The reftable format is a block based format, but allows for variably
sized blocks. This obviously happens for reflog blocks (which are zlib
compressed), but is also accepted for index blocks: In the spec, this
is motivated as
To achieve constant O(1) disk seeks for lookups the index must be
a single level, which is permitted to exceed the file's
configured block size, but not the format's max block size of
15.99 MiB.
Hence, when parsing a block, one cannot be sure of its exact size:
after reading a default-size block (eg. 4kb), the block header may
state that the block is in fact larger.
Before, the code would mark the block as `truncated`, noting
// Its OK during sequential scan for an index block to have been
// partially read and be truncated in-memory. This happens when
// the index block is larger than the file's blockSize. Caller
// will break out of its scan loop once it sees the blockType.
This looks like either
* a remnant of never-implemented functionality. There is no reason to
ever sequentially scan an index block.
* alluding to sequential scan of the data blocks before the index
blocks (eg. scanning refs, which ends when we find the first ref index
block, and we can then ignore the index block).
This comment is followed by code that populates the
restartTbl/restartCnt fields relative to the (possibly truncated)
buffer. If the buffer is truncated, this essentially reads garbage,
leading to OOB array access when using the index block.
Fix this by dropping the truncated logic and issuing a second read if
the first read was short.
Add a test.
We have never observed this failure scenario at Google. We use 64kb
blocksize, which requires us to need fewer index entries. The reftable
spec mentions an Android repo of size 36M. With 64kb blocks, that's
just 562 index entries. Even with historical growth, we are long from
requiring an index whose size exceeds a single block.
When adding the analogous test for seeking refs, there was no failure.
This points to another possibility which is that the code tries to
avoid writing large index blocks for refs.
Thomas Wolf [Sun, 25 Jul 2021 13:44:35 +0000 (15:44 +0200)]
[test] Create keystore with the keytool of the running JDK
Call keytool with the absolute path of "java.home". Otherwise a keytool
for a different, maybe even newer Java version might be picked up, and
then the keystore may not be readable by the JVM used to run the tests.
BatchRefUpdate: Skip saving conflicting ref names and prefixes in memory
Rather than getting all ref names and prefixes and saving them
in memory to perform the check for conflicting names, rely on
RefDirectory.isNameConflicting as it is no longer an expensive
call after it was optimized in Ie994fc.
The old optimization to save ref names and prefixes in memory
was targeted towards making clones faster. With this change,
the clone performance is unaffected when tests were done with
repos containing many(~500k) refs.
Here are few recorded elapsed times for creating 10 branches
using BatchRefUpdate on NFS based repositories with varying
loose refs count. As seen here, this change helps improve the
BatchRefUpdate performance from O(n^2) to O(1).
loose_refs_count with_change without_change
50 241 ms 310 ms
300 263 ms 1502 ms
1k 181 ms 4241 ms
2k 204 ms 6440 ms
9k 158 ms 25930 ms
20k 154 ms 60443 ms
50k 171 ms 135199 ms
110k 157 ms 329450 ms
160k 209 ms 396328 ms
This update improves the Gerrit notedb migration performance
as it uses BatchRefUpdate to write change meta refs similar to
the test performed above.
Update tests to record the number of events fired post-setup and only
assert for events fired during BatchRefUpdate.execute. For tests which
use writeLooseRef to setup refs, create new tests which assert the
number of RefsChangedEvent(s) rather than updating the existing ones
to call RefDirectory.exactRef as it changes the code path.
Avoid having to scan over ALL loose refs to determine if the
name is nested within or is a container of an existing reference.
This can get really expensive if there are too many loose refs.
Instead use exactRef and getRefsByPrefix which scan based on a
prefix.
