Merge branch 'rs/alias-use-copy-array'
[git/git.git] / trace.c
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, see <http://www.gnu.org/licenses/>.
22 */
23
24 #include "cache.h"
25 #include "quote.h"
26
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);
30
31 /* Get a trace file descriptor from "key" env variable. */
32 static int get_trace_fd(struct trace_key *key)
33 {
34 const char *trace;
35
36 /* don't open twice */
37 if (key->initialized)
38 return key->fd;
39
40 trace = getenv(key->key);
41
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;
58 }
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);
65 }
66
67 key->initialized = 1;
68 return key->fd;
69 }
70
71 void trace_disable(struct trace_key *key)
72 {
73 if (key->need_close)
74 close(key->fd);
75 key->fd = 0;
76 key->initialized = 1;
77 key->need_close = 0;
78 }
79
80 static int prepare_trace_line(const char *file, int line,
81 struct trace_key *key, struct strbuf *buf)
82 {
83 static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
84 struct timeval tv;
85 struct tm tm;
86 time_t secs;
87
88 if (!trace_want(key))
89 return 0;
90
91 /* unit tests may want to disable additional trace output */
92 if (trace_want(&trace_bare))
93 return 1;
94
95 /* print current timestamp */
96 gettimeofday(&tv, NULL);
97 secs = tv.tv_sec;
98 localtime_r(&secs, &tm);
99 strbuf_addf(buf, "%02d:%02d:%02d.%06ld ", tm.tm_hour, tm.tm_min,
100 tm.tm_sec, (long) tv.tv_usec);
101
102 #ifdef HAVE_VARIADIC_MACROS
103 /* print file:line */
104 strbuf_addf(buf, "%s:%d ", file, line);
105 /* align trace output (column 40 catches most files names in git) */
106 while (buf->len < 40)
107 strbuf_addch(buf, ' ');
108 #endif
109
110 return 1;
111 }
112
113 static void trace_write(struct trace_key *key, const void *buf, unsigned len)
114 {
115 if (write_in_full(get_trace_fd(key), buf, len) < 0) {
116 warning("unable to write trace for %s: %s",
117 key->key, strerror(errno));
118 trace_disable(key);
119 }
120 }
121
122 void trace_verbatim(struct trace_key *key, const void *buf, unsigned len)
123 {
124 if (!trace_want(key))
125 return;
126 trace_write(key, buf, len);
127 }
128
129 static void print_trace_line(struct trace_key *key, struct strbuf *buf)
130 {
131 strbuf_complete_line(buf);
132 trace_write(key, buf->buf, buf->len);
133 }
134
135 static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
136 const char *format, va_list ap)
137 {
138 struct strbuf buf = STRBUF_INIT;
139
140 if (!prepare_trace_line(file, line, key, &buf))
141 return;
142
143 strbuf_vaddf(&buf, format, ap);
144 print_trace_line(key, &buf);
145 strbuf_release(&buf);
146 }
147
148 static void trace_argv_vprintf_fl(const char *file, int line,
149 const char **argv, const char *format,
150 va_list ap)
151 {
152 struct strbuf buf = STRBUF_INIT;
153
154 if (!prepare_trace_line(file, line, &trace_default_key, &buf))
155 return;
156
157 strbuf_vaddf(&buf, format, ap);
158
159 sq_quote_argv_pretty(&buf, argv);
160 print_trace_line(&trace_default_key, &buf);
161 strbuf_release(&buf);
162 }
163
164 void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
165 const struct strbuf *data)
166 {
167 struct strbuf buf = STRBUF_INIT;
168
169 if (!prepare_trace_line(file, line, key, &buf))
170 return;
171
172 strbuf_addbuf(&buf, data);
173 print_trace_line(key, &buf);
174 strbuf_release(&buf);
175 }
176
177 static uint64_t perf_start_times[10];
178 static int perf_indent;
179
180 uint64_t trace_performance_enter(void)
181 {
182 uint64_t now;
183
184 if (!trace_want(&trace_perf_key))
185 return 0;
186
187 now = getnanotime();
188 perf_start_times[perf_indent] = now;
189 if (perf_indent + 1 < ARRAY_SIZE(perf_start_times))
190 perf_indent++;
191 else
192 BUG("Too deep indentation");
193 return now;
194 }
195
196 static void trace_performance_vprintf_fl(const char *file, int line,
197 uint64_t nanos, const char *format,
198 va_list ap)
199 {
200 static const char space[] = " ";
201 struct strbuf buf = STRBUF_INIT;
202
203 if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
204 return;
205
206 strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
207
208 if (format && *format) {
209 if (perf_indent >= strlen(space))
210 BUG("Too deep indentation");
211
212 strbuf_addf(&buf, ":%.*s ", perf_indent, space);
213 strbuf_vaddf(&buf, format, ap);
214 }
215
216 print_trace_line(&trace_perf_key, &buf);
217 strbuf_release(&buf);
218 }
219
220 #ifndef HAVE_VARIADIC_MACROS
221
222 void trace_printf(const char *format, ...)
