low level js bindings

client/main.js

@@ -5,8 +5,55 @@ function allocate_str(str) {
   return allocate(intArrayFromString(str), ALLOC_NORMAL);
 }
 
-async function main() {
+//low level interface with c code
+function perform_request(url, js_data_callback, js_end_callback) {
+  let end_callback_ptr;
+  let data_callback_ptr;
+  let url_ptr = allocate_str(url);
 
+  let end_callback = () => {
+    Module.removeFunction(end_callback_ptr);
+    Module.removeFunction(data_callback_ptr);
+    _free(url_ptr);
+    
+    js_end_callback();
+  }
+
+  let data_callback = (chunk_ptr, chunk_size) => {
+    let data = Module.HEAPU8.subarray(chunk_ptr, chunk_ptr + chunk_size);
+    let chunk = new Uint8Array(data);
+    js_data_callback(chunk);
+  }
+
+  end_callback_ptr = Module.addFunction(end_callback, "v");
+  data_callback_ptr = Module.addFunction(data_callback, "vii");
+  _perform_request(url_ptr, data_callback_ptr, end_callback_ptr);
+}
+
+function merge_arrays(arrays) {
+  let total_len = arrays.reduce((acc, val) => acc + val.length, 0);
+  let new_array = new Uint8Array(total_len);
+  let offset = 0;
+  for (let array of arrays) {
+    new_array.set(array, offset);
+    offset += array.length;
+  }
+  return new_array;
+}
+
+async function main() {
+  let chunks = [];
+  perform_request("https://ading.dev", (new_data) => {
+    chunks.push(new_data);
+  }, () => {
+    for (let chunk of chunks) {
+      console.log(chunk);
+    }
+
+    let response_data = merge_arrays(chunks);
+    let response_str = new TextDecoder().decode(response_data);
+    console.log(response_str);
+  });
 }
 
 window.onload = () => {