micro-tweak Bytes.to_string, add a test

Author: bobzhang

jscomp/runtime/caml_bytes.ml

@@ -110,8 +110,10 @@ let string_of_large_bytes (bytes : bytes) i len =
       while s_len.contents > 0 do 
         let next = if s_len.contents < 1024 then s_len.contents else seg in
         let tmp_bytes = new_uninitialized next in
-        let () = caml_blit_bytes bytes offset.contents tmp_bytes 0 next in 
-        s .contents <- s.contents ^ Caml_string_extern.of_small_int_array (to_int_array tmp_bytes);
+        for k = 0 to next - 1 do 
+          tmp_bytes.![k] <- bytes.![k + offset.contents]  
+        done;   
+        s.contents <- s.contents ^ Caml_string_extern.of_small_int_array (to_int_array tmp_bytes);
         s_len.contents <- s_len.contents - next ; 
         offset.contents <- offset.contents + next;
       done;

jscomp/test/ext_bytes_test.js

@@ -178,6 +178,16 @@ Bytes.blit_string(a$2, 10, b, 5, 10);
 
 eq("File \"ext_bytes_test.ml\", line 109, characters 7-14", b, Bytes.of_string("\0\0\0\0\0\n\x0b\f\r\x0e\x0f\x10\x11\x12\x13\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"));
 
+var s = Bytes.init(50000, (function (i) {
+        return Char.chr(i % 137);
+      }));
+
+var s1 = Bytes.to_string(s);
+
+var s2 = Bytes.of_string(s1);
+
+eq("File \"ext_bytes_test.ml\", line 115, characters 7-14", s, s2);
+
 Mt.from_pair_suites("Ext_bytes_test", suites.contents);
 
 exports.suites = suites;

jscomp/test/ext_bytes_test.ml

@@ -108,5 +108,10 @@ let () =
     Bytes.blit_string a 10 b 5 10;
     eq __LOC__ b (Bytes.of_string "\000\000\000\000\000\n\011\012\r\014\015\016\017\018\019\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000")
 
+let () = 
+    let s = Bytes.init 50_000 (fun i -> Char.chr (i mod 137)) in 
+    let s1 = Bytes.to_string s in 
+    let s2 = Bytes.of_string s1 in 
+    eq __LOC__ s s2 
 let () =    
     Mt.from_pair_suites __MODULE__ !suites

lib/es6/caml_bytes.js

@@ -102,7 +102,9 @@ function bytes_to_string(a) {
   while(s_len > 0) {
     var next = s_len < 1024 ? s_len : 1024;
     var tmp_bytes = new Array(next);
-    caml_blit_bytes(a, offset, tmp_bytes, 0, next);
+    for(var k = 0; k < next; ++k){
+      tmp_bytes[k] = a[k + offset | 0];
+    }
     s = s + String.fromCharCode.apply(null, tmp_bytes);
     s_len = s_len - next | 0;
     offset = offset + next | 0;

lib/js/caml_bytes.js

@@ -102,7 +102,9 @@ function bytes_to_string(a) {
   while(s_len > 0) {
     var next = s_len < 1024 ? s_len : 1024;
     var tmp_bytes = new Array(next);
-    caml_blit_bytes(a, offset, tmp_bytes, 0, next);
+    for(var k = 0; k < next; ++k){
+      tmp_bytes[k] = a[k + offset | 0];
+    }
     s = s + String.fromCharCode.apply(null, tmp_bytes);
     s_len = s_len - next | 0;
     offset = offset + next | 0;