Update debugSend / debugSend_P (#1788)

- chain debugSend_P into basic _debugSend instead of duplicating code, pass va_list between them
- check if new[] call was successful
- when possible, use stack buffer and fallback to heap buffer only when it is more that 64 chars

code/espurna/config/prototypes.h

@@ -41,8 +41,10 @@ void systemStabilityCounter(uint8_t);
 // -----------------------------------------------------------------------------
 // Debug
 // -----------------------------------------------------------------------------
-void debugSend(const char * format, ...);
-void debugSend_P(PGM_P format, ...);
+
+#include "../libs/DebugSend.h"
+
+void debugSendImpl(const char*);
 extern "C" {
      void custom_crash_callback(struct rst_info*, uint32_t, uint32_t);
 }

code/espurna/debug.ino

@@ -8,6 +8,8 @@ Copyright (C) 2016-2019 by Xose Pérez <xose dot perez at gmail dot com>
 
 #if DEBUG_SUPPORT
 
+#include "libs/DebugSend.h"
+
 #if DEBUG_UDP_SUPPORT
 #include <WiFiUdp.h>
 WiFiUDP _udp_debug;
@@ -36,7 +38,7 @@ char _udp_syslog_header[40] = {0};
     }
 #endif
 
-void _debugSend(const char * message) {
+void debugSendImpl(const char * message) {
 
     const size_t msg_len = strlen(message);
 
@@ -85,42 +87,6 @@ void _debugSend(const char * message) {
 
 }
 
-// -----------------------------------------------------------------------------
-
-void debugSend(const char * format, ...) {
-
-    va_list args;
-    va_start(args, format);
-    char test[1];
-    int len = ets_vsnprintf(test, 1, format, args) + 1;
-    char * buffer = new char[len];
-    ets_vsnprintf(buffer, len, format, args);
-    va_end(args);
-
-    _debugSend(buffer);
-
-    delete[] buffer;
-
-}
-
-void debugSend_P(PGM_P format_P, ...) {
-
-    char format[strlen_P(format_P)+1];
-    memcpy_P(format, format_P, sizeof(format));
-
-    va_list args;
-    va_start(args, format_P);
-    char test[1];
-    int len = ets_vsnprintf(test, 1, format, args) + 1;
-    char * buffer = new char[len];
-    ets_vsnprintf(buffer, len, format, args);
-    va_end(args);
-
-    _debugSend(buffer);
-
-    delete[] buffer;
-
-}
 
 #if DEBUG_WEB_SUPPORT
 

code/espurna/libs/DebugSend.h

@@ -0,0 +1,47 @@
+// -----------------------------------------------------------------------------
+// printf-like debug methods
+// -----------------------------------------------------------------------------
+
+#pragma once
+
+void debugSendImpl(const char*);
+
+void _debugSend(const char * format, va_list args) {
+
+    char temp[64];
+    int len = ets_vsnprintf(temp, sizeof(temp), format, args);
+    if (len < 64) { debugSendImpl(temp); return; }
+
+    auto buffer = new char[len + 1];
+    ets_vsnprintf(buffer, len + 1, format, args);
+
+    debugSendImpl(buffer);
+
+    delete[] buffer;
+
+}
+
+void debugSend(const char* format, ...) {
+
+    va_list args;
+    va_start(args, format);
+
+    _debugSend(format, args);
+
+    va_end(args);
+
+}
+
+void debugSend_P(PGM_P format_P, ...) {
+
+    char format[strlen_P(format_P) + 1];
+    memcpy_P(format, format_P, sizeof(format));
+
+    va_list args;
+    va_start(args, format_P);
+
+    _debugSend(format, args);
+
+    va_end(args);
+
+}