When running on NFS there was a chance that JGits LockFile
semantic is broken because File#createNewFile() may allow
multiple clients to create the same file in parallel. This
change provides a fix which is only used when the new config
option core.supportsAtomicCreateNewFile is set to false. The
default for this option is true. This option can only be set in the
global or the system config file. The repository config file is not
taken into account in this case.
If the config option core.supportsAtomicCreateNewFile is true
then File#createNewFile() is trusted and the behaviour doesn't
change.
But if core.supportsAtomicCreateNewFile is set to false then after
successful creation of the lock file a hardlink to that lock file is
created and the attribute nlink of the lock file is checked to be 2. If
multiple clients manage to create the same lock file nlink would be
greater than 2 showing the error.
This expensive workaround is described in
https://www.time-travellers.org/shane/papers/NFS_considered_harmful.html
section III.d) "Exclusive File Creation"
Change-Id: I3d2cc48d8eb280d5f7039eb94da37804f903be6a
Then list of packed refs was cached in RefDirectory based on mtime of
the packed-refs file. This may fail on NFS when attributes are cached.
A cached mtime of the packed-refs file could cause JGit to trust the
cached content of this file and to overlook that the file is modified.
Honor the config option trustFolderStats and always read the packed-refs
content if the option is false. By default this option is set to true
and this fix is not active.
Change-Id: I2b65cfaa8f4aba2efbf8a5e865d3f09f927e2eec
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>
The cgit archive command creates a prefix (root) directory entry
in the archive file. That entry's time is set to the commit time.
This patch makes jgit's behavior consistent with with cgit:
prefix: hoge/ -> creates prefix directory "hoge/" entry.
prefix: hoge//// -> creates prefix directory "hoge/" entry.
prefix: hoge/foo -> does not create prefix directory entry, but for
each file/directory entry, prefix is added.
Change-Id: I2610e40ce37972c5f7456fdca6337e7fb07176e5
Signed-off-by: Yasuhiro Takagi <ytakagi@bea.hi-ho.ne.jp>
When running an automatic GC on a FileRepository, when the caller
passes a NullProgressMonitor, run the GC in a background thread. Use a
thread pool of size 1 to limit the number of background threads spawned
for background gc in the same application. In the next minor release we
can make the thread pool configurable.
In some cases, the auto GC limit is lower than the true number of
unreachable loose objects, so auto GC will run after every (e.g) fetch
operation. This leads to the appearance of poor fetch performance.
Since these GCs will never make progress (until either the objects
become referenced, or the two week timeout expires), blocking on them
simply reduces throughput.
In the event that an auto GC would make progress, it's still OK if it
runs in the background. The progress will still happen.
This matches the behavior of regular git.
Git (and now jgit) uses the lock file for gc.log to prevent simultaneous
runs of background gc. Further, it writes errors to gc.log, and won't
run background gc if that file is present and recent. If gc.log is too
old (according to the config gc.logexpiry), it will be ignored.
Change-Id: I3870cadb4a0a6763feff252e6eaef99f4aa8d0df
Signed-off-by: David Turner <dturner@twosigma.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
This is a workaround for
https://bugs.openjdk.java.net/browse/JDK-4666701.
Change-Id: Idd04657e8d95a841d72230f8881b6b899daadbc2
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
In the repo manifest documentation [1] the fetch attribute is marked
as "#REQUIRED".
If the fetch attribute is not specified, this would previously result in
NullPointerException. Throw a SAXException instead.
[1] https://gerrit.googlesource.com/git-repo/+/master/docs/manifest-format.txt
Change-Id: Ib8ed8cee6074fe6bf8f9ac6fc7a1664a547d2d49
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
* Parse the base URL in ManifestParser construction. This will signal
errors earlier.
* Simplify stripping of trailing slashes.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Change-Id: I4a86f68c9d7737f71cf20352cfe26288fbd2b463
Add NoPackSignatureException and UnsupportedPackVersionException to
explicitly mark permanent unrecoverable problems with a pack
Assume problem with a pack is permanent only if we are sure the
exception signals a non-transient problem we can't recover from:
- AccessDeniedException: we lack permissions
- CorruptObjectException: we detected corruption
- EOFException: file ended unexpectedly
- NoPackSignatureException: pack has no pack signature
- NoSuchFileException: file has gone missing
- PackMismatchException: pack no longer matches its index
- UnpackException: unpacking failed
- UnsupportedPackIndexVersionException: unsupported pack index version
- UnsupportedPackVersionException: unsupported pack version
Do not attempt to handle Errors since they are thrown for serious
problems applications should not try to recover from.
Change-Id: I2c416ce2b0e23255c4fb03a3f9a0ee237f7a484a
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
A packfile random file open operation may fail with a
FileNotFoundException even if the file exists, possibly
for the temporary lack of resources.
