logging.h

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/**************************************************************************/ /**
 * @brief API wrapper for optional compilation of logging support.
 * @file
 *
 * To enable logging support, include
 * [Google glog](https://github.com/google/glog) in your project, and define
 * the following macro:
 * ```cpp
 * #define P1_HAVE_GLOG 1
 * ```
 *
 * This is typically done during compilation by specifying the
 * `-DP1_HAVE_GLOG=1` command-line argument to the compiler.
 ******************************************************************************/
 
#pragma once
 
// Use Google Logging Library (glog).
#if P1_HAVE_GLOG && !P1_NO_LOGGING
#  include <glog/logging.h>
 
// For internal use only.
#elif P1_HAVE_PORTABLE_LOGGING && !P1_NO_LOGGING
#  include "point_one/common/portability/logging.h"
 
// Disable logging support at compile time.
#else // Logging disabled
 
#  include <ostream>
 
#  if !P1_NO_LOGGING
#    undef P1_NO_LOGGING
#    define P1_NO_LOGGING 1
#  endif // !P1_NO_LOGGING
 
namespace point_one {
namespace fusion_engine {
namespace common {
 
class NullStream : public std::ostream {
 public:
  NullStream() : std::ostream(nullptr) {}
};
 
template <class T>
inline NullStream& operator<<(NullStream& stream, const T&) {
  return stream;
}
 
class NullMessage {
 public:
  static NullStream stream_;
  static NullMessage instance_;
 
  NullStream& stream() { return stream_; }
};
 
} // namespace common
} // namespace fusion_engine
} // namespace point_one
 
#  define P1_NULL_STREAM point_one::fusion_engine::common::NullMessage::stream_
#  define P1_NULL_MESSAGE \
    point_one::fusion_engine::common::NullMessage::instance_
 
#  define COMPACT_GOOGLE_LOG_INFO P1_NULL_MESSAGE
#  define COMPACT_GOOGLE_LOG_WARNING P1_NULL_MESSAGE
#  define COMPACT_GOOGLE_LOG_ERROR P1_NULL_MESSAGE
#  define COMPACT_GOOGLE_LOG_FATAL P1_NULL_MESSAGE
 
#  define LOG(severity) COMPACT_GOOGLE_LOG_##severity.stream()
#  define LOG_IF(severity, condition) COMPACT_GOOGLE_LOG_##severity.stream()
#  define LOG_EVERY_N(verboselevel, n) COMPACT_GOOGLE_LOG_##severity.stream()
#  define LOG_IF_EVERY_N(verboselevel, condition, n) \
    COMPACT_GOOGLE_LOG_##severity.stream()
 
#  define VLOG_IS_ON(verboselevel) false
#  define COMPACT_GOOGLE_VLOG(verboselevel) P1_NULL_MESSAGE
 
#  define VLOG_IF(verboselevel, condition) \
    COMPACT_GOOGLE_VLOG(verboselevel).stream()
#  define VLOG(verboselevel) COMPACT_GOOGLE_VLOG(verboselevel).stream()
#  define VLOG_EVERY_N(verboselevel, n) \
    COMPACT_GOOGLE_VLOG(verboselevel).stream()
#  define VLOG_IF_EVERY_N(verboselevel, condition, n) \
    COMPACT_GOOGLE_VLOG(verboselevel).stream()
 
#endif