From bdc038b5780746d3659b8935bacd5ff89b1e4ffe Mon Sep 17 00:00:00 2001
From: Zackery Spytz <zspytz@gmail.com>
Date: Sun, 3 Feb 2019 17:37:46 -0700
Subject: [PATCH] [OCaml] Cache the result of caml_named_value() in some cases

The result of caml_named_value() can be cached for (slightly)
improved performance.

This is mentioned in the OCaml reference manual.
https://caml.inria.fr/pub/docs/manual-ocaml/intfc.html#sec453

In addition, fix incorrect use of CAMLreturn() in
caml_ptr_val_internal().
---
 Lib/ocaml/ocaml.swg      | 21 +++++++++++----------
 Source/Modules/ocaml.cxx |  6 ++++--
 2 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/Lib/ocaml/ocaml.swg b/Lib/ocaml/ocaml.swg
index 8d9877143..92a3637ce 100644
--- a/Lib/ocaml/ocaml.swg
+++ b/Lib/ocaml/ocaml.swg
@@ -451,27 +451,28 @@ extern "C" {
 	CAMLparam1(v);
 	void *outptr = NULL;
         swig_type_info *outdescr = NULL;
+        static CAML_VALUE *func_val = NULL;
 
 	if( v == Val_unit ) {
 	    *out = 0;
-	    CAMLreturn(0);
+	    CAMLreturn_type(0);
 	}
 	if( !Is_block(v) ) return -1;
 	switch( SWIG_Tag_val(v) ) {
 	case C_int:
 	    if( !caml_long_val( v ) ) {
 		*out = 0;
-		CAMLreturn(0);
+		CAMLreturn_type(0);
 	    } else {
 		*out = 0;
-		CAMLreturn(1);
+		CAMLreturn_type(1);
 	    }
 	    break;
 	case C_obj:
-	    CAMLreturn
-		(caml_ptr_val_internal
-		 (caml_callback(*caml_named_value("caml_obj_ptr"),v),
-		  out,descriptor));
+	    if (!func_val) {
+	        func_val = caml_named_value("caml_obj_ptr");
+	    }
+	    CAMLreturn_type(caml_ptr_val_internal(caml_callback(*func_val, v), out, descriptor));
 	case C_string:
 	    outptr = (void *)String_val(SWIG_Field(v,0));
 	    break;
@@ -481,11 +482,11 @@ extern "C" {
 	    break;
 	default:
 	    *out = 0;
-	    CAMLreturn(1);
+	    CAMLreturn_type(1);
 	    break;
 	}
-	
-	CAMLreturn(SWIG_GetPtr(outptr,out,outdescr,descriptor));
+
+	CAMLreturn_type(SWIG_GetPtr(outptr, out, outdescr, descriptor));
     }
 
     SWIGINTERN void *caml_ptr_val( CAML_VALUE v, swig_type_info *descriptor ) {
diff --git a/Source/Modules/ocaml.cxx b/Source/Modules/ocaml.cxx
index 99f2a98d7..2f5e038bb 100644
--- a/Source/Modules/ocaml.cxx
+++ b/Source/Modules/ocaml.cxx
@@ -1595,10 +1595,12 @@ public:
       /* wrap complex arguments to values */
       Printv(w->code, wrap_args, NIL);
 
-      /* pass the method call on to the Python object */
+      /* pass the method call on to the OCaml object */
       Printv(w->code,
 	     "swig_result = caml_swig_alloc(1,C_list);\n" "SWIG_Store_field(swig_result,0,args);\n" "args = swig_result;\n" "swig_result = Val_unit;\n", 0);
-      Printf(w->code, "swig_result = " "caml_callback3(*caml_named_value(\"swig_runmethod\")," "swig_get_self(),caml_copy_string(\"%s\"),args);\n", Getattr(n, "name"));
+      Printf(w->code, "static CAML_VALUE *swig_ocaml_func_val = NULL;\n" "if (!swig_ocaml_func_val) {\n");
+      Printf(w->code, "  swig_ocaml_func_val = caml_named_value(\"swig_runmethod\");\n  }\n");
+      Printf(w->code, "swig_result = caml_callback3(*swig_ocaml_func_val,swig_get_self(),caml_copy_string(\"%s\"),args);\n", Getattr(n, "name"));
       /* exception handling */
       tm = Swig_typemap_lookup("director:except", n, Swig_cresult_name(), 0);
       if (!tm) {