With a simple shell script(like below) using jgit client to create
1k refs in a new repository on NFS, this change brings down the time
from 12mins to 7mins.
for ref in $(seq 1 1000); do
jgit branch "$ref"
done
Here are few recorded elapsed times to create a new branch on NFS
based repositories with varying loose refs count. As we see here,
this change improves the name conflicting check from O(n^2) to O(1).
loose_refs_count with_change without_change
50 44 ms 164 ms
300 45 ms 1193 ms
1k 38 ms 2610 ms
2k 44 ms 6003 ms
9k 46 ms 27860 ms
20k 45 ms 48591 ms
50k 51 ms 135471 ms
110k 43 ms 294252 ms
160k 52 ms 430976 ms
Thomas Wolf [Tue, 4 May 2021 21:48:56 +0000 (23:48 +0200)]
LockFile: create OutputStream only when needed
Don't create the stream eagerly in lock(); that may cause JGit to
exceed OS or JVM limits on open file descriptors if many locks need
to be created, for instance when creating many refs. Instead create
the output stream only when one really needs to write something.
Bug: 573328
Change-Id: If9441ed40494d46f594a896d34a5c4f56f91ebf4 Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
In a distributed setting, one can have multiple datacenters use
reftables for serving, while the ground truth for the Ref database is
administered centrally. In this setting, replication delays combined
with compaction can cause update-index ranges to overlap.
Such a setting is used at Google, and the JGit code already handles
this correctly (modulo a bugfix that applied in change I8f8215b99a).
Remove the restriction that was applied at FileReftableDatabase.
Petr Hrebejk [Mon, 30 Nov 2020 19:19:53 +0000 (20:19 +0100)]
Fix PackInvalidException when fetch and repack run concurrently
We are running several servers with jGit. We need to run repack from
time to time to keep the repos performant. I.e. after push we test how
many small packs are in the repo and when a threshold is reached we run
the repack.
After upgrading jGit version we've found that if someone does the clone
at the time repack is running the clone sometimes (not always) fails
because the repack removes .pack file used by the clone. Server
exception and client error attached.
I've tracked down the cause and it seems to be introduced between jGit
5.2 (which we upgraded from) and 5.3 and being caused by this commit:
Move throw of PackInvalidException outside the catch -
https://github.com/eclipse/jgit/commit/afef866a44cd65fef292c174cad445b3fb526400
The problem is that when the throw was inside of the try block the last
catch block catched the exception and called openFailed(false) method.
It is true that it called it with invalidate = false, which is wrong.
The real problem though is that with the throw outside of the try block
the openFail is not called at all and the fields activeWindows and
activeCopyRawData are not set to 0. Which affects the later called tests
like: if (++activeCopyRawData == 1 && activeWindows == 0).
The fix for this is relatively simple keeping the throw outside of the
try block and still having the invalid field set to true. I did
exhaustive testing of the change running concurrent clones and pushes
indefinitely and with the patch applied it never fails while without the
patch it takes relatively short to get the error.
Matthias Sohn [Wed, 25 Nov 2020 16:00:09 +0000 (17:00 +0100)]
Ensure that GC#deleteOrphans respects pack lock
If pack or index files are guarded by a pack lock (.keep file)
deleteOrphans() should not touch the respective files protected by the
lock file. Otherwise it may interfere with PackInserter concurrently
inserting a new pack file and its index.
The problem was caused by the following race.
All mentioned files are located in "objects/pack/".
File endings relevant in "pack" dir:
.pack
.keep
.idx
.bitmap
When ReceivePack receives a pack file it executes the following steps:
ReceivePack.service():
receivePackAndCheckConnectivity():
receivePack():
receive the pack
parse the pack, returns packLock (.keep file)
PackInserter.flush():
write tmpPck file: "insert_<random>.pack"
write tmpIdx file: "insert_<random>.idx"
real pack name: "pack-<SHA1>.pack"
real index name: "pack-<SHA1>.idx"
atomic rename tmpPack to realPack
atomic rename tmpIdx to tmpIdx
execute commands
unlock pack by removing .keep file
trigger auto gc if enabled
When PackInserter.flush() renames the temporary pack to the final
"pack-xxx.pack" file the temporary pack index file "insert_xxx.idx"
has no matching .pack file with the same base name for a short interval.
