Andrew's git / gitweb.git / trace.c
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trace.con commit clone: do not let --depth imply --shallow-submodules (18a74a0)
   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
 123void trace_verbatim(struct trace_key *key, const void *buf, unsigned len)
 124{
 125        if (!trace_want(key))
 126                return;
 127        write_or_whine_pipe(get_trace_fd(key), buf, len, err_msg);
 128}
 129
 130static void print_trace_line(struct trace_key *key, struct strbuf *buf)
 131{
 132        strbuf_complete_line(buf);
 133
 134        write_or_whine_pipe(get_trace_fd(key), buf->buf, buf->len, err_msg);
 135        strbuf_release(buf);
 136}
 137
 138static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
 139                             const char *format, va_list ap)
 140{
 141        struct strbuf buf = STRBUF_INIT;
 142
 143        if (!prepare_trace_line(file, line, key, &buf))
 144                return;
 145
 146        strbuf_vaddf(&buf, format, ap);
 147        print_trace_line(key, &buf);
 148}
 149
 150static void trace_argv_vprintf_fl(const char *file, int line,
 151                                  const char **argv, const char *format,
 152                                  va_list ap)
 153{
 154        struct strbuf buf = STRBUF_INIT;
 155
 156        if (!prepare_trace_line(file, line, NULL, &buf))
 157                return;
 158
 159        strbuf_vaddf(&buf, format, ap);
 160
 161        sq_quote_argv(&buf, argv, 0);
 162        print_trace_line(NULL, &buf);
 163}
 164
 165void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
 166                     const struct strbuf *data)
 167{
 168        struct strbuf buf = STRBUF_INIT;
 169
 170        if (!prepare_trace_line(file, line, key, &buf))
 171                return;
 172
 173        strbuf_addbuf(&buf, data);
 174        print_trace_line(key, &buf);
 175}
 176
 177static struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
 178
 179static void trace_performance_vprintf_fl(const char *file, int line,
 180                                         uint64_t nanos, const char *format,
 181                                         va_list ap)
 182{
 183        struct strbuf buf = STRBUF_INIT;
 184
 185        if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
 186                return;
 187
 188        strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
 189
 190        if (format && *format) {
 191                strbuf_addstr(&buf, ": ");
 192                strbuf_vaddf(&buf, format, ap);
 193        }
 194
 195        print_trace_line(&trace_perf_key, &buf);
 196}
 197
 198#ifndef HAVE_VARIADIC_MACROS
 199
 200void trace_printf(const char *format, ...)
 201{
 202        va_list ap;
 203        va_start(ap, format);
 204        trace_vprintf_fl(NULL, 0, NULL, format, ap);
 205        va_end(ap);
 206}
 207
 208void trace_printf_key(struct trace_key *key, const char *format, ...)
 209{
 210        va_list ap;
 211        va_start(ap, format);
 212        trace_vprintf_fl(NULL, 0, key, format, ap);
 213        va_end(ap);
 214}
 215
 216void trace_argv_printf(const char **argv, const char *format, ...)
 217{
 218        va_list ap;
 219        va_start(ap, format);
 220        trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
 221        va_end(ap);
 222}
 223
 224void trace_strbuf(struct trace_key *key, const struct strbuf *data)
 225{
 226        trace_strbuf_fl(NULL, 0, key, data);
 227}
 228
 229void trace_performance(uint64_t nanos, const char *format, ...)
 230{
 231        va_list ap;
 232        va_start(ap, format);
 233        trace_performance_vprintf_fl(NULL, 0, nanos, format, ap);
 234        va_end(ap);
 235}
 236
 237void trace_performance_since(uint64_t start, const char *format, ...)
 238{
 239        va_list ap;
 240        va_start(ap, format);
 241        trace_performance_vprintf_fl(NULL, 0, getnanotime() - start,
 242                                     format, ap);
 243        va_end(ap);
 244}
 245
 246#else
 247
 248void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
 249                         const char *format, ...)
 250{
 251        va_list ap;
 252        va_start(ap, format);
 253        trace_vprintf_fl(file, line, key, format, ap);
 254        va_end(ap);
 255}
 256
 257void trace_argv_printf_fl(const char *file, int line, const char **argv,
 258                          const char *format, ...)
 259{
 260        va_list ap;
 261        va_start(ap, format);
 262        trace_argv_vprintf_fl(file, line, argv, format, ap);
 263        va_end(ap);
 264}
 265
 266void trace_performance_fl(const char *file, int line, uint64_t nanos,
 267                              const char *format, ...)
