Merge pull request 'Improve general readability' (#69) from Hecate/Hash2Pub:readability into mainline

brings several readability enhancements:

- Text is always unqualified
- The Servant API declaration is moved to its own file
- Redundant imports are removed
This commit is contained in:
Trolli Schmittlauch 2020-09-05 16:27:23 +02:00
commit 4d2d6faf1b
4 changed files with 69 additions and 51 deletions

View file

@ -12,16 +12,16 @@ import Control.Concurrent
import Control.Concurrent.Async
import Control.Concurrent.STM
import Control.Exception (Exception (..), try)
import Control.Monad (foldM, forM, forM_, forever, void,
when)
import Control.Monad (foldM, forM_, forever, void, when)
import Control.Monad.IO.Class (liftIO)
import Data.Bifunctor
import qualified Data.ByteString.Lazy.UTF8 as BSUL
import qualified Data.ByteString.UTF8 as BSU
import qualified Data.HashMap.Strict as HMap
import qualified Data.HashSet as HSet
import Data.Maybe (fromMaybe, isJust)
import Data.Maybe (isJust)
import Data.String (fromString)
import Data.Text.Lazy (Text)
import qualified Data.Text.Lazy as Txt
import Data.Text.Normalize (NormalizationMode (NFC), normalize)
import Data.Time.Clock.POSIX
@ -36,6 +36,7 @@ import Servant
import Servant.Client
import Hash2Pub.FediChordTypes
import Hash2Pub.PostService.API
import Hash2Pub.RingMap
@ -48,7 +49,7 @@ data PostService d = PostService
-- ^ for each tag store the subscribers + their queue
, ownSubscriptions :: TVar (HMap.HashMap NodeID POSIXTime)
-- ^ tags subscribed by the own node have an assigned lease time
, ownPosts :: TVar (HSet.HashSet Txt.Text)
, ownPosts :: TVar (HSet.HashSet Text)
-- ^ just store the existence of posts for saving memory,
, relayInQueue :: TQueue (Hashtag, PostID, PostContent)
-- ^ Queue for processing incoming posts of own instance asynchronously
@ -58,9 +59,9 @@ data PostService d = PostService
}
deriving (Typeable)
type Hashtag = Txt.Text
type PostID = Txt.Text
type PostContent = Txt.Text
type Hashtag = Text
type PostID = Text
type PostContent = Text
-- | For each handled tag, store its subscribers and provide a
-- broadcast 'TChan' for enqueuing posts
type RelayTags = RingMap NodeID (TagSubscribersSTM, TChan PostID, Hashtag)
@ -131,38 +132,13 @@ postServiceApplication :: DHT d => PostService d -> Application
postServiceApplication serv = serve exposedPostServiceAPI $ postServer serv
-- | needed for guiding type inference
exposedPostServiceAPI :: Proxy PostServiceAPI
exposedPostServiceAPI = Proxy
-- ========= constants ===========
placeholderPost :: Txt.Text
placeholderPost :: Text
placeholderPost = Txt.take 5120 . Txt.repeat $ 'O' -- size 5KiB
-- ========= HTTP API and handlers =============
type PostServiceAPI = "relay" :> "inbox" :> Capture "hashtag" Txt.Text :> ReqBody '[PlainText] Txt.Text :> PutCreated '[PlainText] NoContent
-- delivery endpoint at responsible relay for delivering posts of $tag for distribution
:<|> "relay" :> "subscribers" :> Capture "senderID" Integer :> ReqBody '[PlainText] Txt.Text :> PostNoContent '[PlainText] Txt.Text
-- endpoint for delivering the subscriptions and outstanding queue
:<|> "post" :> Capture "postid" Txt.Text :> Get '[PlainText] Txt.Text
-- fetch endpoint for posts, full post ID is http://$domain/post/$postid
:<|> "posts" :> ReqBody '[PlainText] Txt.Text :> Post '[PlainText] Txt.Text
-- endpoint for fetching multiple posts at once
:<|> "posts" :> "inbox" :> ReqBody '[PlainText] Txt.Text :> PutCreated '[PlainText] NoContent
-- delivery endpoint of newly published posts of the relay's instance
:<|> "tags" :> Capture "hashtag" Txt.Text :> ReqBody '[PlainText] Txt.Text :> PostCreated '[PlainText] Txt.Text
-- delivery endpoint for posts of $tag at subscribing instance
:<|> "tags" :> Capture "hashtag" Txt.Text :> "subscribe" :> Header "Origin" Txt.Text :> Get '[PlainText] Integer
-- endpoint for subscribing the instance specified in
-- the Origin header to $hashtag.
-- Returns subscription lease time in seconds.
:<|> "tags" :> Capture "hashtag" Txt.Text :> "unsubscribe" :> Header "Origin" Txt.Text :> Get '[PlainText] Txt.Text
-- endpoint for unsubscribing the instance specified in
-- the Origin header to $hashtag
postServer :: DHT d => PostService d -> Server PostServiceAPI
postServer service = relayInbox service
:<|> subscriptionDelivery service
@ -174,7 +150,7 @@ postServer service = relayInbox service
:<|> tagUnsubscribe service
relayInbox :: DHT d => PostService d -> Hashtag -> Txt.Text -> Handler NoContent
relayInbox :: DHT d => PostService d -> Hashtag -> Text -> Handler NoContent
