Change-Id: I86f292039f1b8e499baf05238f55b1d550d098a5
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

EGit Tycho builds on build.eclipse.org frequently hit corrupted artifacts
which leads to broken builds. Cleaning up these corrupted files is tedious
since it requires file system access on the build server. Hence we want to
switch to use job-local m2 repositories. This requires that build artifacts
are shared between the jgit and egit build jobs via p2. Therefore the
bundle org.eclipse.jgit.junit needs to be exposed via p2 repository.

Change-Id: I0ccd7763eede117cb68240fdd25f13d6e6f6a2c1
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Added a new package org.eclipse.jgit.api and a builder-style API for
jgit. Added also the first implementation for two git commands: Commit
and Log.

This API is intended to be used by external components when
functionalities of the standard git commands are required. It will also
help to ease writing JGit tests.

For internal usages this API may often not be optimal because the git
commands are doing much more than required or they expect parameters of
an unappropriate type.

Change-Id: I71ac4839ab9d2f848307eba9252090c586b4146b
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

Currently, if the Index contains a file in more than one stage, only
the last entry (containing the highest stage) will be registered in
GitIndex. For applications it can be useful to not only know about the
highest stage, but also which other stages are present, e.g. to detect
the type of conflict the file is in.

Change-Id: I2d4ff9f6023335d9ba6ea25d8e77c8e283ae53cb
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

The repository state tells in which state the repo is and also which actions
are currently allowed. The state MERGING is telling that a commit is not
possible. But this is only true in the case of unmerged paths in the index.
When we are merging but have resolved all conflicts then we are in a special
state: We are still merging (means the next commit should have multiple
parents) but a commit is now allowed.

Since the MERGING state "canCommit()" cannot be enhanced to return true/false
based on the index state (MERGING is an enum value which does not have a
reference to the repository its state it is representing) I had to introduce a new
state MERGING_RESOLVED. This new state will report that a commit is possible.

CAUTION: there might be the chance that users of jgit previously blindly did a
plain commit (with only one parent) when the RepositoryState allowed them to
do so. With this change these users will now be confronted with a RepositoryState
which says a commit is possible but before they can commit they'll have to
check the MERGE_MESSAGE and MERGE_HEAD files and use the info from these
files.

Change-Id: I0a885e2fe8c85049fb23722351ab89cf2c81a431
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

If two keys are the same length, but don't share the same sequence
of characters, we were incorrectly claiming they still matched due
to a bug in the for loop condition.  I used the wrong variable and
the loop never executed, resulting in equality anytime the two keys
being compared were the same length.

Use the proper local variable to loop through the arrays, and add
a JUnit test to verify equality works as expected.

Change-Id: I4a02400e65a9b2e0da925b05a2cc4b579e1dd33a
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

* changes:
  Favor earlier PackFile instances over later duplicates
  Cleanup duplicated object reuse code in PackWriter

If a loose object was corrupted by truncation, JGit would hang.

Change-Id: I7e4c14f44183a5fcb37c1562e81682bddeba80ad
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

This prevents surprises by implicit updates to newer versions.

Change-Id: I06508036d468fa5299ea774e26a73312bb286ec2
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

The pack files were left open after the test ended, which meant
we could not delete them automatically when the test was over.

Make sure we close the repositories (and thus their underlying packs)
before the tear down finishes.

Bug: 310367
Change-Id: I4d2703efa4b2e0c347ea4f4475777899cf71073e
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

It is incorrect to use Eclipse.org as the providerName now,
we'll use Eclipse JGit.

Change-Id: I1621b93d4f401176704e7c43935a5ce0c8ee8419
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

If a concurrent thread picks up a newly created PackFile and adds
it to the pack list before the IndexPack thread itself can insert
the item onto the front of the list, do nothing and use the item
that was picked up by that other concurrent scanning thread.

This avoids a potential condition where the same pack exists in
memory twice, which causes confusion later during a rescan of the
directory because we don't know exactly which PackFile instance
should be retained into the new list, and which should be discarded.

We can stop searching through the old pack list as soon as the
sort function declares that the item to insert should be before
the item already in the list.  Because the list is always sorted
by modification time (in seconds), we should never encounter a
case where the pack is positioned at the wrong spot in the list.
This early break out still permits an efficient implementation of
the common case, inserting a new pack at the head of the list.

