Andrew's git - gitweb.git/blob

   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, write to the Free Software
  22 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23 */
  24
  25#include "cache.h"
  26#include "quote.h"
  27
  28/* Get a trace file descriptor from "key" env variable. */
  29static int get_trace_fd(struct trace_key *key)
  30{
  31        static struct trace_key trace_default = { "GIT_TRACE" };
  32        const char *trace;
  33
  34        /* use default "GIT_TRACE" if NULL */
  35        if (!key)
  36                key = &trace_default;
  37
  38        /* don't open twice */
  39        if (key->initialized)
  40                return key->fd;
  41
  42        trace = getenv(key->key);
  43
  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;
  62                }
  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;
  70        }
  71
  72        key->initialized = 1;
  73        return key->fd;
  74}
  75
  76void trace_disable(struct trace_key *key)
  77{
  78        if (key->need_close)
  79                close(key->fd);
  80        key->fd = 0;
  81        key->initialized = 1;
  82        key->need_close = 0;
  83}
  84
  85static const char err_msg[] = "Could not trace into fd given by "
  86        "GIT_TRACE environment variable";
  87
  88static int prepare_trace_line(const char *file, int line,
  89                              struct trace_key *key, struct strbuf *buf)
  90{
  91        static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
  92        struct timeval tv;
  93        struct tm tm;
  94        time_t secs;
  95
  96        if (!trace_want(key))
  97                return 0;
  98
  99        set_try_to_free_routine(NULL);  /* is never reset */
 100
 101        /* unit tests may want to disable additional trace output */
 102        if (trace_want(&trace_bare))
 103                return 1;
 104
 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);
 111
 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
 119
 120        return 1;
 121}
 122
 123static void print_trace_line(struct trace_key *key, struct strbuf *buf)
 124{
 125        /* append newline if missing */
 126        if (buf->len && buf->buf[buf->len - 1] != '\n')
 127                strbuf_addch(buf, '\n');
 128
 129        write_or_whine_pipe(get_trace_fd(key), buf->buf, buf->len, err_msg);
 130        strbuf_release(buf);
 131}
 132
 133static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
 134                             const char *format, va_list ap)
 135{
 136        struct strbuf buf = STRBUF_INIT;
 137
 138        if (!prepare_trace_line(file, line, key, &buf))
 139                return;
 140
 141        strbuf_vaddf(&buf, format, ap);
 142        print_trace_line(key, &buf);
 143}
 144
 145static void trace_argv_vprintf_fl(const char *file, int line,
 146                                  const char **argv, const char *format,
 147                                  va_list ap)
 148{
 149        struct strbuf buf = STRBUF_INIT;
 150
 151        if (!prepare_trace_line(file, line, NULL, &buf))
 152                return;
 153
 154        strbuf_vaddf(&buf, format, ap);
 155
 156        sq_quote_argv(&buf, argv, 0);
 157        print_trace_line(NULL, &buf);
 158}
 159
 160void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
 161                     const struct strbuf *data)
 162{
 163        struct strbuf buf = STRBUF_INIT;
 164
 165        if (!prepare_trace_line(file, line, key, &buf))
 166                return;
 167
 168        strbuf_addbuf(&buf, data);
 169        print_trace_line(key, &buf);
 170}
 171
 172static struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
 173
 174static void trace_performance_vprintf_fl(const char *file, int line,
 175                                         uint64_t nanos, const char *format,
 176                                         va_list ap)
 177{
 178        struct strbuf buf = STRBUF_INIT;
 179
 180        if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
 181                return;
 182
 183        strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
 184
 185        if (format && *format) {
 186                strbuf_addstr(&buf, ": ");
 187                strbuf_vaddf(&buf, format, ap);
 188        }
 189
 190        print_trace_line(&trace_perf_key, &buf);
 191}
 192
 193#ifndef HAVE_VARIADIC_MACROS
 194
 195void trace_printf(const char *format, ...)
 196{
 197        va_list ap;
 198        va_start(ap, format);
 199        trace_vprintf_fl(NULL, 0, NULL, format, ap);
 200        va_end(ap);
 201}
 202
 203void trace_printf_key(struct trace_key *key, const char *format, ...)
 204{
 205        va_list ap;
 206        va_start(ap, format);
 207        trace_vprintf_fl(NULL, 0, key, format, ap);
 208        va_end(ap);
 209}
 210
 211void trace_argv_printf(const char **argv, const char *format, ...)
 212{
 213        va_list ap;
 214        va_start(ap, format);
 215        trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
 216        va_end(ap);
 217}
 218
 219void trace_strbuf(struct trace_key *key, const struct strbuf *data)
 220{
 221        trace_strbuf_fl(NULL, 0, key, data);
 222}
 223
 224void trace_performance(uint64_t nanos, const char *format, ...)
 225{
 226        va_list ap;
 227        va_start(ap, format);
 228        trace_performance_vprintf_fl(NULL, 0, nanos, format, ap);
 229        va_end(ap);
 230}
 231
 232void trace_performance_since(uint64_t start, const char *format, ...)
 233{
 234        va_list ap;
 235        va_start(ap, format);
 236        trace_performance_vprintf_fl(NULL, 0, getnanotime() - start,
 237                                     format, ap);
 238        va_end(ap);
 239}
 240
 241#else
 242
 243void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
 244                         const char *format, ...)
 245{
 246        va_list ap;
 247        va_start(ap, format);
 248        trace_vprintf_fl(file, line, key, format, ap);
 249        va_end(ap);
 250}
 251
 252void trace_argv_printf_fl(const char *file, int line, const char **argv,
 253                          const char *format, ...)
