From 8fe574a8f1f2f71b68c89aeacccd05d084a4003d Mon Sep 17 00:00:00 2001
From: James Crayne <jim.crayne@gmail.com>
Date: Mon, 28 May 2018 19:54:59 +0000
Subject: ncLastNMsgs is now CyclicBuffer type

---
 src/Data/CyclicBuffer.hs | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

(limited to 'src/Data/CyclicBuffer.hs')

diff --git a/src/Data/CyclicBuffer.hs b/src/Data/CyclicBuffer.hs
index ab022e3f..0cc87459 100644
--- a/src/Data/CyclicBuffer.hs
+++ b/src/Data/CyclicBuffer.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE FlexibleContexts #-}
-module Data.CyclicBuffer where
+module Data.CyclicBuffer {- TODO: export list -} where
+
 
 import Control.Concurrent.STM
 import Control.Concurrent.STM.TArray
@@ -19,6 +20,7 @@ data CyclicBuffer a = CyclicBuffer
     , qsize   :: Word32
     , buffend :: TVar Word32 -- on incoming, highest packet number handled + 1
     , dropCnt :: TVar Word32
+    , totalCnt :: TVar Word32
     }
 
 cyclicBufferViewList :: CyclicBuffer a -> STM [(Word32,a)]
@@ -30,6 +32,15 @@ cyclicBufferViewList p = do
 getCapacity :: Applicative m => CyclicBuffer t -> m Word32
 getCapacity (CyclicBuffer { qsize }) = pure qsize
 
+getTotal :: CyclicBuffer t -> STM Word32
+getTotal (CyclicBuffer { totalCnt }) = readTVar totalCnt
+
+getDropped :: CyclicBuffer t -> STM Word32
+getDropped (CyclicBuffer { dropCnt }) = readTVar dropCnt
+
+getNextSequenceNum :: CyclicBuffer t -> STM Word32
+getNextSequenceNum (CyclicBuffer { seqno }) = readTVar seqno
+
 -- | Create a new CyclicBuffer with Overwrite on Wrap.
 new :: Word32 -- ^ Capacity of queue.
     -> Word32 -- ^ Initial sequence number.
@@ -41,6 +52,7 @@ new capacity seqstart = do
     seqv <- newTVar seqstart
     bufe <- newTVar 0
     dropped <- newTVar 0
+    total <- newTVar 0
     return CyclicBuffer
         { vwflgs  = flgs
         , pktq    = q
@@ -48,6 +60,7 @@ new capacity seqstart = do
         , qsize   = cap
         , buffend = bufe
         , dropCnt = dropped
+        , totalCnt = total
         }
 
 observeOutOfBand :: CyclicBuffer a -> Word32-> STM ()
@@ -79,14 +92,15 @@ markButNotDequeue CyclicBuffer { vwflgs, pktq, seqno, qsize } = do
     modifyTVar' seqno   succ
     return x
 
--- | Enqueue a packet.  Packets need not be enqueued in order as long as there
--- is spare capacity in the queue.  If the capacity is exceeded, packets are
+-- | Enqueue a packet. If the capacity is exceeded, packets are
 -- dropped and the drop count increased accordingly.
+-- TODO: We no longer really support "out of order"
+--       So perhaps drop the num parameter
 enqueue :: CyclicBuffer a -- ^ The cyclic buffer(queue)
         -> Word32        -- ^ Sequence number of the packet.
         -> a             -- ^ The packet.
         -> STM ()
-enqueue CyclicBuffer{vwflgs, pktq, seqno, qsize, buffend, dropCnt} no x = do
+enqueue CyclicBuffer{vwflgs, pktq, seqno, qsize, buffend, dropCnt, totalCnt} no x = do
     low <- readTVar seqno
     let proj = no - low
     let i = no `mod` qsize
@@ -96,5 +110,7 @@ enqueue CyclicBuffer{vwflgs, pktq, seqno, qsize, buffend, dropCnt} no x = do
             modifyTVar' dropCnt (+1)
     writeArray pktq i (Just x)
     writeArray vwflgs i False -- mark as not viewed
+    modifyTVar' totalCnt (+1)
+    writeTVar seqno (no+1)
     modifyTVar' buffend (\be -> if be - low <= proj then no + 1 else be)
     return ()
-- 
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