Seventh batch
[git.git] / trace.c
blobf726686fd92f0b9f388b7dddeca55edc2ea8d8a8
1 /*
2 * GIT - The information manager from hell
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
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.
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.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, see <http://www.gnu.org/licenses/>.
24 #include "cache.h"
25 #include "quote.h"
27 struct trace_key trace_default_key = { "GIT_TRACE", 0, 0, 0 };
28 struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
29 struct trace_key trace_setup_key = TRACE_KEY_INIT(SETUP);
31 /* Get a trace file descriptor from "key" env variable. */
32 static int get_trace_fd(struct trace_key *key, const char *override_envvar)
34 const char *trace;
36 /* don't open twice */
37 if (key->initialized)
38 return key->fd;
40 trace = override_envvar ? override_envvar : getenv(key->key);
42 if (!trace || !strcmp(trace, "") ||
43 !strcmp(trace, "0") || !strcasecmp(trace, "false"))
44 key->fd = 0;
45 else if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
46 key->fd = STDERR_FILENO;
47 else if (strlen(trace) == 1 && isdigit(*trace))
48 key->fd = atoi(trace);
49 else if (is_absolute_path(trace)) {
50 int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
51 if (fd == -1) {
52 warning("could not open '%s' for tracing: %s",
53 trace, strerror(errno));
54 trace_disable(key);
55 } else {
56 key->fd = fd;
57 key->need_close = 1;
59 } else {
60 warning("unknown trace value for '%s': %s\n"
61 " If you want to trace into a file, then please set %s\n"
62 " to an absolute pathname (starting with /)",
63 key->key, trace, key->key);
64 trace_disable(key);
67 key->initialized = 1;
68 return key->fd;
71 void trace_override_envvar(struct trace_key *key, const char *value)
73 trace_disable(key);
74 key->initialized = 0;
77 * Invoke get_trace_fd() to initialize key using the given value
78 * instead of the value of the environment variable.
80 get_trace_fd(key, value);
83 void trace_disable(struct trace_key *key)
85 if (key->need_close)
86 close(key->fd);
87 key->fd = 0;
88 key->initialized = 1;
89 key->need_close = 0;
92 static int prepare_trace_line(const char *file, int line,
93 struct trace_key *key, struct strbuf *buf)
95 static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
96 struct timeval tv;
97 struct tm tm;
98 time_t secs;
100 if (!trace_want(key))
101 return 0;
103 /* unit tests may want to disable additional trace output */
104 if (trace_want(&trace_bare))
105 return 1;
107 /* print current timestamp */
108 gettimeofday(&tv, NULL);
109 secs = tv.tv_sec;
110 localtime_r(&secs, &tm);
111 strbuf_addf(buf, "%02d:%02d:%02d.%06ld ", tm.tm_hour, tm.tm_min,
112 tm.tm_sec, (long) tv.tv_usec);
114 #ifdef HAVE_VARIADIC_MACROS
115 /* print file:line */
116 strbuf_addf(buf, "%s:%d ", file, line);
117 /* align trace output (column 40 catches most files names in git) */
118 while (buf->len < 40)
119 strbuf_addch(buf, ' ');
120 #endif
122 return 1;
125 static void trace_write(struct trace_key *key, const void *buf, unsigned len)
127 if (write_in_full(get_trace_fd(key, NULL), buf, len) < 0) {
128 warning("unable to write trace for %s: %s",
129 key->key, strerror(errno));
130 trace_disable(key);
134 void trace_verbatim(struct trace_key *key, const void *buf, unsigned len)
136 if (!trace_want(key))
137 return;
138 trace_write(key, buf, len);
141 static void print_trace_line(struct trace_key *key, struct strbuf *buf)
143 strbuf_complete_line(buf);
144 trace_write(key, buf->buf, buf->len);
147 static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
148 const char *format, va_list ap)
150 struct strbuf buf = STRBUF_INIT;
152 if (!prepare_trace_line(file, line, key, &buf))
153 return;
155 strbuf_vaddf(&buf, format, ap);
156 print_trace_line(key, &buf);
157 strbuf_release(&buf);
