feat(sut): add common http client for dumblog

src/sut/dumblog/dumblog.cabal

@@ -36,6 +36,7 @@ library
     , containers
     , directory
     , filepath
+    , http-client
     , http-types
     , journal
     , sqlite-simple
@@ -46,6 +47,7 @@ library
     , warp
 
   exposed-modules:
+    Dumblog.Common.HttpClient
     Dumblog.Journal.Blocker
     Dumblog.Journal.Codec
     Dumblog.Journal.FrontEnd

src/sut/dumblog/src/Dumblog/Common/HttpClient.hs

@@ -0,0 +1,80 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Dumblog.Common.HttpClient where
+
+import Control.Monad (when)
+import qualified Data.ByteString.Char8 as BSChar8
+import Data.ByteString.Lazy.Char8 (ByteString)
+import qualified Data.ByteString.Lazy.Char8 as LBSChar8
+import Network.HTTP.Client
+       ( Manager
+       , Request
+       , RequestBody(RequestBodyLBS)
+       , defaultManagerSettings
+       , httpLbs
+       , httpNoBody
+       , method
+       , newManager
+       , parseRequest
+       , path
+       , requestBody
+       , responseBody
+       , responseStatus
+       )
+import Network.HTTP.Types.Status (ok200)
+import Network.Wai.Handler.Warp (Port)
+
+------------------------------------------------------------------------
+
+data HttpClient = HttpClient
+  { hcManager  :: Manager -- | NOTE: If possible, you should share a single
+                          -- `Manager` between multiple threads and requests.
+  , hcWriteReq :: ByteString -> Request
+  , hcReadReq  :: Int -> Request
+  -- , hcErrors   :: AtomicCounter
+  }
+
+newHttpClient :: String -> Port -> IO HttpClient
+newHttpClient host port = do
+  mgr <- newManager defaultManagerSettings
+  initReq <- parseRequest ("http://" ++ host ++ ":" ++ show port)
+
+  let writeReq :: ByteString -> Request
+      writeReq bs = initReq { method      = "POST"
+                            , requestBody = RequestBodyLBS bs
+                            }
+
+      readReq :: Int -> Request
+      readReq ix = initReq { method = "GET"
+                           , path   = path initReq <> BSChar8.pack (show ix)
+                           }
+
+  return (HttpClient mgr writeReq readReq)
+
+writeHttp :: HttpClient -> ByteString -> IO Int
+writeHttp hc bs = do
+  resp <- httpLbs (hcWriteReq hc bs) (hcManager hc)
+  when (responseStatus resp /= ok200) $
+    return () -- XXX: increment hcErrors
+  return (read (LBSChar8.unpack (responseBody resp)))
+
+readHttp :: HttpClient -> Int -> IO ByteString
+readHttp hc ix = do
+  resp <- httpLbs (hcReadReq hc ix) (hcManager hc)
+  when (responseStatus resp /= ok200) $
+    return () -- XXX: increment hcErrors
+  return (responseBody resp)
+
+writeHttp_ :: HttpClient -> ByteString -> IO ()
+writeHttp_ hc bs = do
+  resp <- httpNoBody (hcWriteReq hc bs) (hcManager hc)
+  when (responseStatus resp /= ok200) $
+    return () -- XXX: increment hcErrors
+  return ()
+
+readHttp_ :: HttpClient -> Int -> IO ()
+readHttp_ hc ix = do
+  resp <- httpNoBody (hcReadReq hc ix) (hcManager hc)
+  when (responseStatus resp /= ok200) $
+    return () -- XXX: increment hcErrors
+  return ()

src/sut/dumblog/src/Dumblog/SQLite/FrontEnd.hs

@@ -44,7 +44,7 @@ httpFrontend queue req respond =
     parseIndex :: Either ByteString Int
     parseIndex =
       case pathInfo req of
-        [t] -> case decimal t of
+        [txt] -> case decimal txt of
           Right (ix, _rest) -> Right ix
           _otherwise -> Left (BSChar8.pack "parseIndex: GET /:ix, :ix isn't an integer")
         _otherwise   -> Left (BSChar8.pack "parseIndex: GET /:ix, :ix missing")