built-in rebase --autostash: leave the current branch alone if possible
[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 };
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 }