How to fast the data transfer rate with WebSocket module 'ws' in Espruino?

Hi, @Gordon

You are right!

Follow your suggestion, I write the "C" native Mask library for websocket module on Espruino.
On Esp32 module, I test the library for some times.
Without Mask-lib, It takes about 64 seconds to transfer 23KB data to a websocket server.
By using Mask-lib, It takes about 1.68 second to do the same work.
Mask-lib can improve the performance of 'ws' about 40 times.

All codes are here:

jswrap_mask.h

[#include](https://forum.espruino.com/search/?q=%23include) "jsvar.h"

JsVar *jswrap_mask_4(JsVar *str);

jswrap_mask.c

[#include](https://forum.espruino.com/search/?q=%23include) "jswrap_mask.h"
[#include](https://forum.espruino.com/search/?q=%23include) "jsinteractive.h"
[#include](https://forum.espruino.com/search/?q=%23include) "jsvar.h"
[#include](https://forum.espruino.com/search/?q=%23include) "jshardware.h"

// Define the JavaScript class
/*JSON{
  "type" : "class",
  "class" : "M"
}*/

// Define the `jswrap_mask_4` to be a `staticmethod` on the `M` class
/*JSON{
  "type" : "staticmethod",
  "class" : "M",
  "name" : "mask4",
  "generate" : "jswrap_mask_4",
  "params" : [
    ["str","JsVar","An object containing a string"]
  ],
  "return" : ["JsVar","Returns a masked string object"]
}
Create a masked string, mask is 4 random chars.
*/
JsVar *jswrap_mask_4(JsVar *str) {
  if (!jsvIsString(str)) {
    return jsvNewFromEmptyString();
  }
  size_t msglength = jsvGetStringLength(str);
  char *masked = (char *)jsvMalloc(msglength+1);
  jsvGetString(str, masked, msglength+1);
  //jsvUnLock(str); // crash?
  char mask[4] = {0,0,0,0};
	//String masked = message; //jsvgetstring
	for (int i = 0; i < 4; i++)
	{
    char a = (char)jshGetRandomNumber();
    mask[i] = a;
	}
	for (int i = 0; i < msglength; i++){
    masked[i] ^= mask[i % 4];
  }
  JsVar *maskedVar = jsvNewFromEmptyString();
  jsvAppendStringBuf(maskedVar, mask, 4);
  jsvAppendStringBuf(maskedVar, masked, msglength);
  jsvFree(masked);
  return maskedVar;
}

Change in ws.js

/** Send message based on opcode type */
WebSocket.prototype.send = function (msg, opcode) {
  opcode = opcode === undefined ? 0x81 : opcode;
  var size = msg.length;
  if (msg.length>125) {
    size = 126;
  }
  this.socket.write(strChr(opcode, size + ( this.masking ? 128 : 0 )));

  if (size == 126) {
    // Need to write extra bytes for longer messages
    this.socket.write(strChr(msg.length >> 8));
    this.socket.write(strChr(msg.length));
  }

  if (this.masking) { // change is here
    this.socket.write(M.mask4(msg)); // using built-in lib instead of JS masking codes 
  } else {
    this.socket.write(msg);
  }
};

Espruino is flexible, Cool!