Revert "Removed the vendored git-lfs and the GitLfs build flag"

This reverts commit efda811404.

Turns out that datalad is building git-annex against debian bullseye.
https://github.com/datalad/git-annex/issues/149

CHANGELOG

@@ -13,7 +13,6 @@ git-annex (10.20221213) UNRELEASED; urgency=medium
     submodules.
   * Added libgcc_s.so.1 to the linux standalone build so pthread_cancel
     will work.
-  * Removed the vendored git-lfs and the GitLfs build flag.
   * Speed up initial scanning for annexed files when built
     with persistent-2.14.4.1
 

COPYRIGHT

@@ -43,6 +43,10 @@ Copyright: 2019 Joey Hess <id@joeyh.name>
            2007-2015 Bryan O'Sullivan
 License: BSD-3-clause
 
+Files: Utility/GitLFS.hs
+Copyright: © 2019 Joey Hess <id@joeyh.name>
+License: AGPL-3+
+
 Files: Utility/*
 Copyright: 2012-2022 Joey Hess <id@joeyh.name>
 License: BSD-2-clause

Remote/GitLFS.hs

@@ -7,6 +7,7 @@
 
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE CPP #-}
 
 module Remote.GitLFS (remote, gen, configKnownUrl) where
 
@@ -43,7 +44,12 @@ import Logs.Remote
 import Logs.RemoteState
 import qualified Git.Config
 
+#ifdef WITH_GIT_LFS
 import qualified Network.GitLFS as LFS
+#else
+import qualified Utility.GitLFS as LFS
+#endif
+
 import Control.Concurrent.STM
 import Data.String
 import Network.HTTP.Types

