{-# LANGUAGE MagicHash #-}
{-# LANGUAGE UnboxedTuples #-}
{-|
'T.Text' variant of the tracing functions in "Debug.Trace".
-}
module Debug.Trace.Text
  ( -- * Eventlog tracing
  -- $eventlog_tracing
    traceEvent
  , traceEventIO

  -- * Execution phase markers
  -- $markers
  , traceMarker
  , traceMarkerIO
  ) where
import Control.Monad (when)
import Foreign.C.String (CString)
import GHC.Exts (Ptr(..), traceEvent#, traceMarker#)
import GHC.IO (IO(..))
import qualified System.IO.Unsafe as Unsafe

import qualified Data.ByteString as B
import qualified Data.Text as T
import qualified Data.Text.Encoding as TE

import Debug.Trace.Flags (userTracingEnabled)

-- $eventlog_tracing
--
-- Eventlog tracing is a performance profiling system. These functions emit
-- extra events into the eventlog. In combination with eventlog profiling
-- tools these functions can be used for monitoring execution and
-- investigating performance problems.

-- | 'T.Text' variant of 'Debug.Trace.traceEvent'.
--
-- \(O(n)\) This function marshals the 'T.Text' into a 'B.ByteString' and
-- convert it into a null-terminated 'Foreign.C.Types.CString'.
--
-- Note that this function doesn't evaluate the 'T.Text' if user tracing
-- in eventlog is disabled.
--
-- The input should be shorter than \(2^{16}\) bytes. Otherwise the RTS
-- generates a broken eventlog.
traceEvent :: T.Text -> a -> a
traceEvent :: Text -> a -> a
traceEvent Text
message a
a
  | Bool
userTracingEnabled = Text -> a -> a
forall a. Text -> a -> a
traceEvent' Text
message a
a
  | Bool
otherwise = a
a

traceEvent' :: T.Text -> a -> a
traceEvent' :: Text -> a -> a
traceEvent' Text
message a
a = IO a -> a
forall a. IO a -> a
Unsafe.unsafeDupablePerformIO (IO a -> a) -> IO a -> a
forall a b. (a -> b) -> a -> b
$ do
  Text -> IO ()
traceEventIO' Text
message
  a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return a
a
{-# NOINLINE traceEvent' #-}

-- | 'T.Text' variant of 'Debug.Trace.traceEventIO'.
--
-- \(O(n)\) This function marshals the 'T.Text' into a 'B.ByteString' and
-- convert it into a null-terminated 'Foreign.C.Types.CString'.
--
-- Note that this function doesn't evaluate the 'T.Text' if user tracing
-- in eventlog is disabled.
--
-- The input should be shorter than \(2^{16}\) bytes. Otherwise the RTS
-- generates a broken eventlog.
traceEventIO :: T.Text -> IO ()
traceEventIO :: Text -> IO ()
traceEventIO Text
message = Bool -> IO () -> IO ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when Bool
userTracingEnabled (IO () -> IO ()) -> IO () -> IO ()
forall a b. (a -> b) -> a -> b
$ Text -> IO ()
traceEventIO' Text
message

traceEventIO' :: T.Text -> IO ()
traceEventIO' :: Text -> IO ()
traceEventIO' Text
message = Text -> (CString -> IO ()) -> IO ()
forall a. Text -> (CString -> IO a) -> IO a
withCString Text
message ((CString -> IO ()) -> IO ()) -> (CString -> IO ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ \(Ptr Addr#
p) -> (State# RealWorld -> (# State# RealWorld, () #)) -> IO ()
forall a. (State# RealWorld -> (# State# RealWorld, a #)) -> IO a
IO ((State# RealWorld -> (# State# RealWorld, () #)) -> IO ())
-> (State# RealWorld -> (# State# RealWorld, () #)) -> IO ()
forall a b. (a -> b) -> a -> b
$ \State# RealWorld
s ->
  case Addr# -> State# RealWorld -> State# RealWorld
forall d. Addr# -> State# d -> State# d
traceEvent# Addr#
p State# RealWorld
s of
    State# RealWorld
s' -> (# State# RealWorld
s', () #)

-- $markers
--
-- When looking at a profile for the execution of a program we often want to
-- be able to mark certain points or phases in the execution and see that
-- visually in the profile.
--
-- For example, a program might have several distinct phases with different
-- performance or resource behaviour in each phase. To properly interpret the
-- profile graph we really want to see when each phase starts and ends.
--
-- Markers let us do this: we can annotate the program to emit a marker at
-- an appropriate point during execution and then see that in a profile.

