module Data.Git.Blob
( Blob(..)
, BlobContents(..)
, ByteSource
, newBlobBase
, createBlob
, getBlobContents
, blobSourceToString
, lookupBlob
, writeBlob )
where
import Data.ByteString as B hiding (map)
import Data.ByteString.Unsafe
import Data.Conduit
import Data.Git.Common
import Data.Git.Error
import Data.Git.Internal
import qualified Prelude
data BlobContents = BlobEmpty
| BlobString B.ByteString
| BlobStream ByteSource
blobSourceToString :: BlobContents -> IO (Maybe B.ByteString)
blobSourceToString BlobEmpty = return Nothing
blobSourceToString (BlobString bs) = return (Just bs)
blobSourceToString (BlobStream bs) = do str <- bs $$ await
case str of
Nothing -> return Nothing
Just str' -> return (Just str')
data Blob = Blob { blobInfo :: Base Blob
, blobContents :: BlobContents }
instance Show Blob where
show x = case gitId (blobInfo x) of
Pending _ -> "Blob..."
Stored y -> "Blob#" ++ show y
instance Updatable Blob where
getId = gitId . blobInfo
objectRepo = gitRepo . blobInfo
objectPtr = gitObj . blobInfo
update = writeBlob
lookupFunction = lookupBlob
#if defined(PROFILING)
loadObject' x y =
maybe (throwIO ObjectLookupFailed) return =<< loadObject x y
#endif
newBlobBase :: Blob -> Base Blob
newBlobBase b = newBase (gitRepo (blobInfo b)) (Pending doWriteBlob) Nothing
createBlob :: B.ByteString -> Repository -> Blob
createBlob text repo
| text == B.empty = error "Cannot create an empty blob"
| otherwise =
Blob { blobInfo = newBase repo (Pending doWriteBlob) Nothing
, blobContents = BlobString text }
lookupBlob :: Oid -> Repository -> IO (Maybe Blob)
lookupBlob oid repo =
lookupObject' oid repo c'git_blob_lookup c'git_blob_lookup_prefix $
\coid obj _ ->
return Blob { blobInfo = newBase repo (Stored coid) (Just obj)
, blobContents = BlobEmpty }
getBlobContents :: Blob -> IO (Blob, BlobContents)
getBlobContents b@(gitId . blobInfo -> Pending _) = return (b, blobContents b)
getBlobContents b@(gitId . blobInfo -> Stored hash)
| BlobEmpty <- contents =
case gitObj (blobInfo b) of
Just blobPtr ->
withForeignPtr blobPtr $ \ptr -> do
size <- c'git_blob_rawsize (castPtr ptr)
buf <- c'git_blob_rawcontent (castPtr ptr)
bstr <- curry unsafePackCStringLen (castPtr buf)
(fromIntegral size)
let contents' = BlobString bstr
return (b { blobContents = contents' }, contents' )
Nothing -> do
b' <- lookupBlob (Oid hash) repo
case b' of
Just blobPtr' -> getBlobContents blobPtr'
Nothing -> return (b, BlobEmpty)
| otherwise = return (b, contents)
where repo = gitRepo (blobInfo b)
contents = blobContents b
writeBlob :: Blob -> IO Blob
writeBlob b@(Blob { blobInfo = Base { gitId = Stored _ } }) = return b
writeBlob b = do hash <- doWriteBlob b
return b { blobInfo = (blobInfo b) { gitId = Stored hash }
, blobContents = BlobEmpty }
doWriteBlob :: Blob -> IO COid
doWriteBlob b = do
ptr <- mallocForeignPtr
r <- withForeignPtr repo (createFromBuffer ptr)
when (r < 0) $ throwIO BlobCreateFailed
return (COid ptr)
where
repo = fromMaybe (error "Repository invalid")
(repoObj (gitRepo (blobInfo b)))
createFromBuffer ptr repoPtr = do
str <- blobSourceToString (blobContents b)
case str of
Nothing -> throw BlobCreateFailed
Just str' -> createBlobFromByteString ptr repoPtr str'
createBlobFromByteString ptr repoPtr bs =
unsafeUseAsCStringLen bs $
uncurry (\cstr len ->
withForeignPtr ptr $ \ptr' ->
c'git_blob_create_frombuffer
ptr' repoPtr (castPtr cstr) (fromIntegral len))