From 672d321616adffe2f643a447bcd83a191061fa0b Mon Sep 17 00:00:00 2001
From: Danila Fedorin <danila.fedorin@gmail.com>
Date: Tue, 28 May 2019 21:35:46 -0700
Subject: [PATCH] Add a "cache view" type to step through a cache access.

---
 src/CacheSim/AccessView.elm | 54 +++++++++++++++++++++++++++++++++++++
 src/CacheSim/Model.elm      |  3 +++
 src/CacheSim/Update.elm     | 10 +++++++
 src/Main.elm                |  2 ++
 4 files changed, 69 insertions(+)
 create mode 100644 src/CacheSim/AccessView.elm

diff --git a/src/CacheSim/AccessView.elm b/src/CacheSim/AccessView.elm
new file mode 100644
index 0000000..c52232d
--- /dev/null
+++ b/src/CacheSim/AccessView.elm
@@ -0,0 +1,54 @@
+module CacheSim.AccessView exposing (..)
+import CacheSim.Cache exposing (..)
+import CacheSim.Hierarchy exposing (..)
+
+type AccessPosition = Down Int | Up Int | Done
+type alias AccessView = (List (AccessEffect Cache), AccessPosition)
+
+accessPositionForward : Int -> AccessPosition -> AccessPosition
+accessPositionForward depth av =
+    case av of
+        Down n -> if n == depth - 1 then Up n else Down (n + 1)
+        Up n -> if n == 0 then Done else Up (n - 1)
+        Done -> Done
+
+accessPositionBack : Int -> AccessPosition -> AccessPosition
+accessPositionBack depth av =
+    case av of
+        Down 0 -> Down 0
+        Down n -> Down (n-1)
+        Up n -> if n == (depth - 1) then Down n else Up (n + 1)
+        Done -> Up 0
+
+accessPositionDone : AccessPosition -> Bool
+accessPositionDone av =
+    case av of
+        Done -> True
+        _ -> False
+
+accessViewForward : AccessView -> AccessView
+accessViewForward (l, ap) = (l, accessPositionForward (List.length l) ap)
+
+accessViewBack : AccessView -> AccessView
+accessViewBack (l, ap) = (l, accessPositionBack (List.length l) ap)
+
+accessViewDone : AccessView -> Bool
+accessViewDone (_, ap) = accessPositionDone ap
+
+effectiveCacheHierarchy : CacheHierarchy -> AccessView -> CacheHierarchy
+effectiveCacheHierarchy c (l, ap) =
+    let
+        finalContents = List.map .output l
+        unaccessed = List.drop (List.length l) c
+        notDone =
+            case ap of
+                Done -> []
+                Down _ -> List.take (List.length l) c
+                Up n -> List.take n c
+        done =
+            case ap of
+                Done -> finalContents
+                Down _ -> []
+                Up n -> List.drop n finalContents
+    in
+        notDone ++ done ++ unaccessed
diff --git a/src/CacheSim/Model.elm b/src/CacheSim/Model.elm
index f188915..3bc3a1d 100644
--- a/src/CacheSim/Model.elm
+++ b/src/CacheSim/Model.elm
@@ -1,10 +1,12 @@
 module CacheSim.Model exposing (..)
 import CacheSim.Raw exposing (..)
 import CacheSim.Hierarchy exposing (..)
+import CacheSim.AccessView exposing (..)
 
 type alias Model =
     { rawHierarchy : RawCacheModelHierarchy
     , hierarchy : Maybe CacheHierarchy
+    , accessView : Maybe AccessView
     }
 type alias Flags = ()
 type Msg
@@ -12,3 +14,4 @@ type Msg
     | CreateRawModel
     | DeleteRawModel Int
     | UseHierarchy (Maybe CacheModelHierarchy)
+    | Access Int
diff --git a/src/CacheSim/Update.elm b/src/CacheSim/Update.elm
index c69d6c0..110736a 100644
--- a/src/CacheSim/Update.elm
+++ b/src/CacheSim/Update.elm
@@ -3,6 +3,7 @@ import CacheSim.Model exposing (..)
 import CacheSim.Hierarchy exposing (..)
 import CacheSim.Raw exposing (..)
 import CacheSim.IntMap exposing (..)
+import CacheSim.AccessView exposing (..)
 
 updateChangeRawModel : Int -> (RawCacheModel -> RawCacheModel) -> Model -> (Model, Cmd Msg)
 updateChangeRawModel l f m =
@@ -36,3 +37,12 @@ updateUseHierarchy cmh m =
         cmd = Cmd.none
     in
         (newModel, cmd)
+
+updateAccess : Int -> Model -> (Model, Cmd Msg)
+updateAccess i m =
+    let
+        accessResult = Maybe.map (accessCacheHierarchy i) m.hierarchy
+        newModel = m
+        cmd = Cmd.none
+    in
+        (newModel, cmd)
diff --git a/src/Main.elm b/src/Main.elm
index 447ba9f..0f83b95 100644
--- a/src/Main.elm
+++ b/src/Main.elm
@@ -18,6 +18,7 @@ init f =
         initialModel =
             { rawHierarchy = testCacheModelHierarchy
             , hierarchy = Nothing
+            , accessView = Nothing
             }
     in
         (initialModel, Cmd.none)
@@ -35,6 +36,7 @@ update msg m =
         CreateRawModel -> updateCreateRawModel m
         DeleteRawModel i -> updateDeleteRawModel i m
         UseHierarchy cmh -> updateUseHierarchy cmh m
+        Access i -> updateAccess i m
 
 subscriptions : Model -> Sub Msg
 subscriptions m = Sub.none