From a84647cb574284b175395aca818e897a2d640937 Mon Sep 17 00:00:00 2001
From: Lucian Wischik <ljw@fb.com>
Date: Tue, 10 Dec 2019 22:46:22 -0800
Subject: [PATCH] expose defered_decl count

Summary:
The deferred-decl machinery already counts how many decls needed to be fetched. But it only incremeents that count if a threshold is provided (and hence has the potential to raise a Defer exception).

I want to re-use that counting machinery, for use in serverless-IDE and other uses of `compute_tast_and_errors`. But those uses are typically single-threaded, don't have a worker queue, and can never defer.

This diff therefore (1) exposes the counter, (2) lets the counter be incremented even if no threshold is provided.

Reviewed By: 2BitSalute

Differential Revision: D18879091

fbshipit-source-id: 5ad7b65bf857de69bbd4c7edfb92e2f672201bc2
---
 hphp/hack/src/typing/deferred_decl.ml        | 10 +++++++---
 hphp/hack/src/typing/typing_check_service.ml |  2 +-
 hphp/hack/src/typing/typing_classes_heap.ml  |  5 +++--
 hphp/hack/test/unit/server_tests.ml          |  7 +++++--
 4 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/hphp/hack/src/typing/deferred_decl.ml b/hphp/hack/src/typing/deferred_decl.ml
index e526610b88d..72cb6f7f1ef 100644
--- a/hphp/hack/src/typing/deferred_decl.ml
+++ b/hphp/hack/src/typing/deferred_decl.ml
@@ -20,10 +20,12 @@ let (counter : int ref) = ref 0
 
 let (enabled : bool ref) = ref true
 
-let should_defer ~(d : Relative_path.t) ~(threshold : int) : unit =
+let should_defer ~(d : Relative_path.t) ~(threshold_opt : int option) : unit =
   if !enabled then (
     counter := !counter + 1;
-    if threshold < !counter then raise (Defer d)
+    match threshold_opt with
+    | Some threshold when threshold < !counter -> raise (Defer d)
+    | _ -> ()
   )
 
 let add ~(d : deferment) : unit =
@@ -34,5 +36,7 @@ let reset ~enable =
   counter := 0;
   enabled := enable
 
-let get ~(f : deferment -> 'a) : 'a list =
+let get_deferments ~(f : deferment -> 'a) : 'a list =
   Relative_path.Set.fold !deferments ~init:[] ~f:(fun d l -> f d :: l)
+
+let get_counter () : int = !counter
diff --git a/hphp/hack/src/typing/typing_check_service.ml b/hphp/hack/src/typing/typing_check_service.ml
index b2172b0cf48..df0c9d7ae46 100644
--- a/hphp/hack/src/typing/typing_check_service.ml
+++ b/hphp/hack/src/typing/typing_check_service.ml
@@ -209,7 +209,7 @@ let process_file
     if InferMissing.global_inference @@ GlobalOptions.tco_infer_missing opts
     then
       Typing_global_inference.StateSubConstraintGraphs.save global_tvenvs;
-    let deferred_files = Deferred_decl.get ~f:(fun d -> Declare d) in
+    let deferred_files = Deferred_decl.get_deferments ~f:(fun d -> Declare d) in
     let result =
       match deferred_files with
       | [] -> (Errors.merge errors' errors, [])
diff --git a/hphp/hack/src/typing/typing_classes_heap.ml b/hphp/hack/src/typing/typing_classes_heap.ml
index 50a710d6636..5c92a744824 100644
--- a/hphp/hack/src/typing/typing_classes_heap.ml
+++ b/hphp/hack/src/typing/typing_classes_heap.ml
@@ -95,8 +95,9 @@ module Classes = struct
           | None ->
             raise Exit
           | Some (file, Naming_table.TClass) ->
-            Option.iter (defer_threshold ()) ~f:(fun threshold ->
-                Deferred_decl.should_defer ~d:file ~threshold);
+            Deferred_decl.should_defer
+              ~d:file
+              ~threshold_opt:(defer_threshold ());
             let class_type =
               Errors.run_in_decl_mode file (fun () ->
                   Decl.declare_class_in_file file class_name)
diff --git a/hphp/hack/test/unit/server_tests.ml b/hphp/hack/test/unit/server_tests.ml
index eeca43b36cc..f433530425e 100644
--- a/hphp/hack/test/unit/server_tests.ml
+++ b/hphp/hack/test/unit/server_tests.ml
@@ -33,7 +33,7 @@ let test_dmesg_parser () =
     input
 
 let ensure_count (count : int) : unit =
-  let deferred = Deferred_decl.get ~f:(fun d -> d) in
+  let deferred = Deferred_decl.get_deferments ~f:(fun d -> d) in
   Asserter.Int_asserter.assert_equals
     count
     (List.length deferred)
@@ -66,7 +66,10 @@ let ensure_threshold ~(threshold : int) ~(limit : int) ~(expected : int) : unit
   for i = 1 to limit do
     let path = Printf.sprintf "foo-%d" i in
     let relative_path = Relative_path.create Relative_path.Dummy path in
-    try Deferred_decl.should_defer ~d:relative_path ~threshold
+    try
+      Deferred_decl.should_defer
+        ~d:relative_path
+        ~threshold_opt:(Some threshold)
     with Deferred_decl.Defer d ->
       Asserter.Bool_asserter.assert_equals
         (i >= threshold)
-- 
2.11.4.GIT