Change-Id: I0c52536ebeeb8e71d95c6420f6db7055ff082dfa
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

LfsProtocolServlet and FileLfsServlet both implement the same
setup of the Gson object.

Factor it out to a common class and reuse it.

Change-Id: I5696404fad140cbff1b712ebb04a7e8bba60e4b4
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

This allows implementations to reject operations that do not
include proper authentication.

Change-Id: If301476d8fb56a0899e424be3789c7576097d185
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Server implementations may need to check what type of operation is
being performed. Add helper methods to make it a bit simpler.

Change-Id: Ia33ed6699ebcb9000ef514ce79bcddbebf94e1c5
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Externalize the error message and make it more specific. Also emit
an error log.

Change-Id: Ie7b1c90c54673bfb8e133fb0aa19a117d4ca6587
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Add a new exception type that server implementations can throw when a
client attempts to make an unauthorized LFS operation, which will result
in HTTP 401 Unauthorized being returned to the client.

An example of this is a Gerrit server that rejects a request to perform
an LFS operation on a ref that is not visible to the caller.

As defined in the LFS spec [1] the request may include authentication,
and per RFC 2616 [2], "401 response indicates that authorization has been
refused for those credentials".

[1] https://github.com/git-lfs/git-lfs/blob/master/docs/api/batch.md
[2] https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

Change-Id: I2aa22e2144df5fb7972df0e3285b77b08ecc63f2
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Change-Id: I7c545d06b1bced678c020fab9af1382bc4416b6e
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Guide implementors which exception to throw in case of errors.

Change-Id: I74fb76cdf6b7cdef513f3fe8c144572e869cc533
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Instead of returning null, LfsProtocolServlet#getLargeFileRepository
should throw LfsUnavailable.

If null is returned, throw a generic LfsException.

Handle LfsException as an internal server error and return HTTP 500.

Change-Id: I33e2a19fcc0fde8aaf0f703860c8fa8ce2de2db5
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Since [1], the git-lfs specification allows the server to return
HTTP 507 if there is insufficient storage for the uploaded object(s).

Add a new exception class, which implementations may throw from the
getRepository() method, causing HTTP 507 to be returned to the client.

[1] https://github.com/github/git-lfs/pull/1473

Change-Id: If5bc0a35fcf870d4216af6ca2f7c8924689ef9c5
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

The git-lfs specification [1] describes the following optional status codes
that may be returned:

429 - The user has hit a rate limit with the server. Though the API does
      not specify any rate limits, implementors are encouraged to set some
      for availability reasons.

509 - Returned if the bandwidth limit for the user or repository has been
      exceeded. The API does not specify any bandwidth limit, but implementors
      may track usage.

Add two new exception classes to represent these cases. Implementations may
throw these from #getLargeFileRepository(), causing the corresponding HTTP
status codes to be returned to the client.

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

Change-Id: I7b93f3cf90f7344c90b1587e07927fdeb167097e
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

If the message is not sent, the client shows:

  Unable to parse HTTP response for POST http://admin@localhost:8080/test-project/info/lfs/objects/batch

Change-Id: I8b72d1aded2bcd41b7389676e2373034625a1379
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

If the Content-Type is not set on error responses, the git-lfs client
does not read the body which contains the error message, and instead
just displays a generic error message.

Also set the charset on the Content-Type header.

Change-Id: I88e6f07f20b622a670e7c5063145dffb8b630aee
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Pretty printing is only used for outputting json content, which is
interpreted by the client and does not need to be pretty printed.

Change-Id: I48e0280241b6b0f5706300ae0f4c9bc461a89110
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Trying to open a new writer on the response causes an illegal state
exception and the response is not sent.

Change-Id: Ic718d23cfb3e74f5691cc2aea7283003af7df207
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Change-Id: I8db29a0313fbc476152cef47f2eaa76954f1e280
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Classes implementing the LFS servlet should be able to inspect the
objects given in the request.

Add a getObjects method. Make the LfsObject class public, and add
accessor methods.

Change-Id: I27961679f620eb3a89dc8521aadd4ea2f936c60e
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

According to the specification [1] the server may return the following
HTTP error responses:

- 403: The user has read, but not write access.
- 404: The repository does not exist for the user.
- 422: Validation error with one or more of the objects in the request.

In the current implementation, however, getLargeFileRepository can only
return null to indicate an error. This results in the error code:

- 503: Service Unavailable

being returned to the client regardless of what the actual reason was.

Add exception classes to cover these cases, derived from a common base
exception, and change the specification of getLargeFileRepository to throw
the base exception.

In LfsProtocolServlet#post, handle the new exceptions and send back the
appropriate HTTP responses as mentioned above.

The specification also mentions several other optional response codes (406,
429, 501, and 509) but these are not implemented in this commit. It should
be trivial to implement them in follow-up commits.

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

Change-Id: I91be6165bcaf856d0cefc533882330962e2fc9b2
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Passing the request and path to the method will allow implementations
to have more control over determination of the backend, for example:

- return different backends for different requests
- accept or refuse requests based on request characteristics
- etc

Change-Id: I1ec6ec54c91a5f0601b620ed18846eb4a3f46783
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

The location of the API v1 documentation has changed. Update the
links accordingly.

Change-Id: If0148a0b573c474bbe157fcb7e6674c0055fe8b4
Signed-off-by: David Pursehouse <david.pursehouse@gmail.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>

This is a simple HTTP server that provides the minimum server side
support required for dumb (non-git aware) transport clients.

We produce the info/refs and objects/info/packs file on the fly
from the local repository state, but otherwise serve data as raw
files from the on-disk structure.

In the future we could better optimize the FileSender class and the
servlets that use it to take advantage of direct file to network
APIs in more advanced servlet containers like Jetty.

Our glue package borrows the idea of a micro embedded DSL from
Google Guice and uses it to configure a collection of Filters
and HttpServlets, all of which are matched against requests using
regular expressions.  If a subgroup exists in the pattern, it is
extracted and used for the path info component of the request.

Change-Id: Ia0f1a425d07d035e344ae54faf8aeb04763e7487
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Per CQ 3448 this is the initial contribution of the JGit project
to eclipse.org.  It is derived from the historical JGit repository
at commit 3a2dd9921c.

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