Source code for duck.etc.internals.profile_app

"""
Module for profiling a Duck application
"""
import cProfile
import pstats




def save_stats(profiler, stats_filepath: str, stream=None):
    """
    Save profile statistics to the file.
    """
    profiler.disable()
    
    if stats_filepath and stream:
        raise TypeError("Please provide one of `stats_filepath` or `stream`, not both.")
        
    if stream:
        stats = pstats.Stats(profiler, stream=stream)
    
    else:
        with open(stats_filepath, "w") as f:
            stats = pstats.Stats(profiler, stream=f)
    
    stats.strip_dirs()
    stats.sort_stats("cumulative")  # Sort by cumulative time
    stats.print_stats() # save stats to file.





def profile_app(app, stats_filepath: str = "profile_app_stats.prof", stream=None):
    """
    Profile a Duck application and write statistics to the stats_filepath.
    
    This is possible when CTRL-C is used to stop server.
    """
    profiler = cProfile.Profile()
    old_pre_stop = app.on_pre_stop
    app.on_pre_stop = lambda: (old_pre_stop(), save_stats(profiler, stats_filepath, stream))
    profiler.enable()
    app.run()