esp_rmaker_ota: Provide option to modify buff size in menuconfig

Author: shixinke-orion

components/esp_rainmaker/Kconfig.projbuild

@@ -135,6 +135,15 @@ menu "ESP RainMaker Config"
             help
                 This allows you to skip the project name check.
 
+        config ESP_RMAKER_OTA_HTTP_RX_BUFFER_SIZE
+            int "OTA HTTP receive buffer size"
+            default 1024
+            range 512 LWIP_TCP_WND_DEFAULT
+            help
+                Increasing this value beyond the default would speed up the OTA download process. 
+                However, please ensure that your application has enough memory headroom to allow this, 
+                else, the OTA may fail.
+                
     endmenu
 
     menu "ESP RainMaker Scheduling"

components/esp_rainmaker/src/ota/esp_rmaker_ota.c

@@ -28,7 +28,8 @@
 static const char *TAG = "esp_rmaker_ota";
 
 #define OTA_REBOOT_TIMER_SEC    10
-#define DEF_HTTP_BUFFER_SIZE    1024
+#define DEF_HTTP_TX_BUFFER_SIZE    1024
+#define DEF_HTTP_RX_BUFFER_SIZE    CONFIG_ESP_RMAKER_OTA_HTTP_RX_BUFFER_SIZE
 
 extern const char esp_rmaker_ota_def_cert[] asm("_binary_rmaker_ota_server_crt_start");
 const char *ESP_RMAKER_OTA_DEFAULT_SERVER_CERT = esp_rmaker_ota_def_cert;
@@ -129,7 +130,7 @@ static esp_err_t esp_rmaker_ota_default_cb(esp_rmaker_ota_handle_t ota_handle, e
     if (!ota_data->url) {
         return ESP_FAIL;
     }
-    int buffer_size_tx = DEF_HTTP_BUFFER_SIZE;
+    int buffer_size_tx = DEF_HTTP_TX_BUFFER_SIZE;
     /* In case received url is longer, we will increase the tx buffer size
      * to accomodate the longer url and other headers.
      */
@@ -141,7 +142,7 @@ static esp_err_t esp_rmaker_ota_default_cb(esp_rmaker_ota_handle_t ota_handle, e
         .url = ota_data->url,
         .cert_pem = ota_data->server_cert,
         .timeout_ms = 5000,
-        .buffer_size = DEF_HTTP_BUFFER_SIZE,
+        .buffer_size = DEF_HTTP_RX_BUFFER_SIZE,
         .buffer_size_tx = buffer_size_tx
     };
 #ifdef CONFIG_ESP_RMAKER_SKIP_COMMON_NAME_CHECK