progress.c

   1 /*
   2  * Simple text-based progress display module for GIT
   3  *
   4  * Copyright (c) 2007 by Nicolas Pitre <nico@fluxnic.net>
   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 "gettext.h"
  13 #include "progress.h"
  14 #include "strbuf.h"
  15 #include "trace.h"
  16
  17 #define TP_IDX_MAX      8
  18
  19 struct throughput {
  20         off_t curr_total;
  21         off_t prev_total;
  22         uint64_t prev_ns;
  23         unsigned int avg_bytes;
  24         unsigned int avg_misecs;
  25         unsigned int last_bytes[TP_IDX_MAX];
  26         unsigned int last_misecs[TP_IDX_MAX];
  27         unsigned int idx;
  28         char display[32];
  29 };
  30
  31 struct progress {
  32         const char *title;
  33         int last_value;
  34         unsigned total;
  35         unsigned last_percent;
  36         unsigned delay;
  37         unsigned delayed_percent_treshold;
  38         struct throughput *throughput;
  39 };
  40
  41 static volatile sig_atomic_t progress_update;
  42
  43 static void progress_interval(int signum)
  44 {
  45         progress_update = 1;
  46 }
  47
  48 static void set_progress_signal(void)
  49 {
  50         struct sigaction sa;
  51         struct itimerval v;
  52
  53         progress_update = 0;
  54
  55         memset(&sa, 0, sizeof(sa));
  56         sa.sa_handler = progress_interval;
  57         sigemptyset(&sa.sa_mask);
  58         sa.sa_flags = SA_RESTART;
  59         sigaction(SIGALRM, &sa, NULL);
  60
  61         v.it_interval.tv_sec = 1;
  62         v.it_interval.tv_usec = 0;
  63         v.it_value = v.it_interval;
  64         setitimer(ITIMER_REAL, &v, NULL);
  65 }
  66
  67 static void clear_progress_signal(void)
  68 {
  69         struct itimerval v = {{0,},};
  70         setitimer(ITIMER_REAL, &v, NULL);
  71         signal(SIGALRM, SIG_IGN);
  72         progress_update = 0;
  73 }
  74
  75 static int is_foreground_fd(int fd)
  76 {
  77         return getpgid(0) == tcgetpgrp(fd);
  78 }
  79
  80 static int display(struct progress *progress, unsigned n, const char *done)
  81 {
  82         const char *eol, *tp;
  83
  84         if (progress->delay) {
  85                 if (!progress_update || --progress->delay)
  86                         return 0;
  87                 if (progress->total) {
  88                         unsigned percent = n * 100 / progress->total;
  89                         if (percent > progress->delayed_percent_treshold) {
  90                                 /* inhibit this progress report entirely */
  91                                 clear_progress_signal();
  92                                 progress->delay = -1;
  93                                 progress->total = 0;
  94                                 return 0;
  95                         }
  96                 }
  97         }
  98
  99         progress->last_value = n;
 100         tp = (progress->throughput) ? progress->throughput->display : "";
 101         eol = done ? done : "   \r";
 102         if (progress->total) {
 103                 unsigned percent = n * 100 / progress->total;
 104                 if (percent != progress->last_percent || progress_update) {
 105                         progress->last_percent = percent;
 106                         if (is_foreground_fd(fileno(stderr)) || done) {
 107                                 fprintf(stderr, "%s: %3u%% (%u/%u)%s%s",
 108                                         progress->title, percent, n,
 109                                         progress->total, tp, eol);
 110                                 fflush(stderr);
 111                         }
 112                         progress_update = 0;
 113                         return 1;
 114                 }
 115         } else if (progress_update) {
 116                 if (is_foreground_fd(fileno(stderr)) || done) {
 117                         fprintf(stderr, "%s: %u%s%s",
 118                                 progress->title, n, tp, eol);
 119                         fflush(stderr);
 120                 }
 121                 progress_update = 0;
 122                 return 1;
 123         }
 124
 125         return 0;
 126 }
 127
 128 static void throughput_string(struct strbuf *buf, off_t total,
 129                               unsigned int rate)
 130 {
 131         strbuf_addstr(buf, ", ");
 132         strbuf_humanise_bytes(buf, total);
 133         strbuf_addstr(buf, " | ");
 134         strbuf_humanise_bytes(buf, rate * 1024);
 135         strbuf_addstr(buf, "/s");
 136 }
 137
 138 void display_throughput(struct progress *progress, off_t total)
 139 {
 140         struct throughput *tp;
 141         uint64_t now_ns;
 142         unsigned int misecs, count, rate;
 143         struct strbuf buf = STRBUF_INIT;
 144
 145         if (!progress)
