Change-Id: I71997a8be83841765111cb7b55506bd8edd8adad
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: I25fb72cc17d7a27b0b69746d907dac9ccd4d7997
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: I985828fd379e4596ae7f1c30a87e55df06a7924e
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: I902cdf1ff92ce8c6e9d80c4965d8d5bd8b9ac6c1
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: Iafab78d6be34d31a13f979b7be67611135c0f8bd
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: Ib831f8870938113bd5338763f90a07d5c108b1de
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: I10835e5aa3618e5033424595942cc1649152cb24
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>