Unified cache implementation for V2 and V3

src/Paket.Core/NuGetV2.fs

@@ -252,33 +252,15 @@ let deleteErrorFile (packageName:PackageName) =
         with
         | _ -> ()
 
+let getDetailsFromNuGet force auth nugetURL packageName version = 
+    getDetailsFromCacheOr
+        force
+        nugetURL
+        packageName
+        version
+        (fun () ->
+            getDetailsFromNuGetViaOData auth nugetURL packageName version)
 
-/// Tries to get download link and direct dependencies from NuGet
-/// Caches calls into json file
-let getDetailsFromNuGet force auth nugetURL (packageName:PackageName) (version:SemVerInfo) = 
-    let cacheFile,errorFile = cacheFile nugetURL packageName version
-    async {
-        try
-            if not force && errorFile.Exists then
-                failwithf "Error file for %O exists at %s" packageName errorFile.FullName
-
-            let! (invalidCache,details) = loadFromCacheOrODataOrV3 force cacheFile.FullName (auth,nugetURL) packageName version
-
-            verbosefn "loaded details for '%O@%O' from url '%s'" packageName version nugetURL
-
-            errorFile.Delete()
-            if invalidCache then
-                try
-                    File.WriteAllText(cacheFile.FullName,JsonConvert.SerializeObject(details))
-                with
-                | _ -> () // if caching fails we should not fail
-            return details
-        with
-        | exn -> 
-            File.AppendAllText(errorFile.FullName,exn.ToString())
-            raise exn
-            return! getDetailsFromNuGetViaOData auth nugetURL packageName version
-    } 
 
 let fixDatesInArchive fileName =
     try
@@ -481,7 +463,7 @@ let DownloadPackage(root, auth, (source : PackageSource), groupName, packageName
             let url, nugetPackage = 
                 match source with 
                 | Nuget source -> 
-                     source.Url, (getDetailsFromNuGet force auth source.Url packageName version)
+                    source.Url, (getDetailsFromNuGet force auth source.Url packageName version)
                 | NugetV3 source ->
                     source.Url, (NuGetV3.GetPackageDetails force source packageName version)
                 | _ -> failwith "shouldnt be here"

src/Paket.Core/NuGetV3.fs

@@ -224,24 +224,10 @@ let loadFromCacheOrGetDetails (force:bool)
 
 /// Uses the NuGet v3 registration endpoint to retrieve package details .
 let GetPackageDetails (force:bool) (source:NugetV3Source) (packageName:PackageName) (version:SemVerInfo) : Async<NuGet.NugetPackageCache> =
-    let cacheFile,errorFile = NuGet.cacheFile source.Url packageName version
-    async {
-        try
-            if not force && errorFile.Exists then
-                failwithf "Error file for %O exists at %s" packageName errorFile.FullName
-
-            let! (invalidCache,details) = loadFromCacheOrGetDetails force cacheFile.FullName source packageName version
-
-            errorFile.Delete()
-            if invalidCache then
-                try
-                    File.WriteAllText(cacheFile.FullName,JsonConvert.SerializeObject(details))
-                with
-                | _ -> () // if caching fails we should not fail
-            return details
-        with
-        | exn -> 
-            File.AppendAllText(errorFile.FullName,exn.ToString())
-            raise exn
-            return! getPackageDetails source packageName version
-    }
+    getDetailsFromCacheOr
+        force
+        source.Url
+        packageName
+        version
+        (fun () ->
+            getPackageDetails source packageName version)

src/Paket.Core/Nuget.fs

@@ -4,9 +4,12 @@ module Paket.NuGet
 open Paket.Utils
 open Paket.Domain
 open Paket.Requirements
+open Paket.Logging
 
 open System.IO
 
+open Newtonsoft.Json
+
 type NugetPackageCache =
     { Dependencies : (PackageName * VersionRequirement * FrameworkRestrictions) list
       PackageName : string
@@ -30,6 +33,40 @@ let inline normalizeUrl(url:string) = url.Replace("https","http").Replace("www."
 let cacheFile nugetURL (packageName:PackageName) (version:SemVerInfo) =
     let h = nugetURL |> normalizeUrl |> hash |> abs
     let packageUrl = sprintf "%O.%s.s%d.json" packageName (version.Normalize()) h
-    let cacheFile = FileInfo(Path.Combine(CacheFolder,packageUrl))
-    let errorFile = FileInfo(cacheFile.FullName + ".failed")
-    cacheFile,  errorFile
+    FileInfo(Path.Combine(CacheFolder,packageUrl))
+
+
+let getDetailsFromCacheOr force nugetURL (packageName:PackageName) (version:SemVerInfo) (get : unit -> NugetPackageCache Async) : NugetPackageCache Async = 
+    let cacheFile = cacheFile nugetURL packageName version
+    let get() = 
+        async {
+            let! result = get()
+            File.WriteAllText(cacheFile.FullName,JsonConvert.SerializeObject(result))
+            return result
+        }
+    async {
+        if not force && cacheFile.Exists then
+            let json = File.ReadAllText(cacheFile.FullName)
+            let result =
+                try
+                    let cachedObject = JsonConvert.DeserializeObject<NugetPackageCache> json
+                    Choice1Of2 cachedObject
+                with
+                | exn -> 
+                    Choice2Of2 exn
+            return!
+                match result with
+                | Choice1Of2 cachedObject -> 
+                    if cachedObject.CacheVersion <> NugetPackageCache.CurrentCacheVersion then
+                        cacheFile.Delete()
+                        get()
+                    else
+                        async { return cachedObject }
+                | Choice2Of2 exn -> 
+                    traceWarnfn "Error loading from cache for package '%s.%s':\n%s" (packageName.ToString()) 
+                                                                                    (version.ToString()) 
+                                                                                    (exn.ToString())
+                    get()
+        else
+            return! get()
+    }