request->send(200, textPlainStr, jsonChartDataCharStr); - Without using String Class - to save heap

README.md

@@ -12,6 +12,21 @@
 ---
 ---
 
+
+*****
+Added a destructive C string interface to send
+
+if called with 
+request->send(200, textPlainStr, ArduinoStr);  // no difference
+request->send(200, textPlainStr, cStr);        // no differfence
+request->send(200, textPlainStr, cStr, false); // this will have to be a cString with enough space to fit the header, it will be memmoved as required, header added, and sent, without creating any large arduino Strings that consume heap
+
+in my application max heap size went from 375k to 66k (which is the lowest possible wit the variables and otehr data I am using)
+
+Seems to work, let me know what you think
+
+
+
 ## Table of contents
 
 * [Table of contents](#table-of-contents)

examples/Ethernet/Async_AdvancedWebServer_MemoryIssues_Send C String/Async_AdvancedWebServer_MemoryIssues_Send C String.ino

@@ -0,0 +1,321 @@
+/****************************************************************************************************************************
+  Async_AdvancedWebServer_MemoryIssues_Send_CString.ino - Dead simple AsyncWebServer for STM32 LAN8720 or built-in LAN8742A Ethernet
+
+  For Portenta_H7 (STM32H7) with Vision-Shield Ethernet
+
+  Portenta_H7_AsyncWebServer is a library for the Portenta_H7 with with Vision-Shield Ethernet
+
+  Based on and modified from ESPAsyncWebServer (https://github.com/me-no-dev/ESPAsyncWebServer)
+  Built by Khoi Hoang https://github.com/khoih-prog/Portenta_H7_AsyncWebServer
+  Licensed under GPLv3 license
+
+  Copyright (c) 2015, Majenko Technologies
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without modification,
+  are permitted provided that the following conditions are met:
+
+  Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+  Redistributions in binary form must reproduce the above copyright notice, this
+  list of conditions and the following disclaimer in the documentation and/or
+  other materials provided with the distribution.
+
+  Neither the name of Majenko Technologies nor the names of its
+  contributors may be used to endorse or promote products derived from
+  this software without specific prior written permission.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+  ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************************************************************/
+
+#if !( defined(ARDUINO_PORTENTA_H7_M7) || defined(ARDUINO_PORTENTA_H7_M4) )
+  #error For Portenta_H7 only
+#endif
+
+#define _PORTENTA_H7_ATCP_LOGLEVEL_     1
+#define _PORTENTA_H7_AWS_LOGLEVEL_      1
+
+#define USE_ETHERNET_PORTENTA_H7        true
+
+#include <Portenta_Ethernet.h>
+#include <Ethernet.h>
+#warning Using Portenta_Ethernet lib for Portenta_H7.
+
+#include <Portenta_H7_AsyncWebServer.h>
+
+#include "SDRAM.h"
+
+// Enter a MAC address and IP address for your controller below.
+#define NUMBER_OF_MAC      20
+
+byte mac[][NUMBER_OF_MAC] =
+{
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x01 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x02 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x03 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x04 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x05 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x06 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x07 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x08 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x09 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0A },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0B },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0C },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0D },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0E },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x0F },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x10 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x11 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x12 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x13 },
+  { 0xDE, 0xAD, 0xBE, 0xEF, 0x32, 0x14 },
+};
+// Select the IP address according to your local network
+IPAddress ip(192, 168, 2, 232);
+
+AsyncWebServer    server(80);
+
+int reqCount = 0;                // number of requests received
+
+#define LED_OFF             HIGH
+#define LED_ON              LOW
+
+
+#define BUFFER_SIZE         768 // a little larger in case required for header shift (destructive send)
+char temp[BUFFER_SIZE];
+
+void handleRoot(AsyncWebServerRequest *request)
+{
+  digitalWrite(LED_BUILTIN, LED_ON);
+
+  int sec = millis() / 1000;
+  int min = sec / 60;
+  int hr = min / 60;
+  int day = hr / 24;
+
+  snprintf(temp, BUFFER_SIZE - 1,
+           "<html>\
+<head>\
+<meta http-equiv='refresh' content='5'/>\
+<title>AsyncWebServer-%s</title>\
+<style>\
+body { background-color: #cccccc; font-family: Arial, Helvetica, Sans-Serif; Color: #000088; }\
