apply: demonstrate a problem applying svn diffs
[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         int last_value;
34         unsigned total;
35         unsigned last_percent;
36         unsigned delay;
37         unsigned delayed_percent_treshold;
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_treshold) {
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 struct progress *start_progress_delay(const char *title, unsigned total,
209                                        unsigned percent_treshold, 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_treshold = percent_treshold;
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_progress(const char *title, unsigned total)
231 {
232         return start_progress_delay(title, total, 0, 0);
233 }
234
235 void stop_progress(struct progress **p_progress)
236 {
237         stop_progress_msg(p_progress, _("done"));
238 }
239
240 void stop_progress_msg(struct progress **p_progress, const char *msg)
241 {
242         struct progress *progress = *p_progress;
243         if (!progress)
244                 return;
245         *p_progress = NULL;
246         if (progress->last_value != -1) {
247                 /* Force the last update */
248                 char *buf;
249                 struct throughput *tp = progress->throughput;
250
251                 if (tp) {
252                         uint64_t now_ns = getnanotime();
253                         unsigned int misecs, rate;
254                         misecs = ((now_ns - progress->start_ns) * 4398) >> 32;
255                         rate = tp->curr_total / (misecs ? misecs : 1);
256                         throughput_string(&tp->display, tp->curr_total, rate);
257                 }
258                 progress_update = 1;
259                 buf = xstrfmt(", %s.\n", msg);
260                 display(progress, progress->last_value, buf);
261                 free(buf);
262         }
263         clear_progress_signal();
264         if (progress->throughput)
265                 strbuf_release(&progress->throughput->display);
266         free(progress->throughput);
267         free(progress);
268 }