Commit Graph

2301 Commits

Author SHA1 Message Date
Matthias Sohn fed2a8a4f9 Add missing dependencies for running FS_POSIXTest in Eclipse
Change-Id: I35fcdfab55ff02943f6185b232e01ce9cfe151a9
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-08-16 16:51:45 +02:00
David Pursehouse cb53db4bff Merge "Ensure FSTest uses MockSystemReader" into stable-5.1 2019-08-12 19:37:11 -04:00
Matthias Sohn 69ce7fc7fb Ensure FSTest uses MockSystemReader
Tests shall not modify ~/.gitconfig. When running tests with bazel this
test failed since bazel isolates tests in a sandbox.

Change-Id: I7dd092afd14972da58a95eb7c200d353f0959fa1
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-08-13 00:26:41 +02:00
Vishal Devgire 9b4a55c0b6 Make supportsAtomicCreateNewFile return true as default
The method org.eclipse.jgit.util.FS.supportsAtomicCreateNewFile()
should default to true as mentioned in docs [1]

org.eclipse.jgit.util.FS_POSIX.supportsAtomicCreateNewFile() method
will set the value to false if the git config
core.supportsatomiccreatenewfile is not set.

It should default to true if the configuration is undefined.

[1]
4169a95a65/org.eclipse.jgit/src/org/eclipse/jgit/util/FS_POSIX.java (L372)

Bug: 544164
Change-Id: I16ccf989a89da2cf4975c200b3228b25ba4c0d55
Signed-off-by: Vishal Devgire <vishaldevgire@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-08-12 14:35:06 +02:00
Matthias Sohn 4d46a68abe Update orbit to R20190602212107-2019-06 to enable backports from master
update
- org.apache.httpcomponents.httpclient to 4.5.6.v20190503-0009
- org.apache.httpcomponents.httpcore to 4.4.10.v20190123-2214
- com.jcraft.jsch" version to 0.1.55.v20190404-1902
- org.mockito to 2.23.0.v20190527-1420
  add its dependencies
    - net.bytebuddy.byte-buddy 1.9.0.v20181107-1410
    - net.bytebuddy.byte-buddy-agent 1.9.0.v20181106-1534
- org.objenesis to 2.6.0.v20180420-1519

CQ: 18303 (objenesis)
CQ: 18703 (httpclient)
CQ: 18704 (httpcore)
CQ: 19588 (jsch)
CQ: 20214 (mockito)
CQ: 20215 (butebuddy)
CQ: 20216 (bytebuddy-agent)
Change-Id: I8d76375de867e32b7818449f843b7c053a717b5e
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-08-12 14:35:06 +02:00
Matthias Sohn 118ee61640 LocalDiskRefTreeDatabaseTest shall use MockSystemReader
It missed to call the setup() method of its super class which prepares
the MockSystemReader

Change-Id: I39858749f8d0115fc6ac7edc8847ffb2bbc85c33
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-08-11 00:06:03 +02:00
Matthias Sohn 12d03a97d8 Ensure we use MockSystemReader in tests
If we use the default system reader FileStoreAttributes cannot persist
attributes in userConfig when tests run in Bazel due to sandboxing.
Hence we need to ensure that all tests use MockSystemReader (and
especially a mocked userConfig).

Change-Id: Ic1ad8e2ec5a150c5433434a5f6667d6c4674c87d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-08-10 23:57:21 +02:00
Matthias Sohn 0bc89fabe2 Disable debug log for FS in org.eclipse.jgit.test
This was enabled unintentionally in 06fc6c7c and spams the test logs. We
can enable this when needed.

