c++ - Buffering Bytes - Node.js Addon -

i want receive wav stream node.js (in add-on). implemented this:

readablestream.on('data', function(chunk) {     var obj1 = addon.buffering(chunk);//my addon }); 

but want buffer information, , create copy of original wav. far can't populate new file bytes.

void buffering(const functioncallbackinfo<v8::value>& args) {   isolate* isolate = isolate::getcurrent();   handlescope scope(isolate);    local<object> bufferobj = args[0]->toobject();   char *buf = node::buffer::data(bufferobj);   if (i == 0){ fp = fopen("copy.wav", "wb"); i++;}    fwrite(buf, 1, sizeof(buf), fp);   fflush(fp);   if (i == 3){ fclose(fp); }   i++;    local<string> devolve = string::newfromutf8(isolate, "buffering_success");//c++--->js   args.getreturnvalue().set(devolve); } 

i don't understand why, sizeof(buf) small. think because of that.

with precious tip of @mat:

nodejs:

readablestream.on('data', function(chunk) {   console.log(chunk);   var size = chunk.length;//<---size of chunk, matt   console.log(size);   var obj1 = addon.buffering(chunk,size);   console.log('pass chunk'); }); 

addon:

void buffering(const functioncallbackinfo<v8::value>& args) {   isolate* isolate = isolate::getcurrent();   handlescope scope(isolate);   int size = args[1]->numbervalue();    local<object> bufferobj = args[0]->toobject();   char *buf = node::buffer::data(bufferobj);   if (i == 0){ fp = fopen("copy.wav", "wb"); i++;}    fwrite(buf, 1, size, fp);   fflush(fp);   if (i == 3){ fclose(fp); }   i++;   local<string> devolve = string::newfromutf8(isolate,"buffering_sucess");//c++--->js   args.getreturnvalue().set(devolve); } 

i remove iterator, "generic" solution. here because number of iterations occur.