If deleteOrphans() ran during that interval it deduced the pack index
file was orphaned. Subsequently the missing pack index caused
MissingObjectExceptions since objects contained in the pack couldn't be
looked up anymore.
Bug: https://bugs.chromium.org/p/gerrit/issues/detail?id=13544
Change-Id: I559c81e4b1d7c487f92a751bd78b987d32c98719 Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Thomas Wolf [Thu, 19 Nov 2020 12:23:05 +0000 (13:23 +0100)]
PacketLineIn: ensure that END != DELIM
Just allocate the two string objects directly. The previously used
new StringBuilder(0).toString() returns the same object for both END
and DELIM when run on Java 15, which breaks the wire protocol since
then END and DELIM cannot be distinguished anymore.
Bug: 568950
Change-Id: I9d54d7bf484948c24b51a094256bd9d38b085f35 Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
(cherry picked from commit 7da0f0a8f37e35e9c3108588f1e6f7a7381d8f77)
Matthias Sohn [Sun, 7 Jun 2020 22:32:51 +0000 (00:32 +0200)]
Merge branch 'master' into stable-5.8
* master:
Add benchmark for strategies how to move a file
Add getter for unpackErrorHandler in ReceivePack
Upgrade maven-project-info-reports-plugin to 3.1.0
Upgrade maven-shade-plugin to 3.2.4
ObjectDirectoryInserter: Open FileOutputStream in try-with-resource
ObjectDirectoryInserter: Remove redundant 'throws' declarations
ObjectDirectory: Further clean up insertUnpackedObject
Add Git#shutdown for releasing resources held by JGit process
ApplyCommand: use context lines to determine hunk location
GPG: don't prompt for a passphrase for unprotected keys
Fix typo in org.eclipse.jgit.ssh.jsch.test MANIFEST
Fix ProtectedMembersInFinalClass warning flagged by error prone
Use version range to define fragment host bundle version
ObjectDirectory: Explicitly handle NoSuchFileException
ObjectDirectory: Fail immediately when atomic move is not supported
Fix jgit packaging
Fix InvalidInlineTag error flagged by error prone
Fix BadComparable error flagged by error prone
Add tests for RawTextComparator.WS_IGNORE_CHANGE.hash()
Update Orbit to R20200529191137 for final Eclipse release 2020-06
Organize manifest of org.eclipse.jgit.pgm
Do not include log4j implementation in jgit
Decouple JSch from JGit Core
Decouple BouncyCastle from JGit Core
Verify that the user home directory is valid
WindowCache: conditional JMX setup
RawTextComparator.WS_IGNORE_CHANGE must not compare whitespace
Revert "PackBitmapIndex: Not buffer inflated bitmap in BasePackBitmapIndex"
Update jetty to 9.4.28.v20200408
Add 4.16 staging target platform
In-memory SSH keys for the "no files" sshd tests
Builder API to configure SshdSessionFactories
TransportHttp: abort on time-out or on SocketException
Ignore core.eol if core.autocrlf=input
Attributes: fix handling of text=auto in combination with eol
Bazel: Remove superfluous dependencies flagged by unused_deps
Log stack trace if CachingKeyPairProvider hits unexpected exception
Update Orbit to S20200519202422 and ant to 1.10.8
Include full IssuerFingerprint in GPG signature
Bazel: Fix src_sha1 of bcpg-jdk15on
Suppress API error for new method BitmapIndex.Bitmap#retrieveCompressed
Fix wrong @since tags added in dcb0265
PackBitmapIndex: Set distance threshold
PackBitmapIndex: Not buffer inflated bitmap in BasePackBitmapIndex
PackBitmapIndex: Remove convertedBitmaps in the Remapper
PackBitmapIndex: Reduce memory usage in GC
PackBitmapIndex: Add AddToBitmapWithCacheFilter class
PackBitmapIndex: Add util methods and builder to BitmapCommit
PackBitmapIndex: Move BitmapCommit to a top-level class
Refactor: Make retriveCompressed an method of the Bitmap class
Fix downloading LFS Object fails behind proxy
