Andrew's git - gitweb.git/blob

d47ea28e88d98c2dab43d6ebc17595513bf645e1
   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
  27struct trace_key trace_default_key = { "GIT_TRACE", 0, 0, 0 };
  28
  29/* Get a trace file descriptor from "key" env variable. */
  30static int get_trace_fd(struct trace_key *key)
  31{
  32        const char *trace;
  33
  34        /* don't open twice */
  35        if (key->initialized)
  36                return key->fd;
  37
  38        trace = getenv(key->key);
  39
  40        if (!trace || !strcmp(trace, "") ||
  41            !strcmp(trace, "0") || !strcasecmp(trace, "false"))
  42                key->fd = 0;
  43        else if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
  44                key->fd = STDERR_FILENO;
  45        else if (strlen(trace) == 1 && isdigit(*trace))
  46                key->fd = atoi(trace);
  47        else if (is_absolute_path(trace)) {
  48                int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
  49                if (fd == -1) {
  50                        warning("could not open '%s' for tracing: %s",
  51                                trace, strerror(errno));
  52                        trace_disable(key);
  53                } else {
  54                        key->fd = fd;
  55                        key->need_close = 1;
  56                }
  57        } else {
  58                warning("unknown trace value for '%s': %s\n"
  59                        "         If you want to trace into a file, then please set %s\n"
  60                        "         to an absolute pathname (starting with /)",
  61                        key->key, trace, key->key);
  62                trace_disable(key);
  63        }
  64
  65        key->initialized = 1;
  66        return key->fd;
  67}
  68
  69void trace_disable(struct trace_key *key)
  70{
  71        if (key->need_close)
  72                close(key->fd);
  73        key->fd = 0;
  74        key->initialized = 1;
  75        key->need_close = 0;
  76}
  77
  78static int prepare_trace_line(const char *file, int line,
  79                              struct trace_key *key, struct strbuf *buf)
  80{
  81        static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
  82        struct timeval tv;
  83        struct tm tm;
  84        time_t secs;
  85
  86        if (!trace_want(key))
  87                return 0;
  88
  89        set_try_to_free_routine(NULL);  /* is never reset */
  90
  91        /* unit tests may want to disable additional trace output */
  92        if (trace_want(&trace_bare))
  93                return 1;
  94
  95        /* print current timestamp */
  96        gettimeofday(&tv, NULL);
  97        secs = tv.tv_sec;
  98        localtime_r(&secs, &tm);
  99        strbuf_addf(buf, "%02d:%02d:%02d.%06ld ", tm.tm_hour, tm.tm_min,
 100                    tm.tm_sec, (long) tv.tv_usec);
 101
 102#ifdef HAVE_VARIADIC_MACROS
 103        /* print file:line */
 104        strbuf_addf(buf, "%s:%d ", file, line);
 105        /* align trace output (column 40 catches most files names in git) */
 106        while (buf->len < 40)
 107                strbuf_addch(buf, ' ');
 108#endif
 109
 110        return 1;
 111}
 112
 113static void trace_write(struct trace_key *key, const void *buf, unsigned len)
 114{
 115        if (write_in_full(get_trace_fd(key), buf, len) < 0) {
 116                warning("unable to write trace for %s: %s",
 117                        key->key, strerror(errno));
 118                trace_disable(key);
 119        }
 120}
 121
 122void trace_verbatim(struct trace_key *key, const void *buf, unsigned len)
 123{
 124        if (!trace_want(key))
 125                return;
 126        trace_write(key, buf, len);
 127}
 128
 129static void print_trace_line(struct trace_key *key, struct strbuf *buf)
 130{
 131        strbuf_complete_line(buf);
 132        trace_write(key, buf->buf, buf->len);
 133        strbuf_release(buf);
 134}
 135
 136static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
