When a new Git instance for an exisiting git repository should be
created there are two use-cases: either the application has already a
Repository instance in hand or the application knows where the
repository resides in the filesystem. Two methods are added to
explicitly support these use-cases: wrap(Repository db) and open(File
gitDir)

Change-Id: I2970e4aa8d4602cb1298f01e5b76bf0f96c492e5
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

When reading refs, avoid reading huge files that were put there
accidentally, but still read the top of e.g. FETCH_HEAD, which
may be longer than our limit. We're only interested in the first line
anyway.

Bug: 340880
Change-Id: I11029b9b443f22019bf80bd3dd942b48b531bc11
Signed-off-by: Carsten Pfieffer <carsten.pfeiffer@gebit.de>
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

The 'Counting objects' phase of PackWriter requires good hit rates
from the DeltaBaseCache while walking trees, the deltas need to find
their bases in the cache in order to inflate in a reasonable time.

If JGit is running in a multi-threaded server, such as Gerrit Code
Review, each thread needs its own DeltaBaseCache to prevent one thread
from evicting the other thread's relevant bases.  Move the cache to be
per-ObjectReader, lazily allocated when required by a PackFile.

Change-Id: If9d5ed06728e813632ae96dcfb811f4860b276e8
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

If a repository has an alternate object database, the alternate has
its references advertised as ".have" lines, which permits the client
to use these as delta base candidates when generating the pack.  If
setCheckReferencedObjectsAreReachable(true) is used, these additional
have lines need to be considered in addition to the advertised refs.

Change-Id: Ie39c6696f9d3ff147ef4405cd5624f6011700ce5
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

We sometimes face the problem that the file .git/index.lock
can't deleted causing JGit operations to fail. Problem is
that LockFile.unlock() simply deletes the lockfile and ignores the
return value of File.delete(). Instead use
FileUtils.delete() with retry option. This method will retry the
deletion of the file at most 10 times with sleeps inbetween.

Bug: 335959
Change-Id: I9598edea9f2304fe12e6f470301211b503434848
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

There should be a way to explictly refresh the refs cached in the
RefDirectory. Since commit c261b28 (use of FileSnapshot) this is
not needed anymore for storage in the filesystem. But for DHT based
storage an explicit refresh may be needed.

Change-Id: I7d30c3496c05e1fb6e9519f3af9f23c6adb93bf9
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

Instead of tracking the length and modification time by hand, rely
on FileSnapshot to tell RefDirectory when the $GIT_DIR/packed-refs
file has been changed or should be re-read from disk.

Change-Id: I067d268dfdca1d39c72dfa536b34e6a239117cc3
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

When the client is clearly making a smart HTTP request to our smart
HTTP server, return any errors like RepositoryNotFoundException or
ServiceNotEnabledException inside of the payload as a Git level ERR
message, rather than an HTTP error code.

This prevents the C Git command line client from retrying a failed
"$URL/info/refs?service=git-upload-pack" request without the smart
service URL, only to fail again with "403 Forbidden" when the dumb
as-is service has been disabled by the server configuration, or is
unavailable because the repository is not on the local filesystem.

Change-Id: I57e8756d5026e885e0ca615979bfcd729703be6c
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Embedding applications can use this hook to watch actions within
UploadPack and possibly reject them. This could be useful to prevent
clones of a large repository from this server, or to stop abusive
negotiation rounds that offer thousands of objects in a single batch.

Change-Id: Id96f1885ac4d61f22c80b6418fff54184b7348ba
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Permit applications embedding GitServlet to wrap the
info/refs?service=$name and /$name operations with a
servlet Filter.

To help applications inspect state of the operation,
expose the UploadPack or ReceivePack object into a
request attribute.  This can be useful for logging,
or to implement throttling of requests like Gerrit
Code Review uses to prevent server overload.

Change-Id: Ib8773c14e2b7a650769bd578aad745e6651210cb
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Take a very simple approach to avoiding delta chains during object
reuse: objects are now always selected from the oldest pack that
contains them.  This prevents cycles because a pack must not have
a cycle in the delta chain.  If both objects A and B are chosen
out of the same source pack then there cannot be an A->B->A cycle.

The oldest pack is also the most likely to have the smallest deltas.
Its the biggest pack in the system and probably came from the clone
(or last GC) of this repository, where all objects were previously
considered and packed tightly together.  If an object appears again
(for example due to a revert and a push into this repository) the
newer copy of won't be nearly as small as the older delta version
of it, even if the newer one is also itself a delta.

ObjectDirectory already enumerates objects during selection in this
newest->oldest order, so it already is supplying these assumptions
to PackWriter.  Taking advantage of this can speed up selection by
a tiny amount by avoiding some tests, but can also help to prevent
a cycle needing to be broken on the fly during writing.

