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