measureMsgPack()
Description
measureMsgPack() computes the length of the MessagePack document that serializeMsgPack() produces.
This function is handy to fill the Content-Length header in an HTTP message.
Signature
size_t measureMsgPack(TSource src);
Arguments
src: the value to serialize. It can be aJsonDocument,JsonArray,JsonArrayConst,JsonObject,JsonObjectConst,JsonVariant, orJsonVariantConst.
Return value
The number of bytes that serializeMsgPack() produces.
Example
// Send headers
client.println("Content-Type: application/msgpack");
client.print("Content-Length: ");
client.println(measureMsgPack(doc));
// Terminate headers
client.println();
// Send body
serializeMsgPack(doc, client);