Change-Id: I9f3042c0e285ff236be65fcc02bdcfdb90efc3af
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-08-10 20:32:07 +02:00
Matthias Sohn 06fc6c7cc0 Bazel: enable logging for tests in org.eclipse.jgit.test
- use slf4j-simple for logging in test runs
- for log configuration see
https://www.slf4j.org/api/org/slf4j/impl/SimpleLogger.html

Change-Id: I9f0a532644b31162c867cd0d63f083296eaf6be5
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-08-10 01:21:18 +02:00
David Pursehouse ad02a7cbad Stop using deprecated Constants.CHARACTER_ENCODING
Change-Id: I105b8a05bc64f249879a0795a059958553cc60c6
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
2019-08-09 12:11:41 +09:00
Matthias Sohn 5a88815b1c Fix OpenSshConfigTest#config
- use FS.DETECTED instead of db.getFS() since the ssh config is
typically in a different place than the repository, the same is used in
OpenSshConfig
- reduce unnecessary repeated writes by introducing wait for one tick of
the file time resolution

Change-Id: Ifac915e97ff420ec5cf8e2f162e351f9f51b6b14
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-08-08 10:10:12 +02:00
Han-Wen Nienhuys e60b9e1879 FileSnapshot: fix bug with timestamp thresholding
Increase the safety factor to 2.5x for extra safety if max of measured
timestamp resolution and measured minimal racy threshold is < 100ms, use
1.25 otherwise since for large filesystem resolution values the
influence of finite resolution of the system clock should be negligible.

Before, not yet using the newly introduced minRacyThreshold measurement,
the threshold was 1.1x FS resolution, and we could issue the
following sequence of events,

  start
  create-file
  read-file (currentTime)
  end

which had the following timestamps:

  create-file 1564589081998
  start 1564589082002
  read 1564589082003
  end 1564589082004

In this case, the difference between create-file and read is 5ms,
which exceeded the 4ms FS resolution, even though the events together
took just 2ms of runtime.

Reproduce with:
  bazel test --runs_per_test=100 \
    //org.eclipse.jgit.test:org_eclipse_jgit_internal_storage_file_FileSnapshotTest

The file system timestamp resolution is 4ms in this case.

This code assumes that the kernel and the JVM use the same clock that
is synchronized with the file system clock. This seems plausible,
given the resolution of System.currentTimeMillis() and the latency for
a gettimeofday system call (typically ~1us), but it would be good to
justify this with specifications.

Also cover a source of flakiness: if the test runs under extreme load,
then we could have

  start
  create-file
  <long delay>
  read
  end

which would register as an unmodified file. Avoid this by skipping the
test if end-start is too big.

[msohn]:
- downported from master to stable-5.1
- skip test if resolution is below 10ms
- adjust safety factor to 1.25 for resolutions above 100ms

Change-Id: I87d2cf035e01c44b7ba8364c410a860aa8e312ef
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-08-07 13:56:08 +02:00
Matthias Sohn 6857138e19 Cache FileStoreAttributeCache per directory
Cache FileStoreAttributeCache entries since looking up FileStore for a
file may be expensive on some platforms.

Implement a simple LRU cache based on ConcurrentHashMap using a simple
long counter to order access to cache entries.

Change-Id: I4881fa938ad2f17712c05da857838073a2fc4ddb
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Signed-off-by: Marc Strapetz <marc.strapetz@syntevo.com>
Also-By: Marc Strapetz <marc.strapetz@syntevo.com>
2019-08-06 14:54:39 +02:00
Matthias Sohn d45219baac Persist minimal racy threshold and allow manual configuration
To enable persisting the minimal racy threshold per FileStore add a
new config option to the user global git configuration:

- Config section is "filesystem"
- Config subsection is concatenation of
  - Java vendor (system property "java.vendor")
  - Java version (system property "java.version")
  - FileStore's name, on Windows we use the attribute volume:vsn instead
    since  the name is not necessarily unique.
  - separated by '|'
  e.g.
    "AdoptOpenJDK|1.8.0_212-b03|/dev/disk1s1"
  The same prefix is used as for filesystem timestamp resolution, so
  both values are stored in the same config section
- The config key for minmal racy threshold is "minRacyThreshold" as a
  time value, supported time units are those supported by
  DefaultTypedConfigGetter#getTimeUnit
- measure for 3 seconds to limit runtime which depends on hardware, OS
  and Java version being used

If the minimal racy threshold is configured for a given FileStore the
configured value is used instead of measuring it.