Utility/GitLFS.hs

@@ -0,0 +1,476 @@
+{- git-lfs API
+ - 
+ - https://github.com/git-lfs/git-lfs/blob/master/docs/api
+ -
+ - Copyright 2019 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU AGPL version 3 or higher.
+ -}
+
+-- | This implementation of the git-lfs API uses http Request and Response,
+-- but leaves actually connecting up the http client to the user.
+--
+-- You'll want to use a Manager that supports https, since the protocol
+-- uses http basic auth.
+--
+-- Some LFS servers, notably Github's, may require a User-Agent header
+-- in some of the requests, in order to allow eg, uploads. No such header
+-- is added by default, so be sure to add your own.
+
+{-# LANGUAGE DeriveGeneric, FlexibleInstances, FlexibleContexts #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE LambdaCase #-}
+
+-- This is a vendored copy of Network.GitLFS from the git-lfs package,
+-- and will be removed once that package is available in all build
+-- environments.
+module Utility.GitLFS (
+	-- * Transfer requests
+	TransferRequest(..),
+	TransferRequestOperation(..),
+	TransferAdapter(..),
+	TransferRequestObject(..),
+	startTransferRequest,
+
+	-- * Responses to transfer requests
+	TransferResponse(..),
+	TransferResponseOperation(..),
+	IsTransferResponseOperation,
+	DownloadOperation(..),
+	UploadOperation(..),
+	OperationParams(..),
+	ParsedTransferResponse(..),
+	parseTransferResponse,
+
+	-- * Making transfers
+	downloadOperationRequest,
+	uploadOperationRequests,
+	ServerSupportsChunks(..),
+
+	-- * Endpoint discovery
+	Endpoint,
+	guessEndpoint,
+	modifyEndpointRequest,
+	sshDiscoverEndpointCommand,
+	parseSshDiscoverEndpointResponse,
+
+	-- * Errors
+	TransferResponseError(..),
+	TransferResponseObjectError(..),
+
+	-- * Additional data types
+	Url,
+	SHA256,
+	GitRef(..),
+	NumSeconds,
+	HTTPHeader,
+	HTTPHeaderValue,
+) where
+
+import Data.Aeson
+import Data.Aeson.Types
+import GHC.Generics
+import Network.HTTP.Client
+import Data.List
+import qualified Data.Map as M
+import qualified Data.Text as T
+import qualified Data.Text.Encoding as E
+import qualified Data.ByteString.Lazy as L
+import qualified Data.CaseInsensitive as CI
+import qualified Network.URI as URI
+
+data TransferRequest = TransferRequest
+	{ req_operation :: TransferRequestOperation
+	, req_transfers :: [TransferAdapter]
+	, req_ref :: Maybe GitRef
+	, req_objects :: [TransferRequestObject]
+	}
+	deriving (Generic, Show)
+
+instance ToJSON TransferRequest where
+	toJSON = genericToJSON transferRequestOptions
+	toEncoding = genericToEncoding transferRequestOptions
+
+instance FromJSON TransferRequest where
+	parseJSON = genericParseJSON transferRequestOptions
+
+transferRequestOptions :: Options
+transferRequestOptions = stripFieldPrefix nonNullOptions
+
+data TransferRequestObject = TransferRequestObject
+	{ req_oid :: SHA256
+	, req_size :: Integer
+	}
+	deriving (Generic, Show)
+
+instance ToJSON TransferRequestObject where
+	toJSON = genericToJSON transferRequestObjectOptions
+	toEncoding = genericToEncoding transferRequestObjectOptions
+
+instance FromJSON TransferRequestObject where
+	parseJSON = genericParseJSON transferRequestObjectOptions
+
+transferRequestObjectOptions :: Options
+transferRequestObjectOptions = stripFieldPrefix defaultOptions
+
+data TransferRequestOperation = RequestDownload | RequestUpload
+	deriving (Show)
+
+instance ToJSON TransferRequestOperation where
+	toJSON RequestDownload = "download"
+	toJSON RequestUpload = "upload"
+
+instance FromJSON TransferRequestOperation where
+	parseJSON (String "download") = pure RequestDownload
+	parseJSON (String "upload") = pure RequestUpload
+	parseJSON invalid = typeMismatch "TransferRequestOperation" invalid
+
+data TransferResponse op = TransferResponse
+	{ transfer :: Maybe TransferAdapter
+	, objects :: [TransferResponseOperation op]
+	}
+	deriving (Generic, Show)
+
+instance IsTransferResponseOperation op => ToJSON (TransferResponse op) where
+	toJSON = genericToJSON nonNullOptions
+	toEncoding = genericToEncoding nonNullOptions
+
+instance IsTransferResponseOperation op => FromJSON (TransferResponse op)
+
+-- | This is an error with a TransferRequest as a whole. It's also possible
+-- for a TransferRequest to overall succeed, but fail for some
+-- objects; such failures use TransferResponseObjectError.
+data TransferResponseError = TransferResponseError
+	{ resperr_message :: T.Text
+	, resperr_request_id :: Maybe T.Text
+	, resperr_documentation_url :: Maybe Url
+	}
+	deriving (Generic, Show)
+
+instance ToJSON TransferResponseError where
+	toJSON = genericToJSON transferResponseErrorOptions
+	toEncoding = genericToEncoding transferResponseErrorOptions
+
+instance FromJSON TransferResponseError where
+	parseJSON = genericParseJSON transferResponseErrorOptions
+
+transferResponseErrorOptions :: Options
+transferResponseErrorOptions = stripFieldPrefix nonNullOptions
+
+-- | An error with a single object within a TransferRequest.
+data TransferResponseObjectError = TransferResponseObjectError
+	{ respobjerr_code :: Int
+	, respobjerr_message :: T.Text
+	}
+	deriving (Generic, Show)
+
+instance ToJSON TransferResponseObjectError where
+	toJSON = genericToJSON transferResponseObjectErrorOptions
