git-annex/Git/Types.hs

{- git data types
 -
 - Copyright 2010-2012 Joey Hess <joey@kitenet.net>
 -
 - Licensed under the GNU GPL version 3 or higher.
 -}

module Git.Types where

import Network.URI
import qualified Data.Map as M

{- Support repositories on local disk, and repositories accessed via an URL.
 -
 - Repos on local disk have a git directory, and unless bare, a worktree.
 -
 - A local repo may not have had its config read yet, in which case all
 - that's known about it is its path.
 -
 - Finally, an Unknown repository may be known to exist, but nothing
 - else known about it.
 -}
data RepoLocation
	= Local { gitdir :: FilePath, worktree :: Maybe FilePath }
	| LocalUnknown FilePath
	| Url URI
	| Unknown
	deriving (Show, Eq)

data Repo = Repo {
	location :: RepoLocation,
	config :: M.Map String String,
	-- a given git config key can actually have multiple values
	fullconfig :: M.Map String [String],
	remotes :: [Repo],
	-- remoteName holds the name used for this repo in remotes
	remoteName :: Maybe String 
} deriving (Show, Eq)

{- A git ref. Can be a sha1, or a branch or tag name. -}
newtype Ref = Ref String
	deriving (Eq)

instance Show Ref where
	show (Ref v) = v

{- Aliases for Ref. -}
type Branch = Ref
type Sha = Ref
type Tag = Ref

{- Types of objects that can be stored in git. -}
data ObjectType = BlobObject | CommitObject | TreeObject
	deriving (Eq)

instance Show ObjectType where
	show BlobObject = "blob"
	show CommitObject = "commit"
	show TreeObject = "tree"

readObjectType :: String -> Maybe ObjectType
readObjectType "blob" = Just BlobObject
readObjectType "commit" = Just CommitObject
readObjectType "tree" = Just TreeObject
readObjectType _ = Nothing

{- Types of blobs. -}
data BlobType = FileBlob | ExecutableBlob | SymlinkBlob
	deriving (Eq)

{- Git uses magic numbers to denote the type of a blob. -}
instance Show BlobType where
	show FileBlob = "100644"
	show ExecutableBlob = "100755"
	show SymlinkBlob = "120000"

readBlobType :: String -> Maybe BlobType
readBlobType "100644" = Just FileBlob
readBlobType "100755" = Just ExecutableBlob
readBlobType "120000" = Just SymlinkBlob
readBlobType _ = Nothing