 137                             const char *format, va_list ap)
 138{
 139        struct strbuf buf = STRBUF_INIT;
 140
 141        if (!prepare_trace_line(file, line, key, &buf))
 142                return;
 143
 144        strbuf_vaddf(&buf, format, ap);
 145        print_trace_line(key, &buf);
 146}
 147
 148static void trace_argv_vprintf_fl(const char *file, int line,
 149                                  const char **argv, const char *format,
 150                                  va_list ap)
 151{
 152        struct strbuf buf = STRBUF_INIT;
 153
 154        if (!prepare_trace_line(file, line, &trace_default_key, &buf))
 155                return;
 156
 157        strbuf_vaddf(&buf, format, ap);
 158
 159        sq_quote_argv(&buf, argv, 0);
 160        print_trace_line(&trace_default_key, &buf);
 161}
 162
 163void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
 164                     const struct strbuf *data)
 165{
 166        struct strbuf buf = STRBUF_INIT;
 167
 168        if (!prepare_trace_line(file, line, key, &buf))
 169                return;
 170
 171        strbuf_addbuf(&buf, data);
 172        print_trace_line(key, &buf);
 173}
 174
 175static struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
 176
 177static void trace_performance_vprintf_fl(const char *file, int line,
 178                                         uint64_t nanos, const char *format,
 179                                         va_list ap)
 180{
 181        struct strbuf buf = STRBUF_INIT;
 182
 183        if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
 184                return;
 185
 186        strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
 187
 188        if (format && *format) {
 189                strbuf_addstr(&buf, ": ");
 190                strbuf_vaddf(&buf, format, ap);
 191        }
 192
 193        print_trace_line(&trace_perf_key, &buf);
 194}
 195
 196#ifndef HAVE_VARIADIC_MACROS
 197
 198void trace_printf(const char *format, ...)
 199{
 200        va_list ap;
 201        va_start(ap, format);
 202        trace_vprintf_fl(NULL, 0, &trace_default_key, format, ap);
 203        va_end(ap);
 204}
 205
 206void trace_printf_key(struct trace_key *key, const char *format, ...)
 207{
 208        va_list ap;
 209        va_start(ap, format);
 210        trace_vprintf_fl(NULL, 0, key, format, ap);
 211        va_end(ap);
 212}
 213
 214void trace_argv_printf(const char **argv, const char *format, ...)
 215{
 216        va_list ap;
 217        va_start(ap, format);
 218        trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
 219        va_end(ap);
 220}
 221
 222void trace_strbuf(struct trace_key *key, const struct strbuf *data)
 223{
 224        trace_strbuf_fl(NULL, 0, key, data);
 225}
 226
 227void trace_performance(uint64_t nanos, const char *format, ...)
 228{
 229        va_list ap;
 230        va_start(ap, format);
 231        trace_performance_vprintf_fl(NULL, 0, nanos, format, ap);
 232        va_end(ap);
 233}
 234
 235void trace_performance_since(uint64_t start, const char *format, ...)
 236{
 237        va_list ap;
 238        va_start(ap, format);
 239        trace_performance_vprintf_fl(NULL, 0, getnanotime() - start,
 240                                     format, ap);
 241        va_end(ap);
 242}
 243
 244#else
 245
 246void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
 247                         const char *format, ...)
 248{
 249        va_list ap;
 250        va_start(ap, format);
 251        trace_vprintf_fl(file, line, key, format, ap);
 252        va_end(ap);
 253}
 254
 255void trace_argv_printf_fl(const char *file, int line, const char **argv,
 256                          const char *format, ...)
 257{
 258        va_list ap;
 259        va_start(ap, format);
 260        trace_argv_vprintf_fl(file, line, argv, format, ap);
 261        va_end(ap);
 262}
 263
 264void trace_performance_fl(const char *file, int line, uint64_t nanos,
 265                              const char *format, ...)