Change-Id: Ice4459bbd4ee9487078aff5257893883d04f05fb
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

There is a potential race condition during insertPack that can lead
to us having the same pack file open twice in the same directory.

A different thread can miss an object on disk, and trigger a scan
of the directory, and notice the pack that was put in by IndexPack.
So the pack winds up in the newly created PackList.

The IndexPack thread then wakes up and finishes its insertPack by
creating a new PackFile and inserting it into position 0 of the list.
We now have the same pack listed twice.

Readers will favor the earlier PackFile instance, because its the
first one they come across as they iterate through the list.

Keep that earlier one when we scan the pack directory again, as
this will avoid needing to purge out all of the windows that may
have been cached.

Of course we should also fix that race condition, but this block
was taking the wrong resolution if this error ever shows up, so
lets first fix the block to use a more sane resolution.

Change-Id: I0d339b9fd1dd8012e8fe5a564b893c0f69109e28
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

This reuse line was identical between the two branches related to
reusing a delta, or reusing a whole object.  Either way they reuse
the body of the object as-is.  So just make that a common function
after the header is written.

Change-Id: I0e6673b8e813c8c08c594ea2ba546fd366339d5d
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

If a corrupt loose object is read, UnpackedObjectLoader was disposing
of the Inflater, and then attempting to return the disposed Inflater
to the InflaterCache.  Since the disposed Inflater had its native
libz resource deallocated and its reference cleared out, the Inflater
threw NullPointerException and refused to reset itself before being
put back into the cache.

Instead of disposing of the Inflater when corruption is found, do
nothing, and allow it to be returned to the cache.  The instance
will get reset, and should be usable by a future caller.

Bug: 310291
Change-Id: I44f2247c08b6e04fa62f8399609341b07508c096
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

* receive-pack-filter:
  ReceivePack: Clarify the check reachable option
  ReceivePack: Micro-optimize object lookup when checking connectivity
  ReceivePack: Correct type of not provided object
  IndexPack: Tighten up new and base object bookkeeping
  ReceivePack: Remove need new,base object id properties
  ReceivePack: Discard IndexPack as soon as possible
  ReceivePack: fix ensureProvidedObjectsVisible on thin packs

Change-Id: I4ef2fcb931f3219872e0519abfcee220191d5133

This option was mis-named from day 1.  Its not checking that the
objects provided by the client are reachable, its actually doing
a scan to prove that objects referenced by the client are already
reachable through another reference on the server, or were sent
as part of the pack from the client.

Rename it checkReferencedObjectsAreReachable, since we really are
trying to validate that objects referenced by the client's actions
are reachable to the client.

We also need to ensure we run checkConnectivity() anytime this is
enabled, even if the caller didn't turn on fsck for object formats.
Otherwise the check would be completely bypassed.

Change-Id: Ic352ddb0ca8464d407c6da5c83573093e018af19
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

If we are checking the visibility of everything referenced in the
pack that isn't already reachable by a reference, it needs to be
in the provided set.  Since the provided set lists everything that
is in this pack, we can avoid checking to see if the blob exists
on disk, because we know it should be there, it was found in the
pack we just consumed.

Change-Id: Ie3c7746f734d13077242100a68e048f1ac18c34a
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

If a tree was referenced but not provided in the pack, report it
as a missing tree and not as a missing blob.

Change-Id: Iab05705349cdf0d30cc3f8afc6698a8d2a941343
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The only current consumer of these collections is ReceivePack,
where it needs to test ObjectId equality between a RevObject and an
ObjectId.  There we were copying from a traditional HashSet<ObjectId>
into an ObjectIdSubclassMap<ObjectId>, as the latter can perform
hashing using ObjectId's native value support, bypassing RevObject's
override on hashCode() and equals().  Instead of doing that copy,
directly create ObjectIdSubclassMap instances inside of ReceivePack.

We also only need to record the objects that do not appear in the
incoming pack, and were therefore copied from the local repositiory
in order to complete delta resolution.  Instead of listing everything
that used an OBJ_REF_DELTA format, list only the objects that we
pulled from the destination repository via a normal ObjectLoader.

ReceivePack can now discard the IndexPack object, and all of its
other data, as soon as these collections are held by the check
connectivity method.  This frees up memory for the ObjectWalk's
own RevObject pool.

