refs.h: remove duplication in function docstrings
[git.git] / trace.c
blob1dc5c7c912d000699b753b1aab5c09a114e26557
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, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 #include "cache.h"
26 #include "quote.h"
28 /* Get a trace file descriptor from "key" env variable. */
29 static int get_trace_fd(struct trace_key *key)
31 static struct trace_key trace_default = { "GIT_TRACE" };
32 const char *trace;
34 /* use default "GIT_TRACE" if NULL */
35 if (!key)
36 key = &trace_default;
38 /* don't open twice */
39 if (key->initialized)
40 return key->fd;
42 trace = getenv(key->key);
44 if (!trace || !strcmp(trace, "") ||
45 !strcmp(trace, "0") || !strcasecmp(trace, "false"))
46 key->fd = 0;
47 else if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
48 key->fd = STDERR_FILENO;
49 else if (strlen(trace) == 1 && isdigit(*trace))
50 key->fd = atoi(trace);
51 else if (is_absolute_path(trace)) {
52 int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
53 if (fd == -1) {
54 fprintf(stderr,
55 "Could not open '%s' for tracing: %s\n"
56 "Defaulting to tracing on stderr...\n",
57 trace, strerror(errno));
58 key->fd = STDERR_FILENO;
59 } else {
60 key->fd = fd;
61 key->need_close = 1;
63 } else {
64 fprintf(stderr, "What does '%s' for %s mean?\n"
65 "If you want to trace into a file, then please set "
66 "%s to an absolute pathname (starting with /).\n"
67 "Defaulting to tracing on stderr...\n",
68 trace, key->key, key->key);
69 key->fd = STDERR_FILENO;
72 key->initialized = 1;
73 return key->fd;
76 void trace_disable(struct trace_key *key)
78 if (key->need_close)
79 close(key->fd);
80 key->fd = 0;
81 key->initialized = 1;
82 key->need_close = 0;
85 static const char err_msg[] = "Could not trace into fd given by "
86 "GIT_TRACE environment variable";
88 static int prepare_trace_line(const char *file, int line,
89 struct trace_key *key, struct strbuf *buf)
91 static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
92 struct timeval tv;
93 struct tm tm;
94 time_t secs;
96 if (!trace_want(key))
97 return 0;
99 set_try_to_free_routine(NULL); /* is never reset */
101 /* unit tests may want to disable additional trace output */
102 if (trace_want(&trace_bare))
103 return 1;
105 /* print current timestamp */
106 gettimeofday(&tv, NULL);
107 secs = tv.tv_sec;
108 localtime_r(&secs, &tm);
109 strbuf_addf(buf, "%02d:%02d:%02d.%06ld ", tm.tm_hour, tm.tm_min,
110 tm.tm_sec, (long) tv.tv_usec);
112 #ifdef HAVE_VARIADIC_MACROS
113 /* print file:line */
114 strbuf_addf(buf, "%s:%d ", file, line);
115 /* align trace output (column 40 catches most files names in git) */
116 while (buf->len < 40)
117 strbuf_addch(buf, ' ');
118 #endif
120 return 1;
123 static void print_trace_line(struct trace_key *key, struct strbuf *buf)
125 strbuf_complete_line(buf);
127 write_or_whine_pipe(get_trace_fd(key), buf->buf, buf->len, err_msg);
128 strbuf_release(buf);
131 static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
132 const char *format, va_list ap)
134 struct strbuf buf = STRBUF_INIT;
136 if (!prepare_trace_line(file, line, key, &buf))
137 return;
139 strbuf_vaddf(&buf, format, ap);
140 print_trace_line(key, &buf);
143 static void trace_argv_vprintf_fl(const char *file, int line,
144 const char **argv, const char *format,
145 va_list ap)
147 struct strbuf buf = STRBUF_INIT;
149 if (!prepare_trace_line(file, line, NULL, &buf))
150 return;
152 strbuf_vaddf(&buf, format, ap);
154 sq_quote_argv(&buf, argv, 0);
155 print_trace_line(NULL, &buf);
158 void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
159 const struct strbuf *data)
161 struct strbuf buf = STRBUF_INIT;
163 if (!prepare_trace_line(file, line, key, &buf))
164 return;
166 strbuf_addbuf(&buf, data);
167 print_trace_line(key, &buf);
170 static struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
172 static void trace_performance_vprintf_fl(const char *file, int line,
173 uint64_t nanos, const char *format,
174 va_list ap)
176 struct strbuf buf = STRBUF_INIT;
178 if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
179 return;
181 strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
183 if (format && *format) {
184 strbuf_addstr(&buf, ": ");
185 strbuf_vaddf(&buf, format, ap);
188 print_trace_line(&trace_perf_key, &buf);
191 #ifndef HAVE_VARIADIC_MACROS
193 void trace_printf(const char *format, ...)
195 va_list ap;
196 va_start(ap, format);
197 trace_vprintf_fl(NULL, 0, NULL, format, ap);
198 va_end(ap);
201 void trace_printf_key(struct trace_key *key, const char *format, ...)
203 va_list ap;
204 va_start(ap, format);
205 trace_vprintf_fl(NULL, 0, key, format, ap);
206 va_end(ap);
209 void trace_argv_printf(const char **argv, const char *format, ...)
211 va_list ap;
212 va_start(ap, format);
213 trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
214 va_end(ap);
217 void trace_strbuf(struct trace_key *key, const struct strbuf *data)
219 trace_strbuf_fl(NULL, 0, key, data);
222 void trace_performance(uint64_t nanos, const char *format, ...)
