tensorflow-haskell/tensorflow-ops/src/TensorFlow/Queue.hs

72 lines
2.8 KiB
Haskell

-- Copyright 2016 TensorFlow authors.
--
-- Licensed under the Apache License, Version 2.0 (the "License");
-- you may not use this file except in compliance with the License.
-- You may obtain a copy of the License at
--
-- http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}
-- | Queues in TensorFlow graph. Very limited support for now.
module TensorFlow.Queue (Queue, makeQueue, enqueue, dequeue) where
import Data.ByteString (ByteString)
import Data.Int (Int64)
import Data.Proxy (Proxy(..))
import Lens.Family2 ((.~), (&))
import TensorFlow.Build (ControlNode, MonadBuild, build, addInitializer, opAttr, opDef)
import TensorFlow.BuildOp (buildOp)
import TensorFlow.ControlFlow (group)
import qualified TensorFlow.GenOps.Core as CoreOps
import TensorFlow.Tensor (Ref, Value, Tensor, TensorList)
import TensorFlow.Types (TensorTypes, fromTensorTypes)
-- | A queue carrying tuples.
data Queue (as :: [*]) = Queue { handle :: Handle }
type Handle = Tensor Ref ByteString
-- | Adds the given values to the queue.
enqueue :: forall as v m . (MonadBuild m, TensorTypes as)
=> Queue as
-> TensorList v as
-> m ControlNode
enqueue = CoreOps.queueEnqueue . handle
-- | Retrieves the values from the queue.
dequeue :: forall as m . (MonadBuild m, TensorTypes as)
=> Queue as
-> m (TensorList Value as)
-- ^ Dequeued tensors. They are coupled in a sense
-- that values appear together, even if they are
-- not consumed together.
dequeue = CoreOps.queueDequeue . handle
-- | Creates a new queue with the given capacity and shared name.
makeQueue :: forall as m . (MonadBuild m, TensorTypes as)
=> Int64 -- ^ The upper bound on the number of elements in
-- this queue. Negative numbers mean no limit.
-> ByteString -- ^ If non-empty, this queue will be shared
-- under the given name across multiple sessions.
-> m (Queue as)
makeQueue capacity sharedName = do
q <- build $ buildOp [] (opDef "FIFOQueue"
& opAttr "component_types" .~ fromTensorTypes (Proxy :: Proxy as)
& opAttr "shared_name" .~ sharedName
& opAttr "capacity" .~ capacity
)
group q >>= addInitializer
return (Queue q)
-- TODO(gnezdo): Figure out the closing story for queues.