When the minimal racy threshold was measured it is persisted in the user
global git configuration.

Rename FileStoreAttributeCache to FileStoreAttributes since this class
is now declared public in order to enable exposing all attributes in one
object.

Example:

[filesystem "AdoptOpenJDK|11.0.3|/dev/disk1s1"]
	timestampResolution = 7000 nanoseconds
	minRacyThreshold = 3440 microseconds

Change-Id: I22195e488453aae8d011b0a8e3276fe3d99deaea
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Also-By: Marc Strapetz <marc.strapetz@syntevo.com>
2019-08-06 14:54:39 +02:00
Matthias Sohn 5911521ba6 Measure minimum racy interval to auto-configure FileSnapshot
By running FileSnapshotTest#detectFileModified we found that the sum of
measured filesystem timestamp resolution and measured clock resolution
may yield a too small interval after a file has been modified which we
need to consider racily clean. In our tests we didn't find this behavior
on all systems we tested on, e.g. on MacOS using APFS and Java 8 and 11
this effect was not observed.

On Linux (SLES 15, kernel 4.12.14-150.22-default) we collected the
following test results using Java 8 and 11:

In 23-98% of 10000 test runs (depending on filesystem type and Java
version) the test failed, which means the effective interval which needs
to be considered racily clean after a file was modified is larger than
the measured file timestamp resolution.

"delta" is the observed interval after a file has been modified but
FileSnapshot did not yet detect the modification:

"resolution" is the measured sum of file timestamp resolution and clock
resolution seen in Java.

Java version    filesystem  failures resolution  min delta   max delta
1.8.0_212-b04   btrfs	    98.6%       1 ms        3.6 ms      6.6 ms
1.8.0_212-b04   ext4        82.6%       3 ms        1.1 ms      4.1 ms
1.8.0_212-b04   xfs         23.8%       4 ms        3.7 ms      3.9 ms
1.8.0_212-b04   zfs         23.1%       3 ms        4.8 ms      5.0 ms
11.0.3+7        btrfs       98.1%       3 us        0.7 ms      4.7 ms
11.0.3+7        ext4        98.1%       6 us        0.7 ms      4.7 ms
11.0.3+7        xfs         98.5%       7 us        0.1 ms      8.0 ms
11.0.3+7        zfs         98.4%       7 us        0.7 ms      5.2 ms

Mac OS
1.8.0_212       APFS        0%          1 s
11.0.3+7        APFS        0%          6 us

The observed delta is not distributed according to a normal gaussian
distribution but rather random in the observed range between "min delta"
and "max delta".

Run this test after measuring file timestamp resolution in
FS.FileAttributeCache to auto-configure JGit since it's unclear what
mechanism is causing this effect.

In FileSnapshot#isRacyClean use the maximum of the measured timestamp
resolution and the measured "delta" as explained above to decide if a
given FileSnapshot is to be considered racily clean. Add a 30% safety
margin to ensure we are on the safe side.

Change-Id: I1c8bb59f6486f174b7bbdc63072777ddbe06694d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-08-06 14:54:35 +02:00
Matthias Sohn 130aa31262 Add test for racy git detection in FileSnapshot
Repeat the test 10000 times to get statistics if measured
fsTimestampResolution is working in practice to detect racy git
situations.

Add a class to compute statistics for this test. Log delta between
lastModified and time when FileSnapshot failed to detect modification.
This happens if the racy git limit determined by measuring filesystem
timestamp resolution and clock resolution is too small. If it would be
correct FileSnapshot would always detect modification or mark it
modified if time since modification is smaller than the racy git limit.

Change-Id: Iabe7af1a7211ca58480f8902d4fa4e366932fc77
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-07-26 15:49:38 +02:00
Matthias Sohn de6df3bdd9 Repeat RefDirectoryTest.testGetRef_DiscoversModifiedLoose 100 times
This should help to detect if measured fsTimeResolution is too small.

