/*

Copyright (c) 2010-2013 Tommaso Urli

Tommaso Urli    tommaso.urli@uniud.it   University of Udine

Permission is hereby granted, free of charge, to any person obtaining

a copy of this software and associated documentation files (the

"Software"), to deal in the Software without restriction, including

without limitation the rights to use, copy, modify, merge, publish,

distribute, sublicense, and/or sell copies of the Software, and to

permit persons to whom the Software is furnished to do so, subject to

the following conditions:

The above copyright notice and this permission notice shall be

included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE

LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION

OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION

WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

*/

#ifndef __sot_core_stopwatch_H__

#define __sot_core_stopwatch_H__

#include <ctime>

#include <iostream>

#include <map>

#include <sstream>

#ifndef WIN32

/* The classes below are exported */

#pragma GCC visibility push(default)

#endif

// Generic stopwatch exception class

struct StopwatchException {

 public:

  std::string error;

};

enum StopwatchMode {

  NONE = 0,      // Clock is not initialized

  CPU_TIME = 1,  // Clock calculates time ranges using ctime and CLOCKS_PER_SEC

  REAL_TIME = 2  // Clock calculates time by asking the operating system how

  // much real time passed

};

#define STOP_WATCH_MAX_NAME_LENGTH 80

/**

    @brief A class representing a stopwatch.

    @code

    Stopwatch swatch();

    @endcode

    The Stopwatch class can be used to measure execution time of code,

    algorithms, etc., // TODO: he Stopwatch can be initialized in two

    time-taking modes, CPU time and real time:

    @code

    swatch.set_mode(REAL_TIME);

    @endcode

    CPU time is the time spent by the processor on a certain piece of code,

    while real time is the real amount of time taken by a certain piece of

    code to execute (i.e. in general if you are doing hard work such as

    image or video editing on a different process the measured time will

    probably increase).

    How does it work? Basically, one wraps the code to be measured with the

    following method calls:

    @code

    swatch.start("My astounding algorithm");

    // Hic est code

    swatch.stop("My astounding algorithm");

    @endcode

    A string representing the code ID is provided so that nested portions of

    code can be profiled separately:

    @code

    swatch.start("My astounding algorithm");

    swatch.start("My astounding algorithm - Super smart init");

    // Initialization

    swatch.stop("My astounding algorithm - Super smart init");

    swatch.start("My astounding algorithm - Main loop");

    // Loop

    swatch.stop("My astounding algorithm - Main loop");

    swatch.stop("My astounding algorithm");

    @endcode

    Note: ID strings can be whatever you like, in the previous example I have

    used "My astounding algorithm - *" only to enforce the fact that the

    measured code portions are part of My astounding algorithm, but there's no

    connection between the three measurements.

    If the code for a certain task is scattered through different files or

    portions of the same file one can use the start-pause-stop method:

    @code

    swatch.start("Setup");

    // First part of setup

    swatch.pause("Setup");

    swatch.start("Main logic");

    // Main logic

    swatch.stop("Main logic");

    swatch.start("Setup");

    // Cleanup (part of the setup)

    swatch.stop("Setup");

    @endcode

    Finally, to report the results of the measurements just run:

    @code

    swatch.report("Code ID");

    @endcode

    Thou can also provide an additional std::ostream& parameter to report() to

    redirect the logging on a different output. Also, you can use the

    get_total/min/max/average_time() methods to get the individual numeric data,

    without all the details of the logging. You can also extend Stopwatch to

    implement your own logging syntax.

    To report all the measurements:

    @code

    swatch.report_all();

    @endcode

    Same as above, you can redirect the output by providing a std::ostream&

    parameter.

*/

class Stopwatch {

 public:

  /** Constructor */

  Stopwatch(StopwatchMode _mode = NONE);

  /** Destructor */

  ~Stopwatch();

  /** Tells if a performance with a certain ID exists */

  bool performance_exists(std::string perf_name);

  /** Initialize stopwatch to use a certain time taking mode */

  void set_mode(StopwatchMode mode);

  /** Start the stopwatch related to a certain piece of code */

  void start(std::string perf_name);

  /** Stops the stopwatch related to a certain piece of code */

  void stop(std::string perf_name);

  /** Stops the stopwatch related to a certain piece of code */

  void pause(std::string perf_name);

  /** Reset a certain performance record */

  void reset(std::string perf_name);

  /** Resets all the performance records */

  void reset_all();

  /** Dump the data of a certain performance record */

  void report(std::string perf_name, int precision = 2,

              std::ostream &output = std::cout);

  /** Dump the data of all the performance records */

  void report_all(int precision = 2, std::ostream &output = std::cout);

  /** Returns total execution time of a certain performance */

  long double get_total_time(std::string perf_name);

  /** Returns average execution time of a certain performance */

  long double get_average_time(std::string perf_name);

  /** Returns minimum execution time of a certain performance */

  long double get_min_time(std::string perf_name);

  /** Returns maximum execution time of a certain performance */

  long double get_max_time(std::string perf_name);

  /** Return last measurement of a certain performance */

  long double get_last_time(std::string perf_name);

  /** Return the time since the start of the last measurement of a given

      performance. */

  long double get_time_so_far(std::string perf_name);

  /** Turn off clock, all the Stopwatch::* methods return without doing

        anything after this method is called. */

  void turn_off();

  /** Turn on clock, restore clock operativity after a turn_off(). */

  void turn_on();

  /** Take time, depends on mode */

  long double take_time();

 protected:

  /** Struct to hold the performance data */

  struct PerformanceData {

          total_time(0),

          min_time(0),

          max_time(0),

          last_time(0),

          paused(false),

    /** Start time */

    long double clock_start;

    /** Cumulative total time */

    long double total_time;

    /** Minimum time */

    long double min_time;

    /** Maximum time */

    long double max_time;

    /** Last time */

    long double last_time;

    /** Tells if this performance has been paused, only for internal use */

    bool paused;

    /** How many cycles have been this stopwatch executed? */

    int stops;

  };

  /** Flag to hold the clock's status */

  bool active;

  /** Time taking mode */

  StopwatchMode mode;

  /** Pointer to the dynamic structure which holds the collection of performance

      data */

  std::map<std::string, PerformanceData> *records_of;

};

Stopwatch &getProfiler();

#ifndef WIN32

#pragma GCC visibility pop

#endif

#endif