4d68eb522f0838c7e9481b30cd004091ef347632
1/*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) 2000-2002 Michael R. Elkins <me@mutt.org>
5 * Copyright (C) 2002-2004 Oswald Buddenhagen <ossi@users.sf.net>
6 * Copyright (C) 2004 Theodore Y. Ts'o <tytso@mit.edu>
7 * Copyright (C) 2006 Mike McCormack
8 * Copyright (C) 2006 Christian Couder
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24
25#include "cache.h"
26#include "quote.h"
27
28/*
29 * "Normalize" a key argument by converting NULL to our trace_default,
30 * and otherwise passing through the value. All caller-facing functions
31 * should normalize their inputs in this way, though most get it
32 * for free by calling get_trace_fd() (directly or indirectly).
33 */
34static void normalize_trace_key(struct trace_key **key)
35{
36 static struct trace_key trace_default = { "GIT_TRACE" };
37 if (!*key)
38 *key = &trace_default;
39}
40
41/* Get a trace file descriptor from "key" env variable. */
42static int get_trace_fd(struct trace_key *key)
43{
44 const char *trace;
45
46 normalize_trace_key(&key);
47
48 /* don't open twice */
49 if (key->initialized)
50 return key->fd;
51
52 trace = getenv(key->key);
53
54 if (!trace || !strcmp(trace, "") ||
55 !strcmp(trace, "0") || !strcasecmp(trace, "false"))
56 key->fd = 0;
57 else if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
58 key->fd = STDERR_FILENO;
59 else if (strlen(trace) == 1 && isdigit(*trace))
60 key->fd = atoi(trace);
61 else if (is_absolute_path(trace)) {
62 int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
63 if (fd == -1) {
64 warning("could not open '%s' for tracing: %s\n"
65 " Defaulting to tracing on stderr...",
66 trace, strerror(errno));
67 key->fd = STDERR_FILENO;
68 } else {
69 key->fd = fd;
70 key->need_close = 1;
71 }
72 } else {
73 warning("unknown trace value for '%s': %s\n"
74 " If you want to trace into a file, then please set %s\n"
75 " to an absolute pathname (starting with /)\n"
76 " Defaulting to tracing on stderr...",
77 key->key, trace, key->key);
78 key->fd = STDERR_FILENO;
79 }
80
81 key->initialized = 1;
82 return key->fd;
83}
84
85void trace_disable(struct trace_key *key)
86{
87 normalize_trace_key(&key);
88
89 if (key->need_close)
90 close(key->fd);
91 key->fd = 0;
92 key->initialized = 1;
93 key->need_close = 0;
94}
95
96static const char err_msg[] = "could not trace into fd given by "
97 "GIT_TRACE environment variable";
98
99static int prepare_trace_line(const char *file, int line,
100 struct trace_key *key, struct strbuf *buf)
101{
102 static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
103 struct timeval tv;
104 struct tm tm;
105 time_t secs;
106
107 if (!trace_want(key))
108 return 0;
109
110 set_try_to_free_routine(NULL); /* is never reset */
111
112 /* unit tests may want to disable additional trace output */
113 if (trace_want(&trace_bare))
114 return 1;
115
116 /* print current timestamp */
117 gettimeofday(&tv, NULL);
118 secs = tv.tv_sec;
119 localtime_r(&secs, &tm);
120 strbuf_addf(buf, "%02d:%02d:%02d.%06ld ", tm.tm_hour, tm.tm_min,
121 tm.tm_sec, (long) tv.tv_usec);
122
123#ifdef HAVE_VARIADIC_MACROS
124 /* print file:line */
125 strbuf_addf(buf, "%s:%d ", file, line);
126 /* align trace output (column 40 catches most files names in git) */
127 while (buf->len < 40)
128 strbuf_addch(buf, ' ');
129#endif
130
131 return 1;
132}
133
134static void trace_write(struct trace_key *key, const void *buf, unsigned len)
135{
136 if (write_in_full(get_trace_fd(key), buf, len) < 0)
137 warning("%s: write error (%s)", err_msg, strerror(errno));