224 va_list ap;
225 va_start(ap, format);
226 trace_performance_vprintf_fl(NULL, 0, nanos, format, ap);
227 va_end(ap);
230 void trace_performance_since(uint64_t start, const char *format, ...)
232 va_list ap;
233 va_start(ap, format);
234 trace_performance_vprintf_fl(NULL, 0, getnanotime() - start,
235 format, ap);
236 va_end(ap);
239 #else
241 void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
242 const char *format, ...)
244 va_list ap;
245 va_start(ap, format);
246 trace_vprintf_fl(file, line, key, format, ap);
247 va_end(ap);
250 void trace_argv_printf_fl(const char *file, int line, const char **argv,
251 const char *format, ...)
253 va_list ap;
254 va_start(ap, format);
255 trace_argv_vprintf_fl(file, line, argv, format, ap);
256 va_end(ap);
259 void trace_performance_fl(const char *file, int line, uint64_t nanos,
260 const char *format, ...)
262 va_list ap;
263 va_start(ap, format);
264 trace_performance_vprintf_fl(file, line, nanos, format, ap);
265 va_end(ap);
268 #endif /* HAVE_VARIADIC_MACROS */
271 static const char *quote_crnl(const char *path)
273 static char new_path[PATH_MAX];
274 const char *p2 = path;
275 char *p1 = new_path;
277 if (!path)
278 return NULL;
280 while (*p2) {
281 switch (*p2) {
282 case '\\': *p1++ = '\\'; *p1++ = '\\'; break;
283 case '\n': *p1++ = '\\'; *p1++ = 'n'; break;
284 case '\r': *p1++ = '\\'; *p1++ = 'r'; break;
285 default:
286 *p1++ = *p2;
288 p2++;
290 *p1 = '\0';
291 return new_path;
294 /* FIXME: move prefix to startup_info struct and get rid of this arg */
295 void trace_repo_setup(const char *prefix)
297 static struct trace_key key = TRACE_KEY_INIT(SETUP);
298 const char *git_work_tree;
299 char *cwd;
301 if (!trace_want(&key))
302 return;
304 cwd = xgetcwd();
306 if (!(git_work_tree = get_git_work_tree()))
307 git_work_tree = "(null)";
309 if (!prefix)
310 prefix = "(null)";
312 trace_printf_key(&key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
313 trace_printf_key(&key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
314 trace_printf_key(&key, "setup: cwd: %s\n", quote_crnl(cwd));
315 trace_printf_key(&key, "setup: prefix: %s\n", quote_crnl(prefix));
317 free(cwd);
320 int trace_want(struct trace_key *key)
322 return !!get_trace_fd(key);
325 #if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC)
327 static inline uint64_t highres_nanos(void)
329 struct timespec ts;
330 if (clock_gettime(CLOCK_MONOTONIC, &ts))
331 return 0;
332 return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec;
335 #elif defined (GIT_WINDOWS_NATIVE)
337 static inline uint64_t highres_nanos(void)
339 static uint64_t high_ns, scaled_low_ns;
340 static int scale;
341 LARGE_INTEGER cnt;
343 if (!scale) {
344 if (!QueryPerformanceFrequency(&cnt))
345 return 0;
347 /* high_ns = number of ns per cnt.HighPart */
348 high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart;
351 * Number of ns per cnt.LowPart is 10^9 / frequency (or
352 * high_ns >> 32). For maximum precision, we scale this factor
353 * so that it just fits within 32 bit (i.e. won't overflow if
354 * multiplied with cnt.LowPart).
356 scaled_low_ns = high_ns;
357 scale = 32;
358 while (scaled_low_ns >= 0x100000000LL) {
359 scaled_low_ns >>= 1;
360 scale--;
364 /* if QPF worked on initialization, we expect QPC to work as well */
365 QueryPerformanceCounter(&cnt);
367 return (high_ns * cnt.HighPart) +
368 ((scaled_low_ns * cnt.LowPart) >> scale);
371 #else
372 # define highres_nanos() 0
373 #endif
375 static inline uint64_t gettimeofday_nanos(void)
377 struct timeval tv;
378 gettimeofday(&tv, NULL);
379 return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
383 * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
384 * (i.e. favoring high precision over wall clock time accuracy).
386 uint64_t getnanotime(void)
388 static uint64_t offset;
389 if (offset > 1) {
390 /* initialization succeeded, return offset + high res time */
391 return offset + highres_nanos();
392 } else if (offset == 1) {
393 /* initialization failed, fall back to gettimeofday */
394 return gettimeofday_nanos();
395 } else {
396 /* initialize offset if high resolution timer works */
397 uint64_t now = gettimeofday_nanos();
398 uint64_t highres = highres_nanos();
399 if (highres)
400 offset = now - highres;
401 else
402 offset = 1;
403 return now;
407 static uint64_t command_start_time;
408 static struct strbuf command_line = STRBUF_INIT;
410 static void print_command_performance_atexit(void)
412 trace_performance_since(command_start_time, "git command:%s",
413 command_line.buf);
416 void trace_command_performance(const char **argv)
418 if (!trace_want(&trace_perf_key))
419 return;
421 if (!command_start_time)
422 atexit(print_command_performance_atexit);
424 strbuf_reset(&command_line);
425 sq_quote_argv(&command_line, argv, 0);
426 command_start_time = getnanotime();