src/progress.c

   1 #include <stdlib.h>
   2 #include <string.h>
   3 #include <time.h>
   4
   5 #include "progress.h"
   6
   7 #define PROGRESS_WINDOW  10
   8
   9
  10 typedef struct {
  11   time_t when;
  12   int completed;
  13 } TIMESTAMP;
  14
  15
  16 struct _PROGRESS {
  17   int total;
  18   int stampcount;
  19   TIMESTAMP stamps[PROGRESS_WINDOW];
  20 };
  21
  22
  23 #define LAST_STAMP(p)   ((p)->stamps[(p)->stampcount-1])
  24 #define FIRST_STAMP(p)  ((p)->stamps[0])
  25
  26
  27 PROGRESS *progress_start (int total) {
  28   PROGRESS *p = malloc(sizeof(PROGRESS));
  29   p->total = total;
  30   p->stampcount = 0;
  31   progress_update(p, 0);
  32   return p;
  33 }
  34
  35
  36 static double progress_estimate (PROGRESS *progress) {
  37   int count;
  38   int left;
  39   double elapsed;
  40   double rate;
  41   //
  42   if (progress->stampcount < 2) return 0.0;
  43   count = LAST_STAMP(progress).completed-FIRST_STAMP(progress).completed;
  44   left = progress->total-LAST_STAMP(progress).completed;
  45   elapsed = (double)(LAST_STAMP(progress).when-FIRST_STAMP(progress).when);
  46   if (elapsed <= 0.1) elapsed = 0.1;
  47   rate = count/elapsed;
  48   return left/rate;
  49 }
  50
  51
  52 double progress_update (PROGRESS *progress, int completed) {
  53   time_t now;
  54   //
  55   time(&now);
  56   /* only return progress every 10 seconds */
  57   if (progress->stampcount > 0 && difftime(now, LAST_STAMP(progress).when) < 10.0) return 0.0;
  58   if (progress->stampcount == PROGRESS_WINDOW) {
  59     memmove(progress->stamps, progress->stamps+1, sizeof(progress->stamps[0])*(PROGRESS_WINDOW-1));
  60     --progress->stampcount;
  61   }
  62   ++progress->stampcount;
  63   LAST_STAMP(progress).completed = completed;
  64   LAST_STAMP(progress).when = now;
  65   return progress_estimate(progress);
  66 }