Motivation: JSch serves as 'default' implementations of the SSH
transport. If a client application does not use it then there is no need
to pull in this dependency.

Move the classes depending on JSch to an OSGi fragment extending the
org.eclipse.jgit bundle and keep them in the same package as before
since moving them to another package would break API. Defer moving them
to a separate package to the next major release.

Add a new feature org.eclipse.jgit.ssh.jsch feature to enable
installation. With that users can now decide which of the ssh client
integrations (JCraft JSch or Apache Mina SSHD) they want to install.
We will remove the JCraft JSch integration in a later step due to the
reasons discussed in bug 520927.

Bug: 553625
Change-Id: I5979c8a9dbbe878a2e8ac0fbfde7230059d74dc2
Also-by: Michael Dardis <git@md-5.net>
Signed-off-by: Michael Dardis <git@md-5.net>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Signed-off-by: David Ostrovsky <david@ostrovsky.org>

See [1] for JMH documentation and [2] how to use JMH in Eclipse.

The benchmarks pom currently cannot use the JGit parent pom due to an
ecj bug [3] regarding annotation processing. Hence for now do not
inherit from the JGit parent pom and copy the compiler plugin
configuration for javac from the parent pom.

After running the Maven build the benchmark can be run using Maven:

$ java -jar org.eclipse.jgit.benchmarks/target/benchmarks.jar

or in Eclipse by running the main method of the SimpleLruCacheBenchmark
class.

[1] https://openjdk.java.net/projects/code-tools/jmh/
[2] http://alblue.bandlem.com/Page/3/index.html
[3] https://eclip.se/532029

CQ: 20517
CQ: 20518
Change-Id: Idca8a9e0980f0b8a9c741c4c9e97d03c62f07c8d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Implement LfsProtocolServlet handling the "Git LFS v1 Batch API"
protocol [1]. Add a simple file system based LFS content store and the
debug-lfs-store command to simplify testing.

Introduce a LargeFileRepository interface to enable additional storage
implementation while reusing the same protocol implementation.

At the client side we have to configure the lfs.url, specify that
we use the batch API and we don't use authentication:

  [lfs]
	  url = http://host:port/lfs
	  batch = true
  [lfs "http://host:port/lfs"]
	  access = none

the git-lfs client appends the "objects/batch" to the lfs.url.

Hard code an Authorization header in the FileLfsRepository.getAction
because then git-lfs client will skip asking for credentials. It will
just forward the Authorization header from the response to the
download/upload request.

The FileLfsServlet supports file content storage for "Large File
Storage" (LFS) server as defined by the Github LFS API [2].

- upload and download of large files is probably network bound hence use
  an asynchronous servlet for good scalability
- simple object storage in file system with 2 level fan-out
- use LockFile to protect writing large objects against multiple
  concurrent uploads of the same object
- to prevent corrupt uploads the uploaded file is rejected if its hash
  doesn't match id given in URL

The debug-lfs-store command is used to run the LfsProtocolServlet and,
optionally, the FileLfsServlet which makes it easier to setup a
local test server.

[1]
https://github.com/github/git-lfs/blob/master/docs/api/http-v1-batch.md
[2] https://github.com/github/git-lfs/tree/master/docs/api

Bug: 472961
Change-Id: I7378da5575159d2195138d799704880c5c82d5f3
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Signed-off-by: Sasa Zivkov <sasa.zivkov@sap.com>

The Large File Storage extension specified by GitHub [1] uses SHA-256 to
compute the ID of large files stored by the extension. Hence implement a
SHA-256 abstraction similar to the SHA-1 abstraction used by JGit.

[1] https://git-lfs.github.com/

Bug: 470333
Change-Id: I3a95954543c8570d73929e55f4a884b55dbf1b7a
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

We should use a template for Mylyn commit messages that matches with our
guidelines for commit messages.

http://wiki.eclipse.org/EGit/Contributor_Guide#Commit_message_guidelines

Bug: 337401
Change-Id: I05812abf0eb0651d22c439142640f173fc2f2ba0
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>