160 static void trace_argv_vprintf_fl(const char *file, int line,
161 const char **argv, const char *format,
162 va_list ap)
164 struct strbuf buf = STRBUF_INIT;
166 if (!prepare_trace_line(file, line, &trace_default_key, &buf))
167 return;
169 strbuf_vaddf(&buf, format, ap);
171 sq_quote_argv_pretty(&buf, argv);
172 print_trace_line(&trace_default_key, &buf);
173 strbuf_release(&buf);
176 void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
177 const struct strbuf *data)
179 struct strbuf buf = STRBUF_INIT;
181 if (!prepare_trace_line(file, line, key, &buf))
182 return;
184 strbuf_addbuf(&buf, data);
185 print_trace_line(key, &buf);
186 strbuf_release(&buf);
189 static uint64_t perf_start_times[10];
190 static int perf_indent;
192 uint64_t trace_performance_enter(void)
194 uint64_t now;
196 if (!trace_want(&trace_perf_key))
197 return 0;
199 now = getnanotime();
200 perf_start_times[perf_indent] = now;
201 if (perf_indent + 1 < ARRAY_SIZE(perf_start_times))
202 perf_indent++;
203 else
204 BUG("Too deep indentation");
205 return now;
208 static void trace_performance_vprintf_fl(const char *file, int line,
209 uint64_t nanos, const char *format,
210 va_list ap)
212 static const char space[] = " ";
213 struct strbuf buf = STRBUF_INIT;
215 if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
216 return;
218 strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
220 if (format && *format) {
221 if (perf_indent >= strlen(space))
222 BUG("Too deep indentation");
224 strbuf_addf(&buf, ":%.*s ", perf_indent, space);
225 strbuf_vaddf(&buf, format, ap);
228 print_trace_line(&trace_perf_key, &buf);
229 strbuf_release(&buf);
232 #ifndef HAVE_VARIADIC_MACROS
234 void trace_printf(const char *format, ...)
236 va_list ap;
237 va_start(ap, format);
238 trace_vprintf_fl(NULL, 0, &trace_default_key, format, ap);
239 va_end(ap);
242 void trace_printf_key(struct trace_key *key, const char *format, ...)
244 va_list ap;
245 va_start(ap, format);
246 trace_vprintf_fl(NULL, 0, key, format, ap);
247 va_end(ap);
250 void trace_argv_printf(const char **argv, const char *format, ...)
252 va_list ap;
253 va_start(ap, format);
254 trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
255 va_end(ap);
258 void trace_strbuf(struct trace_key *key, const struct strbuf *data)
260 trace_strbuf_fl(NULL, 0, key, data);
263 void trace_performance(uint64_t nanos, const char *format, ...)
265 va_list ap;
266 va_start(ap, format);
267 trace_performance_vprintf_fl(NULL, 0, nanos, format, ap);
268 va_end(ap);
271 void trace_performance_since(uint64_t start, const char *format, ...)
273 va_list ap;
274 va_start(ap, format);
275 trace_performance_vprintf_fl(NULL, 0, getnanotime() - start,
276 format, ap);
277 va_end(ap);
280 void trace_performance_leave(const char *format, ...)
282 va_list ap;
283 uint64_t since;
285 if (perf_indent)
286 perf_indent--;
288 if (!format) /* Allow callers to leave without tracing anything */
289 return;
291 since = perf_start_times[perf_indent];
292 va_start(ap, format);
293 trace_performance_vprintf_fl(NULL, 0, getnanotime() - since,
294 format, ap);
295 va_end(ap);
298 #else
300 void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
301 const char *format, ...)
303 va_list ap;
304 va_start(ap, format);
305 trace_vprintf_fl(file, line, key, format, ap);
306 va_end(ap);
309 void trace_argv_printf_fl(const char *file, int line, const char **argv,
310 const char *format, ...)
312 va_list ap;
313 va_start(ap, format);
314 trace_argv_vprintf_fl(file, line, argv, format, ap);
315 va_end(ap);
318 void trace_performance_fl(const char *file, int line, uint64_t nanos,
319 const char *format, ...)
321 va_list ap;
322 va_start(ap, format);
323 trace_performance_vprintf_fl(file, line, nanos, format, ap);
324 va_end(ap);
327 void trace_performance_leave_fl(const char *file, int line,
328 uint64_t nanos, const char *format, ...)