Change-Id: Id1f54dbdedb52b17859904e47776fa3a5887b8be
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-07-24 16:21:54 +02:00
Matthias Sohn 9eff45e4f2 Fix FileSnapshotTests for filesystem with high timestamp resolution
When filesystem timestamp resolution is very high some tests don't work
since runtime of the test setup is too long to reach a racily clean
FileSnapshot. Hence skip these tests when timestamp resolution is higher
than 10 millisecond.

Change-Id: Ie47dd10eda22037b5c1ebff6b6becce0654ea807
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-07-19 14:45:56 +02:00
Matthias Sohn bce4ac97fa Retry deleting test files in FileBasedConfigTest
Change-Id: I304b2b6f2e39f72f620bba53aead60256aed3660
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-07-19 14:45:55 +02:00
Matthias Sohn eda2e95fa8 Measure filesystem timestamp resolution already in test setup
This helps to avoid some time critical tests can't prepare the test
fixture intended since measuring timestamp resolution takes time.

Change-Id: Ib34023e682a106070ca97e98ef16789a4dfb97b4
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-07-19 14:45:55 +02:00
Matthias Sohn 93144f1438 Refactor FileSnapshotTest to use NIO APIs
- use Path instead of File
- create test directories, files and output stream using Files methods
- delete unused list "files"

Change-Id: I8c5c601eca9f613efb5618d33b262277df92a06a
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-07-19 14:45:55 +02:00
Matthias Sohn 95e8264cc8 Use Instant instead of milliseconds for filesystem timestamp handling
This enables higher file timestamp resolution on filesystems like ext4,
Mac APFS (1ns) or NTFS (100ns) providing high timestamp resolution on
filesystem level.

Note:
- on some OSes Java 8,9 truncate milliseconds, see
https://bugs.openjdk.java.net/browse/JDK-8177809, fixed in Java 10
- UnixFileAttributes truncates timestamp resolution to microseconds when
converting the internal representation to FileTime exposed in the API,
see https://bugs.openjdk.java.net/browse/JDK-8181493
- WindowsFileAttributes also provides only microsecond resolution

Change-Id: I25ffff31a3c6f725fc345d4ddc2f26da3b88f6f2
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-07-18 03:27:52 +02:00
Matthias Sohn 79ede0c322 Fix NPE in FS$FileStoreAttributeCache.getFsTimestampResolution
Bug: 548682
Change-Id: I48840d3a68cf1db92c056d218a0d5ed0b9ea4c45
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-07-17 09:42:14 +02:00
Matthias Sohn 09fec1a102 Add debug trace for FileSnapshot
Checking lastModified is time critical hence debug trace is the only way
to analyze issues since debugging is impractical.

Also add configuration for buffering of log4j output to reduce runtime
impact when debug trace is on. Limit buffer to 1MiB and comment this
configuration out since we may not always want to use buffering.

Change-Id: Ib1a0537b67c8dc3fac994a77b42badd974ce6c97
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-07-17 09:42:14 +02:00
Matthias Sohn 0966731cad Increase bazel timeout for long running tests
EolRepositoryTest and GcCommitSelectionTest timed out frequently when
running unit tests using bazel with the default timeout "moderate"
(300s). Increase timeout of these tests to "long" (900s).

Change-Id: I43588cf950f55b50f868d9fe9c66d22bd428a54c
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-07-16 12:11:22 +09:00
David Ostrovsky bbef67e8d0 Bazel: Fix lint warning flagged by buildifier
This change is fixing confusing name warning: [1].

  ./org.eclipse.jgit.test/tests.bzl:12: confusing-name:
  Never use 'l', 'I', or 'O' as names (they're too easily confused
  with 'I', 'l', or '0').

And is also fixing: "All calls to rules or macros should pass arguments
by keyword position argument" warning: [2].

  ./org.eclipse.jgit.test/BUILD:42: positional-args: All calls to rules
  or macros should pass arguments by keyword (arg_name=value) syntax.

