include/keymaster/logger.h

/*
 * Copyright 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef SYSTEM_KEYMASTER_LOGGER_H_
#define SYSTEM_KEYMASTER_LOGGER_H_

#include <stdarg.h>

namespace keymaster {

class Logger {
  public:
    Logger() {}
    virtual ~Logger() {}

    enum LogLevel {
        DEBUG_LVL,    // Messages used only for debugging
        INFO_LVL,     // Informational messages; something is unusual but not wrong
        WARNING_LVL,  // There's an indication of trouble, but it may be okay.
        ERROR_LVL,    // A problem has occurred, but processing can continue
        SEVERE_LVL,   // A severe problem has occurred; likely indicates a defect.
    };

    virtual int log_msg(LogLevel level, const char* fmt, va_list args) const = 0;

    static int Log(LogLevel level, const char* fmt, va_list args);

    __attribute__((format(printf, 2, 3))) static int Log(LogLevel level, const char* fmt, ...);
    __attribute__((format(printf, 1, 2))) static int Debug(const char* fmt, ...);
    __attribute__((format(printf, 1, 2))) static int Info(const char* fmt, ...);
    __attribute__((format(printf, 1, 2))) static int Warning(const char* fmt, ...);
    __attribute__((format(printf, 1, 2))) static int Error(const char* fmt, ...);
    __attribute__((format(printf, 1, 2))) static int Severe(const char* fmt, ...);

  protected:
    static void set_instance(Logger* logger) { instance_ = logger; }

  private:
    // Disallow copying.
    Logger(const Logger&);
    void operator=(const Logger&);

    static Logger* instance_;
};

#define __KM_STR(x) #x
#define __KM_STRINGIFY(x) __KM_STR(x)
#define __KM_FILE_LINE __FILE__ ", Line " __KM_STRINGIFY(__LINE__) ": "

#define LOG_D(fmt, ...) Logger::Debug(__KM_FILE_LINE fmt, ##__VA_ARGS__)
#define LOG_I(fmt, ...) Logger::Info(__KM_FILE_LINE fmt, ##__VA_ARGS__)
#define LOG_W(fmt, ...) Logger::Warning(__KM_FILE_LINE fmt, ##__VA_ARGS__)
#define LOG_E(fmt, ...) Logger::Error(__KM_FILE_LINE fmt, ##__VA_ARGS__)
#define LOG_S(fmt, ...) Logger::Severe(__KM_FILE_LINE fmt, ##__VA_ARGS__)

}  // namespace keymaster

#endif  // SYSTEM_KEYMASTER_LOGGER_H_