330 va_list ap;
331 uint64_t since;
333 if (perf_indent)
334 perf_indent--;
336 if (!format) /* Allow callers to leave without tracing anything */
337 return;
339 since = perf_start_times[perf_indent];
340 va_start(ap, format);
341 trace_performance_vprintf_fl(file, line, nanos - since, format, ap);
342 va_end(ap);
345 #endif /* HAVE_VARIADIC_MACROS */
348 static const char *quote_crnl(const char *path)
350 static struct strbuf new_path = STRBUF_INIT;
352 if (!path)
353 return NULL;
355 strbuf_reset(&new_path);
357 while (*path) {
358 switch (*path) {
359 case '\\': strbuf_addstr(&new_path, "\\\\"); break;
360 case '\n': strbuf_addstr(&new_path, "\\n"); break;
361 case '\r': strbuf_addstr(&new_path, "\\r"); break;
362 default:
363 strbuf_addch(&new_path, *path);
365 path++;
367 return new_path.buf;
370 /* FIXME: move prefix to startup_info struct and get rid of this arg */
371 void trace_repo_setup(const char *prefix)
373 const char *git_work_tree;
374 char *cwd;
376 if (!trace_want(&trace_setup_key))
377 return;
379 cwd = xgetcwd();
381 if (!(git_work_tree = get_git_work_tree()))
382 git_work_tree = "(null)";
384 if (!prefix)
385 prefix = "(null)";
387 trace_printf_key(&trace_setup_key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
388 trace_printf_key(&trace_setup_key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
389 trace_printf_key(&trace_setup_key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
390 trace_printf_key(&trace_setup_key, "setup: cwd: %s\n", quote_crnl(cwd));
391 trace_printf_key(&trace_setup_key, "setup: prefix: %s\n", quote_crnl(prefix));
393 free(cwd);
396 int trace_want(struct trace_key *key)
398 return !!get_trace_fd(key, NULL);
401 #if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC)
403 static inline uint64_t highres_nanos(void)
405 struct timespec ts;
406 if (clock_gettime(CLOCK_MONOTONIC, &ts))
407 return 0;
408 return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec;
411 #elif defined (GIT_WINDOWS_NATIVE)
413 static inline uint64_t highres_nanos(void)
415 static uint64_t high_ns, scaled_low_ns;
416 static int scale;
417 LARGE_INTEGER cnt;
419 if (!scale) {
420 if (!QueryPerformanceFrequency(&cnt))
421 return 0;
423 /* high_ns = number of ns per cnt.HighPart */
424 high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart;
427 * Number of ns per cnt.LowPart is 10^9 / frequency (or
428 * high_ns >> 32). For maximum precision, we scale this factor
429 * so that it just fits within 32 bit (i.e. won't overflow if
430 * multiplied with cnt.LowPart).
432 scaled_low_ns = high_ns;
433 scale = 32;
434 while (scaled_low_ns >= 0x100000000LL) {
435 scaled_low_ns >>= 1;
436 scale--;
440 /* if QPF worked on initialization, we expect QPC to work as well */
441 QueryPerformanceCounter(&cnt);
443 return (high_ns * cnt.HighPart) +
444 ((scaled_low_ns * cnt.LowPart) >> scale);
447 #else
448 # define highres_nanos() 0
449 #endif
451 static inline uint64_t gettimeofday_nanos(void)
453 struct timeval tv;
454 gettimeofday(&tv, NULL);
455 return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
459 * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
460 * (i.e. favoring high precision over wall clock time accuracy).
462 uint64_t getnanotime(void)
464 static uint64_t offset;
465 if (offset > 1) {
466 /* initialization succeeded, return offset + high res time */
467 return offset + highres_nanos();
468 } else if (offset == 1) {
469 /* initialization failed, fall back to gettimeofday */
470 return gettimeofday_nanos();
471 } else {
472 /* initialize offset if high resolution timer works */
473 uint64_t now = gettimeofday_nanos();
474 uint64_t highres = highres_nanos();
475 if (highres)
476 offset = now - highres;
477 else
478 offset = 1;
479 return now;
483 static struct strbuf command_line = STRBUF_INIT;
485 static void print_command_performance_atexit(void)
487 trace_performance_leave("git command:%s", command_line.buf);
490 void trace_command_performance(const char **argv)
492 if (!trace_want(&trace_perf_key))
493 return;
495 if (!command_line.len)
496 atexit(print_command_performance_atexit);
498 strbuf_reset(&command_line);
499 sq_quote_argv_pretty(&command_line, argv);
500 trace_performance_enter();