Merge branch 'zh/read-cache-copy-name-entry-fix'
[alt-git.git] / trace.c
blob794a087c21e100e147665181a592bc811b3c1265
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, const char *override_envvar)
34 const char *trace;
36 /* don't open twice */
37 if (key->initialized)
38 return key->fd;
40 trace = override_envvar ? override_envvar : 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_override_envvar(struct trace_key *key, const char *value)
73 trace_disable(key);
74 key->initialized = 0;
77 * Invoke get_trace_fd() to initialize key using the given value
78 * instead of the value of the environment variable.
80 get_trace_fd(key, value);
83 void trace_disable(struct trace_key *key)
85 if (key->need_close)
86 close(key->fd);
87 key->fd = 0;
88 key->initialized = 1;
89 key->need_close = 0;
92 static int prepare_trace_line(const char *file, int line,
93 struct trace_key *key, struct strbuf *buf)
95 static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
96 struct timeval tv;
97 struct tm tm;
98 time_t secs;
100 if (!trace_want(key))
101 return 0;
103 /* unit tests may want to disable additional trace output */
104 if (trace_want(&trace_bare))
105 return 1;
107 /* print current timestamp */
108 gettimeofday(&tv, NULL);
109 secs = tv.tv_sec;
110 localtime_r(&secs, &tm);
111 strbuf_addf(buf, "%02d:%02d:%02d.%06ld %s:%d", tm.tm_hour, tm.tm_min,
112 tm.tm_sec, (long) tv.tv_usec, file, line);
113 /* align trace output (column 40 catches most files names in git) */
114 while (buf->len < 40)
115 strbuf_addch(buf, ' ');
117 return 1;
120 static void trace_write(struct trace_key *key, const void *buf, unsigned len)
122 if (write_in_full(get_trace_fd(key, NULL), buf, len) < 0) {
123 warning("unable to write trace for %s: %s",
124 key->key, strerror(errno));
125 trace_disable(key);
129 void trace_verbatim(struct trace_key *key, const void *buf, unsigned len)
131 if (!trace_want(key))
132 return;
133 trace_write(key, buf, len);
136 static void print_trace_line(struct trace_key *key, struct strbuf *buf)
138 strbuf_complete_line(buf);
139 trace_write(key, buf->buf, buf->len);
142 static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
143 const char *format, va_list ap)
145 struct strbuf buf = STRBUF_INIT;
147 if (!prepare_trace_line(file, line, key, &buf))
148 return;
150 strbuf_vaddf(&buf, format, ap);
151 print_trace_line(key, &buf);
152 strbuf_release(&buf);
155 static void trace_argv_vprintf_fl(const char *file, int line,
156 const char **argv, const char *format,
157 va_list ap)
159 struct strbuf buf = STRBUF_INIT;
161 if (!prepare_trace_line(file, line, &trace_default_key, &buf))
162 return;
164 strbuf_vaddf(&buf, format, ap);
166 sq_quote_argv_pretty(&buf, argv);
167 print_trace_line(&trace_default_key, &buf);
168 strbuf_release(&buf);
171 void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
172 const struct strbuf *data)
174 struct strbuf buf = STRBUF_INIT;
176 if (!prepare_trace_line(file, line, key, &buf))
177 return;
179 strbuf_addbuf(&buf, data);
180 print_trace_line(key, &buf);
181 strbuf_release(&buf);
184 static uint64_t perf_start_times[10];
185 static int perf_indent;
187 uint64_t trace_performance_enter(void)
189 uint64_t now;
191 if (!trace_want(&trace_perf_key))
192 return 0;
194 now = getnanotime();
195 perf_start_times[perf_indent] = now;
196 if (perf_indent + 1 < ARRAY_SIZE(perf_start_times))
197 perf_indent++;
198 else
199 BUG("Too deep indentation");
200 return now;
203 static void trace_performance_vprintf_fl(const char *file, int line,
204 uint64_t nanos, const char *format,
205 va_list ap)
207 static const char space[] = " ";
208 struct strbuf buf = STRBUF_INIT;
210 if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
211 return;
213 strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
215 if (format && *format) {
216 if (perf_indent >= strlen(space))
217 BUG("Too deep indentation");
219 strbuf_addf(&buf, ":%.*s ", perf_indent, space);
220 strbuf_vaddf(&buf, format, ap);
223 print_trace_line(&trace_perf_key, &buf);
224 strbuf_release(&buf);
227 void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
228 const char *format, ...)
230 va_list ap;
231 va_start(ap, format);
232 trace_vprintf_fl(file, line, key, format, ap);
233 va_end(ap);
236 void trace_argv_printf_fl(const char *file, int line, const char **argv,
237 const char *format, ...)
239 va_list ap;
240 va_start(ap, format);
241 trace_argv_vprintf_fl(file, line, argv, format, ap);
242 va_end(ap);
245 void trace_performance_fl(const char *file, int line, uint64_t nanos,
246 const char *format, ...)
248 va_list ap;
249 va_start(ap, format);
250 trace_performance_vprintf_fl(file, line, nanos, format, ap);
251 va_end(ap);
254 void trace_performance_leave_fl(const char *file, int line,
255 uint64_t nanos, const char *format, ...)
257 va_list ap;
258 uint64_t since;
260 if (perf_indent)
261 perf_indent--;
263 if (!format) /* Allow callers to leave without tracing anything */
264 return;
266 since = perf_start_times[perf_indent];
267 va_start(ap, format);
268 trace_performance_vprintf_fl(file, line, nanos - since, format, ap);
269 va_end(ap);
272 static const char *quote_crnl(const char *path)
274 static struct strbuf new_path = STRBUF_INIT;
276 if (!path)
277 return NULL;
279 strbuf_reset(&new_path);
281 while (*path) {
282 switch (*path) {
283 case '\\': strbuf_addstr(&new_path, "\\\\"); break;
284 case '\n': strbuf_addstr(&new_path, "\\n"); break;
285 case '\r': strbuf_addstr(&new_path, "\\r"); break;
286 default:
287 strbuf_addch(&new_path, *path);
289 path++;
291 return new_path.buf;
294 /* FIXME: move prefix to startup_info struct and get rid of this arg */
295 void trace_repo_setup(const char *prefix)
297 const char *git_work_tree;
298 char *cwd;
300 if (!trace_want(&trace_setup_key))
301 return;
303 cwd = xgetcwd();
305 if (!(git_work_tree = get_git_work_tree()))
306 git_work_tree = "(null)";
308 if (!prefix)
309 prefix = "(null)";
311 trace_printf_key(&trace_setup_key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
312 trace_printf_key(&trace_setup_key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
313 trace_printf_key(&trace_setup_key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
314 trace_printf_key(&trace_setup_key, "setup: cwd: %s\n", quote_crnl(cwd));
315 trace_printf_key(&trace_setup_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, NULL);
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 struct strbuf command_line = STRBUF_INIT;
409 static void print_command_performance_atexit(void)
411 trace_performance_leave("git command:%s", command_line.buf);
414 void trace_command_performance(const char **argv)
416 if (!trace_want(&trace_perf_key))
417 return;
419 if (!command_line.len)
420 atexit(print_command_performance_atexit);
422 strbuf_reset(&command_line);
423 sq_quote_argv_pretty(&command_line, argv);
424 trace_performance_enter();