 266{
 267        va_list ap;
 268        va_start(ap, format);
 269        trace_performance_vprintf_fl(file, line, nanos, format, ap);
 270        va_end(ap);
 271}
 272
 273#endif /* HAVE_VARIADIC_MACROS */
 274
 275
 276static const char *quote_crnl(const char *path)
 277{
 278        static struct strbuf new_path = STRBUF_INIT;
 279
 280        if (!path)
 281                return NULL;
 282
 283        strbuf_reset(&new_path);
 284
 285        while (*path) {
 286                switch (*path) {
 287                case '\\': strbuf_addstr(&new_path, "\\\\"); break;
 288                case '\n': strbuf_addstr(&new_path, "\\n"); break;
 289                case '\r': strbuf_addstr(&new_path, "\\r"); break;
 290                default:
 291                        strbuf_addch(&new_path, *path);
 292                }
 293                path++;
 294        }
 295        return new_path.buf;
 296}
 297
 298/* FIXME: move prefix to startup_info struct and get rid of this arg */
 299void trace_repo_setup(const char *prefix)
 300{
 301        static struct trace_key key = TRACE_KEY_INIT(SETUP);
 302        const char *git_work_tree;
 303        char *cwd;
 304
 305        if (!trace_want(&key))
 306                return;
 307
 308        cwd = xgetcwd();
 309
 310        if (!(git_work_tree = get_git_work_tree()))
 311                git_work_tree = "(null)";
 312
 313        if (!prefix)
 314                prefix = "(null)";
 315
 316        trace_printf_key(&key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
 317        trace_printf_key(&key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
 318        trace_printf_key(&key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
 319        trace_printf_key(&key, "setup: cwd: %s\n", quote_crnl(cwd));
 320        trace_printf_key(&key, "setup: prefix: %s\n", quote_crnl(prefix));
 321
 322        free(cwd);
 323}
 324
 325int trace_want(struct trace_key *key)
 326{
 327        return !!get_trace_fd(key);
 328}
 329
 330#if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC)
 331
 332static inline uint64_t highres_nanos(void)
 333{
 334        struct timespec ts;
 335        if (clock_gettime(CLOCK_MONOTONIC, &ts))
 336                return 0;
 337        return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec;
 338}
 339
 340#elif defined (GIT_WINDOWS_NATIVE)
 341
 342static inline uint64_t highres_nanos(void)
 343{
 344        static uint64_t high_ns, scaled_low_ns;
 345        static int scale;
 346        LARGE_INTEGER cnt;
 347
 348        if (!scale) {
 349                if (!QueryPerformanceFrequency(&cnt))
 350                        return 0;
 351
 352                /* high_ns = number of ns per cnt.HighPart */
 353                high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart;
 354
 355                /*
 356                 * Number of ns per cnt.LowPart is 10^9 / frequency (or
 357                 * high_ns >> 32). For maximum precision, we scale this factor
 358                 * so that it just fits within 32 bit (i.e. won't overflow if
 359                 * multiplied with cnt.LowPart).
 360                 */
 361                scaled_low_ns = high_ns;
 362                scale = 32;
 363                while (scaled_low_ns >= 0x100000000LL) {
 364                        scaled_low_ns >>= 1;
 365                        scale--;
 366                }
 367        }
 368
 369        /* if QPF worked on initialization, we expect QPC to work as well */
 370        QueryPerformanceCounter(&cnt);
 371
 372        return (high_ns * cnt.HighPart) +
 373               ((scaled_low_ns * cnt.LowPart) >> scale);
 374}
 375
 376#else
 377# define highres_nanos() 0
 378#endif
 379
 380static inline uint64_t gettimeofday_nanos(void)
 381{
 382        struct timeval tv;
 383        gettimeofday(&tv, NULL);
 384        return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
 385}
 386
 387/*
 388 * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
 389 * (i.e. favoring high precision over wall clock time accuracy).
 390 */
 391uint64_t getnanotime(void)
 392{
 393        static uint64_t offset;
 394        if (offset > 1) {
 395                /* initialization succeeded, return offset + high res time */
 396                return offset + highres_nanos();
 397        } else if (offset == 1) {
 398                /* initialization failed, fall back to gettimeofday */
 399                return gettimeofday_nanos();
 400        } else {
 401                /* initialize offset if high resolution timer works */
 402                uint64_t now = gettimeofday_nanos();
 403                uint64_t highres = highres_nanos();
 404                if (highres)
 405                        offset = now - highres;
 406                else
 407                        offset = 1;
 408                return now;
 409        }
 410}
 411
 412static uint64_t command_start_time;
 413static struct strbuf command_line = STRBUF_INIT;
 414
 415static void print_command_performance_atexit(void)
 416{
 417        trace_performance_since(command_start_time, "git command:%s",
 418                                command_line.buf);
 419}
 420
 421void trace_command_performance(const char **argv)
 422{
 423        if (!trace_want(&trace_perf_key))
 424                return;
 425
 426        if (!command_start_time)
 427                atexit(print_command_performance_atexit);
 428
 429        strbuf_reset(&command_line);
 430        sq_quote_argv(&command_line, argv, 0);
 431        command_start_time = getnanotime();
 432}