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##
## Copyright (C) 2012-2022 The Octave Project Developers
##
## See the file COPYRIGHT.md in the top-level directory of this
## distribution or <https://octave.org/copyright/>.
##
## This file is part of Octave.
##
## Octave is free software: you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
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## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
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## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <https://www.gnu.org/licenses/>.
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########################################################################

## -*- texinfo -*-
## @deftypefn  {} {} profile on
## @deftypefnx {} {} profile off
## @deftypefnx {} {} profile resume
## @deftypefnx {} {} profile clear
## @deftypefnx {} {@var{S} =} profile ("status")
## @deftypefnx {} {@var{T} =} profile ("info")
## Control the built-in profiler.
##
## @table @code
## @item profile on
## Start the profiler, clearing all previously collected data if there is any.
##
## @item profile off
## Stop profiling.  The collected data can later be retrieved and examined
## with @code{T = profile ("info")}.
##
## @item profile clear
## Clear all collected profiler data.
##
## @item profile resume
## Restart profiling without clearing the old data.  All newly collected
## statistics are added to the existing ones.
##
## @item @var{S} = profile ("status")
## Return a structure with information about the current status of the
## profiler.  At the moment, the only field is @code{ProfilerStatus} which is
## either @qcode{"on"} or @qcode{"off"}.
##
## @item @var{T} = profile ("info")
## Return the collected profiling statistics in the structure @var{T}.  The
## flat profile is returned in the field @code{FunctionTable} which is an
## array of structures, each entry corresponding to a function which was called
## and for which profiling statistics are present.  In addition, the field
## @code{Hierarchical} contains the hierarchical call tree.  Each node has an
## index into the @code{FunctionTable} identifying the function it corresponds
## to as well as data fields for number of calls and time spent at this level
## in the call tree.
## @seealso{profshow, profexplore}
## @end table
## @end deftypefn

function retval = profile (arg)

  if (nargin < 1)
    print_usage ();
  endif

  switch (arg)
    case "on"
      __profiler_enable__ (true);

    case "off"
      __profiler_enable__ (false);

    case "clear"
      __profiler_reset__ ();

    case "resume"
      __profiler_enable__ (true);

    case "status"
      enabled = __profiler_enable__ ();
      if (enabled)
        enabled = "on";
      else
        enabled = "off";
      endif
      retval = struct ("ProfilerStatus", enabled);

    case "info"
      [flat, tree] = __profiler_data__ ();
      retval = struct ("FunctionTable", flat, "Hierarchical", tree);

    otherwise
      warning ("profile: Unrecognized option '%s'", arg);
      print_usage ();

  endswitch

endfunction


%!demo
%! profile on;
%! A = rand (100);
%! B = expm (A);
%! profile off;
%! profile resume;
%! C = sqrtm (A);
%! profile off;
%! T = profile ("info");
%! profshow (T);

%!test
%! on_struct.ProfilerStatus = "on";
%! off_struct.ProfilerStatus = "off";
%! profile ("on");
%! result = logm (rand (200) + 10 * eye (200));
%! assert (profile ("status"), on_struct);
%! profile ("off");
%! assert (profile ("status"), off_struct);
%! profile ("resume");
%! result = logm (rand (200) + 10 * eye (200));
%! profile ("off");
%! assert (profile ("status"), off_struct);
%! info = profile ("info");
%! assert (isstruct (info));
%! assert (size (info), [1, 1]);
%! assert (fieldnames (info), {"FunctionTable"; "Hierarchical"});
%! ftbl = info.FunctionTable;
%! assert (fieldnames (ftbl), {"FunctionName"; "TotalTime"; "NumCalls"; "IsRecursive"; "Parents"; "Children"});
%! hier = info.Hierarchical;
%! assert (fieldnames (hier), {"Index"; "SelfTime"; "TotalTime"; "NumCalls"; "Children"});
%! profile ("clear");
%! info = profile ("info");
%! assert (isstruct (info));
%! assert (size (info), [1, 1]);
%! assert (fieldnames (info), {"FunctionTable"; "Hierarchical"});
%! ftbl = info.FunctionTable;
%! assert (size (ftbl), [0, 1]);
%! assert (fieldnames (ftbl), {"FunctionName"; "TotalTime"; "NumCalls"; "IsRecursive"; "Parents"; "Children"});
%! hier = info.Hierarchical;
%! assert (size (hier), [0, 1]);
%! assert (fieldnames (hier), {"Index"; "SelfTime"; "TotalTime"; "NumCalls"; "Children"});

## Test input validation
%!error <Invalid call> profile ()
%!error profile ("on", 2)
%!error profile ("INVALID_OPTION")