Allow for using custom s3 host with lfs server
ReceivePack: adding IterativeConnectivityChecker
Moving transport/internal -> internal/transport
Fix error occurring during checkout
Change-Id: I675cfb9eee956bab4903f28d8021115afc753dcd Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Matthias Sohn [Fri, 5 Jun 2020 11:01:11 +0000 (13:01 +0200)]
Add benchmark for strategies how to move a file
We can either
- try moving the file and, in case the target directory doesn't exist,
handle the NoSuchFileException this raises to create the target
directory
- or we always first test if the target directory exists and create it
in case it is missing
This means if the target directory of the move already exists the
first strategy is faster by around 25 us/op otherwise the second one
is faster by around 30 us/op. Which one is favorable depends on the
average probability that the target directory exists in real world
scenarios.
Change-Id: I03653b408b859a796508dfa1471b36c65633534e Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Jack Wickham [Fri, 22 May 2020 10:00:18 +0000 (11:00 +0100)]
Add getter for unpackErrorHandler in ReceivePack
The current mechanism for updating the unpack error handler requires
that the error handler is replaced entirely, including communicating
the error to the user. Adding a getter means that delegating
implementations can be constructed so that the error can be processed
before sending to the user, for example for logging.
Change-Id: I4b6f78a041d0f6f5b4076a9a5781565ca3857817 Signed-off-by: Jack Wickham <jwickham@palantir.com>
* stable-5.7:
ObjectDirectoryInserter: Open FileOutputStream in try-with-resource
ObjectDirectoryInserter: Remove redundant 'throws' declarations
ObjectDirectory: Further clean up insertUnpackedObject
ObjectDirectory: Explicitly handle NoSuchFileException
ObjectDirectory: Fail immediately when atomic move is not supported
Change-Id: I05186baa517388680fcc6825c940c4c772f26d32 Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
ObjectWritingException and FileNotFoundException are subclasses
of IOException, which is already declared. Error does not need
to be explicitly declared.
Change-Id: I879820a33e10ec3a7ef676adc9c9148d2b3c4b27 Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
ObjectDirectory: Further clean up insertUnpackedObject
- The code to move the file is repeated. Split it out into a
utility method.
- Remove the catch block for AtomicMoveNotSupportedException which
is redundant because it's handled in exactly the same way as the
IOException further down. The only exception we need to explicitly
handle differently in this block is NoSuchFileException.
- Improve the comments.
Change-Id: Ifc5490953ffb25ecd1c48a06289eccb3f19910c6 Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
Thomas Wolf [Fri, 24 Apr 2020 13:00:01 +0000 (15:00 +0200)]
ApplyCommand: use context lines to determine hunk location
If a hunk does not apply at the position stated in the hunk header
try to determine its position using the old lines (context and
deleted lines).
This is still a far cry from a full git apply: it doesn't do binary
patches, it doesn't handle git's whitespace options, and it's perhaps
not the fastest on big patches. C git hashes the lines and uses these
hashes to speed up matching hunks (and to do its whitespace magic).
Bug: 562348
Change-Id: Id0796bba059d84e648769d5896f497fde0b787dd Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Thomas Wolf [Sat, 9 Nov 2019 21:05:53 +0000 (22:05 +0100)]
GPG: don't prompt for a passphrase for unprotected keys
BouncyCastle supports reading GPG keys without passphrase since 1.62.
Handle this in JGit, too, and don't prompt for a passphrase unless
it's necessary.
