stream through proxy when using fileRetriever

The problem was that when the proxy requests a key be retrieved to its
own temp file, fileRetriever was retriving it to the key's temp
location, and then moving it at the end, which broke streaming.

So, plumb through the path where the key is being retrieved to.

Remote/Directory.hs

@@ -173,7 +173,7 @@ locations d k = NE.map (d P.</>) (keyPaths k)
 locations' :: RawFilePath -> Key -> [RawFilePath]
 locations' d k = NE.toList (locations d k)
 
-{- Returns the location off a Key in the directory. If the key is
+{- Returns the location of a Key in the directory. If the key is
  - present, returns the location that is actually used, otherwise
  - returns the first, default location. -}
 getLocation :: RawFilePath -> Key -> IO RawFilePath

Remote/Directory/LegacyChunked.hs

@@ -98,7 +98,7 @@ store repotop chunksize finalizer k b p = storeHelper repotop finalizer k $ \des
  - :/ This is legacy code..
  -}
 retrieve :: (RawFilePath -> Key -> [RawFilePath]) -> RawFilePath -> Retriever
-retrieve locations d basek p miv c = withOtherTmp $ \tmpdir -> do
+retrieve locations d basek p _dest miv c = withOtherTmp $ \tmpdir -> do
 	showLongNote "This remote uses the deprecated chunksize setting. So this will be quite slow."
 	let tmp = tmpdir P.</> keyFile basek <> ".directorylegacy.tmp"
 	let tmp' = fromRawFilePath tmp
@@ -110,7 +110,7 @@ retrieve locations d basek p miv c = withOtherTmp $ \tmpdir -> do
 		b <- liftIO $ L.readFile tmp'
 		liftIO $ removeWhenExistsWith R.removeLink tmp
 		sink b
-	byteRetriever go basek p miv c
+	byteRetriever go basek p tmp miv c
 
 checkKey :: RawFilePath -> (RawFilePath -> Key -> [RawFilePath]) -> Key -> Annex Bool
 checkKey d locations k = liftIO $

Remote/GCrypt.hs

@@ -409,9 +409,9 @@ store' repo r rsyncopts accessmethod
 	storersync = fileStorer $ Remote.Rsync.store rsyncopts
 
 retrieve :: Remote -> Remote.Rsync.RsyncOpts -> AccessMethod -> Retriever
-retrieve r rsyncopts accessmethod k p miv sink = do
+retrieve r rsyncopts accessmethod k p dest miv sink = do
 	repo <- getRepo r
-	retrieve' repo r rsyncopts accessmethod k p miv sink
+	retrieve' repo r rsyncopts accessmethod k p dest miv sink
 
 retrieve' :: Git.Repo -> Remote -> Remote.Rsync.RsyncOpts -> AccessMethod -> Retriever
 retrieve' repo r rsyncopts accessmethod

Remote/Glacier.hs

@@ -177,7 +177,7 @@ store' r k b p = go =<< glacierEnv c gc u
 		forceSuccessProcess cmd pid
 	go' _ _ _ _ _ = error "internal"
 
-retrieve :: forall a. Remote -> Key -> MeterUpdate -> Maybe IncrementalVerifier -> (ContentSource -> Annex a) -> Annex a
+retrieve :: forall a. Remote -> Key -> MeterUpdate -> RawFilePath -> Maybe IncrementalVerifier -> (ContentSource -> Annex a) -> Annex a
 retrieve = byteRetriever . retrieve'
 
 retrieve' :: forall a. Remote -> Key -> (L.ByteString -> Annex a) -> Annex a

Remote/Helper/Chunked.hs

@@ -294,8 +294,10 @@ retrieveChunks retriever u vc chunkconfig encryptor basek dest basep enc encc
 			let p = maybe basep
 				(offsetMeterUpdate basep . toBytesProcessed)
 				offset
-			v <- tryNonAsync $
+			v <- tryNonAsync $ do
-				retriever (encryptor k) p Nothing $ \content ->
+				let enck = encryptor k
+				objloc <- fromRepo $ gitAnnexTmpObjectLocation enck
+				retriever enck p objloc Nothing $ \content ->
 					bracket (maybe opennew openresume offset) (liftIO . hClose . fst) $ \(h, iv) -> do
 						retrieved iv (Just h) p content
 						let sz = toBytesProcessed $
@@ -316,7 +318,9 @@ retrieveChunks retriever u vc chunkconfig encryptor basek dest basep enc encc
 	getrest p h iv sz bytesprocessed (k:ks) = do
 		let p' = offsetMeterUpdate p bytesprocessed
 		liftIO $ p' zeroBytesProcessed
-		retriever (encryptor k) p' Nothing $ 
+		let enck = encryptor k
+		objloc <- fromRepo $ gitAnnexTmpObjectLocation enck
+		retriever enck p' objloc Nothing $ 
 			retrieved iv (Just h) p'
 		getrest p h iv sz (addBytesProcessed bytesprocessed sz) ks
 