+	toEncoding = genericToEncoding transferResponseObjectErrorOptions
+
+instance FromJSON TransferResponseObjectError where
+	parseJSON = genericParseJSON transferResponseObjectErrorOptions
+
+transferResponseObjectErrorOptions :: Options
+transferResponseObjectErrorOptions = stripFieldPrefix nonNullOptions
+
+data TransferAdapter = Basic
+	deriving (Show)
+
+instance ToJSON TransferAdapter where
+	toJSON Basic = "basic"
+
+instance FromJSON TransferAdapter where
+	parseJSON (String "basic") = pure Basic
+	parseJSON invalid = typeMismatch "basic" invalid
+
+data TransferResponseOperation op = TransferResponseOperation
+	{ resp_oid :: SHA256
+	, resp_size :: Integer
+	, resp_authenticated :: Maybe Bool
+	, resp_actions :: Maybe op
+	, resp_error :: Maybe TransferResponseObjectError
+	}
+	deriving (Generic, Show)
+
+instance ToJSON op => ToJSON (TransferResponseOperation op) where
+	toJSON = genericToJSON transferResponseOperationOptions
+	toEncoding = genericToEncoding transferResponseOperationOptions
+
+instance FromJSON op => FromJSON (TransferResponseOperation op) where
+	parseJSON = genericParseJSON transferResponseOperationOptions
+
+transferResponseOperationOptions :: Options
+transferResponseOperationOptions = stripFieldPrefix nonNullOptions
+
+-- | Class of types that can be responses to a transfer request,
+-- that contain an operation to use to make the transfer.
+class (FromJSON op, ToJSON op) => IsTransferResponseOperation op
+
+data DownloadOperation = DownloadOperation
+	{ download :: OperationParams }
+	deriving (Generic, Show)
+
+instance IsTransferResponseOperation DownloadOperation
+instance ToJSON DownloadOperation
+instance FromJSON DownloadOperation
+
+data UploadOperation = UploadOperation
+	{ upload :: OperationParams
+	, verify :: Maybe OperationParams
+	}
+	deriving (Generic, Show)
+
+instance IsTransferResponseOperation UploadOperation
+
+instance ToJSON UploadOperation where
+	toJSON = genericToJSON nonNullOptions
+	toEncoding = genericToEncoding nonNullOptions
+
+instance FromJSON UploadOperation
+
+data OperationParams = OperationParams
+	{ href :: Url
+	, header :: Maybe (M.Map HTTPHeader HTTPHeaderValue)
+	, expires_in :: Maybe NumSeconds
+	, expires_at :: Maybe T.Text
+	}
+	deriving (Generic, Show)
+
+instance ToJSON OperationParams where
+	toJSON = genericToJSON nonNullOptions
+	toEncoding = genericToEncoding nonNullOptions
+
+instance FromJSON OperationParams
+
+data Verification = Verification
+	{ verification_oid :: SHA256
+	, verification_size :: Integer
+	}
+	deriving (Generic, Show)
+
+instance ToJSON Verification where
+	toJSON = genericToJSON verificationOptions
+	toEncoding = genericToEncoding verificationOptions
+
+instance FromJSON Verification where
+	parseJSON = genericParseJSON verificationOptions
+
+verificationOptions :: Options
+verificationOptions = stripFieldPrefix defaultOptions
+
+-- | Sent over ssh connection when using that to find the endpoint.
+data SshDiscoveryResponse = SshDiscoveryResponse
+	{ endpoint_href :: Url
+	, endpoint_header :: Maybe (M.Map HTTPHeader HTTPHeaderValue)
+	, endpoint_expires_in :: Maybe NumSeconds
+	, endpoint_expires_at :: Maybe T.Text
+	} deriving (Generic, Show)
+
+instance ToJSON SshDiscoveryResponse where
+	toJSON = genericToJSON sshDiscoveryResponseOptions
+	toEncoding = genericToEncoding sshDiscoveryResponseOptions
+
+instance FromJSON SshDiscoveryResponse where
+	parseJSON = genericParseJSON sshDiscoveryResponseOptions
+
+sshDiscoveryResponseOptions :: Options
+sshDiscoveryResponseOptions = stripFieldPrefix nonNullOptions
+
+data GitRef = GitRef
+	{ name :: T.Text }
+	deriving (Generic, Show)
+
+instance FromJSON GitRef
+instance ToJSON GitRef
+
+type SHA256 = T.Text
+
+-- | The endpoint of a git-lfs server.
+data Endpoint = Endpoint Request
+	deriving (Show)
+
+-- | Command to run via ssh with to discover an endpoint. The FilePath is
+-- the location of the git repository on the ssh server.
+--
+-- Note that, when sshing to the server, you should take care that the
+-- hostname you pass to ssh is really a hostname and not something that ssh
+-- will parse an an option, such as -oProxyCommand=".
+sshDiscoverEndpointCommand :: FilePath -> TransferRequestOperation -> [String]
+sshDiscoverEndpointCommand remotepath tro =
+	[ "git-lfs-authenticate"
+	, remotepath
+	, case tro of
+		RequestDownload -> "download"
+		RequestUpload -> "upload"
+	]
+
+-- Internal smart constructor for an Endpoint.
+-- 
+-- Since this uses the LFS batch API, it adds /objects/batch
+-- to the endpoint url. It also adds the necessary headers to use JSON.
+mkEndpoint :: URI.URI -> Maybe Endpoint
+mkEndpoint uri = do
+	r <- requestFromURI uri
+	let r' = addLfsJsonHeaders $ r { path = path r <> "/objects/batch" }
+	return (Endpoint r')
+
+-- | Parse the json output when doing ssh endpoint discovery.
+parseSshDiscoverEndpointResponse :: L.ByteString -> Maybe Endpoint
+parseSshDiscoverEndpointResponse resp = do
+	sr <- decode resp
+	uri <- URI.parseURI (T.unpack (endpoint_href sr))
+	endpoint <- mkEndpoint uri
+	return $ modifyEndpointRequest endpoint $ case endpoint_header sr of
+		Nothing -> id
+		Just headers ->
+			let headers' = map convheader (M.toList headers)
+			in \req -> req
