From bfe49b970e83f1d422d57ece7cebdfe7a56b817c Mon Sep 17 00:00:00 2001
From: Michael Orlitzky <michael@orlitzky.com>
Date: Thu, 12 Apr 2012 22:24:34 -0400
Subject: [PATCH] Use a more flexible curl function to make HTTP requests. Pass
 some default options to curl, hopefully fixing a DNS issue. A little
 documentation cleanup.

---
 src/Twitter/Http.hs | 47 +++++++++++++++++++++++++++++++++------------
 1 file changed, 35 insertions(+), 12 deletions(-)

diff --git a/src/Twitter/Http.hs b/src/Twitter/Http.hs
index bff4288..14b0382 100644
--- a/src/Twitter/Http.hs
+++ b/src/Twitter/Http.hs
@@ -47,8 +47,8 @@ get_user_timeline username = do
   return timeline
 
 
--- Returns the XML representing all of username's statuses that are
--- newer than last_status_id.
+-- | Returns the XML representing all of username's statuses that are
+--   newer than last_status_id.
 get_user_new_statuses :: String -> Integer -> IO (Maybe String)
 get_user_new_statuses username last_status_id = do
   let uri = (user_new_statuses_url username last_status_id)
@@ -56,14 +56,37 @@ get_user_new_statuses username last_status_id = do
   return new_statuses
 
 
--- |Uses the CURL API to retrieve uri. Returns 'Nothing' if there was
--- an error.
+-- | Options that will be passed to every curl request.
+curl_options :: [CurlOption]
+curl_options =
+  [ CurlTimeout 45,
+    -- The Global cache is not thread-friendly.
+    CurlDNSUseGlobalCache False,
+     -- And we don't want to use a DNS cache anyway.
+    CurlDNSCacheTimeout 0 ]
+
+
+-- | Uses the CURL API to retrieve uri. Returns 'Nothing' if there was
+--   an error.
 http_get :: String -> IO (Maybe String)
-http_get uri = withCurlDo $ do
-  resp <- curlGetString uri [CurlTimeout 45]
-
-  case resp of
-    (CurlOK, body) -> return (Just body)
-    (code, _) -> do
-        hPutStrLn stderr ("HTTP Error: " ++ (show code))
-        return Nothing
+http_get uri =
+  withCurlDo $ do
+  -- Create a Curl instance.
+  curl <- initialize
+
+  -- Perform the request, and get back a CurlResponse object.
+  -- The cast is needed to specify how we would like our headers
+  -- and body returned (Strings).
+  resp <- do_curl_ curl uri curl_options :: IO CurlResponse
+
+  -- Pull out the response code as a CurlCode.
+  let code = respCurlCode resp
+  
+  case code of
+    CurlOK -> return $ Just (respBody resp)
+    error_code -> do
+      hPutStrLn stderr ("HTTP Error: " ++ (show error_code))
+      -- If an error occurred, we want to dump as much information as
+      -- possible. If this becomes a problem, we can use respGetInfo to
+      -- query the response object for more information
+      return Nothing
-- 
2.43.2