Only log when enabled to avoid unnecessary printing on stdout (#753)

src/logging.cpp

@@ -36,6 +36,8 @@ void SetLogBool(std::string_view name, bool value) {
     g_log.model_output_values = value;
   else if (name == "model_logits")
     g_log.model_logits = value;
+  else if (name == "ort_lib")
+    g_log.ort_lib = value;
   else
     throw JSON::unknown_value_error{};
 }

src/logging.h

@@ -42,6 +42,7 @@ struct LogItems {
   bool model_output_shapes{};  // Before the model runs there are only the output shapes, no values in them. Useful for pre Session::Run debugging
   bool model_output_values{};  // After the model runs the output tensor values can be displayed
   bool model_logits{};         // Same as model_output_values but only for the logits
+  bool ort_lib{};              // Log the onnxruntime library loading and api calls.
 };
 
 extern LogItems g_log;

src/models/env_utils.cpp

@@ -0,0 +1,57 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+#include "env_utils.h"
+
+#include <stdexcept>
+
+#if _MSC_VER
+#include <Windows.h>
+#endif
+
+namespace Generators {
+
+std::string GetEnvironmentVariable(const char* var_name) {
+#if _MSC_VER
+  // Why getenv() should be avoided on Windows:
+  // https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/getenv-wgetenv
+  // Instead use the Win32 API: GetEnvironmentVariableA()
+
+  // Max limit of an environment variable on Windows including the null-terminating character
+  constexpr DWORD kBufferSize = 32767;
+
+  // Create buffer to hold the result
+  std::string buffer(kBufferSize, '\0');
+
+  // The last argument is the size of the buffer pointed to by the lpBuffer parameter, including the null-terminating character, in characters.
+  // If the function succeeds, the return value is the number of characters stored in the buffer pointed to by lpBuffer, not including the terminating null character.
+  // Therefore, If the function succeeds, kBufferSize should be larger than char_count.
+  auto char_count = ::GetEnvironmentVariableA(var_name, buffer.data(), kBufferSize);
+
+  if (kBufferSize > char_count) {
+    buffer.resize(char_count);
+    return buffer;
+  }
+
+  return {};
+#else
+  const char* val = getenv(var_name);
+  return val == nullptr ? "" : std::string(val);
+#endif  // _MSC_VER
+}
+
+void GetEnvironmentVariable(const char* var_name, bool& value) {
+  std::string str_value = GetEnvironmentVariable(var_name);
+  if (str_value == "1" || str_value == "true") {
+    value = true;
+  } else if (str_value == "0" || str_value == "false") {
+    value = false;
+  } else if (!str_value.empty()) {
+    throw std::invalid_argument("Invalid value for environment variable " + std::string(var_name) + ": " + str_value +
+                                ". Expected '1' or 'true' for true, '0' or 'false' for false.");
+  }
+
+  // Otherwise, value will not be modified.
+}
+
+}  // namespace Generators

src/models/env_utils.h

@@ -0,0 +1,15 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+#include <string>
+
+namespace Generators {
+
+std::string GetEnvironmentVariable(const char* var_name);
+
+// This overload is used to get boolean environment variables.
+// If the environment variable is set to "1" or "true" (case-sensitive), value will be set to true.
+// Otherwise, value will not be modified.
+void GetEnvironmentVariable(const char* var_name, bool& value);
+
+}  // namespace Generators

src/models/onnxruntime_api.h

@@ -73,6 +73,7 @@ p_session_->Run(nullptr, input_names, inputs, std::size(inputs), output_names, o
 #include "onnxruntime_c_api.h"
 #include "../span.h"
 #include "../logging.h"
+#include "env_utils.h"
 
 #if defined(__ANDROID__)
 #include <android/log.h>
@@ -93,11 +94,14 @@ p_session_->Run(nullptr, input_names, inputs, std::size(inputs), output_names, o
 #define PATH_MAX (4096)
 #endif
 
-#define LOG_DEBUG(...) Generators::Log("debug", __VA_ARGS__)
-#define LOG_INFO(...) Generators::Log("info", __VA_ARGS__)
-#define LOG_WARN(...) Generators::Log("warning", __VA_ARGS__)
-#define LOG_ERROR(...) Generators::Log("error", __VA_ARGS__)
-#define LOG_FATAL(...) Generators::Log("fatal", __VA_ARGS__)
+#define LOG_WHEN_ENABLED(LOG_FUNC) \
+  if (Generators::g_log.enabled && Generators::g_log.ort_lib) LOG_FUNC
+
+#define LOG_DEBUG(...) LOG_WHEN_ENABLED(Generators::Log("debug", __VA_ARGS__))
+#define LOG_INFO(...) LOG_WHEN_ENABLED(Generators::Log("info", __VA_ARGS__))
+#define LOG_WARN(...) LOG_WHEN_ENABLED(Generators::Log("warning", __VA_ARGS__))
+#define LOG_ERROR(...) LOG_WHEN_ENABLED(Generators::Log("error", __VA_ARGS__))
+#define LOG_FATAL(...) LOG_WHEN_ENABLED(Generators::Log("fatal", __VA_ARGS__))
 
 #endif
 
@@ -175,6 +179,13 @@ inline void InitApi() {
     return;
   }
 
+  bool ort_lib = false;
+  Generators::GetEnvironmentVariable("ORTGENAI_LOG_ORT_LIB", ort_lib);
+  if (ort_lib) {
+    Generators::SetLogBool("enabled", true);
+    Generators::SetLogBool("ort_lib", true);
+  }
+
 #if defined(__linux__)
   // If the GenAI library links against the onnxruntime library, it will have a dependency on a specific
   // version of OrtGetApiBase.