progress: clear previous progress update dynamically
[git] / 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         struct strbuf counters_sb;
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 void display(struct progress *progress, uint64_t n, const char *done)
83 {
84         const char *tp;
85         struct strbuf *counters_sb = &progress->counters_sb;
86         int show_update = 0;
87         int last_count_len = counters_sb->len;
88
89         if (progress->delay && (!progress_update || --progress->delay))
90                 return;
91
92         progress->last_value = n;
93         tp = (progress->throughput) ? progress->throughput->display.buf : "";
94         if (progress->total) {
95                 unsigned percent = n * 100 / progress->total;
96                 if (percent != progress->last_percent || progress_update) {
97                         progress->last_percent = percent;
98
99                         strbuf_reset(counters_sb);
100                         strbuf_addf(counters_sb,
101                                     "%3u%% (%"PRIuMAX"/%"PRIuMAX")%s", percent,
102                                     (uintmax_t)n, (uintmax_t)progress->total,
103                                     tp);
104                         show_update = 1;
105                 }
106         } else if (progress_update) {
107                 strbuf_reset(counters_sb);
108                 strbuf_addf(counters_sb, "%"PRIuMAX"%s", (uintmax_t)n, tp);
109                 show_update = 1;
110         }
111
112         if (show_update) {
113                 if (is_foreground_fd(fileno(stderr)) || done) {
114                         const char *eol = done ? done : "\r";
115                         size_t clear_len = counters_sb->len < last_count_len ?
116                                         last_count_len - counters_sb->len + 1 :
117                                         0;
118                         fprintf(stderr, "%s: %s%*s", progress->title,
119                                 counters_sb->buf, (int) clear_len, eol);
120                         fflush(stderr);
121                 }
122                 progress_update = 0;
123         }
124 }
125
126 static void throughput_string(struct strbuf *buf, uint64_t total,
127                               unsigned int rate)
128 {
129         strbuf_reset(buf);
130         strbuf_addstr(buf, ", ");
131         strbuf_humanise_bytes(buf, total);
132         strbuf_addstr(buf, " | ");
133         strbuf_humanise_bytes(buf, rate * 1024);
134         strbuf_addstr(buf, "/s");
135 }
136
137 void display_throughput(struct progress *progress, uint64_t total)
138 {
139         struct throughput *tp;
140         uint64_t now_ns;
141         unsigned int misecs, count, rate;
142
143         if (!progress)
144                 return;
145         tp = progress->throughput;
146
147         now_ns = getnanotime();
148
149         if (!tp) {
150                 progress->throughput = tp = calloc(1, sizeof(*tp));
151                 if (tp) {
152                         tp->prev_total = tp->curr_total = total;
153                         tp->prev_ns = now_ns;
154                         strbuf_init(&tp->display, 0);
155                 }
156                 return;
157         }
158         tp->curr_total = total;
159
160         /* only update throughput every 0.5 s */
161         if (now_ns - tp->prev_ns <= 500000000)
162                 return;
163
164         /*
165          * We have x = bytes and y = nanosecs.  We want z = KiB/s:
166          *
167          *      z = (x / 1024) / (y / 1000000000)
168          *      z = x / y * 1000000000 / 1024
169          *      z = x / (y * 1024 / 1000000000)
170          *      z = x / y'
171          *
172          * To simplify things we'll keep track of misecs, or 1024th of a sec
173          * obtained with:
174          *
175          *      y' = y * 1024 / 1000000000
176          *      y' = y * (2^10 / 2^42) * (2^42 / 1000000000)
177          *      y' = y / 2^32 * 4398
178          *      y' = (y * 4398) >> 32
179          */
180         misecs = ((now_ns - tp->prev_ns) * 4398) >> 32;
181
182         count = total - tp->prev_total;
183         tp->prev_total = total;
184         tp->prev_ns = now_ns;
185         tp->avg_bytes += count;
186         tp->avg_misecs += misecs;
187         rate = tp->avg_bytes / tp->avg_misecs;
188         tp->avg_bytes -= tp->last_bytes[tp->idx];
189         tp->avg_misecs -= tp->last_misecs[tp->idx];
190         tp->last_bytes[tp->idx] = count;
191         tp->last_misecs[tp->idx] = misecs;
192         tp->idx = (tp->idx + 1) % TP_IDX_MAX;
193
194         throughput_string(&tp->display, total, rate);
195         if (progress->last_value != -1 && progress_update)
196                 display(progress, progress->last_value, NULL);
197 }
198
199 void display_progress(struct progress *progress, uint64_t n)
200 {
201         if (progress)
202                 display(progress, n, NULL);
203 }
204
205 static struct progress *start_progress_delay(const char *title, uint64_t total,
206                                              unsigned delay)
207 {
208         struct progress *progress = malloc(sizeof(*progress));
209         if (!progress) {
210                 /* unlikely, but here's a good fallback */
211                 fprintf(stderr, "%s...\n", title);
212                 fflush(stderr);
213                 return NULL;
214         }
215         progress->title = title;
216         progress->total = total;
217         progress->last_value = -1;
218         progress->last_percent = -1;
219         progress->delay = delay;
220         progress->throughput = NULL;
221         progress->start_ns = getnanotime();
222         strbuf_init(&progress->counters_sb, 0);
223         set_progress_signal();
224         return progress;
225 }
226
227 struct progress *start_delayed_progress(const char *title, uint64_t total)
228 {
229         return start_progress_delay(title, total, 2);
230 }
231
232 struct progress *start_progress(const char *title, uint64_t total)
233 {
234         return start_progress_delay(title, total, 0);
235 }
236
237 void stop_progress(struct progress **p_progress)
238 {
239         stop_progress_msg(p_progress, _("done"));
240 }
241
242 void stop_progress_msg(struct progress **p_progress, const char *msg)
243 {
244         struct progress *progress = *p_progress;
245         if (!progress)
246                 return;
247         *p_progress = NULL;
248         if (progress->last_value != -1) {
249                 /* Force the last update */
250                 char *buf;
251                 struct throughput *tp = progress->throughput;
252
253                 if (tp) {
254                         uint64_t now_ns = getnanotime();
255                         unsigned int misecs, rate;
256                         misecs = ((now_ns - progress->start_ns) * 4398) >> 32;
257                         rate = tp->curr_total / (misecs ? misecs : 1);
258                         throughput_string(&tp->display, tp->curr_total, rate);
259                 }
260                 progress_update = 1;
261                 buf = xstrfmt(", %s.\n", msg);
262                 display(progress, progress->last_value, buf);
263                 free(buf);
264         }
265         clear_progress_signal();
266         strbuf_release(&progress->counters_sb);
267         if (progress->throughput)
268                 strbuf_release(&progress->throughput->display);
269         free(progress->throughput);
270         free(progress);
271 }