@@ -324,7 +328,7 @@ retrieveChunks retriever u vc chunkconfig encryptor basek dest basep enc encc
 		iv <- startVerifyKeyContentIncrementally vc basek
 		case enc of
 			Just _ -> do
-				retriever (encryptor basek) basep Nothing $
+				retriever (encryptor basek) basep (toRawFilePath dest) Nothing $
 					retrieved iv Nothing basep
 				return (Right iv)
 			-- Not chunked and not encrypted, so ask the
@@ -333,7 +337,7 @@ retrieveChunks retriever u vc chunkconfig encryptor basek dest basep enc encc
 			-- passing the whole file content to the
 			-- incremental verifier though.
 			Nothing -> do
-				retriever (encryptor basek) basep iv $
+				retriever (encryptor basek) basep (toRawFilePath dest) iv $
 					retrieved iv Nothing basep
 				return $ case iv of
 					Nothing -> Right iv

Remote/Helper/Special.hs

@@ -42,6 +42,7 @@ import Types.StoreRetrieve
 import Types.Remote
 import Annex.Verify
 import Annex.UUID
+import Annex.Perms
 import Config
 import Config.Cost
 import Utility.Metered
@@ -106,10 +107,10 @@ byteStorer a k c m = withBytes c $ \b -> a k b m
 -- A Retriever that generates a lazy ByteString containing the Key's
 -- content, and passes it to a callback action which will fully consume it
 -- before returning.
-byteRetriever :: (Key -> (L.ByteString -> Annex a) -> Annex a) -> Key -> MeterUpdate -> Maybe IncrementalVerifier -> (ContentSource -> Annex a) -> Annex a
+byteRetriever :: (Key -> (L.ByteString -> Annex a) -> Annex a) -> Key -> MeterUpdate -> RawFilePath -> Maybe IncrementalVerifier -> (ContentSource -> Annex a) -> Annex a
-byteRetriever a k _m _miv callback = a k (callback . ByteContent)
+byteRetriever a k _m _dest _miv callback = a k (callback . ByteContent)
 
--- A Retriever that writes the content of a Key to a provided file.
+-- A Retriever that writes the content of a Key to a file.
 -- The action is responsible for updating the progress meter as it 
 -- retrieves data. The incremental verifier is updated in the background as
 -- the action writes to the file, but may not be updated with the entire
@@ -119,15 +120,15 @@ fileRetriever a = fileRetriever' $ \f k m miv ->
 	let retrieve = a f k m
 	in tailVerify miv f retrieve
 
-{- A Retriever that writes the content of a Key to a provided file.
+{- A Retriever that writes the content of a Key to a file.
  - The action is responsible for updating the progress meter and the 
  - incremental verifier as it retrieves data.
  -}
 fileRetriever' :: (RawFilePath -> Key -> MeterUpdate -> Maybe IncrementalVerifier -> Annex ()) -> Retriever
-fileRetriever' a k m miv callback = do
+fileRetriever' a k m dest miv callback = do
-	f <- prepTmp k
+	createAnnexDirectory (parentDir dest)
-	a f k m miv
+	a dest k m miv
-	pruneTmpWorkDirBefore f (callback . FileContent . fromRawFilePath)
+	pruneTmpWorkDirBefore dest (callback . FileContent . fromRawFilePath)
 
 {- The base Remote that is provided to specialRemote needs to have
  - storeKey, retrieveKeyFile, removeKey, and checkPresent methods,

Types/StoreRetrieve.hs

@@ -35,12 +35,15 @@ type Storer = Key -> ContentSource -> MeterUpdate -> Annex ()
 -- Throws exception if key is not present, or remote is not accessible.
 --
 -- When it retrieves FileContent, it is responsible for updating the
--- MeterUpdate. And when the IncrementalVerifier is passed to it,
+-- MeterUpdate, and the provided FilePath can be used to store the file
+-- it retrieves. 
+--
+-- When the IncrementalVerifier is passed to it,
 -- and it retrieves FileContent, it can feed some or all of the file's
 -- content to the verifier before running the callback.
 -- This should not be done when it retrieves ByteContent.
 type Retriever = forall a.
-	Key -> MeterUpdate -> Maybe IncrementalVerifier
+	Key -> MeterUpdate -> RawFilePath -> Maybe IncrementalVerifier
 		-> (ContentSource -> Annex a) -> Annex a
 
 -- Action that removes a Key's content from a remote.

doc/todo/git-annex_proxies.mdwn

@@ -30,11 +30,6 @@ Planned schedule of work:
 
 * Currently working on streaming download via proxy from special remote.
 
-* Remotes using fileRetriever retrieve to the temp object file,
-  before it is renamed to the requested file. In the case of a proxy,
-  that is a different file, and so it won't see the file until it's all
-  been transferred and renamed.
-
 ## completed items for September's work on proving behavior of preferred content
 
 * Static analysis to detect "not present", "not balanced", and similar