Instead of managing the FileNotFoundException as any generic
IOException it is best to rethrow the exception but prevent
the packfile for being flagged as invalid until it is actually
opened and read successfully or unsuccessfully.
Bug: 514170
Change-Id: Ie37edba2df77052bceafc0b314fd1d487544bf35
Signed-off-by: Luca Milanesio <luca.milanesio@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Add a new API method to set the recurse mode, and pass the mode into
the fetch command.
Extend the existing FetchCommandRecurseSubmodulesTest to also perform
the same tests for fetch. Rename the test class accordingly.
Change-Id: I12553af47774b4778f7011e1018bd575a7909bd0
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
This provides a place to declare visibility restrictions and
transitive dependencies for each library.
Other targets should only declare dependencies on what they directly
use, making dependencies easier to maintain.
Trim the dependencies of org.eclipse.jgit:jgit to follow that rule.
It declares dependencies on Apache httpcomponents and the servlet
API but doesn't use them.
Tested:
* 'bazel build //...' succeeds
* applying the change https://gerrit-review.googlesource.com/90843
to a copy of Gerrit, following the instructions there, and running
'bazel test //...' in that copy of Gerrit still succeeds
Change-Id: I3ab958ce8b3227019cdbe4cc81e0f042e1541034
This fixes Bazel build:
in srcs attribute of java_library rule //org.eclipse.jgit:jgit:
file '//org.eclipse.jgit:src/org/eclipse/jgit/util/sha1/SHA1.recompress'
is misplaced here (expected .java, .srcjar or .properties).
Another option that was considered is to exclude the non source files.
Change-Id: I7083f27a4a49bf6681c85c7cf7b08a83c9a70c77
Signed-off-by: David Ostrovsky <david@ostrovsky.org>
The FileNotFoundException is typically raised in three conditions:
1. file doesn't exist
2. incompatible read vs. read/write open modes
3. filesystem locking
4. temporary lack of resources (e.g. too many open files)
1. is already managed, 2. would never happen as packs are not
overwritten while with 3. and 4. it is worth logging the exception and
retrying to read the pack again.
Log transient errors using an exponential backoff strategy to avoid
flooding the logs with the same error if consecutive retries to access
the pack fail repeatedly.
Bug: 513435
Change-Id: I03c6f6891de3c343d3d517092eaa75dba282c0cd
Signed-off-by: Luca Milanesio <luca.milanesio@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
The submodule.name.fetchRecurseSubmodules value was being read from the
configuration of the submodule, but it should be read from the config
of the parent repository.
Also, the fetch.recurseSubmodules value from the parent repository's
configuration was not being considered at all.
Fix both of these and add tests. Now the precedence of the recurse mode
is determined as follows:
1. Value passed to the API
2. Value configured in submodule.name.fetchRecurseSubmodules
3. Value configured in fetch.recurseSubmodules
4. Default to "on demand"
Change-Id: Ic23b7c40b5f39135fb3fd754c597dd4bcc94240c
Extend FetchCommand to expose a new method, setRecurseSubmodules(mode),
which allows to set the mode to ON, OFF or ON_DEMAND.
After fetching a repository, its submodules are recursively fetched:
- When the mode is YES, submodules are always fetched.
- When the mode is NO, submodules are not fetched.
- When the mode is ON_DEMAND, submodules are only fetched when the
parent repository receives an update of the submodule and the new
revision is not already in the submodule.
The mode is determined in the following order of precedence:
- Value specified in the API call using setRecurseSubmodules.
- Value specified in the repository's config under the key
submodule.name.fetchRecurseSubmodules
- Defaults to ON_DEMAND if neither of the previous is set.
Extend FetchResult to recursively include results for submodules, as
a map of the submodule path to an instance of FetchResult.
Test setup is based on testCloneRepositoryWithNestedSubmodules.
Change-Id: Ibc841683763307cb76e78e142e0da5b11b1add2a
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
This operation was added recently with the goal to provide some
way to auto-correct invalid user input, or to provide a correction
suggestion to the user -- EGit uses it now that way. But the initial
implementation was very restrictive; it removed all non-ASCII
characters and even slashes.
Understandably end users were not happy with that. Git has no such
restriction to ASCII-only; nor does JGit. Branch names should be
meaningful to the end user, and if a user-supplied branch name is
invalid for technical reasons, a "normalized" name should still
be meaningful to the user.
Rewrite to attempt a minimal fix such that the result will pass
isValidRefName.
* Replace all Unicode whitespace by underscore.
* Replace troublesome special characters by dash.
* Collapse sequences of underscores, dots, and dashes.
* Remove underscores, dots, and dashes following slashes, and
collapse sequences of slashes.