The previous cycle breaking logic wasn't fully correct either.
If a different delta base was chosen, the new delta base might not
have been written into the output pack before the current object,
forcing the use of REF_DELTA when OFS_DELTA is always smaller.
This logic has now been reworked to always re-check the delta base
and ensure it gets written before the current object.

If a cycle occurs, it gets broken the same way as before, by
disabling delta reuse and finding an alternative form of the
object, which may require inflating/deflating in whole format.

Change-Id: I9953ab8be54ceb8b588e1280d6f7edd688887747
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

If the total number of objects to look for reuse on is under 4096
this is really close to a reasonable batch size for the DHT storage
system to lookup at once.  Combine all of the objects into a single
temporary list, perform reuse, and then prune the main lists if any
duplicate objects were detected from a selected CachedPack.

The intention here is to try and avoid 4 tiny sequential lookups
on the storage system when the time to wait for each of those to
finish is higher than the CPU time required to build (and later
GC) this temporary list.

Change-Id: I528daf9d2f7744dc4a6281750c2d61d8f9da9f3a
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Instead of looping over the objectsLists array, always set slot 0 to
null and explicitly work on the 4 indexes that matter.  This kills
some loops and increases the length of the code slightly, but I've
always really disliked that dummy 0 slot.

Change-Id: I5ad938501c1c61f637ffdaff0d0d88e3962d8942
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

During object enumeration for the thin pack, very few objects come
out that are duplicated with the cached pack. Typically these are
only cases where a blob or tree was cherry-picked forward, got a
copy or rename, or was reverted... all relatively infrequent events.

Speed up pruning of the thin pack object list by combining the phase
with the object representation selection. Implementers should already
be offering to reuse the object from the cached pack if it is stored
there, at which point the implementation can perform a very fast type
of containment test using the cached pack's identity rather than yet
another index lookup.  For the local disk case this is probably not a
big improvement, but it does help on the DHT implementation where the
two passes combined into one reduces latency.

Change-Id: I6a07fc75d9075bf6233e967360b6546f9e9a2b33
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

PacketLineOut is already public. Make PacketLineIn partially public
in case an application needs to use some of the pkt-line protocol.

Change-Id: I5b383eca980bd9e16a7dbdb5aed040c6586d4f46
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

* changes:
  Do not normalize URIishes
  Use Ignore to bypass unused test

It fixes 'Corrupted MAC on input' ssh issue.

CQ: 4728
Change-Id: I7de63cb3482488ac938566706edebee8a1cdad3a
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

If the clone command clones into a bare repository it should not try
to checkout HEAD in the end. For bare repos checkout is not possible.

Change-Id: I359719d421b93c9d2e962e3c0eccc2b59235c3d1
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

This merge command accepts the merge strategy as option and uses the
resolve strategy as default. It expects exactly one other
revision which is merged with current head.

Change-Id: Ia8c188b93ade4afabe6a9ccf267faf045f359a3a
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

To be more consistent with what native git does we should allow
to run the InitCommand also on existing git repos.

Change-Id: I833637842631b37dce96ed9729b3a6ed24054056
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>

The snapshot field of a DirCache object for a newly created repository
can be null. This fix prevents a NPE when isModified() is called in
such a situation.

Change-Id: I61a1b45db2d60fdcc0f87373ac6fd75ac4c4a202
Signed-off-by: Philipp Thun <philipp.thun@sap.com>

This change contains a simple renaming. Instead of using the
expression 'abnormal failure', we just treat this kind of situation
as 'failure'. This is specific enough as conflicts are already handled
separately.

Change-Id: I535acdc7d022543ed0f5ac6151b09a6985f4ef38
Signed-off-by: Philipp Thun <philipp.thun@sap.com>

We used to normalize URI's since it seems simple. This however causes
inconsistencies to the user and to out tests. Just pass backslashes
through and make sure our parser can handle them.

Bug: 341062
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>
Change-Id: I2c8e917a086faabcd8749160c2acc9dd05a42838

Change-Id: Ica9e50c0d512865d217f55bf0d100f27878031b9
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

If JGit got a cygwin path it would fail to resolve directories
relative to it.

Also add system property to debug problems with the FS utilities.
Enable debug using -Djgit.fs.debug=1

Furthermore use -Djgit.gitprefix=<path> to set the git prefix
manually.

Change-Id: I5a58ee45c2d2ae5322f87fd6972526169b2918c8
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

Detaching HEAD didn't work in some corner checkout cases.  If, for example,
HEAD is symbolic ref to refs/heads/master, refs/heads/master is ref to commit
c0ffee... then:

    checkout c0ffee...

would leave the HEAD unchanged.

The same symptom occurs when checking out a remote tracking branch or a tag
that references the same commit as refs/heads/master.

In the above case, the RefUpdate class didn't have enough information to decide
if the update needed to detach symbolic ref because it dealt only with new/old
objectIDs. Therefore, this fix introduced the RefUpdate.detachingSymbolicRef
flag.

