-- Copyright (C) 2009 Petr Rockai -- -- Permission is hereby granted, free of charge, to any person -- obtaining a copy of this software and associated documentation -- files (the "Software"), to deal in the Software without -- restriction, including without limitation the rights to use, copy, -- modify, merge, publish, distribute, sublicense, and/or sell copies -- of the Software, and to permit persons to whom the Software is -- furnished to do so, subject to the following conditions: -- -- The above copyright notice and this permission notice shall be -- included in all copies or substantial portions of the Software. -- -- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, -- EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF -- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND -- NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS -- BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN -- ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN -- CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE -- SOFTWARE. module Darcs.Diff( treeDiff ) where import Darcs.Witnesses.Ordered ( FL(..), (+>+) ) import Darcs.Witnesses.Sealed ( Gap(..) ) import Darcs.Repository.Prefs ( FileType(..) ) import Darcs.Patch ( Prim, hunk, canonize, binary , addfile, rmfile, adddir, rmdir, invert) import Storage.Hashed.Tree( diffTrees, zipTrees, TreeItem(..), Tree , readBlob, emptyBlob ) import Storage.Hashed.AnchoredPath( AnchoredPath, anchorPath ) import qualified Data.ByteString.Lazy.Char8 as BLC import qualified Data.ByteString as BS import qualified Data.ByteString.Lazy as BL import Data.List ( sortBy ) import ByteStringUtils( isFunky ) #include "gadts.h" #include "impossible.h" data Diff m = Added (TreeItem m) | Removed (TreeItem m) | Changed (TreeItem m) (TreeItem m) getDiff :: AnchoredPath -> Maybe (TreeItem m) -> Maybe (TreeItem m) -> (AnchoredPath, Diff m) getDiff p Nothing (Just t) = (p, Added t) getDiff p (Just from) (Just to) = (p, Changed from to) getDiff p (Just t) Nothing = (p, Removed t) getDiff p Nothing Nothing = impossible -- zipTrees should never return this treeDiff :: forall m w . (Functor m, Monad m, Gap w) => (FilePath -> FileType) -> Tree m -> Tree m -> m (w (FL Prim)) treeDiff ft t1 t2 = do (from, to) <- diffTrees t1 t2 diffs <- mapM (uncurry diff) $ sortBy organise $ zipTrees getDiff from to return $ foldr (joinGap (+>+)) (emptyGap NilFL) diffs where -- sort into removes, changes, adds, with removes in reverse-path order -- and everything else in forward order organise :: (AnchoredPath, Diff m) -> (AnchoredPath, Diff m) -> Ordering organise (p1, Changed _ _ ) (p2, Changed _ _) = compare p1 p2 organise (p1, Added _) (p2, Added _) = compare p1 p2 organise (p1, Removed _) (p2, Removed _) = compare p2 p1 organise (p1, Removed _) _ = LT organise _ (p1, Removed _) = GT organise (p1, Changed _ _) _ = LT organise _ (p1, Changed _ _) = GT diff :: AnchoredPath -> Diff m -> m (w (FL Prim)) diff _ (Changed (SubTree _) (SubTree _)) = return (emptyGap NilFL) diff p (Removed (SubTree _)) = return $ freeGap (rmdir (anchorPath "" p) :>: NilFL) diff p (Added (SubTree _)) = return $ freeGap (adddir (anchorPath "" p) :>: NilFL) diff p (Added b'@(File _)) = do diff' <- diff p (Changed (File emptyBlob) b') return $ joinGap (:>:) (freeGap (addfile (anchorPath "" p))) diff' diff p (Removed a'@(File _)) = do diff' <- diff p (Changed a' (File emptyBlob)) return $ joinGap (+>+) diff' (freeGap (rmfile (anchorPath "" p) :>: NilFL)) diff p (Changed (File a') (File b')) = do a <- readBlob a' b <- readBlob b' let path = anchorPath "" p case ft path of TextFile | no_bin a && no_bin b -> return $ text_diff path a b _ -> return $ if a /= b then freeGap (binary path (strict a) (strict b) :>: NilFL) else emptyGap NilFL diff p _ = fail $ "Missing case at path " ++ show p text_diff p a b | BL.null a && BL.null b = emptyGap NilFL | BL.null a = freeGap (diff_from_empty p b) | BL.null b = freeGap (diff_to_empty p a) | otherwise = freeGap (line_diff p (linesB a) (linesB b)) line_diff p a b = canonize (hunk p 1 a b) diff_to_empty p x | BLC.last x == '\n' = line_diff p (init $ linesB x) [] | otherwise = line_diff p (linesB x) [BS.empty] diff_from_empty p x = invert (diff_to_empty p x) no_bin = not . isFunky . strict . BL.take 4096 linesB = map strict . BLC.split '\n' strict = BS.concat . BL.toChunks