+				{ requestHeaders = requestHeaders req ++ headers' }
+  where
+	convheader (k, v) = (CI.mk (E.encodeUtf8 k), E.encodeUtf8 v)
+
+-- | Guesses the LFS endpoint from the http url of a git remote.
+--
+-- https://github.com/git-lfs/git-lfs/blob/master/docs/api/server-discovery.md
+guessEndpoint :: URI.URI -> Maybe Endpoint
+guessEndpoint uri = case URI.uriScheme uri of
+	"https:" -> endpoint
+	"http:" -> endpoint
+	_ -> Nothing
+  where
+	endpoint = mkEndpoint $ uri
+		-- force https because the git-lfs protocol uses http
+		-- basic auth tokens, which should not be exposed
+		{ URI.uriScheme = "https:"
+		, URI.uriPath = guessedpath
+		}
+	
+	guessedpath
+		| ".git" `isSuffixOf` URI.uriPath uri =
+			URI.uriPath uri ++ "/info/lfs"
+		| ".git/" `isSuffixOf` URI.uriPath uri =
+			URI.uriPath uri ++ "info/lfs"
+		| otherwise = (droptrailing '/' (URI.uriPath uri)) ++ ".git/info/lfs"
+	
+	droptrailing c = reverse . dropWhile (== c) . reverse
+
+-- | When an Endpoint is used to generate a Request, this allows adjusting
+-- that Request.
+--
+-- This can be used to add http basic authentication to an Endpoint:
+--
+-- > modifyEndpointRequest (guessEndpoint u) (applyBasicAuth "user" "pass")
+modifyEndpointRequest :: Endpoint -> (Request -> Request) -> Endpoint
+modifyEndpointRequest (Endpoint r) f = Endpoint (f r)
+
+-- | Makes a Request that will start the process of making a transfer to or
+-- from the LFS endpoint.
+startTransferRequest :: Endpoint -> TransferRequest -> Request
+startTransferRequest (Endpoint r) tr = r
+	{ method = "POST"
+	, requestBody = RequestBodyLBS (encode tr)
+	}
+
+addLfsJsonHeaders :: Request -> Request
+addLfsJsonHeaders r = r
+	{ requestHeaders = requestHeaders r ++
+		[ ("Accept", lfsjson)
+		, ("Content-Type", lfsjson)
+		]
+	}
+  where
+	lfsjson = "application/vnd.git-lfs+json"
+
+data ParsedTransferResponse op
+	= ParsedTransferResponse (TransferResponse op)
+	| ParsedTransferResponseError TransferResponseError
+	| ParseFailed String
+
+-- | Parse the body of a response to a transfer request.
+parseTransferResponse
+	:: IsTransferResponseOperation op
+	=> L.ByteString
+	-> ParsedTransferResponse op
+parseTransferResponse resp = case eitherDecode resp of
+	Right tr -> ParsedTransferResponse tr
+	-- If unable to decode as a TransferResponse, try to decode
+	-- as a TransferResponseError instead, in case the LFS server
+	-- sent an error message.
+	Left err ->
+		either (const $ ParseFailed err) ParsedTransferResponseError $
+			eitherDecode resp
+
+-- | Builds a http request to perform a download.
+downloadOperationRequest :: DownloadOperation -> Maybe Request
+downloadOperationRequest = fmap fst . operationParamsRequest . download
+
+-- | Builds http request to perform an upload. The content to upload is
+-- provided, along with its SHA256 and size.
+--
+-- When the LFS server requested verification, there will be a second
+-- Request that does that; it should be run only after the upload has
+-- succeeded.
+--
+-- When the LFS server already contains the object, an empty list may be
+-- returned.
+uploadOperationRequests :: UploadOperation -> (ServerSupportsChunks -> RequestBody) -> SHA256 -> Integer -> Maybe [Request]
+uploadOperationRequests op mkcontent oid size = 
+	case (mkdlreq, mkverifyreq) of
+		(Nothing, _) -> Nothing
+		(Just dlreq, Nothing) -> Just [dlreq]
+		(Just dlreq, Just verifyreq) -> Just [dlreq, verifyreq]
+  where
+	mkdlreq = mkdlreq'
+		<$> operationParamsRequest (upload op)
+	mkdlreq' (r, ssc) = r
+		{ method = "PUT"
+		, requestBody = mkcontent ssc
+		}
+	mkverifyreq = mkverifyreq'
+		<$> (operationParamsRequest =<< verify op)
+	mkverifyreq' (r, _ssc) = addLfsJsonHeaders $ r
+		{ method = "POST"
+		, requestBody = RequestBodyLBS $ encode $
+			Verification oid size
+		}
+
+-- | When the LFS server indicates that it supports Transfer-Encoding chunked,
+-- this will contain a true value, and the RequestBody provided to
+-- uploadOperationRequests may be created using RequestBodyStreamChunked.
+-- Otherwise, that should be avoided as the server may not support the
+-- chunked encoding.
+newtype ServerSupportsChunks = ServerSupportsChunks Bool
+
+operationParamsRequest :: OperationParams -> Maybe (Request, ServerSupportsChunks)
+operationParamsRequest ps = do
+	r <- parseRequest (T.unpack (href ps))
+	let headers = map convheader $ maybe [] M.toList (header ps)
+	let headers' = filter allowedheader headers
+	let ssc = ServerSupportsChunks $
+		any (== ("Transfer-Encoding", "chunked")) headers
+	return (r { requestHeaders = headers' }, ssc)
+  where
+	convheader (k, v) = (CI.mk (E.encodeUtf8 k), E.encodeUtf8 v)
+	-- requestHeaders is not allowed to set Transfer-Encoding or 
+	-- Content-Length; copying those over blindly could request in a
+	-- malformed request.
+	allowedheader (k, _) = k /= "Transfer-Encoding"
+		&& k /= "Content-Length"
+
+type Url = T.Text
+
+type NumSeconds = Integer
+
+type HTTPHeader = T.Text
+
+type HTTPHeaderValue = T.Text
+
+-- Prevent Nothing from serializing to null.
+nonNullOptions :: Options
+nonNullOptions = defaultOptions { omitNothingFields = True }
+
+-- Remove prefix from field names.
+stripFieldPrefix :: Options -> Options
+stripFieldPrefix o =
+	o { fieldLabelModifier = drop 1 . dropWhile (/= '_') }

