#54 Use system value for defaultReadBufferSize

ChangeLog.md

@@ -1,5 +1,9 @@
 # ChangeLog for streaming-commons
 
+## 0.2.1.2
+
+* Update `defaultReadBufferSize` to use system default instead of hardcoded value [#54](https://github.com/fpco/streaming-commons/issues/54)
+
 ## 0.2.1.1
 
 * Fix a failing test case (invalid `ByteString` copying), does not affect library itself

Data/Streaming/Network.hs

@@ -94,7 +94,7 @@ module Data.Streaming.Network
 import qualified Network.Socket as NS
 import Data.Streaming.Network.Internal
 import Control.Concurrent (threadDelay)
-import Control.Exception (IOException, try, SomeException, throwIO, bracketOnError)
+import Control.Exception (IOException, try, SomeException, throwIO, bracketOnError, bracket)
 import Network.Socket (Socket, AddrInfo, SocketType)
 import Network.Socket.ByteString (recv, sendAll)
 import System.IO.Error (isDoesNotExistError)
@@ -108,7 +108,7 @@ import Control.Concurrent (forkIO)
 import Control.Monad (forever)
 import Data.IORef (IORef, newIORef, atomicModifyIORef)
 import Data.Array.Unboxed ((!), UArray, listArray)
-import System.IO.Unsafe (unsafePerformIO)
+import System.IO.Unsafe (unsafePerformIO, unsafeDupablePerformIO)
 import System.Random (randomRIO)
 import System.IO.Error (isFullErrorType, ioeGetErrorType)
 #if WINDOWS
@@ -263,8 +263,10 @@ bindPortUDP = bindPortGen NS.Datagram
 bindRandomPortUDP :: HostPreference -> IO (Int, Socket)
 bindRandomPortUDP = bindRandomPortGen NS.Datagram
 
+{-# NOINLINE defaultReadBufferSize #-}
 defaultReadBufferSize :: Int
-defaultReadBufferSize = 32768
+defaultReadBufferSize = unsafeDupablePerformIO $
+  bracket (NS.socket NS.AF_INET NS.Stream 0) NS.close (\sock -> NS.getSocketOption sock NS.RecvBuffer)
 
 #if !WINDOWS
 -- | Attempt to connect to the given Unix domain socket path.

streaming-commons.cabal

@@ -1,5 +1,5 @@
 name:                streaming-commons
-version:             0.2.1.1
+version:             0.2.1.2
 synopsis:            Common lower-level functions needed by various streaming data libraries
 description:         Provides low-dependency functionality commonly needed by various streaming data libraries, such as conduit and pipes.
 homepage:            https://github.com/fpco/streaming-commons

test/Data/Streaming/NetworkSpec.hs

@@ -14,6 +14,10 @@ import           Test.Hspec.QuickCheck
 
 spec :: Spec
 spec = do
+    describe "getDefaultReadBufferSize" $ do
+        it "sanity" $ do
+            getReadBufferSize (clientSettingsTCP 8080 "localhost") >= 4096 `shouldBe` True
+
     describe "getUnassignedPort" $ do
         it "sanity" $ replicateM_ 100000 $ do
             port <- getUnassignedPort