From 12dfc56a7321ffeb204e3978b6010992ee4df8dc Mon Sep 17 00:00:00 2001
From: Trolli Schmittlauch <t.schmittlauch@orlives.de>
Date: Sat, 19 Sep 2020 23:01:55 +0200
Subject: [PATCH] fediChordInit returns a RealNode, manages vservers as map

- contributes to #34
---
 src/Hash2Pub/FediChord.hs      | 20 +++++++++++---------
 src/Hash2Pub/FediChordTypes.hs |  6 ++++--
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/src/Hash2Pub/FediChord.hs b/src/Hash2Pub/FediChord.hs
index 9f14a1e..0dcba44 100644
--- a/src/Hash2Pub/FediChord.hs
+++ b/src/Hash2Pub/FediChord.hs
@@ -73,6 +73,8 @@ import           Data.IP                       (IPv6, fromHostAddress6,
                                                 toHostAddress6)
 import           Data.List                     ((\\))
 import qualified Data.Map.Strict               as Map
+import qualified Data.HashMap.Strict           as HMap
+import           Data.HashMap.Strict           (HashMap)
 import           Data.Maybe                    (catMaybes, fromJust, fromMaybe,
                                                 isJust, isNothing, mapMaybe)
 import qualified Data.Set                      as Set
@@ -96,11 +98,11 @@ import           Debug.Trace                   (trace)
 fediChordInit :: (Service s (RealNodeSTM s))
               => FediChordConf
               -> (RealNodeSTM s -> IO (s (RealNodeSTM s)))     -- ^ runner function for service
-              -> IO (Socket, LocalNodeStateSTM s)
+              -> IO (Socket, RealNodeSTM s)
 fediChordInit initConf serviceRunner = do
     emptyLookupCache <- newTVarIO Map.empty
     let realNode = RealNode {
-            vservers = []
+            vservers = HMap.empty
           , nodeConfig = initConf
           , bootstrapNodes = confBootstrapNodes initConf
           , lookupCacheSTM = emptyLookupCache
@@ -110,13 +112,13 @@ fediChordInit initConf serviceRunner = do
     -- launch service and set the reference in the RealNode
     serv <- serviceRunner realNodeSTM
     atomically . modifyTVar' realNodeSTM $ \rn -> rn { nodeService = serv }
-    -- initialise a single vserver
-    initialState <- nodeStateInit realNodeSTM
-    initialStateSTM <- newTVarIO initialState
+    -- TODO: k-choices way of joining, so far just initialise a single vserver
+    firstVS <- nodeStateInit realNodeSTM
+    firstVSSTM <- newTVarIO firstVS
     -- add vserver to list at RealNode
-    atomically . modifyTVar' realNodeSTM $ \rn -> rn { vservers = initialStateSTM:vservers rn }
-    serverSock <- mkServerSocket (getIpAddr initialState) (getDhtPort initialState)
-    pure (serverSock, initialStateSTM)
+    atomically . modifyTVar' realNodeSTM $ \rn -> rn { vservers = HMap.insert (getNid firstVS) firstVSSTM (vservers rn) }
+    serverSock <- mkServerSocket (confIP initConf) (fromIntegral $ confDhtPort initConf)
+    pure (serverSock, realNodeSTM)
 
 -- | initialises the 'NodeState' for this local node.
 -- Separated from 'fediChordInit' to be usable in tests.
@@ -757,7 +759,7 @@ updateLookupCache :: RealNodeSTM s -> NodeID -> IO (Maybe (String, PortNumber))
 updateLookupCache nodeSTM keyToLookup = do
     (node, lookupSource) <- atomically $ do
         node <- readTVar nodeSTM
-        let firstVs = headMay (vservers node)
+        let firstVs = headMay (HMap.elems $ vservers node)
         lookupSource <- case firstVs of
                           Nothing -> pure Nothing
                           Just vs -> Just <$> readTVar vs
diff --git a/src/Hash2Pub/FediChordTypes.hs b/src/Hash2Pub/FediChordTypes.hs
index d8bbe4c..fd9d0f9 100644
--- a/src/Hash2Pub/FediChordTypes.hs
+++ b/src/Hash2Pub/FediChordTypes.hs
@@ -71,6 +71,8 @@ import           Data.Function                 (on)
 import qualified Data.Hashable                 as Hashable
 import           Data.List                     (delete, nub, sortBy)
 import qualified Data.Map.Strict               as Map
+import           Data.HashMap.Strict           (HashMap)
+import qualified Data.HashMap.Strict           as HMap
 import           Data.Maybe                    (fromJust, fromMaybe, isJust,
                                                 isNothing, mapMaybe)
 import qualified Data.Set                      as Set
@@ -151,8 +153,8 @@ a `localCompare` b
 -- Also contains shared data and config values.
 -- TODO: more data structures for k-choices bookkeeping
 data RealNode s = RealNode
-    { vservers       :: [LocalNodeStateSTM s]
-    -- ^ references to all active versers
+    { vservers       :: HashMap NodeID (LocalNodeStateSTM s)
+    -- ^ map of all active VServer node IDs to their node state
     , nodeConfig     :: FediChordConf
     -- ^ holds the initial configuration read at program start
     , bootstrapNodes :: [(String, PortNumber)]