223 {
224 va_list ap;
225 va_start(ap, format);
226 trace_vprintf_fl(NULL, 0, &trace_default_key, format, ap);
227 va_end(ap);
228 }
229
230 void trace_printf_key(struct trace_key *key, const char *format, ...)
231 {
232 va_list ap;
233 va_start(ap, format);
234 trace_vprintf_fl(NULL, 0, key, format, ap);
235 va_end(ap);
236 }
237
238 void trace_argv_printf(const char **argv, const char *format, ...)
239 {
240 va_list ap;
241 va_start(ap, format);
242 trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
243 va_end(ap);
244 }
245
246 void trace_strbuf(struct trace_key *key, const struct strbuf *data)
247 {
248 trace_strbuf_fl(NULL, 0, key, data);
249 }
250
251 void trace_performance(uint64_t nanos, const char *format, ...)
252 {
253 va_list ap;
254 va_start(ap, format);
255 trace_performance_vprintf_fl(NULL, 0, nanos, format, ap);
256 va_end(ap);
257 }
258
259 void trace_performance_since(uint64_t start, const char *format, ...)
260 {
261 va_list ap;
262 va_start(ap, format);
263 trace_performance_vprintf_fl(NULL, 0, getnanotime() - start,
264 format, ap);
265 va_end(ap);
266 }
267
268 void trace_performance_leave(const char *format, ...)
269 {
270 va_list ap;
271 uint64_t since;
272
273 if (perf_indent)
274 perf_indent--;
275
276 if (!format) /* Allow callers to leave without tracing anything */
277 return;
278
279 since = perf_start_times[perf_indent];
280 va_start(ap, format);
281 trace_performance_vprintf_fl(NULL, 0, getnanotime() - since,
282 format, ap);
283 va_end(ap);
284 }
285
286 #else
287
288 void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
289 const char *format, ...)
290 {
291 va_list ap;
292 va_start(ap, format);
293 trace_vprintf_fl(file, line, key, format, ap);
294 va_end(ap);
295 }
296
297 void trace_argv_printf_fl(const char *file, int line, const char **argv,
298 const char *format, ...)
299 {
300 va_list ap;
301 va_start(ap, format);
302 trace_argv_vprintf_fl(file, line, argv, format, ap);
303 va_end(ap);
304 }
305
306 void trace_performance_fl(const char *file, int line, uint64_t nanos,
307 const char *format, ...)
308 {
309 va_list ap;
310 va_start(ap, format);
311 trace_performance_vprintf_fl(file, line, nanos, format, ap);
312 va_end(ap);
313 }
314
315 void trace_performance_leave_fl(const char *file, int line,
316 uint64_t nanos, const char *format, ...)