* Strip leading and trailing sequences of slashes, dots, dashes,
and underscores.
* Avoid the ".lock" extension.
* Avoid the Windows reserved device names.
* If input name is null return an empty String so callers don't need to
check for null.
This still allows branch names with single slashes as separators
between components, avoids some pitfalls that isValidRefName() tests
for, and leaves other character untouched and thus allows non-ASCII
branch names.
Also move the function from the bottom of the file up to where
isValidRefName is implemented.
Bug: 512508
Change-Id: Ia0576d9b2489162208c05e51c6d54e9f0c88c3a7
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Update SHA1 class to include a Java port of sha1dc[1]'s ubc_check,
which can detect the attack pattern used by the SHAttered[2] authors.
Given the shattered example files that have the same SHA-1, this
modified implementation can identify there is risk of collision given
only one file in the pair:
$ jgit ...
[main] WARN org.eclipse.jgit.util.sha1.SHA1 - SHA-1 collision 38762cf7f55934b34d179ae6a4c80cadccbb7f0a
When JGit detects probability of a collision the SHA1 class now warns
on the logger, reporting the object's SHA-1 hash, and then throws a
Sha1CollisionException to the caller.
From the paper[3] by Marc Stevens, the probability of a false positive
identification of a collision is about 14 * 2^(-160), sufficiently low
enough for any detected collision to likely be a real collision.
git-core[4] may adopt sha1dc before the system migrates to an entirely
new hash function. This commit enables JGit to remain compatible with
that move to sha1dc, and help protect users by warning if similar
attacks as SHAttered are identified.
Performance declined about 8% (detection off), now:
MessageDigest 238.41 MiB/s
MessageDigest 244.52 MiB/s
MessageDigest 244.06 MiB/s
MessageDigest 242.58 MiB/s
SHA1 216.77 MiB/s (was ~240.83 MiB/s)
SHA1 220.98 MiB/s
SHA1 221.76 MiB/s
SHA1 221.34 MiB/s
This decline in throughput is attributed to the step loop unrolling in
compress(), which was necessary to easily fit the UbcCheck logic into
the hash function. Using helper functions s1-s4 reduces the code
explosion, providing acceptable throughput.
With detection enabled (default):
SHA1 detectCollision 180.12 MiB/s
SHA1 detectCollision 181.59 MiB/s
SHA1 detectCollision 181.64 MiB/s
SHA1 detectCollision 182.24 MiB/s
sha1dc (native C) ~206.28 MiB/s
sha1dc (native C) ~204.47 MiB/s
sha1dc (native C) ~203.74 MiB/s
Average time across 100,000 calls to hash 4100 bytes (such as a commit
or tree) for the various algorithms available to JGit also shows SHA1
is slower than MessageDigest, but by an acceptable margin:
MessageDigest 17 usec
SHA1 18 usec
SHA1 detectCollision 22 usec
Time to index-pack for git.git (217982 objects, 69 MiB) has increased:
MessageDigest SHA1 w/ detectCollision
------------- -----------------------
20.12s 25.25s
19.87s 25.48s
20.04s 25.26s
avg 20.01s 25.33s +26%
Being implemented in Java with these additional safety checks is
clearly a penalty, but throughput is still acceptable given the
increased security against object name collisions.
[1] https://github.com/cr-marcstevens/sha1collisiondetection
[2] https://shattered.it/
[3] https://marc-stevens.nl/research/papers/C13-S.pdf
[4] https://public-inbox.org/git/20170223230621.43anex65ndoqbgnf@sigill.intra.peff.net/
Change-Id: I9fe4c6d8fc5e5a661af72cd3246c9e67b1b9fee6
The TreeWalk filtering classes need to support the three different
meanings of the return value the path comparison generates.
A new path comparison method (isPathMatch) is created with
three distinct return values (isPathPrefix use value '0' to
encode two of these) which will makes it possible for the logical
operators (especially NOT) to aggregate a correct verdict.
A filter like: AND(Path("path"), NOT(Path("path/to/other")))
Should filter out 'path/to/other/file', but not 'path/to/my/file'.
The path-limiting feature when testing path/to/my/file, would
result to run test for the following paths:
path
path/to
path/to/my
path/to/my/file
isPathPrefix('path/to/other') will return '0' for the first two
and since there is no way for NOT to distinguish between an exact
match and a match indicating that the tested path is a 'parent',
it will incorrectly return false and thus remove everything below
'path' immediately.
isPathMatch has a distinguished value for 'parent' matches that
will be preserved through the logic operators and should not
cause an over-eager removal of paths.
The functionality of isPathPrefix is required by other parts
and is untouched.
Unit tests are included to ensure that the logical functionality
is correct and can be preserved.
