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prevent cache invariant querying when not joined

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This commit is contained in:
Trolli Schmittlauch 2020-07-01 18:22:28 +02:00
parent abbe664ca1
commit 8d349212b4
2 changed files with 13 additions and 7 deletions
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9
src/Hash2Pub/DHTProtocol.hs
View file

@ -32,6 +32,7 @@ module Hash2Pub.DHTProtocol
, ackRequest , ackRequest
, isPossibleSuccessor , isPossibleSuccessor
, isPossiblePredecessor , isPossiblePredecessor
, isJoined
, closestCachePredecessors , closestCachePredecessors
) )
where where
@ -213,8 +214,8 @@ markCacheEntryAsVerified timestamp nid = RingMap . Map.adjust adjustFunc nid . g
-- | uses the successor and predecessor list of a node as an indicator for whether a -- | uses the successor and predecessor list of a node as an indicator for whether a
-- node has properly joined the DHT -- node has properly joined the DHT
isJoined_ :: LocalNodeState -> Bool isJoined :: LocalNodeState -> Bool
isJoined_ ns = not . all null $ [successors ns, predecessors ns] isJoined ns = not . all null $ [successors ns, predecessors ns]
-- | the size limit to be used when serialising messages for sending -- | the size limit to be used when serialising messages for sending
sendMessageSize :: Num i => i sendMessageSize :: Num i => i
@ -260,8 +261,8 @@ handleIncomingRequest nsSTM sendQ msgSet sourceAddr = do
-- ToDo: figure out what happens if not joined -- ToDo: figure out what happens if not joined
QueryID -> Just <$> respondQueryID nsSTM msgSet QueryID -> Just <$> respondQueryID nsSTM msgSet
-- only when joined -- only when joined
Leave -> if isJoined_ ns then Just <$> respondLeave nsSTM msgSet else pure Nothing Leave -> if isJoined ns then Just <$> respondLeave nsSTM msgSet else pure Nothing
Stabilise -> if isJoined_ ns then Just <$> respondStabilise nsSTM msgSet else pure Nothing Stabilise -> if isJoined ns then Just <$> respondStabilise nsSTM msgSet else pure Nothing
) )
-- for single part request, response starts with part number 1. For multipart requests, response starts with part number n+1. -- for single part request, response starts with part number 1. For multipart requests, response starts with part number n+1.

11
src/Hash2Pub/FediChord.hs
View file

@ -253,7 +253,9 @@ checkCacheSliceInvariants :: LocalNodeState
-> NodeCache -> NodeCache
-> [NodeID] -- ^ list of middle IDs of slices not -> [NodeID] -- ^ list of middle IDs of slices not
-- ^ fulfilling the invariant -- ^ fulfilling the invariant
checkCacheSliceInvariants ns = checkPredecessorSlice jEntries (getNid ns) startBound lastPred <> checkSuccessorSlice jEntries (getNid ns) startBound lastSucc checkCacheSliceInvariants ns
| isJoined ns = checkPredecessorSlice jEntries (getNid ns) startBound lastPred <> checkSuccessorSlice jEntries (getNid ns) startBound lastSucc
| otherwise = const []
where where
jEntries = jEntriesPerSlice ns jEntries = jEntriesPerSlice ns
lastPred = getNid <$> lastMay (predecessors ns) lastPred = getNid <$> lastMay (predecessors ns)
@ -340,7 +342,7 @@ stabiliseThread nsSTM = forever $ do
-- try looking up additional neighbours if list too short -- try looking up additional neighbours if list too short
forM_ [(length $ predecessors updatedNs)..(kNeighbours updatedNs)] (\_ -> do forM_ [(length $ predecessors updatedNs)..(kNeighbours updatedNs)] (\_ -> do
ns' <- readTVarIO nsSTM ns' <- readTVarIO nsSTM
nextEntry <- requestQueryID ns' $ pred . getNid $ atDef (toRemoteNodeState ns') (predecessors ns') (-1) nextEntry <- requestQueryID ns' $ pred . getNid $ lastDef (toRemoteNodeState ns') (predecessors ns')
atomically $ do atomically $ do
latestNs <- readTVar nsSTM latestNs <- readTVar nsSTM
writeTVar nsSTM $ addPredecessors [nextEntry] latestNs writeTVar nsSTM $ addPredecessors [nextEntry] latestNs
@ -348,7 +350,7 @@ stabiliseThread nsSTM = forever $ do
forM_ [(length $ successors updatedNs)..(kNeighbours updatedNs)] (\_ -> do forM_ [(length $ successors updatedNs)..(kNeighbours updatedNs)] (\_ -> do
ns' <- readTVarIO nsSTM ns' <- readTVarIO nsSTM
nextEntry <- requestQueryID ns' $ succ . getNid $ atDef (toRemoteNodeState ns') (successors ns') (-1) nextEntry <- requestQueryID ns' $ succ . getNid $ lastDef (toRemoteNodeState ns') (successors ns')
atomically $ do atomically $ do
latestNs <- readTVar nsSTM latestNs <- readTVar nsSTM
writeTVar nsSTM $ addSuccessors [nextEntry] latestNs writeTVar nsSTM $ addSuccessors [nextEntry] latestNs
@ -460,6 +462,9 @@ fediMessageHandler :: TQueue (BS.ByteString, SockAddr) -- ^ send queue
-> LocalNodeStateSTM -- ^ acting NodeState -> LocalNodeStateSTM -- ^ acting NodeState
-> IO () -> IO ()
fediMessageHandler sendQ recvQ nsSTM = do fediMessageHandler sendQ recvQ nsSTM = do
-- Read node state just once, assuming that all relevant data for this function does
-- not change.
-- Other functions are passed the nsSTM reference and thus can get the latest state.
nsSnap <- readTVarIO nsSTM nsSnap <- readTVarIO nsSTM
-- handling multipart messages: -- handling multipart messages:
-- Request parts can be insert into a map (key: (sender IP against spoofing, request ID), value: timestamp + set of message parts, handle all of them when size of set == parts) before being handled. This map needs to be purged periodically by a separate thread and can be protected by an MVar for fairness. -- Request parts can be insert into a map (key: (sender IP against spoofing, request ID), value: timestamp + set of message parts, handle all of them when size of set == parts) before being handled. This map needs to be purged periodically by a separate thread and can be protected by an MVar for fairness.