fixes execution time reported in dryRun in case of no dependencies changed

Author: OlegZee

core/DependencyAnalysis.fs

@@ -10,7 +10,6 @@ type ChangeReason =
     | NotChanged
     | Depends of Target
     | DependsMissingTarget of Target
-    | Refs of string list
     | FilesChanged of string list
     | Other of string
 
@@ -25,10 +24,6 @@ let getExecTime ctx target =
     (fun ch -> Storage.GetResult(target, ch)) |> ctx.Db.PostAndReply
     |> Option.fold (fun _ r -> r.Steps |> List.sumBy (fun s -> s.OwnTime)) 0<ms>
 
-let targetName = function
-| PhonyAction a -> a
-| FileTarget file -> file.Name
-
 /// Gets single dependency state and reason of a change.
 let getDepState getVar getFileList (getChangedDeps: Target -> ChangeReason list) = function
     | FileDep (a:File, wrtime) when not((File.exists a) && abs((File.getLastWriteTime a - wrtime).TotalMilliseconds) < TimeCompareToleranceMs) ->
@@ -111,8 +106,13 @@ let getChangeReasons ctx getTargetDeps target =
 
 // gets task duration and list of targets it depends on. No clue why one method does both.
 let getDurationDeps ctx getDeps t =
-    let collectTargets = List.collect (function |Depends t |DependsMissingTarget t -> [t] | _ -> [])
-    getExecTime ctx t, getDeps t |> collectTargets
+    let deps = getDeps t |> List.collect (function |Depends t |DependsMissingTarget t -> [t] | _ -> [])
+    match deps with
+    | [] -> 0<ms>, []
+    | _ -> (getExecTime ctx t, deps)
+//    |> fun (tt,dd) ->
+//        printfn "For task %A duration:%A deps:%A" t tt dd
+//        (tt,dd)
 
 /// Dumps all dependencies for particular target
 let dumpDeps (ctx: ExecContext) (target: Target list) =

core/ExecCore.fs

@@ -194,16 +194,19 @@ module internal ExecCore =
 
         let targetGroups = groups |> List.map (List.map (makeTarget ctx)) in 
         let toSec v = float (v / 1<ms>) * 0.001
-        let endTime = Progress.estimateEndTime2 (getDurationDeps ctx getDeps) options.Threads targetGroups |> toSec
+        let endTime = Progress.estimateEndTime (getDurationDeps ctx getDeps) options.Threads targetGroups |> toSec
 
         targetGroups |> List.collect id |> List.iter (showTargetStatus 0)
-
-        let parallelismMsg =
-            let endTimeTotal = Progress.estimateEndTime2 (getDurationDeps ctx getDeps) 1 targetGroups |> toSec
-            if options.Threads > 1 && endTimeTotal > endTime * 1.05 then
-                sprintf "\n\tTotal tasks duration is (estimate) in %As\n\tParallelist degree: %.2f" endTimeTotal (endTimeTotal / endTime)
-            else ""
-        ctx.Logger.Log Message "\n\n\tBuild will be completed (estimate) in %As%s\n" endTime parallelismMsg
+        let alldeps = targetGroups |> List.collect id |> List.collect getDeps
+        if List.isEmpty alldeps then
+            ctx.Logger.Log Message "\n\n\tNo changed dependencies. Nothing to do.\n"
+        else
+            let parallelismMsg =
+                let endTimeTotal = Progress.estimateEndTime (getDurationDeps ctx getDeps) 1 targetGroups |> toSec
+                if options.Threads > 1 && endTimeTotal > endTime * 1.05 then
+                    sprintf "\n\tTotal tasks duration is (estimate) in %As\n\tParallelist degree: %.2f" endTimeTotal (endTimeTotal / endTime)
+                else ""
+            ctx.Logger.Log Message "\n\n\tBuild will be completed (estimate) in %As%s\n" endTime parallelismMsg
 
     let rec unwindAggEx (e:System.Exception) = seq {
         match e with

core/Progress.fs

@@ -170,17 +170,10 @@ let emptyProgress () =
             }
         loop ())
 
-/// <summary>
-/// Gets estimated execution time.
-/// </summary>
-let estimateEndTime getDurationDeps threadCount group =
-    let machine_state = {Cpu = BusyUntil 0<ms> |> List.replicate threadCount; Tasks = Map.empty}
-    snd <| execMany machine_state getDurationDeps group
-
 /// <summary>
 /// Gets estimated execution time for several target groups. Each group start when previous group is completed and runs in parallel.
 /// </summary>
-let estimateEndTime2 getDurationDeps threadCount groups =
+let estimateEndTime getDurationDeps threadCount groups =
     let machine_state = {Cpu = BusyUntil 0<ms> |> List.replicate threadCount; Tasks = Map.empty}
 
     groups |> List.fold (fun (state, _) group ->