317 {
318 va_list ap;
319 uint64_t since;
320
321 if (perf_indent)
322 perf_indent--;
323
324 if (!format) /* Allow callers to leave without tracing anything */
325 return;
326
327 since = perf_start_times[perf_indent];
328 va_start(ap, format);
329 trace_performance_vprintf_fl(file, line, nanos - since, format, ap);
330 va_end(ap);
331 }
332
333 #endif /* HAVE_VARIADIC_MACROS */
334
335
336 static const char *quote_crnl(const char *path)
337 {
338 static struct strbuf new_path = STRBUF_INIT;
339
340 if (!path)
341 return NULL;
342
343 strbuf_reset(&new_path);
344
345 while (*path) {
346 switch (*path) {
347 case '\\': strbuf_addstr(&new_path, "\\\\"); break;
348 case '\n': strbuf_addstr(&new_path, "\\n"); break;
349 case '\r': strbuf_addstr(&new_path, "\\r"); break;
350 default:
351 strbuf_addch(&new_path, *path);
352 }
353 path++;
354 }
355 return new_path.buf;
356 }
357
358 /* FIXME: move prefix to startup_info struct and get rid of this arg */
359 void trace_repo_setup(const char *prefix)
360 {
361 const char *git_work_tree;
362 char *cwd;
363
364 if (!trace_want(&trace_setup_key))
365 return;
366
367 cwd = xgetcwd();
368
369 if (!(git_work_tree = get_git_work_tree()))
370 git_work_tree = "(null)";
371
372 if (!prefix)
373 prefix = "(null)";
374
375 trace_printf_key(&trace_setup_key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
376 trace_printf_key(&trace_setup_key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
377 trace_printf_key(&trace_setup_key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
378 trace_printf_key(&trace_setup_key, "setup: cwd: %s\n", quote_crnl(cwd));
379 trace_printf_key(&trace_setup_key, "setup: prefix: %s\n", quote_crnl(prefix));
380
381 free(cwd);
382 }
383
384 int trace_want(struct trace_key *key)
385 {
386 return !!get_trace_fd(key);
387 }
388
389 #if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC)
390
391 static inline uint64_t highres_nanos(void)
392 {
393 struct timespec ts;
394 if (clock_gettime(CLOCK_MONOTONIC, &ts))
395 return 0;
396 return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec;
397 }
398
399 #elif defined (GIT_WINDOWS_NATIVE)
400
401 static inline uint64_t highres_nanos(void)
402 {
403 static uint64_t high_ns, scaled_low_ns;
404 static int scale;
405 LARGE_INTEGER cnt;
406
407 if (!scale) {
408 if (!QueryPerformanceFrequency(&cnt))
409 return 0;
410
411 /* high_ns = number of ns per cnt.HighPart */
412 high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart;
413
414 /*
415 * Number of ns per cnt.LowPart is 10^9 / frequency (or
416 * high_ns >> 32). For maximum precision, we scale this factor
417 * so that it just fits within 32 bit (i.e. won't overflow if
418 * multiplied with cnt.LowPart).
419 */
420 scaled_low_ns = high_ns;
421 scale = 32;
422 while (scaled_low_ns >= 0x100000000LL) {
423 scaled_low_ns >>= 1;
424 scale--;
425 }
426 }
427
428 /* if QPF worked on initialization, we expect QPC to work as well */
429 QueryPerformanceCounter(&cnt);
430
431 return (high_ns * cnt.HighPart) +
432 ((scaled_low_ns * cnt.LowPart) >> scale);
433 }
434
435 #else
436 # define highres_nanos() 0
437 #endif
438
439 static inline uint64_t gettimeofday_nanos(void)
440 {
441 struct timeval tv;
442 gettimeofday(&tv, NULL);
443 return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
444 }
445
446 /*
447 * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
448 * (i.e. favoring high precision over wall clock time accuracy).
449 */
450 uint64_t getnanotime(void)
451 {
452 static uint64_t offset;
453 if (offset > 1) {
454 /* initialization succeeded, return offset + high res time */
455 return offset + highres_nanos();
456 } else if (offset == 1) {
457 /* initialization failed, fall back to gettimeofday */
458 return gettimeofday_nanos();
459 } else {
460 /* initialize offset if high resolution timer works */
461 uint64_t now = gettimeofday_nanos();
462 uint64_t highres = highres_nanos();
463 if (highres)
464 offset = now - highres;
465 else
466 offset = 1;
467 return now;
468 }
469 }
470
471 static struct strbuf command_line = STRBUF_INIT;
472
473 static void print_command_performance_atexit(void)
474 {
475 trace_performance_leave("git command:%s", command_line.buf);
476 }
477
478 void trace_command_performance(const char **argv)
479 {
480 if (!trace_want(&trace_perf_key))
481 return;
482
483 if (!command_line.len)
484 atexit(print_command_performance_atexit);
485
486 strbuf_reset(&command_line);
487 sq_quote_argv_pretty(&command_line, argv);
488 trace_performance_enter();
489 }