Remove the IO bottleneck.

Don't redundantly readIO/parse the rulesets; do this once, lazily
carrying out the involved operations. Rulesets are invariant over
executions.

This improves performance by a few orders of magnitude. Though at some
point we should substitute linear search for lookup on a generalised
suffix tree of rooted domains.

Breaking interface change, though I'll likely restore the old form
soon with IO TH.

README.md

@@ -9,11 +9,12 @@ connections when possible."
 
 ```haskell
 λ: :m + Data.HTTPSEverywhere.Rules Network.URI
+λ: rulesets <- getRulesets
 λ: let Just eff = parseURI "http://www.eff.org/document/eff-and-aclu-amicus-brief-klayman"
-λ: rewriteURL eff
+λ: rewriteURL rulesets eff
 https://www.eff.org/document/eff-and-aclu-amicus-brief-klayman
 λ: :m + Network.HTTP.Client Network.HTTP.Client.TLS Control.Applicative Control.Lens
 λ: (req, hub) <- (,) <*> getUri <$> parseUrl "https://github.com/fmap/https-everywhere-rules"
-λ: newManager tlsManagerSettings >>= httpNoBody req <&> destroyCookieJar . responseCookieJar >>= mapM (rewriteCookie hub)
+λ: newManager tlsManagerSettings >>= httpNoBody req <&> destroyCookieJar . responseCookieJar >>= mapM (rewriteCookie rulesets hub)
 [Cookie {cookie_name = "_gh_sess", cookie_value = "eyJzZXNzaW9uX2lkIjoiNjBlM2FiOTIxNTdhZTNhNDE5YWQ0ZTk4ZWQzNDRjMjEiLCJzcHlfcmVwbyI6ImZtYXAvaHR0cHMtZXZlcnl3aGVyZS1ydWxlcyIsInNweV9yZXBvX2F0IjoxNDA4ODk2OTM2LCJfY3NyZl90b2tlbiI6IktkbTlwN2JqNGptVmhrYjFIUm9BbkV0a1JTQXRDUXJid2g4VWo4N1g0Q1U9In0%3D--d378daa262b8c12bb82246d5de6b3adc353a3db7", cookie_expiry_time = 3013-12-25 00:00:00 UTC, cookie_domain = "github.com", cookie_path = "/", cookie_creation_time = 2014-08-24 16:15:37.815144 UTC, cookie_last_access_time = 2014-08-24 16:15:37.815144 UTC, cookie_persistent = False, cookie_host_only = True, cookie_secure_only = True, cookie_http_only = True},Cookie {cookie_name = "logged_in", cookie_value = "no", cookie_expiry_time = 2034-08-24 16:15:36 UTC, cookie_domain = "github.com", cookie_path = "/", cookie_creation_time = 2014-08-24 16:15:37.815144 UTC, cookie_last_access_time = 2014-08-24 16:15:37.815144 UTC, cookie_persistent = True, cookie_host_only = False, cookie_secure_only = True, cookie_http_only = True}]
 ```

examples/CountUpgradeable.hs

@@ -6,7 +6,7 @@ import "foldl" Control.Foldl (Fold(..))
 import qualified "foldl" Control.Foldl as Foldl
 import "base" Control.Monad (forever)
 import "base" Data.Bool (bool)
-import "https-everywhere-rules" Data.HTTPSEverywhere.Rules (rewriteURL)
+import "https-everywhere-rules" Data.HTTPSEverywhere.Rules (rewriteURL, RuleSet, getRulesets)
 import "base" Data.Monoid (Sum(..))
 import "network-uri" Network.URI (URI, parseURI)
 import "pipes" Pipes (Pipe, Producer, lift, yield, await, (>->))
@@ -16,10 +16,10 @@ import qualified "pipes" Pipes.Prelude as Pipes (fold)
 parse :: Monad m => Pipe String URI m ()
 parse = forever $ parseURI <$> await >>= maybe (return ()) yield
 
-check :: Pipe URI Bool IO ()
-check = forever $ do
+check :: [RuleSet] -> Pipe URI Bool IO ()
+check rs = forever $ do
   src <- await
-  tgt <- lift $ rewriteURL src
+  tgt <- lift $ rewriteURL rs src
   yield $ src /= tgt
 
 fold :: Monad m => Fold a b -> Producer a m () -> m b
@@ -29,4 +29,6 @@ proportion :: Fold Bool (Int, Int)
 proportion = (,) <$> Foldl.foldMap (Sum . bool 0 1) getSum <*> Foldl.length
 
 main :: IO ()
-main = fold proportion (stdinLn >-> parse >-> check) >>= print
+main = do
+  rulesets <- getRulesets
+  fold proportion (stdinLn >-> parse >-> check rulesets) >>= print

examples/RedirectProxy.hs

@@ -8,7 +8,7 @@ import "base" Data.Monoid ((<>))
 import "bytestring" Data.ByteString.Char8 (pack, unpack)
 import "http-proxy" Network.HTTP.Proxy (runProxySettings, defaultProxySettings, Settings(..), Request(..))
 import "http-types" Network.HTTP.Types (status302)
-import "https-everywhere-rules" Data.HTTPSEverywhere.Rules (rewriteURL)
+import "https-everywhere-rules" Data.HTTPSEverywhere.Rules (getRulesets, rewriteURL, RuleSet)
 import "network-uri" Network.URI (URI, parseURI)
 import "wai" Network.Wai (Response, responseLBS)
 