Make two passes over the private key files, a first pass without
passphrase provider. If that succeeds it has managed to read a
matching key without passphrase. Otherwise, ask the user for
the passphrase and make a second pass over the key files.
BouncyCastle 1.65 still has no method to get the GPG "key grip" from
a given public key, so JGit still cannot determine the correct file
to read up front. (The file name is the key grip as 40 hex digits,
upper case, with extension ".key").
Bug: 548763
Change-Id: I448181276548c08716d913c7ba1b4bc64c62f952 Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
David Ostrovsky [Fri, 22 May 2020 06:03:41 +0000 (08:03 +0200)]
Fix ProtectedMembersInFinalClass warning flagged by error prone
Running recent error prone version complaining on that code:
CharacterHead.java:22: error: [ProtectedMembersInFinalClass] Make
members of final classes package-private: <init>
protected CharacterHead(char expectedCharacter) {
^
(see https://errorprone.info/bugpattern/ProtectedMembersInFinalClass)
Did you mean 'CharacterHead(char expectedCharacter) {'
Bug: 562756
Change-Id: Ic46a0b07e46235592f6e63db631f583303420b73 Signed-off-by: David Ostrovsky <david@ostrovsky.org>
On the first attempt to move the temp file, NoSuchFileException can
be raised if the destination folder does not exist. Instead of handling
this implicitly in the catch of IOException and then continuing to
create the destination folder and try again, explicitly catch it and
create the destination folder. If any other IOException occurs, treat
it as an unexpected error and return FAILURE.
Subsequently, on the second attempt to move the temp file, if ANY kind
of IOException occurs, also consider this an unexpected error and
return FAILURE.
In both catch blocks for IOException, add logging at ERROR level.
Change-Id: I9de9ee3d2b368be36e02ee1c0daf8e844f7e46c8 Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
ObjectDirectory: Fail immediately when atomic move is not supported
If atomic move is not supported, AtomicMoveNotSupportedException will
be thrown on the first attempt to move the temp file. There is no
point attempting the move operation a second time because it will only
fail for the same reason.
Add an immediate return of FAILURE on the first occasion. Remove the
unnecessary handling of the exception in the second block.
Change-Id: I4658a8b37cfec2d7ef0217c8346e512968d0964c Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
Matthias Sohn [Wed, 3 Jun 2020 11:51:46 +0000 (13:51 +0200)]
Fix jgit packaging
- new jsch and gpg.bc fragments need to be included in their features
as fragments and require only the jgit bundle (not the jgit feature)
- feature org.eclipse.jgit should no longer include bouncycastle
- add missing url for gpg.bc feature in category.xml
- don't mark features as patch features
David Ostrovsky [Fri, 22 May 2020 05:53:59 +0000 (07:53 +0200)]
Fix InvalidInlineTag error flagged by error prone
Running recent error prone version complaining on that code:
RefDatabase.java:444: error: [InvalidInlineTag] Tag name `linkObjectId`
is unknown.
* Includes peeled {@linkObjectId}s. This is the inverse lookup of
^
(see https://errorprone.info/bugpattern/InvalidInlineTag)
Bug: 562756
Change-Id: If91da51d5138fb753c0550eeeb9e3883a394123d Signed-off-by: David Ostrovsky <david@ostrovsky.org>
David Ostrovsky [Fri, 22 May 2020 05:49:49 +0000 (07:49 +0200)]
Fix BadComparable error flagged by error prone
Running recent error prone version complaining on that code:
LfsPointer.java:171: error: [BadComparable] Possible sign flip from
narrowing conversion
return (int) (getSize() - o.getSize());
^
(see https://errorprone.info/bugpattern/BadComparable)
Did you mean 'return Long.compare(getSize(), o.getSize());'?
Bug: 562756
Change-Id: I0522f1025319a9290c448a064fbafdb4b16d1d59 Signed-off-by: David Ostrovsky <david@ostrovsky.org>
projects / jgit.git / log