Merge branch 'rb/hpe'
[git.git] / trace.c
blobfa4a2e7120e405f3cf2d12422802b785f9e37fad
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)
34 const char *trace;
36 /* don't open twice */
37 if (key->initialized)
38 return key->fd;
40 trace = 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_disable(struct trace_key *key)
73 if (key->need_close)
74 close(key->fd);
75 key->fd = 0;
76 key->initialized = 1;
77 key->need_close = 0;
80 static int prepare_trace_line(const char *file, int line,
81 struct trace_key *key, struct strbuf *buf)
83 static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
84 struct timeval tv;
85 struct tm tm;
86 time_t secs;
88 if (!trace_want(key))
89 return 0;
91 set_try_to_free_routine(NULL); /* is never reset */
93 /* unit tests may want to disable additional trace output */
94 if (trace_want(&trace_bare))
95 return 1;
97 /* print current timestamp */
98 gettimeofday(&tv, NULL);
99 secs = tv.tv_sec;
100 localtime_r(&secs, &tm);
101 strbuf_addf(buf, "%02d:%02d:%02d.%06ld ", tm.tm_hour, tm.tm_min,
102 tm.tm_sec, (long) tv.tv_usec);
104 #ifdef HAVE_VARIADIC_MACROS
105 /* print file:line */
106 strbuf_addf(buf, "%s:%d ", file, line);
107 /* align trace output (column 40 catches most files names in git) */
108 while (buf->len < 40)
109 strbuf_addch(buf, ' ');
110 #endif
112 return 1;
115 static void trace_write(struct trace_key *key, const void *buf, unsigned len)
117 if (write_in_full(get_trace_fd(key), buf, len) < 0) {
118 warning("unable to write trace for %s: %s",
119 key->key, strerror(errno));
120 trace_disable(key);
124 void trace_verbatim(struct trace_key *key, const void *buf, unsigned len)
126 if (!trace_want(key))
127 return;
128 trace_write(key, buf, len);
131 static void print_trace_line(struct trace_key *key, struct strbuf *buf)
133 strbuf_complete_line(buf);
134 trace_write(key, buf->buf, buf->len);
137 static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
138 const char *format, va_list ap)
140 struct strbuf buf = STRBUF_INIT;
142 if (!prepare_trace_line(file, line, key, &buf))
143 return;
145 strbuf_vaddf(&buf, format, ap);
146 print_trace_line(key, &buf);
147 strbuf_release(&buf);
150 static void trace_argv_vprintf_fl(const char *file, int line,
151 const char **argv, const char *format,
152 va_list ap)
154 struct strbuf buf = STRBUF_INIT;
156 if (!prepare_trace_line(file, line, &trace_default_key, &buf))
157 return;
159 strbuf_vaddf(&buf, format, ap);
161 sq_quote_argv_pretty(&buf, argv);
162 print_trace_line(&trace_default_key, &buf);
163 strbuf_release(&buf);
166 void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
167 const struct strbuf *data)
169 struct strbuf buf = STRBUF_INIT;
171 if (!prepare_trace_line(file, line, key, &buf))
172 return;
174 strbuf_addbuf(&buf, data);
175 print_trace_line(key, &buf);
176 strbuf_release(&buf);
179 static uint64_t perf_start_times[10];
180 static int perf_indent;
182 uint64_t trace_performance_enter(void)
184 uint64_t now;
186 if (!trace_want(&trace_perf_key))
187 return 0;
189 now = getnanotime();
190 perf_start_times[perf_indent] = now;
191 if (perf_indent + 1 < ARRAY_SIZE(perf_start_times))
192 perf_indent++;
193 else
194 BUG("Too deep indentation");
195 return now;
198 static void trace_performance_vprintf_fl(const char *file, int line,
199 uint64_t nanos, const char *format,
200 va_list ap)
202 static const char space[] = " ";
203 struct strbuf buf = STRBUF_INIT;
205 if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
206 return;
208 strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
210 if (format && *format) {
211 if (perf_indent >= strlen(space))
212 BUG("Too deep indentation");
214 strbuf_addf(&buf, ":%.*s ", perf_indent, space);
215 strbuf_vaddf(&buf, format, ap);
218 print_trace_line(&trace_perf_key, &buf);
219 strbuf_release(&buf);
222 #ifndef HAVE_VARIADIC_MACROS
224 void trace_printf(const char *format, ...)
226 va_list ap;
227 va_start(ap, format);
228 trace_vprintf_fl(NULL, 0, &trace_default_key, format, ap);
229 va_end(ap);
232 void trace_printf_key(struct trace_key *key, const char *format, ...)
234 va_list ap;
235 va_start(ap, format);
236 trace_vprintf_fl(NULL, 0, key, format, ap);
237 va_end(ap);
240 void trace_argv_printf(const char **argv, const char *format, ...)
242 va_list ap;
243 va_start(ap, format);
244 trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
245 va_end(ap);
248 void trace_strbuf(struct trace_key *key, const struct strbuf *data)
250 trace_strbuf_fl(NULL, 0, key, data);
253 void trace_performance(uint64_t nanos, const char *format, ...)
255 va_list ap;
256 va_start(ap, format);
257 trace_performance_vprintf_fl(NULL, 0, nanos, format, ap);
258 va_end(ap);
261 void trace_performance_since(uint64_t start, const char *format, ...)
263 va_list ap;
264 va_start(ap, format);
265 trace_performance_vprintf_fl(NULL, 0, getnanotime() - start,
266 format, ap);
267 va_end(ap);
270 void trace_performance_leave(const char *format, ...)
