SimpleStreamingPostTest.ino

#include <Arduino.h>

#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>

#include <ESP8266HTTPClient.h>

#define USE_SERIAL Serial
// Firebase host.
#define FBASE ""

ESP8266WiFiMulti WiFiMulti;

static const char kFirebaseFingerprint[] =
      "7A 54 06 9B DC 7A 25 B3 86 8D 66 53 48 2C 0B 96 42 C7 B3 0A";


void setup() {

    USE_SERIAL.begin(9600);
  USE_SERIAL.printf("Mem at start %d", ESP.getFreeHeap());

    USE_SERIAL.println();
    USE_SERIAL.println();
    USE_SERIAL.println();

    for(uint8_t t = 0; t > 0; t--) {
        USE_SERIAL.printf("[SETUP] WAIT %d...\n", t);
        USE_SERIAL.flush();
        delay(1000);
    }

    WiFiMulti.addAP("GoogleGuest", "");
}

void post() {  
  USE_SERIAL.println("POSTING ...");
  USE_SERIAL.printf("Mem before posting %d", ESP.getFreeHeap());
  HTTPClient http;
  
  http.begin(FBASE, 443, "/post.json", true, kFirebaseFingerprint);
  
  int httpCode = http.sendRequest("POST","1");  
  USE_SERIAL.printf("POST ... code: %d\n", httpCode);
  if (httpCode < 0) {
    USE_SERIAL.printf("POST failed, error: %s\n", http.errorToString(httpCode).c_str());
  }
  http.end();
}

void loop() {
    // wait for WiFi connection
    if((WiFiMulti.run() == WL_CONNECTED)) {
        HTTPClient http;

        USE_SERIAL.print("[HTTP] begin...\n");

        // configure server and url
        http.begin(FBASE, 443, "/", true, kFirebaseFingerprint);

        // needed for fbase streaming
        http.addHeader("Accept", "text/event-stream");
        const char* headers_to_collect[] = {"Location"};
        http.collectHeaders(headers_to_collect, 1);

        USE_SERIAL.print("[HTTP] GET...\n");
        
        USE_SERIAL.printf("Mem before stream %d\n", ESP.getFreeHeap());        
        int httpCode = http.sendRequest("GET","");
        USE_SERIAL.printf("Mem after stream %d\n", ESP.getFreeHeap());
        USE_SERIAL.printf("[HTTP] GET... code: %d\n", httpCode);
        
        while(httpCode == 307) {
          USE_SERIAL.print("Redirect:");
          USE_SERIAL.println(http.header("Location"));
          http.begin(http.header("Location"), kFirebaseFingerprint);
          httpCode = http.GET();
        }
        int itr = 1;
        if(httpCode > 0) {
            // HTTP header has been send and Server response header has been handled
            //USE_SERIAL.printf("[HTTP] GET... code: %d\n", httpCode);

            // file found at server
            if(httpCode == HTTP_CODE_OK) {

                // get lenght of document (is -1 when Server sends no Content-Length header)
                int len = http.getSize();

                // create buffer for read
                uint8_t buff[128] = { 0 };

                // get tcp stream
                WiFiClient * stream = http.getStreamPtr();

                // read all data from server
                while(http.connected() && (len > 0 || len == -1)) {
                    // get available data size
                    size_t size = stream->available();

                    if(size) {
                        // read up to 128 byte
                        int c = stream->readBytes(buff, ((size > sizeof(buff)) ? sizeof(buff) : size));

                        // write it to Serial
                        //USE_SERIAL.write(buff, c);
                        USE_SERIAL.println(c);

                        if(len > 0) {
                            len -= c;
                        }
                    }
                    delay(250);
                    if (itr++ % 30 == 0) {
                      post();
                    }
                }

                USE_SERIAL.println();
                USE_SERIAL.print("[HTTP] connection closed or file end.\n");

            }
        } else {
            USE_SERIAL.printf("[HTTP] GET... failed, error: %s\n", http.errorToString(httpCode).c_str());
        }

        http.end();
    }

    delay(10000);
}