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