progress.c

   1 /*
   2  * Simple text-based progress display module for GIT
   3  *
   4  * Copyright (c) 2007 by Nicolas Pitre <nico@cam.org>
   5  *
   6  * This code is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include "git-compat-util.h"
  12 #include "progress.h"
  13
  14 #define TP_IDX_MAX      8
  15
  16 struct throughput {
  17         struct timeval prev_tv;
  18         unsigned long count;
  19         unsigned long avg_bytes;
  20         unsigned long last_bytes[TP_IDX_MAX];
  21         unsigned int avg_misecs;
  22         unsigned int last_misecs[TP_IDX_MAX];
  23         unsigned int idx;
  24         char display[20];
  25 };
  26
  27 struct progress {
  28         const char *title;
  29         int last_value;
  30         unsigned total;
  31         unsigned last_percent;
  32         unsigned delay;
  33         unsigned delayed_percent_treshold;
  34         struct throughput *throughput;
  35 };
  36
  37 static volatile sig_atomic_t progress_update;
  38
  39 static void progress_interval(int signum)
  40 {
  41         progress_update = 1;
  42 }
  43
  44 static void set_progress_signal(void)
  45 {
  46         struct sigaction sa;
  47         struct itimerval v;
  48
  49         progress_update = 0;
  50
  51         memset(&sa, 0, sizeof(sa));
  52         sa.sa_handler = progress_interval;
  53         sigemptyset(&sa.sa_mask);
  54         sa.sa_flags = SA_RESTART;
  55         sigaction(SIGALRM, &sa, NULL);
  56
  57         v.it_interval.tv_sec = 1;
  58         v.it_interval.tv_usec = 0;
  59         v.it_value = v.it_interval;
  60         setitimer(ITIMER_REAL, &v, NULL);
  61 }
  62
  63 static void clear_progress_signal(void)
  64 {
  65         struct itimerval v = {{0,},};
  66         setitimer(ITIMER_REAL, &v, NULL);
  67         signal(SIGALRM, SIG_IGN);
  68         progress_update = 0;
  69 }
  70
  71 static int display(struct progress *progress, unsigned n, int done)
  72 {
  73         char *eol, *tp;
  74
  75         if (progress->delay) {
  76                 if (!progress_update || --progress->delay)
  77                         return 0;
  78                 if (progress->total) {
  79                         unsigned percent = n * 100 / progress->total;
  80                         if (percent > progress->delayed_percent_treshold) {
  81                                 /* inhibit this progress report entirely */
  82                                 clear_progress_signal();
  83                                 progress->delay = -1;
  84                                 progress->total = 0;
  85                                 return 0;
  86                         }
  87                 }
  88         }
  89
  90         progress->last_value = n;
  91         tp = (progress->throughput) ? progress->throughput->display : "";
  92         eol = done ? ", done.   \n" : "   \r";
  93         if (progress->total) {
  94                 unsigned percent = n * 100 / progress->total;
  95                 if (percent != progress->last_percent || progress_update) {
  96                         progress->last_percent = percent;
  97                         fprintf(stderr, "%s: %3u%% (%u/%u)%s%s",
  98                                 progress->title, percent, n,
  99                                 progress->total, tp, eol);
 100                         progress_update = 0;
 101                         return 1;
 102                 }
 103         } else if (progress_update) {
 104                 fprintf(stderr, "%s: %u%s%s", progress->title, n, tp, eol);
 105                 progress_update = 0;
 106                 return 1;
 107         }
 108
 109         return 0;
 110 }
 111
 112 void display_throughput(struct progress *progress, unsigned long n)
 113 {
 114         struct throughput *tp;
 115         struct timeval tv;
 116         unsigned int misecs;
 117
 118         if (!progress)
 119                 return;
 120         tp = progress->throughput;
 121
 122         gettimeofday(&tv, NULL);
 123
 124         if (!tp) {
 125                 progress->throughput = tp = calloc(1, sizeof(*tp));
 126                 if (tp)
 127                         tp->prev_tv = tv;
 128                 return;
 129         }
 130
 131         tp->count += n;
 132
 133         /*
 134          * We have x = bytes and y = microsecs.  We want z = KiB/s:
 135          *
 136          *      z = (x / 1024) / (y / 1000000)
 137          *      z = x / y * 1000000 / 1024
 138          *      z = x / (y * 1024 / 1000000)
 139          *      z = x / y'
 140          *
 141          * To simplify things we'll keep track of misecs, or 1024th of a sec
 142          * obtained with:
 143          *
 144          *      y' = y * 1024 / 1000000
 145          *      y' = y / (1000000 / 1024)
 146          *      y' = y / 977
 147          */
 148         misecs = (tv.tv_sec - tp->prev_tv.tv_sec) * 1024;
 149         misecs += (int)(tv.tv_usec - tp->prev_tv.tv_usec) / 977;
 150
 151         if (misecs > 512) {
 152                 tp->prev_tv = tv;
 153                 tp->avg_bytes += tp->count;
 154                 tp->avg_misecs += misecs;
 155                 snprintf(tp->display, sizeof(tp->display),
 156                          ", %lu KiB/s", tp->avg_bytes / tp->avg_misecs);
 157                 tp->avg_bytes -= tp->last_bytes[tp->idx];
 158                 tp->avg_misecs -= tp->last_misecs[tp->idx];
 159                 tp->last_bytes[tp->idx] = tp->count;
 160                 tp->last_misecs[tp->idx] = misecs;
 161                 tp->idx = (tp->idx + 1) % TP_IDX_MAX;
 162                 tp->count = 0;
 163         }
 164 }
 165
 166 int display_progress(struct progress *progress, unsigned n)
 167 {
 168         return progress ? display(progress, n, 0) : 0;
 169 }
 170
 171 struct progress *start_progress_delay(const char *title, unsigned total,
 172                                        unsigned percent_treshold, unsigned delay)
 173 {
 174         struct progress *progress = malloc(sizeof(*progress));
 175         if (!progress) {
 176                 /* unlikely, but here's a good fallback */
 177                 fprintf(stderr, "%s...\n", title);
 178                 return NULL;
 179         }
 180         progress->title = title;
 181         progress->total = total;
 182         progress->last_value = -1;
 183         progress->last_percent = -1;
 184         progress->delayed_percent_treshold = percent_treshold;
 185         progress->delay = delay;
 186         progress->throughput = NULL;
 187         set_progress_signal();
 188         return progress;
 189 }
 190
 191 struct progress *start_progress(const char *title, unsigned total)
 192 {
 193         return start_progress_delay(title, total, 0, 0);
 194 }
 195
 196 void stop_progress(struct progress **p_progress)
 197 {
 198         struct progress *progress = *p_progress;
 199         if (!progress)
 200                 return;
 201         *p_progress = NULL;
 202         if (progress->last_value != -1) {
 203                 /* Force the last update */
 204                 progress_update = 1;
 205                 display(progress, progress->last_value, 1);
 206         }
 207         clear_progress_signal();
 208         free(progress->throughput);
 209         free(progress);
 210 }