 254{
 255        va_list ap;
 256        va_start(ap, format);
 257        trace_argv_vprintf_fl(file, line, argv, format, ap);
 258        va_end(ap);
 259}
 260
 261void trace_performance_fl(const char *file, int line, uint64_t nanos,
 262                              const char *format, ...)
 263{
 264        va_list ap;
 265        va_start(ap, format);
 266        trace_performance_vprintf_fl(file, line, nanos, format, ap);
 267        va_end(ap);
 268}
 269
 270#endif /* HAVE_VARIADIC_MACROS */
 271
 272
 273static const char *quote_crnl(const char *path)
 274{
 275        static char new_path[PATH_MAX];
 276        const char *p2 = path;
 277        char *p1 = new_path;
 278
 279        if (!path)
 280                return NULL;
 281
 282        while (*p2) {
 283                switch (*p2) {
 284                case '\\': *p1++ = '\\'; *p1++ = '\\'; break;
 285                case '\n': *p1++ = '\\'; *p1++ = 'n'; break;
 286                case '\r': *p1++ = '\\'; *p1++ = 'r'; break;
 287                default:
 288                        *p1++ = *p2;
 289                }
 290                p2++;
 291        }
 292        *p1 = '\0';
 293        return new_path;
 294}
 295
 296/* FIXME: move prefix to startup_info struct and get rid of this arg */
 297void trace_repo_setup(const char *prefix)
 298{
 299        static struct trace_key key = TRACE_KEY_INIT(SETUP);
 300        const char *git_work_tree;
 301        char *cwd;
 302
 303        if (!trace_want(&key))
 304                return;
 305
 306        cwd = xgetcwd();
 307
 308        if (!(git_work_tree = get_git_work_tree()))
 309                git_work_tree = "(null)";
 310
 311        if (!prefix)
 312                prefix = "(null)";
 313
 314        trace_printf_key(&key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
 315        trace_printf_key(&key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
 316        trace_printf_key(&key, "setup: cwd: %s\n", quote_crnl(cwd));
 317        trace_printf_key(&key, "setup: prefix: %s\n", quote_crnl(prefix));
 318
 319        free(cwd);
 320}
 321
 322int trace_want(struct trace_key *key)
 323{
 324        return !!get_trace_fd(key);
 325}
 326
 327#ifdef HAVE_CLOCK_GETTIME
 328
 329static inline uint64_t highres_nanos(void)
 330{
 331        struct timespec ts;
 332        if (clock_gettime(CLOCK_MONOTONIC, &ts))
 333                return 0;
 334        return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec;
 335}
 336
 337#elif defined (GIT_WINDOWS_NATIVE)
 338
 339static inline uint64_t highres_nanos(void)
 340{
 341        static uint64_t high_ns, scaled_low_ns;
 342        static int scale;
 343        LARGE_INTEGER cnt;
 344
 345        if (!scale) {
 346                if (!QueryPerformanceFrequency(&cnt))
 347                        return 0;
 348
 349                /* high_ns = number of ns per cnt.HighPart */
 350                high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart;
 351
 352                /*
 353                 * Number of ns per cnt.LowPart is 10^9 / frequency (or
 354                 * high_ns >> 32). For maximum precision, we scale this factor
 355                 * so that it just fits within 32 bit (i.e. won't overflow if
 356                 * multiplied with cnt.LowPart).
 357                 */
 358                scaled_low_ns = high_ns;
 359                scale = 32;
 360                while (scaled_low_ns >= 0x100000000LL) {
 361                        scaled_low_ns >>= 1;
 362                        scale--;
 363                }
 364        }
 365
 366        /* if QPF worked on initialization, we expect QPC to work as well */
 367        QueryPerformanceCounter(&cnt);
 368
 369        return (high_ns * cnt.HighPart) +
 370               ((scaled_low_ns * cnt.LowPart) >> scale);
 371}
 372
 373#else
 374# define highres_nanos() 0
 375#endif
 376
 377static inline uint64_t gettimeofday_nanos(void)
 378{
 379        struct timeval tv;
 380        gettimeofday(&tv, NULL);
 381        return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
 382}
 383
 384/*
 385 * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
 386 * (i.e. favoring high precision over wall clock time accuracy).
 387 */
 388uint64_t getnanotime(void)
 389{
 390        static uint64_t offset;
 391        if (offset > 1) {
 392                /* initialization succeeded, return offset + high res time */
 393                return offset + highres_nanos();
 394        } else if (offset == 1) {
 395                /* initialization failed, fall back to gettimeofday */
 396                return gettimeofday_nanos();
 397        } else {
 398                /* initialize offset if high resolution timer works */
 399                uint64_t now = gettimeofday_nanos();
 400                uint64_t highres = highres_nanos();
 401                if (highres)
 402                        offset = now - highres;
 403                else
 404                        offset = 1;
 405                return now;
 406        }
 407}
 408
 409static uint64_t command_start_time;
 410static struct strbuf command_line = STRBUF_INIT;
 411
 412static void print_command_performance_atexit(void)
 413{
 414        trace_performance_since(command_start_time, "git command:%s",
 415                                command_line.buf);
 416}
 417
 418void trace_command_performance(const char **argv)
 419{
 420        if (!trace_want(&trace_perf_key))
 421                return;
 422
 423        if (!command_start_time)
 424                atexit(print_command_performance_atexit);
 425
 426        strbuf_reset(&command_line);
 427        sq_quote_argv(&command_line, argv, 0);
 428        command_start_time = getnanotime();
 429}