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         struct strbuf display;
  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_threshold;
  38         struct throughput *throughput;
  39         uint64_t start_ns;
  40 };
  41
  42 static volatile sig_atomic_t progress_update;
  43
  44 static void progress_interval(int signum)
  45 {
  46         progress_update = 1;
  47 }
  48
  49 static void set_progress_signal(void)
  50 {
  51         struct sigaction sa;
  52         struct itimerval v;
  53
  54         progress_update = 0;
  55
  56         memset(&sa, 0, sizeof(sa));
  57         sa.sa_handler = progress_interval;
  58         sigemptyset(&sa.sa_mask);
  59         sa.sa_flags = SA_RESTART;
  60         sigaction(SIGALRM, &sa, NULL);
  61
  62         v.it_interval.tv_sec = 1;
  63         v.it_interval.tv_usec = 0;
  64         v.it_value = v.it_interval;
  65         setitimer(ITIMER_REAL, &v, NULL);
  66 }
  67
  68 static void clear_progress_signal(void)
  69 {
  70         struct itimerval v = {{0,},};
  71         setitimer(ITIMER_REAL, &v, NULL);
  72         signal(SIGALRM, SIG_IGN);
  73         progress_update = 0;
  74 }
  75
  76 static int is_foreground_fd(int fd)
  77 {
  78         int tpgrp = tcgetpgrp(fd);
  79         return tpgrp < 0 || tpgrp == getpgid(0);
  80 }
  81
  82 static int display(struct progress *progress, unsigned n, const char *done)
  83 {
  84         const char *eol, *tp;
  85
  86         if (progress->delay) {
  87                 if (!progress_update || --progress->delay)
  88                         return 0;
  89                 if (progress->total) {
  90                         unsigned percent = n * 100 / progress->total;
  91                         if (percent > progress->delayed_percent_threshold) {
  92                                 /* inhibit this progress report entirely */
  93                                 clear_progress_signal();
  94                                 progress->delay = -1;
  95                                 progress->total = 0;
  96                                 return 0;
  97                         }
  98                 }
  99         }
 100
 101         progress->last_value = n;
 102         tp = (progress->throughput) ? progress->throughput->display.buf : "";
 103         eol = done ? done : "   \r";
 104         if (progress->total) {
 105                 unsigned percent = n * 100 / progress->total;
 106                 if (percent != progress->last_percent || progress_update) {
 107                         progress->last_percent = percent;
 108                         if (is_foreground_fd(fileno(stderr)) || done) {
 109                                 fprintf(stderr, "%s: %3u%% (%u/%u)%s%s",
 110                                         progress->title, percent, n,
 111                                         progress->total, tp, eol);
 112                                 fflush(stderr);
 113                         }
 114                         progress_update = 0;
 115                         return 1;
 116                 }
 117         } else if (progress_update) {
 118                 if (is_foreground_fd(fileno(stderr)) || done) {
 119                         fprintf(stderr, "%s: %u%s%s",
 120                                 progress->title, n, tp, eol);
 121                         fflush(stderr);
 122                 }
 123                 progress_update = 0;
 124                 return 1;
 125         }
 126
 127         return 0;
 128 }
 129
 130 static void throughput_string(struct strbuf *buf, off_t total,
 131                               unsigned int rate)
 132 {
 133         strbuf_reset(buf);
 134         strbuf_addstr(buf, ", ");
 135         strbuf_humanise_bytes(buf, total);
 136         strbuf_addstr(buf, " | ");
 137         strbuf_humanise_bytes(buf, rate * 1024);
 138         strbuf_addstr(buf, "/s");
 139 }
 140
 141 void display_throughput(struct progress *progress, off_t total)
 142 {
 143         struct throughput *tp;
 144         uint64_t now_ns;
 145         unsigned int misecs, count, rate;
 146
 147         if (!progress)
 148                 return;