relayInbox serv tag posts = do
let
-- skip checking whether the post actually contains the tag, just drop full post
@ -202,7 +178,7 @@ newtype UnhandledTagException = UnhandledTagException String
instance Exception UnhandledTagException
subscriptionDelivery :: DHT d => PostService d -> Integer -> Txt.Text -> Handler Txt.Text
subscriptionDelivery :: DHT d => PostService d -> Integer -> Text -> Handler Text
subscriptionDelivery serv senderID subList = do
let
tagSubs = Txt.lines subList
@ -236,7 +212,7 @@ subscriptionDelivery serv senderID subList = do
Right _ -> pure ""
-- TODO: check and only accept tags in own (future?) responsibility
where
processTag :: TVar RelayTags -> Txt.Text -> STM ()
processTag :: TVar RelayTags -> Text -> STM ()
processTag subscriberSTM tagData = do
let
tag:subText:lease:posts:_ = Txt.splitOn "," tagData
@ -247,7 +223,7 @@ subscriptionDelivery serv senderID subList = do
enqueueSubscription subscriberSTM (normaliseTag tag) sub postList leaseTime
postFetch :: PostService d -> Txt.Text -> Handler Txt.Text
postFetch :: PostService d -> Text -> Handler Text
postFetch serv postID = do
postSet <- liftIO . readTVarIO . ownPosts $ serv
if HSet.member postID postSet
@ -256,7 +232,7 @@ postFetch serv postID = do
else throwError $ err404 { errBody = "No post found with this ID" }
postMultiFetch :: PostService d -> Txt.Text -> Handler Txt.Text
postMultiFetch :: PostService d -> Text -> Handler Text
postMultiFetch serv postIDs = do
let idList = Txt.lines postIDs
postSet <- liftIO . readTVarIO . ownPosts $ serv
@ -268,7 +244,7 @@ postMultiFetch serv postIDs = do
) "" idList
postInbox :: PostService d -> Txt.Text -> Handler NoContent
postInbox :: PostService d -> Text -> Handler NoContent
postInbox serv post = do
-- extract contained hashtags
let
@ -278,13 +254,13 @@ postInbox serv post = do
-- add ID to own posts
liftIO . atomically $ modifyTVar' (ownPosts serv) (HSet.insert postId)
-- enqueue a relay job for each tag
liftIO $ forM_ (containedTags :: [Txt.Text]) (\tag ->
liftIO $ forM_ (containedTags :: [Text]) (\tag ->
atomically $ writeTQueue (relayInQueue serv) (tag, postId, post)
)
pure NoContent
tagDelivery :: PostService d -> Txt.Text -> Txt.Text -> Handler Txt.Text
tagDelivery :: PostService d -> Text -> Text -> Handler Text
tagDelivery serv hashtag posts = do
let postIDs = Txt.lines posts
subscriptions <- liftIO . readTVarIO . ownSubscriptions $ serv
@ -295,7 +271,7 @@ tagDelivery serv hashtag posts = do
pure ()
pure $ "Received a postID for tag " <> hashtag
tagSubscribe :: DHT d => PostService d -> Txt.Text -> Maybe Txt.Text -> Handler Integer
tagSubscribe :: DHT d => PostService d -> Text -> Maybe Text -> Handler Integer
tagSubscribe serv hashtag origin = do
responsible <- liftIO $ isResponsibleFor (baseDHT serv) (hashtagToId hashtag)
if not responsible
@ -314,7 +290,7 @@ tagSubscribe serv hashtag origin = do
pure $ round leaseTime
tagUnsubscribe :: DHT d => PostService d -> Txt.Text -> Maybe Txt.Text -> Handler Txt.Text
tagUnsubscribe :: DHT d => PostService d -> Text -> Maybe Text -> Handler Text
tagUnsubscribe serv hashtag origin = do
responsible <- liftIO $ isResponsibleFor (baseDHT serv) (hashtagToId hashtag)
if not responsible
@ -334,8 +310,15 @@ tagUnsubscribe serv hashtag origin = do
clientAPI :: Proxy PostServiceAPI
clientAPI = Proxy
relayInboxClient :<|> subscriptionDeliveryClient :<|> postFetchClient :<|> postMultiFetchClient :<|> postInboxClient :<|> tagDeliveryClient :<|> tagSubscribeClient :<|> tagUnsubscribeClient = client clientAPI
relayInboxClient :: Text -> Text -> ClientM NoContent
relayInboxClient :<|> subscriptionDeliveryClient
:<|> postFetchClient
:<|> postMultiFetchClient
:<|> postInboxClient
:<|> tagDeliveryClient
:<|> tagSubscribeClient
:<|> tagUnsubscribeClient
= client clientAPI
-- | Deliver the subscriber list of all hashtags in the interval [fromTag, toTag]
@ -543,7 +526,7 @@ lookupTagSubscriptions tag = rMapLookup (hashtagToId tag)
-- normalise the unicode representation of a string to NFC
normaliseTag :: Txt.Text -> Txt.Text
normaliseTag :: Text -> Text
normaliseTag = Txt.fromStrict . normalize NFC . Txt.toStrict
@ -601,7 +584,7 @@ fetchTagPosts serv = forever $ do
-- TODO: batching, retry
-- TODO: process multiple in parallel
pIdUri <- atomically . readTQueue $ postFetchQueue serv
fetchReq <- HTTP.parseRequest . Txt.unpack $pIdUri
fetchReq <- HTTP.parseRequest . Txt.unpack $ pIdUri
resp <- try $ HTTP.httpLbs fetchReq (httpMan serv) :: IO (Either HTTP.HttpException (HTTP.Response BSUL.ByteString))
case resp of
Right response ->

