React Native

Receive a 4-byte Length Prefix from a Socket

Demonstrates Socket.ReceiveCount, which reads a four-byte length prefix as a signed 32-bit integer. A return value of -1 indicates failure.

Background. Reading the length prefix first tells the application exactly how many bytes to read for the message body, which is a reliable way to know when a full message has arrived.

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React Native

import { Socket } from '@chilkat/react-native'

async function chilkatExample() {
  const socket = new Socket();

  // Connect to the server using TLS.
  const bTls = true;
  const maxWaitMs = 5000;
  try {
    await socket.connectAsync('example.com', 5000, bTls, maxWaitMs);
  } catch {
    console.log(socket.lastErrorText);
    return;
  }

  // Read a four-byte length prefix as a signed 32-bit integer (network byte order by default).  A
  // return value of -1 indicates failure.
  const messageLength = await socket.receiveCountAsync();
  if (messageLength < 0) {
    console.log(socket.lastErrorText);
    return;
  }

  console.log(`The peer will send ${messageLength} bytes.`);
}