Getting recent typechecks is actually possible now

Previously the code compaired the file version number as managed by the vscode language server with the file hash given by FCS.
Now we hash the file and compair using that hash.
Also we now pass the source code in, without which we could never get recent results.

This should result in some serious speedups and stop that problem where files constantly get rechecked.

Author: faldor20

src/FSharpLanguageServer/Program.fs

@@ -229,8 +229,9 @@ type Server(client: ILanguageClient) =
             | _, None ->
                 return Error(sprintf "%s was closed" file.FullName)
             | Ok(projectOptions), Some(sourceText) ->
-                match checker.TryGetRecentCheckResultsForFile(file.FullName, projectOptions) with
+                match checker.TryGetRecentCheckResultsForFile(file.FullName, projectOptions,sourceText|>SourceText.ofString) with
                 | Some(parse, _, _) ->
+                    lgVerb "Getting cached parsing for file {@file}"file.FullName  
                     return Ok parse
                 | None ->
                     try
@@ -265,10 +266,11 @@ type Server(client: ILanguageClient) =
                     | parseResult, FSharpCheckFileAnswer.Succeeded(checkResult) -> return Ok(parseResult, checkResult)
                 }
 
-                match checker.TryGetRecentCheckResultsForFile(file.FullName, projectOptions) with
-                | Some(parseResult, checkResult, version) ->
-                    lgVerb2 "Getting typecheck for file with version {newVers}, previous version {oldVers}"  sourceVersion version
-                    if allowCached && version = sourceVersion then
+                match checker.TryGetRecentCheckResultsForFile(file.FullName, projectOptions,SourceText.ofString sourceText) with
+                | Some(parseResult, checkResult, hash) ->
+                    let newHash= sourceText.GetHashCode()
+                    lgVerb2 "Getting typecheck for file with hash {newHash}, previous hash {oldHash}"  newHash hash
+                    if allowCached && hash = newHash then
                         lgInfof "cached allowed and version is same,using recent Typecheck results"
                         return Ok(parseResult, checkResult)
                     else if allowCached && allowStale then
@@ -280,7 +282,7 @@ type Server(client: ILanguageClient) =
                             lgInfof "Re-compile timed out, using stale results"
                             return Ok(parseResult, checkResult)
                     else
-                        lgInfo2 "Checking: cannot use stale results and currentVersion {currentVers} did not match cached version {cachedVers}" version sourceVersion
+                        lgInfo2 "Checking: cannot use stale results and currenthash {currentVers} did not match cached hash {cachedVers}" newHash hash 
                         return! recompile
                 | _ ->
                     lgInfof "recompiling file becuase could not get parseTesult or checkResult"

src/FSharpLanguageServer/ProjectManager.fs

@@ -348,7 +348,9 @@ type ProjectManager(checker: FSharpChecker) =
 
 
     /// All transitive deps of anproject, including itself
-    let transitiveDeps(fsprojOrFsx: FileInfo) = //TODO: this is terrible project checker is stupid solution to this problem
+    let transitiveDeps (fsprojOrFsx: FileInfo) = //TODO: this is terrible project checker is stupid solution to this problem
+        let timer=Diagnostics.Stopwatch.StartNew()
+    
         let touched = new HashSet<String>()
         let result = new List<FSharpProjectOptions>()
         let rec walk(options: FSharpProjectOptions) =
@@ -361,7 +363,10 @@ type ProjectManager(checker: FSharpChecker) =
                 result.Add(options)
         let root = cache.Get(fsprojOrFsx, analyzeLater)
         walk(root.resolved.Value.options)
-        List.ofSeq(result)
+        let deps=List.ofSeq(result)
+        timer.Stop()
+        lgDebug2 "Getting transitive deps for {@file} took {@time}ms" fsprojOrFsx.Name timer.ElapsedMilliseconds
+        deps
     /// Find all .fsproj files referenced by a .sln file
     let slnProjectReferences (sln: FileInfo): list<FileInfo> =
         // From https://github.com/OmniSharp/omnisharp-roslyn/blob/master/src/OmniSharp.MSBuild/SolutionParsing/ProjectBlock.cs
@@ -480,7 +485,8 @@ type ProjectManager(checker: FSharpChecker) =
     /// All transitive dependencies of `projectFile`, in dependency order
     member this.TransitiveDeps(projectFile: FileInfo): FSharpProjectOptions list =
         //transitiveDeps(projectFile)(fun x ->this.FindProjectOptions (FileInfo(x.FileName))) //TODO: this might be terrible 
-        transitiveDeps(projectFile)
+        transitiveDeps (projectFile)
+
     /// Is `targetSourceFile` visible from `fromSourceFile`?
     member this.IsVisible(targetSourceFile: FileInfo, fromSourceFile: FileInfo) =
         match this.FindProjectOptions(fromSourceFile) with

src/LSP/DocumentStore.fs

@@ -7,7 +7,8 @@ open System.Collections.Generic
 open System.Text
 open Types 
 open BaseTypes
-type private Version = {
+open FSharp
+type private VolatileFile = {
     text: StringBuilder 
     mutable version: int
 }
@@ -36,7 +37,7 @@ open DocumentStoreUtils
 
 type DocumentStore() = 
     /// All open documents, organized by absolute path
-    let activeDocuments = new Dictionary<string, Version>()
+    let activeDocuments = new Dictionary<string, VolatileFile>()
     /// Replace a section of an open file
     let patch(doc: VersionedTextDocumentIdentifier, range: Range, text: string): unit = 
         let file = FileInfo(doc.uri.LocalPath)