Merge branch 'ew/svn-crlf'
[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
30 /* Get a trace file descriptor from "key" env variable. */
31 static int get_trace_fd(struct trace_key *key)
32 {
33 const char *trace;
34
35 /* don't open twice */
36 if (key->initialized)
37 return key->fd;
38
39 trace = getenv(key->key);
40
41 if (!trace || !strcmp(trace, "") ||
42 !strcmp(trace, "0") || !strcasecmp(trace, "false"))
43 key->fd = 0;
44 else if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
45 key->fd = STDERR_FILENO;
46 else if (strlen(trace) == 1 && isdigit(*trace))
47 key->fd = atoi(trace);
48 else if (is_absolute_path(trace)) {
49 int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
50 if (fd == -1) {
51 warning("could not open '%s' for tracing: %s",
52 trace, strerror(errno));
53 trace_disable(key);
54 } else {
55 key->fd = fd;
56 key->need_close = 1;
57 }
58 } else {
59 warning("unknown trace value for '%s': %s\n"
60 " If you want to trace into a file, then please set %s\n"
61 " to an absolute pathname (starting with /)",
62 key->key, trace, key->key);
63 trace_disable(key);
64 }
65
66 key->initialized = 1;
67 return key->fd;
68 }
69
70 void trace_disable(struct trace_key *key)
71 {
72 if (key->need_close)
73 close(key->fd);
74 key->fd = 0;
75 key->initialized = 1;
76 key->need_close = 0;
77 }
78
79 static int prepare_trace_line(const char *file, int line,
80 struct trace_key *key, struct strbuf *buf)
81 {
82 static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
83 struct timeval tv;
84 struct tm tm;
85 time_t secs;
86
87 if (!trace_want(key))
88 return 0;
89
90 set_try_to_free_routine(NULL); /* is never reset */
91
92 /* unit tests may want to disable additional trace output */
93 if (trace_want(&trace_bare))
94 return 1;
95
96 /* print current timestamp */
97 gettimeofday(&tv, NULL);
98 secs = tv.tv_sec;
99 localtime_r(&secs, &tm);
100 strbuf_addf(buf, "%02d:%02d:%02d.%06ld ", tm.tm_hour, tm.tm_min,
101 tm.tm_sec, (long) tv.tv_usec);
102
103 #ifdef HAVE_VARIADIC_MACROS
104 /* print file:line */
105 strbuf_addf(buf, "%s:%d ", file, line);
106 /* align trace output (column 40 catches most files names in git) */
107 while (buf->len < 40)
108 strbuf_addch(buf, ' ');
109 #endif
110
111 return 1;
112 }
113
114 static void trace_write(struct trace_key *key, const void *buf, unsigned len)
115 {
116 if (write_in_full(get_trace_fd(key), buf, len) < 0) {
117 warning("unable to write trace for %s: %s",
118 key->key, strerror(errno));
119 trace_disable(key);
120 }
121 }
122
123 void trace_verbatim(struct trace_key *key, const void *buf, unsigned len)
124 {
125 if (!trace_want(key))
126 return;
127 trace_write(key, buf, len);
128 }
129
130 static void print_trace_line(struct trace_key *key, struct strbuf *buf)
131 {
132 strbuf_complete_line(buf);
133 trace_write(key, buf->buf, buf->len);
134 strbuf_release(buf);
135 }
136
137 static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
138 const char *format, va_list ap)
139 {
140 struct strbuf buf = STRBUF_INIT;
141
142 if (!prepare_trace_line(file, line, key, &buf))
143 return;
144
145 strbuf_vaddf(&buf, format, ap);
146 print_trace_line(key, &buf);
147 }
148
149 static void trace_argv_vprintf_fl(const char *file, int line,
150 const char **argv, const char *format,
151 va_list ap)
152 {
153 struct strbuf buf = STRBUF_INIT;
154
155 if (!prepare_trace_line(file, line, &trace_default_key, &buf))
156 return;
157
158 strbuf_vaddf(&buf, format, ap);
159
160 sq_quote_argv(&buf, argv, 0);
161 print_trace_line(&trace_default_key, &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 }
175
176 static void trace_performance_vprintf_fl(const char *file, int line,
177 uint64_t nanos, const char *format,
178 va_list ap)
179 {
180 struct strbuf buf = STRBUF_INIT;
181
182 if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
183 return;
184
185 strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
186
187 if (format && *format) {
188 strbuf_addstr(&buf, ": ");
189 strbuf_vaddf(&buf, format, ap);
190 }
191
192 print_trace_line(&trace_perf_key, &buf);
193 }
194
195 #ifndef HAVE_VARIADIC_MACROS
196
197 void trace_printf(const char *format, ...)
198 {
199 va_list ap;
200 va_start(ap, format);
201 trace_vprintf_fl(NULL, 0, &trace_default_key, format, ap);
202 va_end(ap);
203 }
204
205 void trace_printf_key(struct trace_key *key, const char *format, ...)
206 {
207 va_list ap;
208 va_start(ap, format);
209 trace_vprintf_fl(NULL, 0, key, format, ap);
210 va_end(ap);
211 }
212
213 void trace_argv_printf(const char **argv, const char *format, ...)
214 {
215 va_list ap;
216 va_start(ap, format);
217 trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
218 va_end(ap);
219 }
220
221 void trace_strbuf(struct trace_key *key, const struct strbuf *data)
222 {
223 trace_strbuf_fl(NULL, 0, key, data);
224 }
225
226 void trace_performance(uint64_t nanos, const char *format, ...)
227 {
228 va_list ap;
229 va_start(ap, format);
230 trace_performance_vprintf_fl(NULL, 0, nanos, format, ap);
231 va_end(ap);
232 }
233
234 void trace_performance_since(uint64_t start, const char *format, ...)