-- | 'T.Text' variant of 'Debug.Trace.traceMarker'.
--
-- \(O(n)\) This function marshals the 'T.Text' into a 'B.ByteString' and
-- convert it into a null-terminated 'Foreign.C.Types.CString'.
--
-- Note that this function doesn't evaluate the 'T.Text' if user tracing
-- in eventlog is disabled.
--
-- The input should be shorter than \(2^{16}\) bytes. Otherwise the RTS
-- generates a broken eventlog.
traceMarker :: T.Text -> a -> a
traceMarker :: Text -> a -> a
traceMarker Text
message a
a
  | Bool
userTracingEnabled = Text -> a -> a
forall a. Text -> a -> a
traceMarker' Text
message a
a
  | Bool
otherwise = a
a

traceMarker' :: T.Text -> a -> a
traceMarker' :: Text -> a -> a
traceMarker' Text
message a
a = IO a -> a
forall a. IO a -> a
Unsafe.unsafeDupablePerformIO (IO a -> a) -> IO a -> a
forall a b. (a -> b) -> a -> b
$ do
  Text -> IO ()
traceMarkerIO' Text
message
  a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return a
a
{-# NOINLINE traceMarker' #-}

-- | 'T.Text' variant of 'Debug.Trace.traceMarkerIO'.
--
-- \(O(n)\) This function marshals the 'T.Text' into a 'B.ByteString' and
-- convert it into a null-terminated 'Foreign.C.Types.CString'.
--
-- Note that this function doesn't evaluate the 'T.Text' if user tracing
-- in eventlog is disabled.
--
-- The input should be shorter than \(2^{16}\) bytes. Otherwise the RTS
-- generates a broken eventlog.
traceMarkerIO :: T.Text -> IO ()
traceMarkerIO :: Text -> IO ()
traceMarkerIO Text
message = Bool -> IO () -> IO ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when Bool
userTracingEnabled (IO () -> IO ()) -> IO () -> IO ()
forall a b. (a -> b) -> a -> b
$ Text -> IO ()
traceMarkerIO' Text
message

traceMarkerIO' :: T.Text -> IO ()
traceMarkerIO' :: Text -> IO ()
traceMarkerIO' Text
message = Text -> (CString -> IO ()) -> IO ()
forall a. Text -> (CString -> IO a) -> IO a
withCString Text
message ((CString -> IO ()) -> IO ()) -> (CString -> IO ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ \(Ptr Addr#
p) -> (State# RealWorld -> (# State# RealWorld, () #)) -> IO ()
forall a. (State# RealWorld -> (# State# RealWorld, a #)) -> IO a
IO ((State# RealWorld -> (# State# RealWorld, () #)) -> IO ())
-> (State# RealWorld -> (# State# RealWorld, () #)) -> IO ()
forall a b. (a -> b) -> a -> b
$ \State# RealWorld
s ->
  case Addr# -> State# RealWorld -> State# RealWorld
forall d. Addr# -> State# d -> State# d
traceMarker# Addr#
p State# RealWorld
s of
    State# RealWorld
s' -> (# State# RealWorld
s', () #)

withCString :: T.Text -> (CString -> IO a) -> IO a
withCString :: Text -> (CString -> IO a) -> IO a
withCString Text
text = ByteString -> (CString -> IO a) -> IO a
forall a. ByteString -> (CString -> IO a) -> IO a
B.useAsCString (Text -> ByteString
TE.encodeUtf8 Text
text)