[1] https://github.com/bazelbuild/buildtools/blob/master/WARNINGS.md#confusing-name
[2] https://github.com/bazelbuild/buildtools/blob/master/WARNINGS.md#positional-args

Change-Id: If5c28ec8a1ddc1d1b1035bd07b838a2a564aea4f
Signed-off-by: David Ostrovsky <david@ostrovsky.org>
2019-07-16 12:10:31 +09:00
David Pursehouse 0aa8eca5f1 Bazel: Add missing dependencies for ArchiveCommandTest
Dependencies on commons-compress, xz, and jgit-archive are required
for the build to succeed.

Change-Id: I42f3721078a240ad93b8dcab909e66b9bfff0b56
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
2019-07-16 12:10:31 +09:00
David Pursehouse e54fde8616 Bazel: Remove FileTreeIteratorWithTimeControl from BUILD file
FileTreeIteratorWithTimeControl was deleted in a024759, but was
not removed from the BUILD file, thus causing the bazel build to
fail.

Change-Id: I892c0ffcac947298d0d6009374ee2c5d9afefb66
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
2019-07-16 11:20:21 +09:00
Matthias Sohn 121c957405 Add support for nanoseconds and microseconds for Config#getTimeUnit
Change-Id: I0a5828438810dd23790cba52d7ae2e055c6a3fc9
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-07-11 10:12:04 +02:00
Matthias Sohn a024759cf5 Delete unused FileTreeIteratorWithTimeControl
The only usage of this test iterator was removed in df637928d. Hence
delete this iterator and associated test.

Change-Id: I47710133ec3edc675c21db210960c024982668c6
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-07-11 10:00:23 +02:00
Han-Wen Nienhuys 84e6c24e58 FileSnapshot#equals: consider UNKNOWN_SIZE
Add a unittest.

In commit I5485db55 ("Fix FileSnapshot's consideration of file size"),
the special casing of UNKNOWN_SIZE was forgotten.

This change, together with I493f3b57b ("Measure file timestamp
resolution used in FileSnapshot") introduced a regression that would
occasionally surface in Gerrit integration tests marked UseLocalDisk,
with the symptom that creating the Admin user in NoteDb failed with a
LOCK_FAILURE.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Change-Id: I7ffd972581f815c144f810481103c7985af5feb0
2019-07-09 15:33:23 +02:00
Matthias Sohn 1159f9dd7c Fix RacyGitTests#testRacyGitDetection
This test case assumed file system timestamp resolution of 1 second. On
filesystems with a finer resolution this test fails since the index
entry is only smudged if the file index entry's lastModified and the
lastModified of the git index itself are within the same filesystem
timer tick. Fix this by ensuring that these timestamps are identical
which should work for any filesystem timer resolution.

Bug: 548188
Change-Id: Id84d59e1cfeb48fa008f8f27f2f892c4f73985de
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>
2019-07-03 21:34:27 +02:00
Masaya Suzuki df637928d2 Change RacyGitTests to create a racy git situation in a stable way
By using File#setLastModified, we can create a racy git situation
stably.

Tested with --runs_per_test=100

Bug: 526111
Change-Id: I60b3632d353e19f335668325aa603640be423f58
Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
2019-06-19 10:43:03 +02:00
David Pursehouse f18b5010fc Deprecate Constants.CHARACTER_ENCODING in favor of StandardCharsets.UTF_8
Change-Id: I621ba174235a6fb56236e54d24bce704bb5afb28
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
2019-06-19 10:43:01 +02:00
Matthias Sohn 9387288a86 Fix non-deterministic hash of archives created by ArchiveCommand
Archives created by the ArchiveCommand didn't produce deterministic
archive hashes. For RevCommits RevWalk.parseTree returns the root tree
instead of the RevCommit hence retrieving the commit's timestamp didn't
work. Instead use RevWalk.parseAny and extract the tree manually.

Archive entries store timestamps with 1 second resolution hence we need
to wait longer when creating the same archive twice and compare archive
hashes. Otherwise hash comparison in tests wouldn't fail without this
patch.