+</style>\
+</head>\
+<body>\
+<h2>AsyncWebServer_Portenta_H7!</h2>\
+<h3>running on %s</h3>\
+<p>Uptime: %d d %02d:%02d:%02d</p>\
+<img src=\"/test.svg\" />\
+</body>\
+</html>", BOARD_NAME, BOARD_NAME, day, hr % 24, min % 60, sec % 60);
+
+  request->send(200, "text/html", temp, false);
+
+  digitalWrite(LED_BUILTIN, LED_OFF);
+}
+
+void handleNotFound(AsyncWebServerRequest *request)
+{
+  digitalWrite(LED_BUILTIN, LED_ON);
+  String message = "File Not Found\n\n";
+
+  message += "URI: ";
+  message += request->url();
+  message += "\nMethod: ";
+  message += (request->method() == HTTP_GET) ? "GET" : "POST";
+  message += "\nArguments: ";
+  message += request->args();
+  message += "\n";
+
+  for (uint8_t i = 0; i < request->args(); i++)
+  {
+    message += " " + request->argName(i) + ": " + request->arg(i) + "\n";
+  }
+
+  request->send(404, "text/plain", message);
+  digitalWrite(LED_BUILTIN, LED_OFF);
+}
+
+void PrintHeapData(String hIn){
+  mbed_stats_heap_t heap_stats;
+
+  Serial.print("HEAP DATA - ");
+  Serial.print(hIn);
+
+  mbed_stats_heap_get(&heap_stats);
+  Serial.print("  Cur heap: ");
+  Serial.print(heap_stats.current_size);
+  Serial.print("  Res Size: ");
+  Serial.print(heap_stats.reserved_size);
+  Serial.print("  Max heap: ");
+  Serial.println(heap_stats.max_size);
+}
+
+
+char *cStr;
+
+
+void drawGraph(AsyncWebServerRequest *request) 
+{
+  char temp[80];
+
+  cStr[0] = '\0';
+
+  strcat(cStr, "<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" width=\"1810\" height=\"150\">\n");
+  strcat(cStr, "<rect width=\"1810\" height=\"150\" fill=\"rgb(250, 230, 210)\" stroke-width=\"2\" stroke=\"rgb(0, 0, 0)\" />\n");
+  strcat(cStr, "<g stroke=\"blue\">\n");
+  int y = rand() % 130;
+
+  for (int x = 10; x < 5000; x += 10)
+  {
+    int y2 = rand() % 130;
+    sprintf(temp, "<line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke-width=\"2\" />\n", x, 140 - y, x + 10, 140 - y2);
+    strcat(cStr, temp);
+    y = y2;
+  }
+
+  strcat(cStr, "</g>\n</svg>\n");
+
+  PrintHeapData("Pre Send");
+
+  Serial.print("Out String Length=");
+  Serial.println(strlen(cStr));
+
+  request->send(200, "image/svg+xml", cStr, false);
+
+  PrintHeapData("Post Send");
+}
+
+
+void setup()
+{
+  pinMode(LED_BUILTIN, OUTPUT);
+  digitalWrite(LED_BUILTIN, LED_OFF);
+
+  Serial.begin(115200);
+  while (!Serial && millis() < 5000);
+
+  delay(200);
+
+  Serial.print("\nStart Async_AdvancedWebServer_MemoryIssues_Send_CString on "); Serial.print(BOARD_NAME);
+  Serial.print(" with "); Serial.println(SHIELD_TYPE);
+  Serial.println(PORTENTA_H7_ASYNC_TCP_VERSION);
+  Serial.println(PORTENTA_H7_ASYNC_WEBSERVER_VERSION);
+
+  SDRAM.begin();
+
+  cStr = (char *)SDRAM.malloc(100000);    // make a little larger than required
+
+  if (cStr == NULL) {
+    Serial.println("Unable top Allocate RAM");
+    for(;;);
+  }
+
+  ///////////////////////////////////
+
+  // start the ethernet connection and the server
+  // Use random mac
+  uint16_t index = millis() % NUMBER_OF_MAC;
+
+  // Use Static IP
+  //Ethernet.begin(mac[index], ip);
+  // Use DHCP dynamic IP and random mac
+  Ethernet.begin(mac[index]);
+
+  if (Ethernet.hardwareStatus() == EthernetNoHardware)
+  {
+    Serial.println("No Ethernet found. Stay here forever");
+
+    while (true)
+    {
+      delay(1); // do nothing, no point running without Ethernet hardware
+    }
+  }
+
+  if (Ethernet.linkStatus() == LinkOFF)
+  {
+    Serial.println("Not connected Ethernet cable");
+  }
+
+  Serial.print(F("Using mac index = "));
+  Serial.println(index);
+
+  Serial.print(F("Connected! IP address: "));
+  Serial.println(Ethernet.localIP());
+
+  ///////////////////////////////////
+
+  server.on("/", HTTP_GET, [](AsyncWebServerRequest * request)
+  {
+    handleRoot(request);
+  });
+
+  server.on("/test.svg", HTTP_GET, [](AsyncWebServerRequest * request)
+  {
+    drawGraph(request);
+  });
+
+  server.on("/inline", [](AsyncWebServerRequest * request)
+  {
+    request->send(200, "text/plain", "This works as well");
+  });
+
+  server.onNotFound(handleNotFound);
+
+  server.begin();
+
+  Serial.print(F("HTTP EthernetWebServer is @ IP : "));
+  Serial.println(Ethernet.localIP());
+
+
+  PrintHeapData("Pre Create Arduino String");
+
+}
+
+void heartBeatPrint()
+{
+  static int num = 1;
+
+  Serial.print(F("."));
+
+  if (num == 80)
+  {
+    Serial.println();
+    num = 1;
+  }
+  else if (num++ % 10 == 0)
+  {
+    Serial.print(F(" "));
+  }
+}
+
+void check_status()
+{
+  static unsigned long checkstatus_timeout = 0;
+
+#define STATUS_CHECK_INTERVAL     10000L
+
+  // Send status report every STATUS_REPORT_INTERVAL (60) seconds: we don't need to send updates frequently if there is no status change.
+  if ((millis() > checkstatus_timeout) || (checkstatus_timeout == 0))
+  {
+    heartBeatPrint();
+    checkstatus_timeout = millis() + STATUS_CHECK_INTERVAL;
+  }
+}
+
+void loop()
+{
+  check_status();
+}