i have the following code , what will be the data looking like in dataBuffer: 
#include <Wire.h>
#include <esp_now.h>
#include <WiFi.h>
#include <esp_wifi.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define BUFFER_SIZE (SCREEN_WIDTH * SCREEN_HEIGHT / 8)

#define I2C_DEV_ADDR 0x3C
#define CHANNEL 1
//#define MAX_POSSIBLE_DATA_SIZE 256   // This should be the largest data size you ever expect


uint8_t dataBuffer[BUFFER_SIZE];
unsigned int bufferHead = 0;
unsigned int bufferTail = 0;
unsigned int currentDataSize = 0;  // Current size of data received

//uint8_t dataArray[MAX_POSSIBLE_DATA_SIZE];
//uint8_t currentDataSize = 0;  // Current size of data received

esp_now_peer_info_t slave;
bool isSlavePaired = false;  // Track if slave is currently paired

void onReceive(int len) {
  currentDataSize = len;
  for (int i = 0; i < len; i++) {
    addToBuffer(Wire.read());
  }
  sendData();
}

void addToBuffer(uint8_t data) {
  bufferHead = (bufferHead + 1) % BUFFER_SIZE;  // Wrap around if buffer is full
  dataBuffer[bufferHead] = data;
  if (bufferHead == bufferTail) {
    bufferTail = (bufferTail + 1) % BUFFER_SIZE;  // Remove oldest data when buffer is full
  }
}


void sendData() {
  const uint8_t* peer_addr = slave.peer_addr;
  esp_err_t result = esp_now_send(peer_addr, dataBuffer + bufferTail, currentDataSize);

  if (result == ESP_OK) {
    Serial.println("Success");
  } else {
    Serial.println("Send Error");
  }
}

void InitESPNow() {
    WiFi.disconnect();

    for(int retries = 0; retries < 3; retries++) {
        if (esp_now_init() == ESP_OK) {
            Serial.println("ESPNow Init Success");
            break;
        }
        else {
            if(retries == 2) {
                Serial.println("ESPNow Init Failed 3 times, restarting...");
                delay(1000);
                ESP.restart();
            }
            delay(500);
        }
    }
}

bool manageSlave() {
    if (slave.channel == CHANNEL) {
        bool exists = esp_now_is_peer_exist(slave.peer_addr);
        if (exists) {
            Serial.println("Already Paired");
            return true;
        } else {
            esp_err_t addStatus = esp_now_add_peer(&slave);
            if (addStatus == ESP_OK) {
                Serial.println("Pair success");
                return true;
            } else {
                Serial.println("Pairing Error");
            }
        }
    } else {
        Serial.println("No Slave found to process");
    }
    return false;
}

void OnDataSent(const uint8_t* mac_addr, esp_now_send_status_t status) {
  char macStr[18];
  snprintf(macStr, sizeof(macStr), "%02x:%02x:%02x:%02x:%02x:%02x",
    mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
  Serial.print("Last Packet Sent to: ");
  Serial.println(macStr);
  Serial.print("Last Packet Send Status: ");
  Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
}

void setup() {
  Serial.begin(115200);
  Serial.setDebugOutput(true);

  Wire.onReceive(onReceive);
  Wire.begin((uint8_t)I2C_DEV_ADDR);

  WiFi.mode(WIFI_STA);
  esp_wifi_set_channel(CHANNEL, WIFI_SECOND_CHAN_NONE);

  Serial.println("ESPNow/Basic/Master Example");
  Serial.print("STA MAC: ");
  Serial.println(WiFi.macAddress());
  Serial.print("STA CHANNEL ");
  Serial.println(WiFi.channel());

    InitESPNow();
    esp_now_register_send_cb(OnDataSent);
}

void ScanForSlave() {
    int16_t scanResults = WiFi.scanNetworks();
    memset(&slave, 0, sizeof(slave));
    
    if (scanResults == 0) {
        Serial.println("No WiFi devices in AP Mode found");
    } else {
        for (int i = 0; i < scanResults; ++i) {
            String SSID = WiFi.SSID(i);
            String BSSIDstr = WiFi.BSSIDstr(i);
            
            if (SSID.indexOf("Slave") == 0) {
                int mac[6];
                if (6 == sscanf(BSSIDstr.c_str(), "%x:%x:%x:%x:%x:%x", &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5])) {
                    for (int ii = 0; ii < 6; ++ii) {
                        slave.peer_addr[ii] = (uint8_t)mac[ii];
                    }
                }
                
                slave.channel = CHANNEL;
                slave.encrypt = 0;
                
                break;
            }
        }
    }
    
    WiFi.scanDelete();
}

void loop() {
    if(!isSlavePaired) {
        ScanForSlave();
        isSlavePaired = manageSlave();
        if (!isSlavePaired) {
            Serial.println("Slave pair failed!");
            delay(5000);  // Wait for 5 seconds before trying again
        }
    }
}