138}
139
140void trace_verbatim(struct trace_key *key, const void *buf, unsigned len)
141{
142 if (!trace_want(key))
143 return;
144 trace_write(key, buf, len);
145}
146
147static void print_trace_line(struct trace_key *key, struct strbuf *buf)
148{
149 strbuf_complete_line(buf);
150 trace_write(key, buf->buf, buf->len);
151 strbuf_release(buf);
152}
153
154static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
155 const char *format, va_list ap)
156{
157 struct strbuf buf = STRBUF_INIT;
158
159 if (!prepare_trace_line(file, line, key, &buf))
160 return;
161
162 strbuf_vaddf(&buf, format, ap);
163 print_trace_line(key, &buf);
164}
165
166static void trace_argv_vprintf_fl(const char *file, int line,
167 const char **argv, const char *format,
168 va_list ap)
169{
170 struct strbuf buf = STRBUF_INIT;
171
172 if (!prepare_trace_line(file, line, NULL, &buf))
173 return;
174
175 strbuf_vaddf(&buf, format, ap);
176
177 sq_quote_argv(&buf, argv, 0);
178 print_trace_line(NULL, &buf);
179}
180
181void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
182 const struct strbuf *data)
183{
184 struct strbuf buf = STRBUF_INIT;
185
186 if (!prepare_trace_line(file, line, key, &buf))
187 return;
188
189 strbuf_addbuf(&buf, data);
190 print_trace_line(key, &buf);
191}
192
193static struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
194
195static void trace_performance_vprintf_fl(const char *file, int line,
196 uint64_t nanos, const char *format,
197 va_list ap)
198{
199 struct strbuf buf = STRBUF_INIT;
200
201 if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
202 return;
203
204 strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
205
206 if (format && *format) {
207 strbuf_addstr(&buf, ": ");
208 strbuf_vaddf(&buf, format, ap);
209 }
210
211 print_trace_line(&trace_perf_key, &buf);
212}
213
214#ifndef HAVE_VARIADIC_MACROS
215
216void trace_printf(const char *format, ...)
217{
218 va_list ap;
219 va_start(ap, format);
220 trace_vprintf_fl(NULL, 0, NULL, format, ap);
221 va_end(ap);
222}
223
224void trace_printf_key(struct trace_key *key, const char *format, ...)
225{
226 va_list ap;
227 va_start(ap, format);
228 trace_vprintf_fl(NULL, 0, key, format, ap);
229 va_end(ap);
230}
231
232void trace_argv_printf(const char **argv, const char *format, ...)
233{
234 va_list ap;
235 va_start(ap, format);
236 trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
237 va_end(ap);
238}
239
240void trace_strbuf(struct trace_key *key, const struct strbuf *data)
241{
242 trace_strbuf_fl(NULL, 0, key, data);
243}
244
245void trace_performance(uint64_t nanos, const char *format, ...)
246{
247 va_list ap;
248 va_start(ap, format);
249 trace_performance_vprintf_fl(NULL, 0, nanos, format, ap);
250 va_end(ap);
251}
252
253void trace_performance_since(uint64_t start, const char *format, ...)
254{
255 va_list ap;
256 va_start(ap, format);
257 trace_performance_vprintf_fl(NULL, 0, getnanotime() - start,
258 format, ap);
259 va_end(ap);
260}
261
262#else
263
264void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
265 const char *format, ...)
266{
267 va_list ap;
268 va_start(ap, format);
269 trace_vprintf_fl(file, line, key, format, ap);
270 va_end(ap);
271}
272
273void trace_argv_printf_fl(const char *file, int line, const char **argv,
274 const char *format, ...)
275{
276 va_list ap;
277 va_start(ap, format);
278 trace_argv_vprintf_fl(file, line, argv, format, ap);
279 va_end(ap);
280}
281
282void trace_performance_fl(const char *file, int line, uint64_t nanos,
283 const char *format, ...)