debian/control

@@ -82,7 +82,6 @@ Build-Depends:
 	libghc-vector-dev,
 	libghc-unliftio-core-dev,
 	libghc-filepath-bytestring-dev,
-	libghc-git-lfs-dev (>= 1.2.0),
 	libghc-criterion-dev,
 	lsof [linux-any],
 	ikiwiki,

git-annex.cabal

@@ -284,6 +284,10 @@ Flag DebugLocks
 Flag Dbus
   Description: Enable dbus support
 
+Flag GitLfs
+  Description: Build with git-lfs library (rather than vendored copy)
+  Default: True
+
 source-repository head
   type: git
   location: git://git-annex.branchable.com/
@@ -386,8 +390,7 @@ Executable git-annex
    blaze-builder,
    clientsession,
    template-haskell,
-   shakespeare (>= 2.0.11),
+   shakespeare (>= 2.0.11)
-   git-lfs (>= 1.2.0)
   CC-Options: -Wall
   GHC-Options: -Wall -fno-warn-tabs  -Wincomplete-uni-patterns
   Default-Language: Haskell2010
@@ -420,6 +423,12 @@ Executable git-annex
   else
     Build-Depends: unix (>= 2.7.2)
 
+  if flag(GitLfs)
+    Build-Depends: git-lfs (>= 1.2.0)
+    CPP-Options: -DWITH_GIT_LFS
+  else
+    Other-Modules: Utility.GitLFS
+  
   if flag(Assistant) && ! os(solaris) && ! os(gnu)
     CPP-Options: -DWITH_ASSISTANT -DWITH_WEBAPP
     Other-Modules:

stack.yaml

@@ -8,6 +8,7 @@ flags:
     dbus: false
     debuglocks: false
     benchmark: true
+    gitlfs: true
 packages:
 - '.'
 resolver: lts-18.13

standalone/linux/stack-i386ancient.yaml

@@ -8,6 +8,7 @@ flags:
     dbus: false
     debuglocks: false
     benchmark: false
+    gitlfs: true
 packages:
 - '.'
 extra-deps: