include elapsedTime in Activity

Time is relative, so the debug-me proof chain doesn't prove when things
happened, but it's still useful to have some idea of how long things
took to happen. This makes --replay work with logs gotten by --download.

Log still includes loggedTimestamp. This is a bit redundant, and is
unused now, but it's useful for log files to record when messages were
received.

This commit was sponsored by Riku Voipio.

1 files changed, 21 insertions, 2 deletions

diff --git a/Types.hs b/Types.hs
index 04855f4..c202f14 100644
--- a/Types.hs
+++ b/Types.hs
@@ -16,6 +16,8 @@ import Val
 import Memory
 import Serialization
 
+import Data.Time.Clock.POSIX
+
 -- | Things that the developer sees.
 data Seen = Seen
 	{ seenData :: Val
@@ -48,7 +50,8 @@ instance DataSize a => DataSize (Message a) where
 	dataSize (ControlMessage c) = dataSize c
 
 -- | An activity (either Entered or Seen) with a pointer
--- to a previous Activity.
+-- to a previous Activity, and the amount of time elapsed since the
+-- previous Activity.
 --
 -- The Signature is over both the data in the activity, and its pointer.
 --
@@ -57,13 +60,15 @@ instance DataSize a => DataSize (Message a) where
 data Activity a = Activity
 	{ activity :: a
 	, prevActivity :: Maybe Hash
+	, elapsedTime :: Maybe ElapsedTime
 	, activitySignature :: Signature
 	}
 	deriving (Show, Generic)
 
 instance DataSize a => DataSize (Activity a) where
 	dataSize a = dataSize (activity a) 
-		+ maybe 0 dataSize (prevActivity a) 
+		+ maybe 0 dataSize (prevActivity a)
+		+ maybe 0 dataSize (elapsedTime a)
 		+ dataSize (activitySignature a)
 
 -- | A control message, which can be sent asynchronously.
@@ -136,11 +141,25 @@ newtype GpgSig = GpgSig Val
 instance DataSize GpgSig where
 	dataSize (GpgSig s) = dataSize s
 
+-- | Elapsed time in seconds.
+newtype ElapsedTime = ElapsedTime Double
+	deriving (Show, Generic, Eq)
+
+mkElapsedTime :: POSIXTime -> POSIXTime -> ElapsedTime
+mkElapsedTime start end = ElapsedTime $ fromRational $ toRational (end - start)
+
+instance DataSize ElapsedTime where
+	dataSize _ = 16 -- 128 bit Double
+
 data LogMessage
 	= User (Message Seen)
 	| Developer (Message Entered)
 	deriving (Show, Generic)
 
+instance Binary ElapsedTime
+instance ToJSON ElapsedTime
+instance FromJSON ElapsedTime
+
 instance DataSize LogMessage where
 	dataSize (User a) = dataSize a
 	dataSize (Developer a) = dataSize a