284{
285 va_list ap;
286 va_start(ap, format);
287 trace_performance_vprintf_fl(file, line, nanos, format, ap);
288 va_end(ap);
289}
290
291#endif /* HAVE_VARIADIC_MACROS */
292
293
294static const char *quote_crnl(const char *path)
295{
296 static struct strbuf new_path = STRBUF_INIT;
297
298 if (!path)
299 return NULL;
300
301 strbuf_reset(&new_path);
302
303 while (*path) {
304 switch (*path) {
305 case '\\': strbuf_addstr(&new_path, "\\\\"); break;
306 case '\n': strbuf_addstr(&new_path, "\\n"); break;
307 case '\r': strbuf_addstr(&new_path, "\\r"); break;
308 default:
309 strbuf_addch(&new_path, *path);
310 }
311 path++;
312 }
313 return new_path.buf;
314}
315
316/* FIXME: move prefix to startup_info struct and get rid of this arg */
317void trace_repo_setup(const char *prefix)
318{
319 static struct trace_key key = TRACE_KEY_INIT(SETUP);
320 const char *git_work_tree;
321 char *cwd;
322
323 if (!trace_want(&key))
324 return;
325
326 cwd = xgetcwd();
327
328 if (!(git_work_tree = get_git_work_tree()))
329 git_work_tree = "(null)";
330
331 if (!prefix)
332 prefix = "(null)";
333
334 trace_printf_key(&key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
335 trace_printf_key(&key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
336 trace_printf_key(&key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
337 trace_printf_key(&key, "setup: cwd: %s\n", quote_crnl(cwd));
338 trace_printf_key(&key, "setup: prefix: %s\n", quote_crnl(prefix));
339
340 free(cwd);
341}
342
343int trace_want(struct trace_key *key)
344{
345 return !!get_trace_fd(key);
346}
347
348#if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC)
349
350static inline uint64_t highres_nanos(void)
351{
352 struct timespec ts;
353 if (clock_gettime(CLOCK_MONOTONIC, &ts))
354 return 0;
355 return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec;
356}
357
358#elif defined (GIT_WINDOWS_NATIVE)
359
360static inline uint64_t highres_nanos(void)
361{
362 static uint64_t high_ns, scaled_low_ns;
363 static int scale;
364 LARGE_INTEGER cnt;
365
366 if (!scale) {
367 if (!QueryPerformanceFrequency(&cnt))
368 return 0;
369
370 /* high_ns = number of ns per cnt.HighPart */
371 high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart;
372
373 /*
374 * Number of ns per cnt.LowPart is 10^9 / frequency (or
375 * high_ns >> 32). For maximum precision, we scale this factor
376 * so that it just fits within 32 bit (i.e. won't overflow if
377 * multiplied with cnt.LowPart).
378 */
379 scaled_low_ns = high_ns;
380 scale = 32;
381 while (scaled_low_ns >= 0x100000000LL) {
382 scaled_low_ns >>= 1;
383 scale--;
384 }
385 }
386
387 /* if QPF worked on initialization, we expect QPC to work as well */
388 QueryPerformanceCounter(&cnt);
389
390 return (high_ns * cnt.HighPart) +
391 ((scaled_low_ns * cnt.LowPart) >> scale);
392}
393
394#else
395# define highres_nanos() 0
396#endif
397
398static inline uint64_t gettimeofday_nanos(void)
399{
400 struct timeval tv;
401 gettimeofday(&tv, NULL);
402 return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
403}
404
405/*
406 * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
407 * (i.e. favoring high precision over wall clock time accuracy).
408 */
409uint64_t getnanotime(void)
410{
411 static uint64_t offset;
412 if (offset > 1) {
413 /* initialization succeeded, return offset + high res time */
414 return offset + highres_nanos();
415 } else if (offset == 1) {
416 /* initialization failed, fall back to gettimeofday */
417 return gettimeofday_nanos();
418 } else {
419 /* initialize offset if high resolution timer works */
420 uint64_t now = gettimeofday_nanos();
421 uint64_t highres = highres_nanos();
422 if (highres)
423 offset = now - highres;
424 else
425 offset = 1;
426 return now;
427 }
428}
429
430static uint64_t command_start_time;
431static struct strbuf command_line = STRBUF_INIT;
432
433static void print_command_performance_atexit(void)
434{
435 trace_performance_since(command_start_time, "git command:%s",
436 command_line.buf);
437}
438
439void trace_command_performance(const char **argv)
440{
441 if (!trace_want(&trace_perf_key))
442 return;
443
444 if (!command_start_time)
445 atexit(print_command_performance_atexit);
446
447 strbuf_reset(&command_line);
448 sq_quote_argv(&command_line, argv, 0);
449 command_start_time = getnanotime();
450}