From 76b0a522daa8ed65b7de196fb6f46b58846f3b41 Mon Sep 17 00:00:00 2001
From: Andrew Gibiansky <andrew.gibiansky@gmail.com>
Date: Sat, 25 Jul 2015 21:47:36 -0700
Subject: [PATCH 1/3] Adding unsafeCreate to allow for deserialization of Bloom
 filters.

---
 Data/BloomFilter.hs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Data/BloomFilter.hs b/Data/BloomFilter.hs
index 2210cef..99ff62d 100644
--- a/Data/BloomFilter.hs
+++ b/Data/BloomFilter.hs
@@ -106,6 +106,17 @@ instance NFData (Bloom a) where
 logBitsInHash :: Int
 logBitsInHash = 5 -- logPower2 bitsInHash
 
+-- | Create an immutable Bloom filter from the underlying bit array.
+-- This creates a valid Bloom filter if and only if the arguments passed to
+-- @unsafeCreate@ are the same as those that were passed to @create@ or @new@ for the original Bloom filter.
+unsafeCreate :: (a -> [Hash])        -- ^ family of hash functions to use
+             -> Int                  -- ^ number of bits in filter
+             -> UArray Int Hash      -- ^ Underlying bit array.
+             -> Bloom a
+unsafeCreate hash numBits bits =
+  (create hash numBits (\_ -> return ())) { bitArray = bits }
+
+
 -- | Create an immutable Bloom filter, using the given setup function
 -- which executes in the 'ST' monad.
 --

From 556d076b94ec6c24c4a591e062ba61de7e9076dc Mon Sep 17 00:00:00 2001
From: Andrew Gibiansky <andrew.gibiansky@gmail.com>
Date: Sat, 25 Jul 2015 22:09:50 -0700
Subject: [PATCH 2/3] Export unsafeCreate

---
 Data/BloomFilter.hs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Data/BloomFilter.hs b/Data/BloomFilter.hs
index 99ff62d..2890acd 100644
--- a/Data/BloomFilter.hs
+++ b/Data/BloomFilter.hs
@@ -70,6 +70,7 @@ module Data.BloomFilter
 
     -- | The raw bit array used by the immutable 'Bloom' type.
     , bitArray
+    , unsafeCreate
     ) where
 
 import Control.Monad (liftM, forM_)

From 77ecea115faa7b937cec6aa93d4164bcf79ad3c6 Mon Sep 17 00:00:00 2001
From: Andrew Gibiansky <andrew.gibiansky@gmail.com>
Date: Sun, 26 Jul 2015 12:10:58 -0700
Subject: [PATCH 3/3] Trying again

---
 Data/BloomFilter.hs | 32 ++++++++++++++++++++------------
 bloomfilter.cabal   |  1 +
 2 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/Data/BloomFilter.hs b/Data/BloomFilter.hs
index 2890acd..d4b324e 100644
--- a/Data/BloomFilter.hs
+++ b/Data/BloomFilter.hs
@@ -70,7 +70,8 @@ module Data.BloomFilter
 
     -- | The raw bit array used by the immutable 'Bloom' type.
     , bitArray
-    , unsafeCreate
+    , serialize
+    , unsafeDeserialize
     ) where
 
 import Control.Monad (liftM, forM_)
@@ -86,6 +87,9 @@ import qualified Data.BloomFilter.Mutable.Internal as MB
 import Data.BloomFilter.Mutable.Internal (Hash, MBloom)
 import Data.Word (Word32)
 
+import Data.Serialize
+import Data.ByteString (ByteString)
+
 import Prelude hiding (elem, length, notElem,
                        (/), (*), div, divMod, mod, rem)
 
@@ -107,17 +111,6 @@ instance NFData (Bloom a) where
 logBitsInHash :: Int
 logBitsInHash = 5 -- logPower2 bitsInHash
 
--- | Create an immutable Bloom filter from the underlying bit array.
--- This creates a valid Bloom filter if and only if the arguments passed to
--- @unsafeCreate@ are the same as those that were passed to @create@ or @new@ for the original Bloom filter.
-unsafeCreate :: (a -> [Hash])        -- ^ family of hash functions to use
-             -> Int                  -- ^ number of bits in filter
-             -> UArray Int Hash      -- ^ Underlying bit array.
-             -> Bloom a
-unsafeCreate hash numBits bits =
-  (create hash numBits (\_ -> return ())) { bitArray = bits }
-
-
 -- | Create an immutable Bloom filter, using the given setup function
 -- which executes in the 'ST' monad.
 --
@@ -332,6 +325,21 @@ logPower2 k = go 0 k
     where go j 1 = j
           go j n = go (j+1) (n `shiftR` 1)
 
+serialize :: Bloom a -> ByteString
+serialize bloom = encode (shift bloom, mask bloom, bitArray bloom)
+
+unsafeDeserialize :: (a -> [Hash]) -> ByteString -> Either String (Bloom a)
+unsafeDeserialize hashes bs =
+  case decode bs of
+    Left err -> Left err
+    Right (shift, mask, bitArray) -> Right $ B
+      { hashes = hashes
+      , shift = shift
+      , mask = mask
+      , bitArray = bitArray
+      }
+
+
 -- $overview
 --
 -- Each of the functions for creating Bloom filters accepts two parameters:
diff --git a/bloomfilter.cabal b/bloomfilter.cabal
index 821a5d7..6cd6107 100644
--- a/bloomfilter.cabal
+++ b/bloomfilter.cabal
@@ -20,6 +20,7 @@ library
     array,
     base       >= 4.4 && < 5,
     bytestring >= 0.9,
+    cereal >= 0.4,
     deepseq
   exposed-modules:  Data.BloomFilter
                     Data.BloomFilter.Easy