Bug: 548312
Change-Id: I437d515de51cf68265584d28a8446cebe6341b79
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-06-19 10:43:00 +02:00
Matthias Sohn 2d0a1adf05 Update Maven plugins and cleanup Maven warnings
update Maven plugins
- jacoco-maven-plugin to 0.8.4
- japicmp-maven-plugin to 0.14.1
- maven-compiler-plugin to 3.8.1
- maven-deploy-plugin to 3.0.0-M1
- maven-enforcer-plugin to 3.0.0-M2
- maven-install-plugin to 3.0.0-M1
- maven-jar-plugin to 3.1.2
- maven-javadoc-plugin to 3.1.0
- maven-jxr-plugin to 3.0.0
- maven-pmd-plugin to 3.12.0
- maven-resources-plugin to 3.1.0
- maven-shade-plugin to 3.2.1
- maven-source-plugin to 3.1.0
- maven-surefire-plugin to 3.0.0-M3
- spotbugs-maven-plugin to 3.1.12
- tycho to 1.3.0
- tycho-pack200a-plugin to 1.3.0
- tycho-pack200b-plugin to 1.3.0

Cleanup Maven warnings
- pin version of all used Maven plugins
- remove deprecated way to declare minimum Maven version

Change-Id: If23e2e2bb03e5e1e7b1eb9d4924a8faa0aa3704e
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-06-18 16:55:44 +02:00
David Pursehouse 6d0168a414 Make inner classes static where possible
As reported by Error Prone:

An inner class should be static unless it references members of its
enclosing class. An inner class that is made non-static unnecessarily
uses more memory and does not make the intent of the class clear.

See https://errorprone.info/bugpattern/ClassCanBeStatic

Change-Id: Ib99d120532630dba63cf400cc1c61c318286fc41
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
(cherry picked from commit ee40efcea4)
2019-06-17 07:48:34 +02:00
Matthias Sohn 57ccca75e6 Prepare 5.1.9-SNAPSHOT builds
Change-Id: I60571e4e0bea04bb2c25ef3d0332a9ab6895db06
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-06-05 15:23:56 +02:00
Matthias Sohn 2fe587fcfd JGit v5.1.8.201906050907-r
Change-Id: Iae0ffe161df2ca8a800d21688d6b7d7419dfb640
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-06-05 15:06:56 +02:00
Christian Halstrick 5f8d91fded Test detecting modified packfiles
Test that JGit detects that packfiles have changed even if they are
repacked multiple times in one tick of the filesystem timer.

Test that this detection works also when repacking doesn't change the
length or the filekey of the packfile. In this case where a modified
file can't be detected by looking at file metadata JGit should still
detect too fast modification by racy git checks and trigger rescanning
the pack list and consequently rereading of packfile content.

Change-Id: I67682cfb807c58afc6de9375224ff7489d6618fb
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-06-05 14:57:02 +02:00
Matthias Sohn 9a7d3b053a Extend FileSnapshot for packfiles to also use checksum to detect changes
If the attributes of FileSnapshot don't detect modification of a
packfile read the packfile's checksum and compare it against the
checksum cached in the loaded packfile.

Since reading the checksum needs less IO than reloading the complete
packfile this may help to reduce the overhead to detect modficiation
when a gc completes while ObjectDirectory scans for packfiles in another
thread.

Bug: 546891
Change-Id: I9811b497eb11b8a85ae689081dc5d949ca8c4be5
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-06-04 18:15:17 +02:00
Matthias Sohn 5d0286eb7c Add FileSnapshot test testing recognition of file size changes
Change-Id: Ibcd76a5e6e4183ada0be1d4436ce957243f2094d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-05-29 23:41:45 +02:00
Matthias Sohn 43b06f51f9 Capture reason for result of FileSnapshot#isModified
This allows to verify the expected behavior in
FileSnapshotTest#testSimulatePackfileReplacement and enables extending
FileSnapshot for packfiles to read the packfile's checksum as another
criterion to detect modifications without reading the full content.

Also add another field capturing the result of the last check if
lastModified was racily clean.

Remove unnecessary determination of raciness in the constructor. It was
determined twice in all relevant cases.

