data structure for RealNode holds common config and management data

contributes to #56, #34, #2

app/Main.hs

@@ -16,10 +16,13 @@ main = do
     -- ToDo: parse and pass config
     -- probably use `tomland` for that
     conf <- readConfig
+    -- TODO: first initialise 'RealNode', then the vservers
     -- ToDo: load persisted caches, bootstrapping nodes …
     (serverSock, thisNode) <- fediChordInit conf
     -- currently no masking is necessary, as there is nothing to clean up
     cacheWriterThread <- forkIO $ cacheWriter thisNode
+    thisNodeSnap <- readTVarIO thisNode
+    realNode <- readTVarIO $ parentRealNode thisNodeSnap
     -- try joining the DHT using one of the provided bootstrapping nodes
     let
         tryJoining (bn:bns) = do
@@ -28,7 +31,7 @@ main = do
               Left err -> putStrLn ("join error: " <> err) >> tryJoining bns
               Right joined -> pure $ Right joined
         tryJoining [] = pure $ Left "Exhausted all bootstrap points for joining."
-    joinedState <- tryJoining $ confBootstrapNodes conf
+    joinedState <- tryJoining $ bootstrapNodes realNode
     either (\err -> do
         -- handle unsuccessful join
 

src/Hash2Pub/FediChord.hs

@@ -41,6 +41,7 @@ module Hash2Pub.FediChord (
   , fediChordJoin
   , fediChordBootstrapJoin
   , fediMainThreads
+  , RealNode (..)
   , nodeStateInit
   , mkServerSocket
   , mkSendSocket
@@ -90,26 +91,35 @@ import           Debug.Trace                   (trace)
 -- | initialise data structures, compute own IDs and bind to listening socket
 -- ToDo: load persisted state, thus this function already operates in IO
 fediChordInit :: FediChordConf -> IO (Socket, LocalNodeStateSTM)
-fediChordInit conf = do
-    initialState <- nodeStateInit conf
+fediChordInit initConf = do
+    let realNode = RealNode {
+            vservers = []
+          , nodeConfig = initConf
+          , bootstrapNodes = confBootstrapNodes initConf
+                            }
+    realNodeSTM <- newTVarIO realNode
+    initialState <- nodeStateInit realNodeSTM
     initialStateSTM <- newTVarIO initialState
     serverSock <- mkServerSocket (getIpAddr initialState) (getDhtPort initialState)
     pure (serverSock, initialStateSTM)
 
 -- | initialises the 'NodeState' for this local node.
 -- Separated from 'fediChordInit' to be usable in tests.
-nodeStateInit :: FediChordConf -> IO LocalNodeState
-nodeStateInit conf = do
+nodeStateInit :: RealNodeSTM -> IO LocalNodeState
+nodeStateInit realNodeSTM = do
+    realNode <- readTVarIO realNodeSTM
     cacheSTM <- newTVarIO initCache
     q <- atomically newTQueue
     let
+        conf = nodeConfig realNode
+        vsID = 0
         containedState = RemoteNodeState {
             domain = confDomain conf
           , ipAddr = confIP conf
-          , nid = genNodeID (confIP conf) (confDomain conf) 0
+          , nid = genNodeID (confIP conf) (confDomain conf) $ fromInteger vsID
           , dhtPort = toEnum $ confDhtPort conf
           , servicePort = 0
-          , vServerID = 0
+          , vServerID = vsID
                                           }
         initialState = LocalNodeState {
             nodeState = containedState
@@ -121,6 +131,7 @@ nodeStateInit conf = do
           , lNumBestNodes = 3
           , pNumParallelQueries = 2
           , jEntriesPerSlice = 2
+          , parentRealNode = realNodeSTM
                                            }
     pure initialState
 

src/Hash2Pub/FediChordTypes.hs

@@ -13,6 +13,8 @@ module Hash2Pub.FediChordTypes (
   , LocalNodeState (..)
   , LocalNodeStateSTM
   , RemoteNodeState (..)
+  , RealNode (..)
+  , RealNodeSTM
   , setSuccessors
   , setPredecessors
   , NodeCache
@@ -132,6 +134,19 @@ a `localCompare` b
     wayForwards = getNodeID (b - a)
     wayBackwards = getNodeID (a - b)
 
+-- | Data for managing the virtual server nodes of this real node.
+-- Also contains shared data and config values.
+-- TODO: more data structures for k-choices bookkeeping
+data RealNode = RealNode
+    { vservers       :: [LocalNodeStateSTM]
+    -- ^ references to all active versers
+    , nodeConfig     :: FediChordConf
+    -- ^ holds the initial configuration read at program start
+    , bootstrapNodes :: [(String, PortNumber)]
+    -- ^ nodes to be used as bootstrapping points, new ones learned during operation
+    }
+
+type RealNodeSTM = TVar RealNode
 
 -- | represents a node and all its important state
 data RemoteNodeState = RemoteNodeState
@@ -172,6 +187,8 @@ data LocalNodeState = LocalNodeState
     -- ^ number of parallel sent queries
     , jEntriesPerSlice    :: Int
     -- ^ number of desired entries per cache slice
+    , parentRealNode      :: RealNodeSTM
+    -- ^ the parent node managing this vserver instance
     }
     deriving (Show, Eq)
 

test/FediChordSpec.hs

@@ -1,6 +1,7 @@
 {-# LANGUAGE OverloadedStrings #-}
 module FediChordSpec where
 
+import           Control.Concurrent.STM.TVar
 import           Control.Exception
 import           Data.ASN1.Parse             (runParseASN1)
 import qualified Data.ByteString             as BS
@@ -292,11 +293,20 @@ exampleNodeState = RemoteNodeState {
                    }
 
 exampleLocalNode :: IO LocalNodeState
-exampleLocalNode = nodeStateInit $ FediChordConf {
+exampleLocalNode = nodeStateInit =<< (newTVarIO $ RealNode {
+            vservers = []
+          , nodeConfig = exampleFediConf
+          , bootstrapNodes = confBootstrapNodes exampleFediConf
+                                                        })
+
+
+exampleFediConf :: FediChordConf
+exampleFediConf = FediChordConf {
     confDomain = "example.social"
   , confIP = exampleIp
   , confDhtPort = 2342
                                                     }
+
 exampleNodeDomain :: String
 exampleNodeDomain = "example.social"
 exampleVs :: (Integral i) => i