faster union merge of multiple branches into index

only write index once
This commit is contained in:
Joey Hess 2011-10-07 13:17:54 -04:00
parent 5414bbce58
commit 3acdba3995
3 changed files with 21 additions and 26 deletions

View file

@ -7,6 +7,7 @@
module Git.UnionMerge (
merge,
merge_index,
update_index,
update_index_line,
ls_tree
@ -18,24 +19,24 @@ import Data.Maybe
import Data.String.Utils
import qualified Data.ByteString.Lazy.Char8 as L
import Common
import Git
import Utility.SafeCommand
{- Performs a union merge between two branches, staging it in the index.
- Any previously staged changes in the index will be lost.
-
- When only one branch is specified, it is merged into the index.
- In this case, previously staged changes in the index are preserved.
-
- Should be run with a temporary index file configured by Git.useIndex.
-}
merge :: Repo -> [String] -> IO ()
merge g (x:y:[]) = do
merge :: Repo -> String -> String -> IO ()
merge g x y = do
a <- ls_tree g x
b <- merge_trees g x y
update_index g (a++b)
merge g [x] = merge_tree_index g x >>= update_index g
merge _ _ = error "wrong number of branches to merge"
{- Merges a list of branches into the index. Previously staged changed in
- the index are preserved (and participate in the merge). -}
merge_index :: Repo -> [String] -> IO ()
merge_index g bs = update_index g =<< concat <$> mapM (merge_tree_index g) bs
{- Feeds a list into update-index. Later items in the list can override
- earlier ones, so the list can be generated from any combination of