272 va_list ap;
273 uint64_t since;
275 if (perf_indent)
276 perf_indent--;
278 if (!format) /* Allow callers to leave without tracing anything */
279 return;
281 since = perf_start_times[perf_indent];
282 va_start(ap, format);
283 trace_performance_vprintf_fl(NULL, 0, getnanotime() - since,
284 format, ap);
285 va_end(ap);
288 #else
290 void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
291 const char *format, ...)
293 va_list ap;
294 va_start(ap, format);
295 trace_vprintf_fl(file, line, key, format, ap);
296 va_end(ap);
299 void trace_argv_printf_fl(const char *file, int line, const char **argv,
300 const char *format, ...)
302 va_list ap;
303 va_start(ap, format);
304 trace_argv_vprintf_fl(file, line, argv, format, ap);
305 va_end(ap);
308 void trace_performance_fl(const char *file, int line, uint64_t nanos,
309 const char *format, ...)
311 va_list ap;
312 va_start(ap, format);
313 trace_performance_vprintf_fl(file, line, nanos, format, ap);
314 va_end(ap);
317 void trace_performance_leave_fl(const char *file, int line,
318 uint64_t nanos, const char *format, ...)
320 va_list ap;
321 uint64_t since;
323 if (perf_indent)
324 perf_indent--;
326 if (!format) /* Allow callers to leave without tracing anything */
327 return;
329 since = perf_start_times[perf_indent];
330 va_start(ap, format);
331 trace_performance_vprintf_fl(file, line, nanos - since, format, ap);
332 va_end(ap);
335 #endif /* HAVE_VARIADIC_MACROS */
338 static const char *quote_crnl(const char *path)
340 static struct strbuf new_path = STRBUF_INIT;
342 if (!path)
343 return NULL;
345 strbuf_reset(&new_path);
347 while (*path) {
348 switch (*path) {
349 case '\\': strbuf_addstr(&new_path, "\\\\"); break;
350 case '\n': strbuf_addstr(&new_path, "\\n"); break;
351 case '\r': strbuf_addstr(&new_path, "\\r"); break;
352 default:
353 strbuf_addch(&new_path, *path);
355 path++;
357 return new_path.buf;
360 /* FIXME: move prefix to startup_info struct and get rid of this arg */
361 void trace_repo_setup(const char *prefix)
363 const char *git_work_tree;
364 char *cwd;
366 if (!trace_want(&trace_setup_key))
367 return;
369 cwd = xgetcwd();
371 if (!(git_work_tree = get_git_work_tree()))
372 git_work_tree = "(null)";
374 if (!prefix)
375 prefix = "(null)";
377 trace_printf_key(&trace_setup_key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
378 trace_printf_key(&trace_setup_key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
379 trace_printf_key(&trace_setup_key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
380 trace_printf_key(&trace_setup_key, "setup: cwd: %s\n", quote_crnl(cwd));
381 trace_printf_key(&trace_setup_key, "setup: prefix: %s\n", quote_crnl(prefix));
383 free(cwd);
386 int trace_want(struct trace_key *key)
388 return !!get_trace_fd(key);
391 #if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC)
393 static inline uint64_t highres_nanos(void)
395 struct timespec ts;
396 if (clock_gettime(CLOCK_MONOTONIC, &ts))
397 return 0;
398 return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec;
401 #elif defined (GIT_WINDOWS_NATIVE)
403 static inline uint64_t highres_nanos(void)
405 static uint64_t high_ns, scaled_low_ns;
406 static int scale;
407 LARGE_INTEGER cnt;
409 if (!scale) {
410 if (!QueryPerformanceFrequency(&cnt))
411 return 0;
413 /* high_ns = number of ns per cnt.HighPart */
414 high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart;
417 * Number of ns per cnt.LowPart is 10^9 / frequency (or
418 * high_ns >> 32). For maximum precision, we scale this factor
419 * so that it just fits within 32 bit (i.e. won't overflow if
420 * multiplied with cnt.LowPart).
422 scaled_low_ns = high_ns;
423 scale = 32;
424 while (scaled_low_ns >= 0x100000000LL) {
425 scaled_low_ns >>= 1;
426 scale--;
430 /* if QPF worked on initialization, we expect QPC to work as well */
431 QueryPerformanceCounter(&cnt);
433 return (high_ns * cnt.HighPart) +
434 ((scaled_low_ns * cnt.LowPart) >> scale);
437 #else
438 # define highres_nanos() 0
439 #endif
441 static inline uint64_t gettimeofday_nanos(void)
443 struct timeval tv;
444 gettimeofday(&tv, NULL);
445 return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
449 * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
450 * (i.e. favoring high precision over wall clock time accuracy).
452 uint64_t getnanotime(void)
454 static uint64_t offset;
455 if (offset > 1) {
456 /* initialization succeeded, return offset + high res time */
457 return offset + highres_nanos();
458 } else if (offset == 1) {
459 /* initialization failed, fall back to gettimeofday */
460 return gettimeofday_nanos();
461 } else {
462 /* initialize offset if high resolution timer works */
463 uint64_t now = gettimeofday_nanos();
464 uint64_t highres = highres_nanos();
465 if (highres)
466 offset = now - highres;
467 else
468 offset = 1;
469 return now;
473 static struct strbuf command_line = STRBUF_INIT;
475 static void print_command_performance_atexit(void)
477 trace_performance_leave("git command:%s", command_line.buf);
480 void trace_command_performance(const char **argv)
482 if (!trace_want(&trace_perf_key))
483 return;
485 if (!command_line.len)
486 atexit(print_command_performance_atexit);
488 strbuf_reset(&command_line);
489 sq_quote_argv_pretty(&command_line, argv);
490 trace_performance_enter();