 268{
 269        va_list ap;
 270        va_start(ap, format);
 271        trace_performance_vprintf_fl(file, line, nanos, format, ap);
 272        va_end(ap);
 273}
 274
 275#endif /* HAVE_VARIADIC_MACROS */
 276
 277
 278static const char *quote_crnl(const char *path)
 279{
 280        static struct strbuf new_path = STRBUF_INIT;
 281
 282        if (!path)
 283                return NULL;
 284
 285        strbuf_reset(&new_path);
 286
 287        while (*path) {
 288                switch (*path) {
 289                case '\\': strbuf_addstr(&new_path, "\\\\"); break;
 290                case '\n': strbuf_addstr(&new_path, "\\n"); break;
 291                case '\r': strbuf_addstr(&new_path, "\\r"); break;
 292                default:
 293                        strbuf_addch(&new_path, *path);
 294                }
 295                path++;
 296        }
 297        return new_path.buf;
 298}
 299
 300/* FIXME: move prefix to startup_info struct and get rid of this arg */
 301void trace_repo_setup(const char *prefix)
 302{
 303        static struct trace_key key = TRACE_KEY_INIT(SETUP);
 304        const char *git_work_tree;
 305        char *cwd;
 306
 307        if (!trace_want(&key))
 308                return;
 309
 310        cwd = xgetcwd();
 311
 312        if (!(git_work_tree = get_git_work_tree()))
 313                git_work_tree = "(null)";
 314
 315        if (!prefix)
 316                prefix = "(null)";
 317
 318        trace_printf_key(&key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
 319        trace_printf_key(&key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
 320        trace_printf_key(&key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
 321        trace_printf_key(&key, "setup: cwd: %s\n", quote_crnl(cwd));
 322        trace_printf_key(&key, "setup: prefix: %s\n", quote_crnl(prefix));
 323
 324        free(cwd);
 325}
 326
 327int trace_want(struct trace_key *key)
 328{
 329        return !!get_trace_fd(key);
 330}
 331
 332#if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC)
 333
 334static inline uint64_t highres_nanos(void)
 335{
 336        struct timespec ts;
 337        if (clock_gettime(CLOCK_MONOTONIC, &ts))
 338                return 0;
 339        return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec;
 340}
 341
 342#elif defined (GIT_WINDOWS_NATIVE)
 343
 344static inline uint64_t highres_nanos(void)
 345{
 346        static uint64_t high_ns, scaled_low_ns;
 347        static int scale;
 348        LARGE_INTEGER cnt;
 349
 350        if (!scale) {
 351                if (!QueryPerformanceFrequency(&cnt))
 352                        return 0;
 353
 354                /* high_ns = number of ns per cnt.HighPart */
 355                high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart;
 356
 357                /*
 358                 * Number of ns per cnt.LowPart is 10^9 / frequency (or
 359                 * high_ns >> 32). For maximum precision, we scale this factor
 360                 * so that it just fits within 32 bit (i.e. won't overflow if
 361                 * multiplied with cnt.LowPart).
 362                 */
 363                scaled_low_ns = high_ns;
 364                scale = 32;
 365                while (scaled_low_ns >= 0x100000000LL) {
 366                        scaled_low_ns >>= 1;
 367                        scale--;
 368                }
 369        }
 370
 371        /* if QPF worked on initialization, we expect QPC to work as well */
 372        QueryPerformanceCounter(&cnt);
 373
 374        return (high_ns * cnt.HighPart) +
 375               ((scaled_low_ns * cnt.LowPart) >> scale);
 376}
 377
 378#else
 379# define highres_nanos() 0
 380#endif
 381
 382static inline uint64_t gettimeofday_nanos(void)
 383{
 384        struct timeval tv;
 385        gettimeofday(&tv, NULL);
 386        return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
 387}
 388
 389/*
 390 * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
 391 * (i.e. favoring high precision over wall clock time accuracy).
 392 */
 393uint64_t getnanotime(void)
 394{
 395        static uint64_t offset;
 396        if (offset > 1) {
 397                /* initialization succeeded, return offset + high res time */
 398                return offset + highres_nanos();
 399        } else if (offset == 1) {
 400                /* initialization failed, fall back to gettimeofday */
 401                return gettimeofday_nanos();
 402        } else {
 403                /* initialize offset if high resolution timer works */
 404                uint64_t now = gettimeofday_nanos();
 405                uint64_t highres = highres_nanos();
 406                if (highres)
 407                        offset = now - highres;
 408                else
 409                        offset = 1;
 410                return now;
 411        }
 412}
 413
 414static uint64_t command_start_time;
 415static struct strbuf command_line = STRBUF_INIT;
 416
 417static void print_command_performance_atexit(void)
 418{
 419        trace_performance_since(command_start_time, "git command:%s",
 420                                command_line.buf);
 421}
 422
 423void trace_command_performance(const char **argv)
 424{
 425        if (!trace_want(&trace_perf_key))
 426                return;
 427
 428        if (!command_start_time)
 429                atexit(print_command_performance_atexit);
 430
 431        strbuf_reset(&command_line);
 432        sq_quote_argv(&command_line, argv, 0);
 433        command_start_time = getnanotime();
 434}