@@ -18,12 +18,14 @@ import "wai" Network.Wai (Response, responseLBS)
 httpRedirect :: URI -> Response
 httpRedirect to = responseLBS status302 [("Location", pack . show $ to)] ""
 
-tryHTTPS :: Request -> IO (Either Response Request)
-tryHTTPS Request{..} = case parseURI . unpack $ requestPath <> queryString of
-  Just uri -> rewriteURL uri <&> \rewrite -> if rewrite == uri
+tryHTTPS :: [RuleSet] -> Request -> IO (Either Response Request)
+tryHTTPS rs Request{..} = case parseURI . unpack $ requestPath <> queryString of
+  Just uri -> rewriteURL rs uri <&> \rewrite -> if rewrite == uri
     then return Request{..}
     else Left $ httpRedirect rewrite
   Nothing -> return $ Right Request{..}
 
 main :: IO ()
-main = runProxySettings $ defaultProxySettings { proxyRequestModifier = tryHTTPS }
+main = do
+  rulesets <- getRulesets
+  runProxySettings $ defaultProxySettings { proxyRequestModifier = tryHTTPS rulesets }

src/Data/HTTPSEverywhere/Rules.hs

@@ -1,4 +1,6 @@
 module Data.HTTPSEverywhere.Rules (
+  RuleSet,
+  getRulesets,
   rewriteURL,
   rewriteCookie
 ) where
@@ -12,11 +14,11 @@ import Network.URI (URI)
 import Pipes ((>->))
 import Pipes.Prelude (head, null)
 import Control.Monad (join)
-import Data.HTTPSEverywhere.Rules.Internal (getRulesetsMatching, havingRulesThatTrigger, havingCookieRulesThatTrigger, setSecureFlag)
+import Data.HTTPSEverywhere.Rules.Internal (getRulesets, getRulesetsMatching, havingRulesThatTrigger, havingCookieRulesThatTrigger, setSecureFlag, RuleSet)
 
-rewriteURL :: URI -> IO URI
-rewriteURL url = getRulesetsMatching url >-> havingRulesThatTrigger url & head <&> fromMaybe url . join
+rewriteURL :: [RuleSet] -> URI -> IO URI
+rewriteURL rs url = getRulesetsMatching rs url >-> havingRulesThatTrigger url & head <&> fromMaybe url . join
 
-rewriteCookie :: URI -> Cookie -> IO Cookie
-rewriteCookie url cookie = null producer <&> setSecureFlag cookie `bool` cookie
-  where producer = getRulesetsMatching url >-> havingCookieRulesThatTrigger cookie
+rewriteCookie :: [RuleSet] -> URI -> Cookie -> IO Cookie
+rewriteCookie rs url cookie = null producer <&> setSecureFlag cookie `bool` cookie
+  where producer = getRulesetsMatching rs url >-> havingCookieRulesThatTrigger cookie

src/Data/HTTPSEverywhere/Rules/Internal.hs

@@ -1,10 +1,12 @@
 {-# LANGUAGE CPP #-}
 
 module Data.HTTPSEverywhere.Rules.Internal (
+  getRulesets,
   getRulesetsMatching,
   havingRulesThatTrigger,
   havingCookieRulesThatTrigger,
   setSecureFlag,
+  RuleSet,
 #ifdef TEST
   hasTargetMatching,
   hasTriggeringRuleOn,
@@ -23,20 +25,23 @@ import Data.Maybe (isJust)
 import Network.HTTP.Client (Cookie(..))
 import Network.URI (URI)
 import Pipes (Pipe, Producer, for, each, await, yield, lift, (>->))
-import Pipes.Prelude (filter)
+import Pipes.Prelude (filter, toListM)
 
 import Data.HTTPSEverywhere.Rules.Internal.Parser (parseRuleSets)
 import qualified Data.HTTPSEverywhere.Rules.Internal.Raw as Raw (getRule, getRules)
 import Data.HTTPSEverywhere.Rules.Internal.Types (RuleSet(..), Target(..), Exclusion(..), Rule(..), CookieRule(..))
 
-getRulesets :: Producer RuleSet IO ()
-getRulesets = lift Raw.getRules
+getRulesets' :: Producer RuleSet IO ()
+getRulesets' = lift Raw.getRules
           >>= flip (for . each) (flip (for . each) yield <=< lift . (parseRuleSets <$$> Raw.getRule))
 
-getRulesetsMatching :: URI -> Producer RuleSet IO ()
-getRulesetsMatching url = getRulesets
-                      >-> filter (flip hasTargetMatching url)
-                      >-> filter (not . flip hasExclusionMatching url)
+getRulesets :: IO [RuleSet]
+getRulesets = toListM getRulesets'
+
+getRulesetsMatching :: [RuleSet] -> URI -> Producer RuleSet IO ()
+getRulesetsMatching rs url = each rs
+                         >-> filter (flip hasTargetMatching url)
+                         >-> filter (not . flip hasExclusionMatching url)
 
 havingRulesThatTrigger :: URI -> Pipe RuleSet (Maybe URI) IO ()
 havingRulesThatTrigger url = flip hasTriggeringRuleOn url <$> await