 146                 return;
 147         tp = progress->throughput;
 148
 149         now_ns = getnanotime();
 150
 151         if (!tp) {
 152                 progress->throughput = tp = calloc(1, sizeof(*tp));
 153                 if (tp) {
 154                         tp->prev_total = tp->curr_total = total;
 155                         tp->prev_ns = now_ns;
 156                 }
 157                 return;
 158         }
 159         tp->curr_total = total;
 160
 161         /* only update throughput every 0.5 s */
 162         if (now_ns - tp->prev_ns <= 500000000)
 163                 return;
 164
 165         /*
 166          * We have x = bytes and y = nanosecs.  We want z = KiB/s:
 167          *
 168          *      z = (x / 1024) / (y / 1000000000)
 169          *      z = x / y * 1000000000 / 1024
 170          *      z = x / (y * 1024 / 1000000000)
 171          *      z = x / y'
 172          *
 173          * To simplify things we'll keep track of misecs, or 1024th of a sec
 174          * obtained with:
 175          *
 176          *      y' = y * 1024 / 1000000000
 177          *      y' = y * (2^10 / 2^42) * (2^42 / 1000000000)
 178          *      y' = y / 2^32 * 4398
 179          *      y' = (y * 4398) >> 32
 180          */
 181         misecs = ((now_ns - tp->prev_ns) * 4398) >> 32;
 182
 183         count = total - tp->prev_total;
 184         tp->prev_total = total;
 185         tp->prev_ns = now_ns;
 186         tp->avg_bytes += count;
 187         tp->avg_misecs += misecs;
 188         rate = tp->avg_bytes / tp->avg_misecs;
 189         tp->avg_bytes -= tp->last_bytes[tp->idx];
 190         tp->avg_misecs -= tp->last_misecs[tp->idx];
 191         tp->last_bytes[tp->idx] = count;
 192         tp->last_misecs[tp->idx] = misecs;
 193         tp->idx = (tp->idx + 1) % TP_IDX_MAX;
 194
 195         throughput_string(&buf, total, rate);
 196         strncpy(tp->display, buf.buf, sizeof(tp->display));
 197         strbuf_release(&buf);
 198         if (progress->last_value != -1 && progress_update)
 199                 display(progress, progress->last_value, NULL);
 200 }
 201
 202 int display_progress(struct progress *progress, unsigned n)
 203 {
 204         return progress ? display(progress, n, NULL) : 0;
 205 }
 206
 207 struct progress *start_progress_delay(const char *title, unsigned total,
 208                                        unsigned percent_treshold, unsigned delay)
 209 {
 210         struct progress *progress = malloc(sizeof(*progress));
 211         if (!progress) {
 212                 /* unlikely, but here's a good fallback */
 213                 fprintf(stderr, "%s...\n", title);
 214                 fflush(stderr);
 215                 return NULL;
 216         }
 217         progress->title = title;
 218         progress->total = total;
 219         progress->last_value = -1;
 220         progress->last_percent = -1;
 221         progress->delayed_percent_treshold = percent_treshold;
 222         progress->delay = delay;
 223         progress->throughput = NULL;
 224         set_progress_signal();
 225         return progress;
 226 }
 227
 228 struct progress *start_progress(const char *title, unsigned total)
 229 {
 230         return start_progress_delay(title, total, 0, 0);
 231 }
 232
 233 void stop_progress(struct progress **p_progress)
 234 {
 235         stop_progress_msg(p_progress, _("done"));
 236 }
 237
 238 void stop_progress_msg(struct progress **p_progress, const char *msg)
 239 {
 240         struct progress *progress = *p_progress;
 241         if (!progress)
 242                 return;
 243         *p_progress = NULL;
 244         if (progress->last_value != -1) {
 245                 /* Force the last update */
 246                 char buf[128], *bufp;
 247                 size_t len = strlen(msg) + 5;
 248                 struct throughput *tp = progress->throughput;
 249
 250                 bufp = (len < sizeof(buf)) ? buf : xmalloc(len + 1);
 251                 if (tp) {
 252                         struct strbuf strbuf = STRBUF_INIT;
 253                         unsigned int rate = !tp->avg_misecs ? 0 :
 254                                         tp->avg_bytes / tp->avg_misecs;
 255                         throughput_string(&strbuf, tp->curr_total, rate);
 256                         strncpy(tp->display, strbuf.buf, sizeof(tp->display));
 257                         strbuf_release(&strbuf);
 258                 }
 259                 progress_update = 1;
 260                 sprintf(bufp, ", %s.\n", msg);
 261                 display(progress, progress->last_value, bufp);
 262                 if (buf != bufp)
 263                         free(bufp);
 264         }
 265         clear_progress_signal();
 266         free(progress->throughput);
 267         free(progress);
 268 }