Cache platform penalty calculation - references #487

fsprojects · Jan 2, 2015 · 2d85a2f · 2d85a2f
1 parent b6476a3
commit 2d85a2f
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diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
@@ -1,3 +1,6 @@
+#### 0.20.15 - 02.01.2015
+* PERFORMANCE: Cache platform penalty calculation - https://github.com/fsprojects/Paket/issues/487
+
 #### 0.20.14 - 02.01.2015
 * BUGFIX: Detect the version of a GitHub gist correctly - https://github.com/fsprojects/Paket/issues/499
 

diff --git a/src/Paket.Core/PlatformMatching.fs b/src/Paket.Core/PlatformMatching.fs
@@ -11,15 +11,24 @@ let inline split (path : string) =
 
 let inline extractPlatforms path = split path |> Array.choose FrameworkIdentifier.Extract
 
+let private penalties = Collections.Generic.Dictionary<_,_>()
+
 let rec getPlatformPenalty (targetPlatform:FrameworkIdentifier) (packagePlatform:FrameworkIdentifier) =
     if packagePlatform = targetPlatform then
         0
     else
-        targetPlatform.SupportedPlatforms
-        |> List.map (fun target -> getPlatformPenalty target packagePlatform)
-        |> List.append [maxPenalty]
-        |> List.min
-        |> fun p -> p + 1
+        let key = targetPlatform,packagePlatform
+        match penalties.TryGetValue key with
+        | true, penalty -> penalty
+        | _ ->
+            let penalty =
+                targetPlatform.SupportedPlatforms
+                |> List.map (fun target -> getPlatformPenalty target packagePlatform)
+                |> List.append [maxPenalty]
+                |> List.min
+                |> fun p -> p + 1
+            penalties.[key] <- penalty
+            penalty
 
 let getPathPenalty (path:string) (platform:FrameworkIdentifier) =
     if String.IsNullOrWhiteSpace path then