Use stack buffer when tokenizing smaller buffers (#26336)

* Only allocate logging buffer when required buffer size is larger than 32 bytes

* Fix CI issue

* Fix compiler warning

src/lib/support/logging/CHIPLogging.cpp

@@ -62,19 +62,41 @@ void HandleTokenizedLog(uint32_t levels, pw_tokenizer_Token token, pw_tokenizer_
  pw_tokenizer_EncodeArgs(types, args, encoded_message + sizeof(token), sizeof(encoded_message) - sizeof(token));
  va_end(args);
 
- uint8_t log_category = levels >> 8 & 0xFF;
- uint8_t log_module = levels & 0xFF;
- char * buffer = (char *) chip::Platform::MemoryAlloc(2 * encoded_size + 1);
+ uint8_t log_category  = levels >> 8 & 0xFF;
+ uint8_t log_module  = levels & 0xFF;
+ char * logging_buffer = nullptr;
 
- if (buffer)
+ // To reduce the number of alloc/free that is happening we will use a stack
+ // buffer when buffer required to log is small.
+ char stack_buffer[32];
+ char * allocated_buffer = nullptr;
+ size_t required_buffer_size = 2 * encoded_size + 1;
+
+ if (required_buffer_size > sizeof(stack_buffer))
  {
- for (int i = 0; i < encoded_size; i++)
+ allocated_buffer = (char *) chip::Platform::MemoryAlloc(required_buffer_size);
+ if (allocated_buffer)
  {
- sprintf(buffer + 2 * i, "%02x", encoded_message[i]);
+ logging_buffer = allocated_buffer;
  }
- buffer[2 * encoded_size] = '\0';
- Log(log_module, log_category, "%s", buffer);
- chip::Platform::MemoryFree(buffer);
+ }
+ else
+ {
+ logging_buffer = stack_buffer;
+ }
+
+ if (logging_buffer)
+ {
+ for (size_t i = 0; i < encoded_size; i++)
+ {
+ sprintf(logging_buffer + 2 * i, "%02x", encoded_message[i]);
+ }
+ logging_buffer[2 * encoded_size] = '\0';
+ Log(log_module, log_category, "%s", logging_buffer);
+ }
+ if (allocated_buffer)
+ {
+ chip::Platform::MemoryFree(allocated_buffer);
  }
 }