Bug: 315166
Change-Id: I085c98b77ea8f9104a213978ea0d4ac6fd58f49b
Signed-off-by: Sasa Zivkov <sasa.zivkov@sap.com>

Bug: 340928
Change-Id: I870b77eeffa70a57891d7253a06ad7d44d808ee4
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

In case an underlying cherry-pick fails due to uncommitted changes, a
RebaseCommand shall fail and roll-back changes.

Change-Id: Ic22eb047fb03ac2c8391f777036b7dbf22a1b061
Signed-off-by: Philipp Thun <philipp.thun@sap.com>

The Checkout command line command was added to JGit but it wasn't
registered in the list of available commands.
Additionally, the 'force' option was named '---force' (triple '-').

Change-Id: I259773932fa9aec3bb29e215740e67c834566f6f
Signed-off-by: Sasa Zivkov <sasa.zivkov@sap.com>

Allow users of the GIT api to get to know the state of their
workingtree and index by adding a status command. The implementation
is mainly a wrapper around IndexDiff class. Better support for multiple
stages in the index (conflict situations) is still missing. An
appropriate change to IndexDiff and StatusCommand will come in a
subsequent commit.

Bug: 337296
Change-Id: Idb390375a68611853c1c903299ec678c89b081dc
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

The RemoteSession interface operates like a simplified version of
java.lang.Runtime with a single exec method (and a disconnect
method). It returns a java.lang.Process, which should begin execution
immediately. Note that this greatly simplifies the interface for
running commands. There is no longer a connect method, and most
implementations will contain the bulk of their code inside
Process.exec, or a constructor called by Process.exec. (See the
revised implementations of JschSession and ExtSession.)
Implementations can now configure their connections properly without
either ignoring the proper use of the interface or trying to adhere
to an overly strict interface with odd rules about what methods are
called first.  For example, Jsch needs to create the output stream
before executing, which it now does in the process constructor. These
changes should make it much easier to add alternate session
implementations in the future.

Also-by: John D Eblen <jdeblen@comcast.net>
Bug: 336749
CQ: 5004
Change-Id: Iece43632086afadf175af6638255041ccaf2bfbb
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

In order to distinguish cherry-pick failures caused by conflicts vs.
'abnormal failures' (e.g. due to unstaged changes or a dirty
worktree), a CherryPickResult class is introduced and returned by
CherryPickCommand.call() instead of a RevCommit. This new class is
similar to MergeResult and RebaseResult. The CherryPickResult contains
all necessary information, e.g. paths causing the cherry-pick (a merge
called within, respectively) to fail. This allows callers to better
react on failures.

Change-Id: I5db57b9259e82ed118e4bf4ec94463efe68b8c1f
Signed-off-by: Philipp Thun <philipp.thun@sap.com>
Signed-off-by: Mathias Kinzler <mathias.kinzler@sap.com>

Add a test case for PullCommand for the successful merge case and test
that the short ref name is used.

Change-Id: I16cbbc88595f73e5512f984e67f93f87ee0fe242
Signed-off-by: Robin Stocker <robin@nibor.org>

java.lang.IndexOutOfBoundsException
at java.nio.ByteBuffer.wrap(ByteBuffer.java:352)
at org.eclipse.jgit.util.RawParseUtils.decodeNoFallback(RawParseUtils.java:913)
at org.eclipse.jgit.util.RawParseUtils.decode(RawParseUtils.java:880)
at org.eclipse.jgit.util.RawParseUtils.decode(RawParseUtils.java:839)
at org.eclipse.jgit.storage.file.ReflogReader$Entry.<init>(ReflogReader.java:102)
at org.eclipse.jgit.storage.file.ReflogReader.getReverseEntries(ReflogReader.java:183)
at org.eclipse.jgit.storage.file.ReflogReader.getReverseEntries(ReflogReader.java:162)

Change-Id: I22a18bc7193962e5018c40a75337f9976b585c40

Add paths causing abnormal merge failures (e.g. due to unstaged
changes) to the MergeResult returned by MergeCommand. This helps
callers to better handle (e.g. present) merge results.

Change-Id: Idb8cf04c5cecfb6a12cb880e16febfc3b9358564
Signed-off-by: Philipp Thun <philipp.thun@sap.com>

This change moves commonly used methods into the RepositoryTestCase
base class.

Change-Id: I56a46c31ee1661c7ce22eb755ab23da8bc9f5da2
Signed-off-by: Philipp Thun <philipp.thun@sap.com>

Frequently enough I'm wondering how much of a pack is commits vs.
trees, and the total line doesn't really tell us this because its
a gross total from the pack. Computing the counts per object type
is simple during packing, as PackWriter already has everything in
memory broken up by object type.  Its virtually free to get these
values and track them.

Change-Id: Id5e6b1902ea909c72f103a0fbca5d8bc316f9ab3
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>