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@ -0,0 +1,37 @@
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE InstanceSigs #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE TypeOperators #-}
module Hash2Pub.PostService.API where
import Data.Text.Lazy (Text)
import Servant
type PostServiceAPI = "relay" :> "inbox" :> Capture "hashtag" Text :> ReqBody '[PlainText] Text :> PutCreated '[PlainText] NoContent
-- delivery endpoint at responsible relay for delivering posts of $tag for distribution
:<|> "relay" :> "subscribers" :> Capture "senderID" Integer :> ReqBody '[PlainText] Text :> PostNoContent '[PlainText] Text
-- endpoint for delivering the subscriptions and outstanding queue
:<|> "post" :> Capture "postid" Text :> Get '[PlainText] Text
-- fetch endpoint for posts, full post ID is http://$domain/post/$postid
:<|> "posts" :> ReqBody '[PlainText] Text :> Post '[PlainText] Text
-- endpoint for fetching multiple posts at once
:<|> "posts" :> "inbox" :> ReqBody '[PlainText] Text :> PutCreated '[PlainText] NoContent
-- delivery endpoint of newly published posts of the relay's instance
:<|> "tags" :> Capture "hashtag" Text :> ReqBody '[PlainText] Text :> PostCreated '[PlainText] Text
-- delivery endpoint for posts of $tag at subscribing instance
:<|> "tags" :> Capture "hashtag" Text :> "subscribe" :> Header "Origin" Text :> Get '[PlainText] Integer
-- endpoint for subscribing the instance specified in
-- the Origin header to $hashtag.
-- Returns subscription lease time in seconds.
:<|> "tags" :> Capture "hashtag" Text :> "unsubscribe" :> Header "Origin" Text :> Get '[PlainText] Text
-- endpoint for unsubscribing the instance specified in
-- the Origin header to $hashtag
-- | needed for guiding type inference
exposedPostServiceAPI :: Proxy PostServiceAPI
exposedPostServiceAPI = Proxy

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@ -1,7 +1,5 @@
module Hash2Pub.ProtocolTypes where
import qualified Data.Map as Map
import Data.Maybe (mapMaybe)
import qualified Data.Set as Set
import Data.Time.Clock.POSIX (POSIXTime)

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@ -23,7 +23,7 @@ instance (Bounded k, Ord k, Eq a) => Eq (RingMap k a) where
a == b = getRingMap a == getRingMap b
instance (Bounded k, Ord k, Show k, Show a) => Show (RingMap k a) where
show rmap = shows "RingMap " (show $ getRingMap rmap)
show rmap = shows ("RingMap " :: String) (show $ getRingMap rmap)
-- | entry of a 'RingMap' that holds a value and can also
-- wrap around the lookup direction at the edges of the name space.
@ -207,7 +207,7 @@ takeEntriesUntil_ :: (Integral i, Bounded k, Ord k)
-> Maybe i -- possible number limit
-> [a]
-> [a]
takeEntriesUntil_ rmap' getterFunc' havingReached previousEntry (Just remaining) takeAcc
takeEntriesUntil_ _rmap' _getterFunc' _havingReached _previousEntry (Just remaining) takeAcc
-- length limit reached
| remaining <= 0 = takeAcc
takeEntriesUntil_ rmap' getterFunc' havingReached previousEntry numLimit takeAcc =