Revert "data type that starts off using a set but converts to a bloom filter when large"

This reverts commit 7e2c4ed216.

I was not able to use this in the end..
See comment in the previous commit.

Annex/BloomFilter.hs

@@ -1,13 +1,10 @@
 {- git-annex bloom filter
  -
- - Copyright 2010-2020 Joey Hess <id@joeyh.name>
+ - Copyright 2010-2015 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
 
-{-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-
 module Annex.BloomFilter where
 
 import Annex.Common
@@ -15,10 +12,6 @@ import qualified Annex
 import Utility.Bloom
 
 import Control.Monad.ST
-import Data.STRef
-import Data.Hashable
-import qualified Data.HashSet as S
-import qualified Data.ByteString as B
 
 {- A bloom filter capable of holding half a million keys with a
  - false positive rate of 1 in 10000000 uses around 16 mb of memory,
@@ -35,7 +28,7 @@ bloomBitsHashes = do
 	case safeSuggestSizing capacity (1 / fromIntegral accuracy) of
 		Left e -> do
 			warning $ "bloomfilter " ++ e ++ "; falling back to sane value"
-			-- precalculated value for 500000 (1/10000000)
+			-- precaulculated value for 500000 (1/10000000)
 			return (16777216,23)
 		Right v -> return v
 
@@ -47,10 +40,7 @@ bloomBitsHashes = do
  - Once the action completes, the mutable filter is frozen
  - for later use.
  -}
-genBloomFilter
-	:: Utility.Bloom.Hashable v
-	=> ((v -> Annex ()) -> Annex ())
-	-> Annex (Bloom v)
+genBloomFilter :: Hashable v => ((v -> Annex ()) -> Annex ()) -> Annex (Bloom v)
 genBloomFilter populate = do
 	(numbits, numhashes) <- bloomBitsHashes
 	bloom <- lift $ newMB (cheapHashes numhashes) numbits
@@ -61,80 +51,3 @@ genBloomFilter populate = do
 
 bloomFilter :: [v] -> Bloom v -> [v]
 bloomFilter l bloom = filter (\v -> v `notElemB` bloom) l
-
-{- This starts off as a HashSet, and is only converted to a bloom filter
- - if it grows too large.
- - 
- - The advantage is, if it stays a HashSet, queries do not have false
- - positives.
- -}
-data BloomableFilter v
-	= BloomableFilter (S.HashSet (BloomBytes v))
-	| BloomedFilter (Bloom (BloomBytes v))
-	deriving (Show)
-
-newtype BloomBytes v = BloomBytes B.ByteString
-	deriving (Show, Eq, Utility.Bloom.Hashable, Data.Hashable.Hashable)
-
-class BloomableBytes v where
-	toBloomBytes :: v -> BloomBytes v
-
-instance BloomableBytes B.ByteString where
-	toBloomBytes = BloomBytes
-
-instance BloomableBytes Key where
-	toBloomBytes = BloomBytes . serializeKey'
-
-{- The HashSet is grown until it uses around as much memory as the bloom
- - filter is configured to use. So peak memory use is 2x when the HashSet
- - is full and is being converted to the bloom filter.
- -}
-genBloomableFilter
-	:: BloomableBytes v
-	=> ((v -> Annex ()) -> Annex ())
-	-> Annex (BloomableFilter v)
-genBloomableFilter populate = do
-	(numbits, numhashes) <- bloomBitsHashes
-	-- A HashSet is a tree, so there's some memory overhead beyond
-	-- storing the values. Use 2/3 of the memory for storing
-	-- the values, and reserve the rest for that overhead.
-	let maxsz = (numbits `div` 8) `div` 3 * 2
-	bv <- lift $ newMB (cheapHashes numhashes) numbits
-	sv <- lift $ newSTRef S.empty
-	szv <- lift $ newSTRef (Just 0)
-	populate $ \v -> lift $ readSTRef szv >>= \case
-		Just n 
-			| n < maxsz -> do
-				let bb@(BloomBytes b) = toBloomBytes v
-				modifySTRef' sv (S.insert bb)
-				modifySTRef' szv (fmap (+ B.length b))
-			| otherwise -> do
-				s <- readSTRef sv
-				forM_ (S.toList s) $
-					insertMB bv
-				modifySTRef' sv (const S.empty)
-				modifySTRef' szv (const Nothing)
-				insertMB bv (toBloomBytes v)
-		Nothing -> insertMB bv (toBloomBytes v)
-	lift $ readSTRef szv >>= \case
-		Just _ -> BloomableFilter <$> readSTRef sv
-		Nothing -> BloomedFilter <$> unsafeFreezeMB bv
-  where
-	lift = liftIO . stToIO
-
-data ElemWithFalsePositives
-	= ElemNo
-	| ElemYes
-	| ElemProbablyYes
-	deriving (Show)
-
-elemB' :: (BloomableBytes v) => v -> BloomableFilter v -> ElemWithFalsePositives
-elemB' v (BloomedFilter b) =
-	case elemB (toBloomBytes v) b of
-		True -> ElemProbablyYes
-		False -> ElemNo
-elemB' v (BloomableFilter s) =
-	case S.member (toBloomBytes v) s of
-		True -> ElemYes
-		False -> ElemNo
-

debian/control

@@ -29,7 +29,6 @@ Build-Depends:
 	libghc-aeson-dev,
 	libghc-tagsoup-dev,
 	libghc-unordered-containers-dev,
-	libghc-hashable-dev,
 	libghc-ifelse-dev,
 	libghc-bloomfilter-dev,
 	libghc-edit-distance-dev,

git-annex.cabal

@@ -361,7 +361,6 @@ Executable git-annex
    vector,
    tagsoup,
    unordered-containers,
-   hashable,
    feed (>= 1.0.0),
    regex-tdfa,
    socks,