remote, add Types.GC, use in deleteSpecific

hnix-store-remote/hnix-store-remote.cabal

@@ -84,6 +84,7 @@ library
     , System.Nix.Store.Remote.Socket
     , System.Nix.Store.Remote.Types
     , System.Nix.Store.Remote.Types.Activity
+    , System.Nix.Store.Remote.Types.GC
     , System.Nix.Store.Remote.Types.CheckMode
     , System.Nix.Store.Remote.Types.Logger
     , System.Nix.Store.Remote.Types.ProtoVersion

hnix-store-remote/src/System/Nix/Store/Remote.hs

@@ -169,11 +169,11 @@ buildDerivation p drv buildMode = do
 -- | Delete store paths
 deleteSpecific
  :: HashSet StorePath -- ^ Paths to delete
- -> MonadStore (HashSet StorePath, Word64) -- ^ (Paths deleted, Bytes freed)
+ -> MonadStore GCResult
 deleteSpecific paths = do
   storeDir <- getStoreDir
   runOpArgs CollectGarbage $ do
-    putEnum GCDeleteSpecific
+    putEnum GCAction_DeleteSpecific
     putPaths storeDir paths
     putBool False -- ignoreLiveness
     putInt (maxBound :: Word64) -- maxFreedBytes
@@ -181,10 +181,11 @@ deleteSpecific paths = do
     putInt (0::Int)
     putInt (0::Int)
   getSocketIncremental $ do
-    deletedPaths <- getPathsOrFail storeDir
-    bytesFreed <- getInt
+    gcResult_deletedPaths <- getPathsOrFail storeDir
+    gcResult_bytesFreed <- getInt
+    -- TODO: who knows
     _ :: Int <- getInt
-    pure (deletedPaths, bytesFreed)
+    pure GCResult{..}
 
 ensurePath :: StorePath -> MonadStore ()
 ensurePath pn = do

hnix-store-remote/src/System/Nix/Store/Remote/Protocol.hs

@@ -152,11 +152,3 @@ runStoreOpts' sockFamily sockAddr storeRootDir code =
       $ (`runReaderT` sock)
       $ (`runStateT` (Nothing, []))
       $ runExceptT (greet >> code)
-
-data GCAction
-  = GCReturnLive
-  | GCReturnDead
-  | GCDeleteDead
-  | GCDeleteSpecific
-  deriving (Eq, Show, Enum)
-

hnix-store-remote/src/System/Nix/Store/Remote/Serialize.hs

@@ -61,6 +61,12 @@ instance Serialize BuildResult where
     putTime startTime
     putTime stopTime
 
+-- * GCAction
+--
+instance Serialize GCAction where
+  get = getEnum
+  put = putEnum
+
 -- * ProtoVersion
 
 -- protoVersion_major & 0xFF00

hnix-store-remote/src/System/Nix/Store/Remote/Types.hs

@@ -1,5 +1,6 @@
 module System.Nix.Store.Remote.Types
   ( module System.Nix.Store.Remote.Types.Activity
+  , module System.Nix.Store.Remote.Types.GC
   , module System.Nix.Store.Remote.Types.CheckMode
   , module System.Nix.Store.Remote.Types.Logger
   , module System.Nix.Store.Remote.Types.ProtoVersion
@@ -10,6 +11,7 @@ module System.Nix.Store.Remote.Types
   ) where
 
 import System.Nix.Store.Remote.Types.Activity
+import System.Nix.Store.Remote.Types.GC
 import System.Nix.Store.Remote.Types.CheckMode
 import System.Nix.Store.Remote.Types.Logger
 import System.Nix.Store.Remote.Types.ProtoVersion

hnix-store-remote/src/System/Nix/Store/Remote/Types/GC.hs

@@ -0,0 +1,45 @@
+{-|
+Description : Garbage collection actions / options
+Maintainer  : srk <srk@48.io>
+|-}
+module System.Nix.Store.Remote.Types.GC (
+    GCAction(..)
+  , GCOptions(..)
+  , GCResult(..)
+  ) where
+
+import Data.HashSet (HashSet)
+import Data.Word (Word64)
+import GHC.Generics (Generic)
+import System.Nix.StorePath (StorePath)
+
+data GCAction
+  = GCAction_ReturnLive -- ^ Return the set of paths reachable from roots (closure)
+  | GCAction_ReturnDead -- ^ Return unreachable paths
+  | GCAction_DeleteDead -- ^ Delete unreachable paths
+  | GCAction_DeleteSpecific -- ^ Delete specified paths
+  deriving (Bounded, Eq, Enum, Generic, Ord, Show)
+
+ -- | Garbage collector operation options
+data GCOptions = GCOptions
+  { -- | Operation
+    gcOptions_operation :: GCAction
+    -- | If set, then reachability from the roots is ignored (unused)
+  , gcOptions_ignoreLiveness :: Bool
+    -- | Paths to delete for @GCAction_DeleteSpecific@
+  , gcOptions_pathsToDelete :: HashSet StorePath
+    -- | Stop after `gcOptions_maxFreed` bytes have been freed
+  , gcOptions_maxFreed :: Integer
+  } deriving (Eq, Generic, Ord, Show)
+
+data GCResult = GCResult
+ { -- | Depending on the action, the GC roots,
+   -- or the paths that would be or have been deleted
+   gcResult_deletedPaths :: HashSet StorePath
+   -- | The number of bytes that would be or was freed for
+   --
+   --      - @GCAction_ReturnDead@
+   --      - @GCAction_DeleteDead@
+   --      - @GCAction_DeleteSpecific@
+ , gcResult_bytesFreed :: Word64
+ } deriving (Eq, Generic, Ord, Show)

hnix-store-remote/tests-io/NixDaemon.hs

@@ -285,7 +285,7 @@ spec_protocol = Hspec.around withNixDaemon $
           liftIO $ forM_ tempRootList $ \entry -> do
             removeFile $ mconcat [ tempRootsDir, "/", entry ]
 
-          (deletedPaths, deletedBytes) <- deleteSpecific (HS.fromList [path])
-          deletedPaths `shouldBe` HS.fromList [path]
-          deletedBytes `shouldBe` 4
+          GCResult{..} <- deleteSpecific (HS.fromList [path])
+          gcResult_deletedPaths `shouldBe` HS.fromList [path]
+          gcResult_bytesFreed `shouldBe` 4
 

hnix-store-remote/tests/SerializeSpec.hs

@@ -156,6 +156,12 @@ spec = parallel $ do
       it' "ResolvesToAlreadyValid" BuildStatus_ResolvesToAlreadyValid 13
       it' "NoSubstituters"         BuildStatus_NoSubstituters         14
 
+    describe "GCAction enum order matches Nix" $ do
+      it' "ReturnLive"     GCAction_ReturnLive     0
+      it' "ReturnDead"     GCAction_ReturnDead     1
+      it' "DeleteDead"     GCAction_DeleteDead     2
+      it' "DeleteSpecific" GCAction_DeleteSpecific 3
+
     describe "Logger" $ do
       describe "Activity enum order matches Nix" $ do
         it' "CopyPath"      Activity_CopyPath      100