Embed the Wasm code inside the JavaScript script

ocaml-wasm · Dec 5, 2024 · ce10931 · ce10931
1 parent 889e292
commit ce10931
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Showing 4 changed files with 44 additions and 26 deletions.
diff --git a/compiler/bin-wasm_of_ocaml/compile.ml b/compiler/bin-wasm_of_ocaml/compile.ml
@@ -479,7 +479,7 @@ let run
                (Link.build_runtime_arguments
                   ~missing_primitives
                   ~wasm_dir:dir
-                  ~link_spec:[ wasm_name, None ]
+                  ~link_spec:[ (*`Name wasm_name*) `File tmp_wasm_file', None ]
                   ~separate_compilation:false
                   ~generated_js:[ None, generated_js ]
                   ())

diff --git a/compiler/lib-wasm/link.ml b/compiler/lib-wasm/link.ml
@@ -540,23 +540,32 @@ let build_runtime_arguments
       , EArr
           (List.map
              ~f:(fun (m, deps) ->
-               Javascript.Element
-                 (EArr
-                    [ Element (EStr (Utf8_string.of_string_exn m))
-                    ; Element
-                        (match deps with
-                        | None ->
-                            ENum (Javascript.Num.of_targetint (Targetint.of_int_exn 0))
-                        | Some l ->
-                            EArr
-                              (List.map
-                                 ~f:(fun i ->
-                                   Javascript.Element
-                                     (ENum
-                                        (Javascript.Num.of_targetint
-                                           (Targetint.of_int_exn i))))
-                                 l))
-                    ]))
+               let deps =
+                 Javascript.Element
+                   (match deps with
+                   | None -> ENum (Javascript.Num.of_targetint (Targetint.of_int_exn 0))
+                   | Some l ->
+                       EArr
+                         (List.map
+                            ~f:(fun i ->
+                              Javascript.Element
+                                (ENum
+                                   (Javascript.Num.of_targetint (Targetint.of_int_exn i))))
+                            l))
+               in
+               match m with
+               | `Name m ->
+                   Javascript.Element
+                     (EArr [ Element (EStr (Utf8_string.of_string_exn m)); deps ])
+               | `File f ->
+                   let contents =
+                     f
+                     |> Fs.read_file
+                     |> Base64.encode_string
+                     |> Utf8_string.of_string_exn
+                   in
+                   Javascript.Element
+                     (EArr [ ElementHole; deps; Javascript.Element (EStr contents) ]))
              link_spec) )
     ; "generated", generated_js
     ; "src", EStr (Utf8_string.of_string_exn (Filename.basename wasm_dir))
@@ -814,7 +823,10 @@ let link ~output_file ~linkall ~enable_source_maps ~files =
     ( interfaces
     , dir
     , let to_link = compute_dependencies ~files_to_link ~files in
-      List.combine module_names (None :: None :: to_link) @ [ start_module, None ] )
+      List.combine
+        (List.map ~f:(fun nm -> `Name nm) module_names)
+        (None :: None :: to_link)
+      @ [ `Name start_module, None ] )
   in
   let missing_primitives = compute_missing_primitives interfaces in
   if times () then Format.eprintf "    copy wasm files: %a@." Timer.print t;

diff --git a/compiler/lib-wasm/link.mli b/compiler/lib-wasm/link.mli
@@ -45,7 +45,7 @@ val add_info :
   -> unit
 
 val build_runtime_arguments :
-     link_spec:(string * int list option) list
+     link_spec:([ `Name of string | `File of string ] * int list option) list
   -> separate_compilation:bool
   -> missing_primitives:string list
   -> wasm_dir:string

diff --git a/runtime/wasm/runtime.js b/runtime/wasm/runtime.js
@@ -493,20 +493,26 @@
     return fetch(url);
   }
   const loadCode = isNode ? loadRelative : fetchRelative;
-  async function instantiateModule(code) {
-    return isNode
-      ? WebAssembly.instantiate(await code, imports, options)
-      : WebAssembly.instantiateStreaming(code, imports, options);
+  async function decodeCode(code) {
+    return fetch("data:application/wasm;base64," + code);
+  }
+  async function instantiateModule(code, stream) {
+    return stream
+      ? WebAssembly.instantiateStreaming(code, imports, options)
+      : WebAssembly.instantiate(await code, imports, options);
   }
   async function instantiateFromDir() {
     imports.OCaml = {};
     const deps = [];
     async function loadModule(module, isRuntime) {
       const sync = module[1].constructor !== Array;
       async function instantiate() {
-        const code = loadCode(src + "/" + module[0] + ".wasm");
+        const code = module[0]
+          ? loadCode(src + "/" + module[0] + ".wasm")
+          : decodeCode(module[2]);
+        const stream = !(isNode && module[0]);
         await Promise.all(sync ? deps : module[1].map((i) => deps[i]));
-        const wasmModule = await instantiateModule(code);
+        const wasmModule = await instantiateModule(code, stream);
         Object.assign(
           isRuntime ? imports.env : imports.OCaml,
           wasmModule.instance.exports,