very short abbreviations that are under 8 hex digits do not
have values in w2. Use w1 as the Java hashCode() instead, so
that the prefix of the abbreviation is always included in the
hashing function used by any java.util.Collection type.
Change-Id: Idaf69f86b62630ba4a022d31b4c293c6d138f557
SpotBugs [1] is the spiritual successor of FindBugs, carrying on from
the point where it left off with support of its community.
[1] http://spotbugs.readthedocs.io/
Change-Id: I127f2c54b04265b6565e780116617ffa8a4d7eaf
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
In a server scenario such as Gerrit Code Review, there may be many
atomic BatchRefUpdates contending for locks on both the packed-refs file
and some subset of loose refs. We already retry lock acquisition to
improve this situation slightly, but we can do better by using an
in-process lock. This way, instead of retrying and potentially exceeding
their timeout, different threads sharing the same Repository instance
can wait on a fair lock without having to touch the disk lock. Since a
server is probably already using RepositoryCache anyway, there is a high
likelihood of reusing the Repository instance.
Change-Id: If5dd1dc58f0ce62f26131fd5965a0e21a80e8bd3
If a repo frequently uses PackedBatchRefUpdates, there is likely to be
contention on the packed-refs file, so it's not appropriate to fail
immediately the first time we fail to acquire a lock. Add some logic to
RefDirectory to support general retrying of lock acquisition.
Currently, there is a hard-coded wait starting at 100ms and backing off
exponentially to 1600ms, for about 3s of total wait. This is no worse
than the hard-coded backoff that JGit does elsewhere, e.g. in
FileUtils#delete. One can imagine a scheme that uses per-repository
configuration of backoff, and the current interface would support this
without changing any callers.
Change-Id: I4764e11270d9336882483eb698f67a78a401c251
Shawn Pearce
Thomas Wolf
Christian Halstrick
Matthias Sohn
Dave Borowitz
David Pursehouse
Han-Wen Nienhuys
Terry Parker