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         uint64_t last_value;
  34         uint64_t 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, uint64_t 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%% (%"PRIuMAX"/%"PRIuMAX")%s%s",
 110                                         progress->title, percent,
 111                                         (uintmax_t)n, (uintmax_t)progress->total,
 112                                         tp, eol);
 113                                 fflush(stderr);
 114                         }
 115                         progress_update = 0;
 116                         return 1;
 117                 }
 118         } else if (progress_update) {
 119                 if (is_foreground_fd(fileno(stderr)) || done) {
 120                         fprintf(stderr, "%s: %"PRIuMAX"%s%s",
 121                                 progress->title, (uintmax_t)n, tp, eol);
 122                         fflush(stderr);
 123                 }
 124                 progress_update = 0;
 125                 return 1;
 126         }
 127
 128         return 0;
 129 }
 130
 131 static void throughput_string(struct strbuf *buf, uint64_t total,
 132                               unsigned int rate)
 133 {
 134         strbuf_reset(buf);
 135         strbuf_addstr(buf, ", ");
 136         strbuf_humanise_bytes(buf, total);
 137         strbuf_addstr(buf, " | ");
 138         strbuf_humanise_bytes(buf, rate * 1024);
 139         strbuf_addstr(buf, "/s");
 140 }
 141
 142 void display_throughput(struct progress *progress, uint64_t total)
 143 {
 144         struct throughput *tp;
 145         uint64_t now_ns;
 146         unsigned int misecs, count, rate;
 147
 148         if (!progress)
 149                 return;
 150         tp = progress->throughput;
 151
 152         now_ns = getnanotime();
 153
 154         if (!tp) {
 155                 progress->throughput = tp = calloc(1, sizeof(*tp));
 156                 if (tp) {
 157                         tp->prev_total = tp->curr_total = total;
 158                         tp->prev_ns = now_ns;
 159                         strbuf_init(&tp->display, 0);
 160                 }
 161                 return;
 162         }
 163         tp->curr_total = total;
 164
 165         /* only update throughput every 0.5 s */
 166         if (now_ns - tp->prev_ns <= 500000000)
 167                 return;
 168
 169         /*
 170          * We have x = bytes and y = nanosecs.  We want z = KiB/s:
 171          *
 172          *      z = (x / 1024) / (y / 1000000000)
 173          *      z = x / y * 1000000000 / 1024
 174          *      z = x / (y * 1024 / 1000000000)
 175          *      z = x / y'
 176          *
 177          * To simplify things we'll keep track of misecs, or 1024th of a sec
 178          * obtained with:
 179          *
 180          *      y' = y * 1024 / 1000000000
 181          *      y' = y * (2^10 / 2^42) * (2^42 / 1000000000)
 182          *      y' = y / 2^32 * 4398
 183          *      y' = (y * 4398) >> 32
 184          */
 185         misecs = ((now_ns - tp->prev_ns) * 4398) >> 32;
 186
 187         count = total - tp->prev_total;
 188         tp->prev_total = total;
 189         tp->prev_ns = now_ns;
 190         tp->avg_bytes += count;
 191         tp->avg_misecs += misecs;
 192         rate = tp->avg_bytes / tp->avg_misecs;
 193         tp->avg_bytes -= tp->last_bytes[tp->idx];
 194         tp->avg_misecs -= tp->last_misecs[tp->idx];
 195         tp->last_bytes[tp->idx] = count;
 196         tp->last_misecs[tp->idx] = misecs;
 197         tp->idx = (tp->idx + 1) % TP_IDX_MAX;
 198
 199         throughput_string(&tp->display, total, rate);
 200         if (progress->last_value != -1 && progress_update)
 201                 display(progress, progress->last_value, NULL);
 202 }
 203
 204 int display_progress(struct progress *progress, uint64_t n)
 205 {
 206         return progress ? display(progress, n, NULL) : 0;
 207 }
 208
 209 static struct progress *start_progress_delay(const char *title, uint64_t total,
 210                                              unsigned percent_threshold, unsigned delay)
 211 {
 212         struct progress *progress = malloc(sizeof(*progress));
 213         if (!progress) {
 214                 /* unlikely, but here's a good fallback */
 215                 fprintf(stderr, "%s...\n", title);
 216                 fflush(stderr);
 217                 return NULL;
 218         }
 219         progress->title = title;
 220         progress->total = total;
 221         progress->last_value = -1;
 222         progress->last_percent = -1;
 223         progress->delayed_percent_threshold = percent_threshold;
 224         progress->delay = delay;
 225         progress->throughput = NULL;
 226         progress->start_ns = getnanotime();
 227         set_progress_signal();
 228         return progress;
 229 }
 230
 231 struct progress *start_delayed_progress(const char *title, uint64_t total)
 232 {
 233         return start_progress_delay(title, total, 0, 2);
 234 }
 235
 236 struct progress *start_progress(const char *title, uint64_t total)
 237 {
 238         return start_progress_delay(title, total, 0, 0);
 239 }
 240
 241 void stop_progress(struct progress **p_progress)
 242 {
 243         stop_progress_msg(p_progress, _("done"));
 244 }
 245
 246 void stop_progress_msg(struct progress **p_progress, const char *msg)
 247 {
 248         struct progress *progress = *p_progress;
 249         if (!progress)
 250                 return;
 251         *p_progress = NULL;
 252         if (progress->last_value != -1) {
 253                 /* Force the last update */
 254                 char *buf;
 255                 struct throughput *tp = progress->throughput;
 256
 257                 if (tp) {
 258                         uint64_t now_ns = getnanotime();
 259                         unsigned int misecs, rate;
 260                         misecs = ((now_ns - progress->start_ns) * 4398) >> 32;
 261                         rate = tp->curr_total / (misecs ? misecs : 1);
 262                         throughput_string(&tp->display, tp->curr_total, rate);
 263                 }
 264                 progress_update = 1;
 265                 buf = xstrfmt(", %s.\n", msg);
 266                 display(progress, progress->last_value, buf);
 267                 free(buf);
 268         }
 269         clear_progress_signal();
 270         if (progress->throughput)
 271                 strbuf_release(&progress->throughput->display);
 272         free(progress->throughput);
 273         free(progress);
 274 }