feat(http): Enhance response buffer management with pre-allocation and capacity tracking

main/network/http_handler.cpp

@@ -3,6 +3,7 @@
 #include "esp_log.h"
 #include "string.h"
 #include <cstring>
+#include <algorithm>
 
 esp_err_t http_event_handler(esp_http_client_event_t *evt) {
   HttpHandler* handler = static_cast<HttpHandler*>(evt->user_data);
@@ -10,7 +11,14 @@ esp_err_t http_event_handler(esp_http_client_event_t *evt) {
   switch (evt->event_id) {
     case HTTP_EVENT_ON_DATA:
       if (handler && evt->data_len > 0) {
-        char* new_buffer = new char[handler->response_size + evt->data_len + 1];
+        // Pre-allocate with some extra capacity to reduce reallocations
+        size_t new_capacity = handler->response_size + evt->data_len + 1;
+        // Double capacity if we already have data, to amortize reallocation cost
+        if (handler->response_size > 0) {
+          new_capacity = std::max(new_capacity, (handler->response_size * 2) + 1);
+          new_capacity = std::min(new_capacity, (size_t)65536); // Cap at 64KB
+        }
+        char* new_buffer = new char[new_capacity];
         if (handler->response_buffer && handler->response_size > 0) {
           memcpy(new_buffer, handler->response_buffer, handler->response_size);
           delete[] handler->response_buffer;
@@ -19,6 +27,7 @@ esp_err_t http_event_handler(esp_http_client_event_t *evt) {
         handler->response_size += evt->data_len;
         new_buffer[handler->response_size] = '\0';
         handler->response_buffer = new_buffer;
+        handler->response_capacity = new_capacity;
       }
       break;
     default:

main/network/http_handler.h

@@ -55,4 +55,5 @@ private:
   WifiHandler* wifiHandler;
   char* response_buffer;
   size_t response_size;
+  size_t response_capacity = 0;
 };