Change-Id: I22ef71b45c2045a0202e7fd550a770ee1f6f38a6
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

These are more like internal implementation details of how IndexPack
works with ReceivePack to validate the incoming object stream.
Callers who are embedding the ReceivePack logic in their own
application don't really need to know the details of which objects
were used for delta bases in the incoming thin pack, or exactly
which objects were newly transmitted.

Hide these from the API, as exposing them through ReceivePack was
an early mistake.

Change-Id: I7ee44a314fa19e6a8520472ce05de92c324ad43e
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The IndexPack object carries a good bit of state within itself about
the objects received over the wire.  The earlier we can discard it,
the sooner the GC is able to reclaim this chunk of memory for other
uses.  So drop it as soon as we are certain the pack is valid and we
have no connectivity concerns.

Change-Id: I1e8bc87c2e9183733043622237a064e55957891f
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

If ensureProvidedObjectsVisible is enabled we expected any trees or
blobs directly reachable from an advertised reference to be marked
with UNINTERESTING.  Unfortunately ObjectWalk doesn't bother setting
this until the traversal is complete.  Even then it won't necessarily
set it on every tree if the corresponding commit wasn't popped.

When we are going to check the base objects for the received pack,
ensure the UNINTERESTING flag gets carried into every immediately
reachable tree or blob, because these are the ones that the client
might try to use as delta bases in a thin pack.

Change-Id: I5d5fdcf07e25ac9fc360e79a25dff491925e4101
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

The Iterator contract says next() shall throw NoSuchElementException
if there are no more items remaining in the iteration.  We got this
wrong when I originally wrote the implementation, so fix it.

Change-Id: Iea25e6569ead5c8b3128b8a368c5b2caebec7ecc
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

This class behaves like a cross between a Set and a Map, sometimes
we might expect to use the method isEmpty() to test for size() == 0.
So implement it, reducing the surprise folks get when they are given
one of these objects.

Change-Id: I0d68e1243da8e62edf79c6ba4fd925f643e80a88
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

If we need to append less than 20 bytes in order to fix a thin pack
and make it complete, we need to set the length of our file back to
the actual number of bytes used because the original SHA-1 footer was
not completely overwritten.  That extra data will confuse the header
and footer fixup logic when it tries to read to the end of the file.

This isn't a very common case to occur, which is why we've never
seen it before.  Getting a delta that requires a whole object which
uses less than 20 bytes in pack representation is really hard.
Generally a delta generator won't make these, because the delta
would be bigger than simply deflating the whole object.  I only
managed to do this with a hand-crafted pack file where a 1 byte
delta was pointed to a 1 byte whole object.

Normally we try really hard to avoid truncating, because its
typically not safe across network filesystems.  But the odds of
this occurring are very low.  This truncation is done on a file
we have open for writing, will append more content onto, and is
a temporary file that we won't move into position for others to
see until we've validated its SHA-1 is sane.  I don't think the
truncate on NFS issue is something we need to worry about here.

Change-Id: I102b9637dfd048dc833c050890d142f43c1e75ae
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Since cc905e7d "Make Repository.getConfig aware of changed config"
its invalid to have a null result from FileBasedConfig.getFile(), as
the path is used to stat the location on disk before returning the
Config object from Repository.getConfig().

Mock out the isOutdated() method to return false all of the time
in the mock test environment, so we don't crash with an NPE when
this mock user configuration is being called.

Change-Id: I0b4d9cbd346d5dc225ec12674da905c35457fa7c
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

We can avoid one stat call by trying to perform a directory
listing without checking if the reference File is a directory.
Attempting a directory listing is defined to return. The other
case for null returns from list is when an I/O error occcurs.

Both cases are now intepreted as a possible plain reference. I/O
errors when reading plain references will be handled (ignored)
in scanRef().

Change-Id: I9906ed8c42eab4d6029c781aab87b3b07c1a1d2c
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

In the current implementation Repository reads user and repository 
config only at creation point of time.
The new implementatiopn checks in Repository.getConfig if user or 
repository config have changed on disk and reload the config if 
required. 

Change-Id: Ibd97515919ef66c6f8aa1a4fe8a11a6711335dad
Signed-off-by: Jens Baumgart <jens.baumgart@sap.com>