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         int tpgrp = tcgetpgrp(fd);
  78         return tpgrp < 0 || tpgrp == getpgid(0);
  79 }
  80
  81 static int display(struct progress *progress, unsigned n, const char *done)
  82 {
  83         const char *eol, *tp;
  84
  85         if (progress->delay) {
  86                 if (!progress_update || --progress->delay)
  87                         return 0;
  88                 if (progress->total) {
  89                         unsigned percent = n * 100 / progress->total;
  90                         if (percent > progress->delayed_percent_treshold) {
  91                                 /* inhibit this progress report entirely */
  92                                 clear_progress_signal();
  93                                 progress->delay = -1;
  94                                 progress->total = 0;
  95                                 return 0;
  96                         }
  97                 }
  98         }
  99
 100         progress->last_value = n;
 101         tp = (progress->throughput) ? progress->throughput->display : "";
 102         eol = done ? done : "   \r";
 103         if (progress->total) {
 104                 unsigned percent = n * 100 / progress->total;
 105                 if (percent != progress->last_percent || progress_update) {
 106                         progress->last_percent = percent;
 107                         if (is_foreground_fd(fileno(stderr)) || done) {
 108                                 fprintf(stderr, "%s: %3u%% (%u/%u)%s%s",
 109                                         progress->title, percent, n,
 110                                         progress->total, tp, eol);
 111                                 fflush(stderr);
 112                         }
 113                         progress_update = 0;
 114                         return 1;
 115                 }
 116         } else if (progress_update) {
 117                 if (is_foreground_fd(fileno(stderr)) || done) {
 118                         fprintf(stderr, "%s: %u%s%s",
 119                                 progress->title, n, tp, eol);
 120                         fflush(stderr);
 121                 }
 122                 progress_update = 0;
 123                 return 1;
 124         }
 125
 126         return 0;
 127 }
 128
 129 static void throughput_string(struct strbuf *buf, off_t total,
 130                               unsigned int rate)
 131 {
 132         strbuf_addstr(buf, ", ");
 133         strbuf_humanise_bytes(buf, total);
 134         strbuf_addstr(buf, " | ");
 135         strbuf_humanise_bytes(buf, rate * 1024);
 136         strbuf_addstr(buf, "/s");
 137 }
 138
 139 void display_throughput(struct progress *progress, off_t total)
 140 {
 141         struct throughput *tp;
 142         uint64_t now_ns;
 143         unsigned int misecs, count, rate;
 144         struct strbuf buf = STRBUF_INIT;
 145
 146         if (!progress)
 147                 return;
 148         tp = progress->throughput;
 149
 150         now_ns = getnanotime();
 151
 152         if (!tp) {
 153                 progress->throughput = tp = calloc(1, sizeof(*tp));
 154                 if (tp) {
 155                         tp->prev_total = tp->curr_total = total;
 156                         tp->prev_ns = now_ns;
 157                 }
 158                 return;
 159         }
 160         tp->curr_total = total;
 161
 162         /* only update throughput every 0.5 s */
 163         if (now_ns - tp->prev_ns <= 500000000)
 164                 return;
 165
 166         /*
 167          * We have x = bytes and y = nanosecs.  We want z = KiB/s:
 168          *
 169          *      z = (x / 1024) / (y / 1000000000)
 170          *      z = x / y * 1000000000 / 1024
 171          *      z = x / (y * 1024 / 1000000000)
 172          *      z = x / y'
 173          *
 174          * To simplify things we'll keep track of misecs, or 1024th of a sec
 175          * obtained with:
 176          *
 177          *      y' = y * 1024 / 1000000000
 178          *      y' = y * (2^10 / 2^42) * (2^42 / 1000000000)
 179          *      y' = y / 2^32 * 4398
 180          *      y' = (y * 4398) >> 32
 181          */
 182         misecs = ((now_ns - tp->prev_ns) * 4398) >> 32;
 183
 184         count = total - tp->prev_total;
 185         tp->prev_total = total;
 186         tp->prev_ns = now_ns;
 187         tp->avg_bytes += count;
 188         tp->avg_misecs += misecs;
 189         rate = tp->avg_bytes / tp->avg_misecs;
 190         tp->avg_bytes -= tp->last_bytes[tp->idx];
 191         tp->avg_misecs -= tp->last_misecs[tp->idx];
 192         tp->last_bytes[tp->idx] = count;
 193         tp->last_misecs[tp->idx] = misecs;
 194         tp->idx = (tp->idx + 1) % TP_IDX_MAX;
 195
 196         throughput_string(&buf, total, rate);
 197         strncpy(tp->display, buf.buf, sizeof(tp->display));
 198         strbuf_release(&buf);
 199         if (progress->last_value != -1 && progress_update)
 200                 display(progress, progress->last_value, NULL);
 201 }
 202
 203 int display_progress(struct progress *progress, unsigned n)
 204 {
 205         return progress ? display(progress, n, NULL) : 0;
 206 }
 207
 208 struct progress *start_progress_delay(const char *title, unsigned total,
 209                                        unsigned percent_treshold, unsigned delay)
 210 {
 211         struct progress *progress = malloc(sizeof(*progress));
 212         if (!progress) {
 213                 /* unlikely, but here's a good fallback */
 214                 fprintf(stderr, "%s...\n", title);
 215                 fflush(stderr);
 216                 return NULL;
 217         }
 218         progress->title = title;
 219         progress->total = total;
 220         progress->last_value = -1;
 221         progress->last_percent = -1;
 222         progress->delayed_percent_treshold = percent_treshold;
 223         progress->delay = delay;
 224         progress->throughput = NULL;
 225         set_progress_signal();
 226         return progress;
 227 }
 228
 229 struct progress *start_progress(const char *title, unsigned total)
 230 {
 231         return start_progress_delay(title, total, 0, 0);
 232 }
 233
 234 void stop_progress(struct progress **p_progress)
 235 {
 236         stop_progress_msg(p_progress, _("done"));
 237 }
 238
 239 void stop_progress_msg(struct progress **p_progress, const char *msg)
 240 {
 241         struct progress *progress = *p_progress;
 242         if (!progress)
 243                 return;
 244         *p_progress = NULL;
 245         if (progress->last_value != -1) {
 246                 /* Force the last update */
 247                 char buf[128], *bufp;
 248                 size_t len = strlen(msg) + 5;
 249                 struct throughput *tp = progress->throughput;
 250
 251                 bufp = (len < sizeof(buf)) ? buf : xmalloc(len + 1);
 252                 if (tp) {
 253                         struct strbuf strbuf = STRBUF_INIT;
 254                         unsigned int rate = !tp->avg_misecs ? 0 :
 255                                         tp->avg_bytes / tp->avg_misecs;
 256                         throughput_string(&strbuf, tp->curr_total, rate);
 257                         strncpy(tp->display, strbuf.buf, sizeof(tp->display));
 258                         strbuf_release(&strbuf);
 259                 }
 260                 progress_update = 1;
 261                 sprintf(bufp, ", %s.\n", msg);
 262                 display(progress, progress->last_value, bufp);
 263                 if (buf != bufp)
 264                         free(bufp);
 265         }
 266         clear_progress_signal();
 267         free(progress->throughput);
 268         free(progress);
 269 }