/*****************************************************************************
*
* perf_extract.c 2014.05.24 Smythies
*      program to parse times out of a "perf script" report, and calculate
*      delta t since the last time.
*      There seems to be large gaps in runnings of the intel_pstate driver
*                                                                     Smythies
*****************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_LENGTH 2000  /* maximum line length */
#define MAX_SAMPLES 1000000 /* maximum number of samples */

void main(int argc, char **argv){

   double dt[MAX_SAMPLES]; /* array of delta time numbers */
   char in_buffer[MAX_LENGTH];
   char *infile, *outfile;
   char *index;
   FILE *inf, *out;
   double new_time, old_time, max_time, min_time;
   int sample, i;

   switch(argc){
   case 3:
      infile = argv[1];
      outfile = argv[2];
      break;
   default:
      printf("perf_extract infile outfile\n");
      printf("  parse times out of a perf script report, and calculate delta t since the last time from infile to an MATK plottable outfile\n");
      exit(-1);
   } /* endcase */

   printf("perf_extract: Begin...\n");

   if((inf = fopen(infile, "rt")) == NULL){
      printf("Unable to open input file '%s'\n", infile);
      exit(-1);
   } /* endif */

   if((out = fopen(outfile, "wt")) == NULL){
      printf("Error opening output file '%s'\n", outfile);
      exit(-1);
   } /* endif */

   sample = 0;
   max_time = 0.0;
   min_time = 5000000.0;
   while((fgets(in_buffer, MAX_LENGTH, inf)) != NULL){ /* do infile line at a time */
      if((index = strstr(in_buffer, "[007] ")) != NULL){ /* find search string if it is there */
         sscanf(index, "[007] %lf", &new_time);
         if( sample != 0){
            dt[sample -1] = new_time - old_time;
            if(dt[sample-1] > max_time) max_time = dt[sample-1];
            if(dt[sample-1] < min_time) min_time = dt[sample-1];
         } /* endif */
         sample++;
         old_time = new_time;
         if(sample == MAX_SAMPLES){
            printf("perf_extract: Hit maximum number of samples, the rest ignored\n");
            break;
         } /* endif */
      } else {
            printf("perf_extract: Got an odd line. This should not occur, but continuing anyhow.\n");
      } /* endif */
   } /* endwhile */
   printf("perf_extract: Number of samples: %d  Delta time: Min: %lf  Max: %lf\n", sample, min_time, max_time);
   printf("perf_extract: dumping to output file '%s'\n", outfile);
   for(i = 0; i < sample-1; i++){
      fprintf(out, "%d %5.3lf\n", i, dt[i]);
   } /* endfor */
   fclose(inf);
   fclose(out);
   printf("perf_extract: Done. Exiting...\n");
} /* endprogram */