Change-Id: Ice2ca9406f09f1b179569e99b86a0e5d77baa20d
Signed-off-by: Magnus Vigerlöf <magnus.vigerlof@gmail.com>
Allow SHA1 instances to be reused to compute another hash value, and
resume caching them in ObjectInserter and PackParser. This shaves a
small amount of running time off parsing git.git's pack file:
before after
------ ------
25.25s 25.55s
25.48s 25.06s
25.26s 24.94s
Almost noise (small difference), but recycling the instances reduces
some stress on the memory allocator finding two 80 word message block
arrays needed for hashing and collision detection.
Change-Id: I4af88a720e81460293bc5c5d1d3db1a831e7e228
Generate names for objects using only the pure Java SHA1
implementation, but continue using MessageDigest in tests.
This opens the possibility of changing the hashing function
to incorporate additional safety measures, such as those
used in sha1dc[1].
Since MessageDigest has higher throughput, continue using
MessageDigest for computing pack, idx and DirCache trailers.
These are less likely to be sensitive to SHAttered[2] types
of attacks, as Git uses them to detect random bit flips
during transfer, and not for content identity.
[1] https://github.com/cr-marcstevens/sha1collisiondetection
[2] https://shattered.it/
Change-Id: If6da98334201f7f20cb916e46f782c45f373784e
This implementation is derived straight from the description written
in RFC 3174. On Mac OS X with Java 1.8.0_91 it offers similar
throughput as MessageDigest SHA-1:
system 239.75 MiB/s
system 244.71 MiB/s
system 245.00 MiB/s
system 244.92 MiB/s
sha1 234.08 MiB/s
sha1 244.50 MiB/s
sha1 242.99 MiB/s
sha1 241.73 MiB/s
This is the fastest implementation I could come up with. Common SHA-1
implementation tricks such as unrolling loops creates a method too
large for the JIT to effectively optimize, resulting in lower overall
hashing throughput. Using a preprocessor to perform the register
renaming of A-E also didn't help, as again the method was too large
for the JIT to effectively optimize.
Fortunately the fastest version is a naive, straight-forward
implementation very close to the description in RFC 3174.
Change-Id: I228b05c4a294ca2ad51386cf0e47978c68e1aa42
Since the introduction of generic type parameter inference in Java 7,
it's not necessary to explicitly specify the type of generic parameters.
Enable the warning in Eclipse, and fix all occurrences.
Change-Id: I9158caf1beca5e4980b6240ac401f3868520aad0
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
In 0bff481d45 to accurately use the two
limits it was necessary to move the LimitedInputStream out of the
PacketLineIn and further down to the PackParser. Unfortuantely this
didn't survive review, as a buggy test failed and the "fix" was to
drop this part of the code.
The maxPackSizeLimit should apply to the pack stream, not the pkt-line
framing used to send commands to control the ReceivePack instance. The
commands are controlled using a different limit. The failing test allowed
too many bytes in the pack and was only failing because it was including
the command framing. The correct fix for the test was simply to drop the
limit lower, to more closely match the actual pack size.
Change-Id: I47d3885b9d7d527e153df7ac9c62fc2865ceecf4
Set missingOverrideAnnotation=warning in Eclipse compiler preferences
which enables the warning:
The method <method> of type <type> should be tagged with @Override
since it actually overrides a superclass method
Justification for this warning is described in:
http://stackoverflow.com/a/94411/381622
Enabling this causes in excess of 1000 warnings across the entire
code-base. They are very easy to fix automatically with Eclipse's
"Quick Fix" tool.
Fix all of them except 2 which cause compilation failure when the
project is built with mvn; add TODO comments on those for further
investigation.
Change-Id: I5772061041fd361fe93137fd8b0ad356e748a29c
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
Add a new method setTagOpt which sets the annotated tag behavior during
fetch. Pass the option to the fetch command.
No explicit tests are added; the fetch with tags functionality is already
covered by the tests of the fetch command.
Change-Id: I131e1f68d8fcced178d8fa48abf7ffab17f8e173
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
Archived zip files for a same commit have different MD5 hash because
mdate and mdate in the header of zip entries are not specified. In
this case, Commons Compress sets an archived time.
In the original git implementation, it's set a commit time:
e2b2d6a172/archive.c (L378)
By this fix, archive command sets the commit time to ZipArchiveEntry
when RevCommit is given as an archiving target.
Change-Id: I30dd8710e910cdf42d57742f8709e9803930a123
Signed-off-by: Naoki Takezoe <takezoe@gmail.com>
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Matthias Sohn
Christian Halstrick
Yasuhiro Takagi
David Turner
Han-Wen Nienhuys
Luca Milanesio
David Pursehouse
Jonathan Nieder
David Ostrovsky
Andrey Loskutov
Thomas Wolf
Shawn Pearce
Magnus Vigerlöf
Naoki Takezoe