Change-Id: I100a2f49d7949693d7b72daa89437e166f1dc107
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-05-29 23:41:45 +02:00
Matthias Sohn d31a0c0b5d Skip FileSnapshotTest#testSimulatePackfileReplacement on Windows
NTFS does not support FileKey hence ignore this test on Windows.

Change-Id: I7b53a591daa5e03eb5e401b5b26d612ab68ce10d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-05-29 23:41:43 +02:00
Matthias Sohn 1e8b68cbc5 Tune max heap size for tests
This is an attempt to fix crashes observed on the new Jenkins
infrastructure running on Kubernetes [1].

Increase it to 512m for
- org.eclipse.jgit.ant.test
- org.eclipse.jgit.http.test
- org.eclipse.jgit.lfs.server.test
- org.eclipse.jgit.lfs.test
- org.eclipse.jgit.pgm.test

Decrease it to 768m for
- org.eclipse.jgit.test

[1] e.g. https://ci-staging.eclipse.org/jgit/job/stable/job/jgit.gerrit/16074/console

Change-Id: Id074ed0f7bcb8a13da649a547342af2a08439d9f
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
(cherry picked from commit e19e859977)
2019-05-29 23:39:55 +02:00
Matthias Sohn 0e33b32ab7 Fix FileSnapshotTest.testNewFileNoWait() to match its javadoc
testNewFileNoWait() was identical to testNewFileWithWait() but claims it
doesn't wait at all. Hence remove the waits.

Change-Id: I49b8ca5cb49a43c55fe61870c18c42f32fb4b74d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-05-27 10:49:51 +02:00
Matthias Sohn 91101414ae Include filekey file attribute when comparing FileSnapshots
Due to finite filesystem timestamp resolution the last modified
timestamp of files cannot detect file changes which happened in the
immediate past (less than one filesystem timer tick ago).

Some filesystems expose unique file identifiers, e.g. inodes in Posix
filesystems which are named filekeys in Java's BasicFileAttributes. Use
them as another means to detect file modifications based on stat
information.

Running git gc on a repository yields a new packfile with the same id as
a packfile which existed before the gc if these packfiles contain the
same set of objects. The content of the old and the new packfile might
differ if a different PackConfig was used when writing the packfile.
Considering filekeys in FileSnapshot may help to detect such packfile
modifications.

Bug: 546891
Change-Id: I711a80328c55e1a31171d540880b8e80ec1fe095
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-05-22 08:13:56 +02:00
Matthias Sohn b513b77477 Measure file timestamp resolution used in FileSnapshot
FileSnapshot.notRacyClean() assumed a worst case filesystem timestamp
resolution of 2.5 sec (FAT has a resolution of 2 sec). Instead measure
timestamp resolution to avoid unnecessary IO caused by false positives
in detecting the racy git problem caused by finite filesystem timestamp
resolution [1].

Cache the measured resolution per FileStore since timestamp resolution
depends on the respective filesystem type. If timestamp resolution
cannot be measured or fails due to an exception fallback to the worst
case FAT timestamp resolution and avoid caching this value.

Add a 10% safety margin in FileSnapshot.notRacyClean(), though running
FsTest.testFsTimestampResolution() 1000 times which is not using a
safety margin didn't fail on Mac using APFS and Java 8, 11, 12.

Measured Java file timestamp resolution: [2]

[1] https://github.com/git/git/blob/master/Documentation/technical/racy-git.txt
[2] https://docs.google.com/spreadsheets/d/1imy0y6WmRqBf0kjCxzxj2X7M50eIVfa7oaUIzEOHmjo

Bug: 546891
Change-Id: I493f3b57b6b306285ffa7d392339d253e5966ab8
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-05-22 08:13:22 +02:00
Matthias Sohn c2945bd261 Prepare 5.1.8-SNAPSHOT builds
Change-Id: I331bbaefd42ef94673ae8565c9b2b3af9eadfda0
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-04-20 10:51:17 +02:00
Matthias Sohn 22e41cfd56 JGit v5.1.7.201904200442-r
Change-Id: Ifaa3a88c5e117912a8c691b8b8369dd9a17faebb
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
2019-04-20 10:42:58 +02:00