235 {
236 va_list ap;
237 va_start(ap, format);
238 trace_performance_vprintf_fl(NULL, 0, getnanotime() - start,
239 format, ap);
240 va_end(ap);
241 }
242
243 #else
244
245 void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
246 const char *format, ...)
247 {
248 va_list ap;
249 va_start(ap, format);
250 trace_vprintf_fl(file, line, key, format, ap);
251 va_end(ap);
252 }
253
254 void trace_argv_printf_fl(const char *file, int line, const char **argv,
255 const char *format, ...)
256 {
257 va_list ap;
258 va_start(ap, format);
259 trace_argv_vprintf_fl(file, line, argv, format, ap);
260 va_end(ap);
261 }
262
263 void trace_performance_fl(const char *file, int line, uint64_t nanos,
264 const char *format, ...)
265 {
266 va_list ap;
267 va_start(ap, format);
268 trace_performance_vprintf_fl(file, line, nanos, format, ap);
269 va_end(ap);
270 }
271
272 #endif /* HAVE_VARIADIC_MACROS */
273
274
275 static const char *quote_crnl(const char *path)
276 {
277 static struct strbuf new_path = STRBUF_INIT;
278
279 if (!path)
280 return NULL;
281
282 strbuf_reset(&new_path);
283
284 while (*path) {
285 switch (*path) {
286 case '\\': strbuf_addstr(&new_path, "\\\\"); break;
287 case '\n': strbuf_addstr(&new_path, "\\n"); break;
288 case '\r': strbuf_addstr(&new_path, "\\r"); break;
289 default:
290 strbuf_addch(&new_path, *path);
291 }
292 path++;
293 }
294 return new_path.buf;
295 }
296
297 /* FIXME: move prefix to startup_info struct and get rid of this arg */
298 void trace_repo_setup(const char *prefix)
299 {
300 static struct trace_key key = TRACE_KEY_INIT(SETUP);
301 const char *git_work_tree;
302 char *cwd;
303
304 if (!trace_want(&key))
305 return;
306
307 cwd = xgetcwd();
308
309 if (!(git_work_tree = get_git_work_tree()))
310 git_work_tree = "(null)";
311
312 if (!prefix)
313 prefix = "(null)";
314
315 trace_printf_key(&key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
316 trace_printf_key(&key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
317 trace_printf_key(&key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
318 trace_printf_key(&key, "setup: cwd: %s\n", quote_crnl(cwd));
319 trace_printf_key(&key, "setup: prefix: %s\n", quote_crnl(prefix));
320
321 free(cwd);
322 }
323
324 int trace_want(struct trace_key *key)
325 {
326 return !!get_trace_fd(key);
327 }
328
329 #if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC)
330
331 static inline uint64_t highres_nanos(void)
332 {
333 struct timespec ts;
334 if (clock_gettime(CLOCK_MONOTONIC, &ts))
335 return 0;
336 return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec;
337 }
338
339 #elif defined (GIT_WINDOWS_NATIVE)
340
341 static inline uint64_t highres_nanos(void)
342 {
343 static uint64_t high_ns, scaled_low_ns;
344 static int scale;
345 LARGE_INTEGER cnt;
346
347 if (!scale) {
348 if (!QueryPerformanceFrequency(&cnt))
349 return 0;
350
351 /* high_ns = number of ns per cnt.HighPart */
352 high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart;
353
354 /*
355 * Number of ns per cnt.LowPart is 10^9 / frequency (or
356 * high_ns >> 32). For maximum precision, we scale this factor
357 * so that it just fits within 32 bit (i.e. won't overflow if
358 * multiplied with cnt.LowPart).
359 */
360 scaled_low_ns = high_ns;
361 scale = 32;
362 while (scaled_low_ns >= 0x100000000LL) {
363 scaled_low_ns >>= 1;
364 scale--;
365 }
366 }
367
368 /* if QPF worked on initialization, we expect QPC to work as well */
369 QueryPerformanceCounter(&cnt);
370
371 return (high_ns * cnt.HighPart) +
372 ((scaled_low_ns * cnt.LowPart) >> scale);
373 }
374
375 #else
376 # define highres_nanos() 0
377 #endif
378
379 static inline uint64_t gettimeofday_nanos(void)
380 {
381 struct timeval tv;
382 gettimeofday(&tv, NULL);
383 return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
384 }
385
386 /*
387 * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
388 * (i.e. favoring high precision over wall clock time accuracy).
389 */
390 uint64_t getnanotime(void)
391 {
392 static uint64_t offset;
393 if (offset > 1) {
394 /* initialization succeeded, return offset + high res time */
395 return offset + highres_nanos();
396 } else if (offset == 1) {
397 /* initialization failed, fall back to gettimeofday */
398 return gettimeofday_nanos();
399 } else {
400 /* initialize offset if high resolution timer works */
401 uint64_t now = gettimeofday_nanos();
402 uint64_t highres = highres_nanos();
403 if (highres)
404 offset = now - highres;
405 else
406 offset = 1;
407 return now;
408 }
409 }
410
411 static uint64_t command_start_time;
412 static struct strbuf command_line = STRBUF_INIT;
413
414 static void print_command_performance_atexit(void)
415 {
416 trace_performance_since(command_start_time, "git command:%s",
417 command_line.buf);
418 }
419
420 void trace_command_performance(const char **argv)
421 {
422 if (!trace_want(&trace_perf_key))
423 return;
424
425 if (!command_start_time)
426 atexit(print_command_performance_atexit);
427
428 strbuf_reset(&command_line);
429 sq_quote_argv(&command_line, argv, 0);
430 command_start_time = getnanotime();
431 }