 149         tp = progress->throughput;
 150
 151         now_ns = getnanotime();
 152
 153         if (!tp) {
 154                 progress->throughput = tp = calloc(1, sizeof(*tp));
 155                 if (tp) {
 156                         tp->prev_total = tp->curr_total = total;
 157                         tp->prev_ns = now_ns;
 158                         strbuf_init(&tp->display, 0);
 159                 }
 160                 return;
 161         }
 162         tp->curr_total = total;
 163
 164         /* only update throughput every 0.5 s */
 165         if (now_ns - tp->prev_ns <= 500000000)
 166                 return;
 167
 168         /*
 169          * We have x = bytes and y = nanosecs.  We want z = KiB/s:
 170          *
 171          *      z = (x / 1024) / (y / 1000000000)
 172          *      z = x / y * 1000000000 / 1024
 173          *      z = x / (y * 1024 / 1000000000)
 174          *      z = x / y'
 175          *
 176          * To simplify things we'll keep track of misecs, or 1024th of a sec
 177          * obtained with:
 178          *
 179          *      y' = y * 1024 / 1000000000
 180          *      y' = y * (2^10 / 2^42) * (2^42 / 1000000000)
 181          *      y' = y / 2^32 * 4398
 182          *      y' = (y * 4398) >> 32
 183          */
 184         misecs = ((now_ns - tp->prev_ns) * 4398) >> 32;
 185
 186         count = total - tp->prev_total;
 187         tp->prev_total = total;
 188         tp->prev_ns = now_ns;
 189         tp->avg_bytes += count;
 190         tp->avg_misecs += misecs;
 191         rate = tp->avg_bytes / tp->avg_misecs;
 192         tp->avg_bytes -= tp->last_bytes[tp->idx];
 193         tp->avg_misecs -= tp->last_misecs[tp->idx];
 194         tp->last_bytes[tp->idx] = count;
 195         tp->last_misecs[tp->idx] = misecs;
 196         tp->idx = (tp->idx + 1) % TP_IDX_MAX;
 197
 198         throughput_string(&tp->display, total, rate);
 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 static struct progress *start_progress_delay(const char *title, unsigned total,
 209                                              unsigned percent_threshold, 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_threshold = percent_threshold;
 223         progress->delay = delay;
 224         progress->throughput = NULL;
 225         progress->start_ns = getnanotime();
 226         set_progress_signal();
 227         return progress;
 228 }
 229
 230 struct progress *start_delayed_progress(const char *title, unsigned total)
 231 {
 232         return start_progress_delay(title, total, 0, 2);
 233 }
 234
 235 struct progress *start_progress(const char *title, unsigned total)
 236 {
 237         return start_progress_delay(title, total, 0, 0);
 238 }
 239
 240 void stop_progress(struct progress **p_progress)
 241 {
 242         stop_progress_msg(p_progress, _("done"));
 243 }
 244
 245 void stop_progress_msg(struct progress **p_progress, const char *msg)
 246 {
 247         struct progress *progress = *p_progress;
 248         if (!progress)
 249                 return;
 250         *p_progress = NULL;
 251         if (progress->last_value != -1) {
 252                 /* Force the last update */
 253                 char *buf;
 254                 struct throughput *tp = progress->throughput;
 255
 256                 if (tp) {
 257                         uint64_t now_ns = getnanotime();
 258                         unsigned int misecs, rate;
 259                         misecs = ((now_ns - progress->start_ns) * 4398) >> 32;
 260                         rate = tp->curr_total / (misecs ? misecs : 1);
 261                         throughput_string(&tp->display, tp->curr_total, rate);
 262                 }
 263                 progress_update = 1;
 264                 buf = xstrfmt(", %s.\n", msg);
 265                 display(progress, progress->last_value, buf);
 266                 free(buf);
 267         }
 268         clear_progress_signal();
 269         if (progress->throughput)
 270                 strbuf_release(&progress->throughput->display);
 271         free(progress->throughput);
 272         free(progress);
 273 }