f204a7d88a03261403f2f93b5525ac2cc4646446
   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/*
  29 * "Normalize" a key argument by converting NULL to our trace_default,
  30 * and otherwise passing through the value. All caller-facing functions
  31 * should normalize their inputs in this way, though most get it
  32 * for free by calling get_trace_fd() (directly or indirectly).
  33 */
  34static void normalize_trace_key(struct trace_key **key)
  35{
  36        static struct trace_key trace_default = { "GIT_TRACE" };
  37        if (!*key)
  38                *key = &trace_default;
  39}
  40
  41/* Get a trace file descriptor from "key" env variable. */
  42static int get_trace_fd(struct trace_key *key)
  43{
  44        const char *trace;
  45
  46        normalize_trace_key(&key);
  47
  48        /* don't open twice */
  49        if (key->initialized)
  50                return key->fd;
  51
  52        trace = getenv(key->key);
  53
  54        if (!trace || !strcmp(trace, "") ||
  55            !strcmp(trace, "0") || !strcasecmp(trace, "false"))
  56                key->fd = 0;
  57        else if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
  58                key->fd = STDERR_FILENO;
  59        else if (strlen(trace) == 1 && isdigit(*trace))
  60                key->fd = atoi(trace);
  61        else if (is_absolute_path(trace)) {
  62                int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
  63                if (fd == -1) {
  64                        fprintf(stderr,
  65                                "Could not open '%s' for tracing: %s\n"
  66                                "Defaulting to tracing on stderr...\n",
  67                                trace, strerror(errno));
  68                        key->fd = STDERR_FILENO;
  69                } else {
  70                        key->fd = fd;
  71                        key->need_close = 1;
  72                }
  73        } else {
  74                fprintf(stderr, "What does '%s' for %s mean?\n"
  75                        "If you want to trace into a file, then please set "
  76                        "%s to an absolute pathname (starting with /).\n"
  77                        "Defaulting to tracing on stderr...\n",
  78                        trace, key->key, key->key);
  79                key->fd = STDERR_FILENO;
  80        }
  81
  82        key->initialized = 1;
  83        return key->fd;
  84}
  85
  86void trace_disable(struct trace_key *key)
  87{
  88        normalize_trace_key(&key);
  89
  90        if (key->need_close)
  91                close(key->fd);
  92        key->fd = 0;
  93        key->initialized = 1;
  94        key->need_close = 0;
  95}
  96
  97static const char err_msg[] = "Could not trace into fd given by "
  98        "GIT_TRACE environment variable";
  99
 100static int prepare_trace_line(const char *file, int line,
 101                              struct trace_key *key, struct strbuf *buf)
 102{
 103        static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
 104        struct timeval tv;
 105        struct tm tm;
 106        time_t secs;
 107
 108        if (!trace_want(key))
 109                return 0;
 110
 111        set_try_to_free_routine(NULL);  /* is never reset */
 112
 113        /* unit tests may want to disable additional trace output */
 114        if (trace_want(&trace_bare))
 115                return 1;
 116
 117        /* print current timestamp */
 118        gettimeofday(&tv, NULL);
 119        secs = tv.tv_sec;
 120        localtime_r(&secs, &tm);
 121        strbuf_addf(buf, "%02d:%02d:%02d.%06ld ", tm.tm_hour, tm.tm_min,
 122                    tm.tm_sec, (long) tv.tv_usec);
 123
 124#ifdef HAVE_VARIADIC_MACROS
 125        /* print file:line */
 126        strbuf_addf(buf, "%s:%d ", file, line);
 127        /* align trace output (column 40 catches most files names in git) */
 128        while (buf->len < 40)
 129                strbuf_addch(buf, ' ');
 130#endif
 131
 132        return 1;
 133}
 134
 135void trace_verbatim(struct trace_key *key, const void *buf, unsigned len)
 136{
 137        if (!trace_want(key))
 138                return;
 139        write_or_whine_pipe(get_trace_fd(key), buf, len, err_msg);
 140}
 141
 142static void print_trace_line(struct trace_key *key, struct strbuf *buf)
 143{
 144        strbuf_complete_line(buf);
 145
 146        write_or_whine_pipe(get_trace_fd(key), buf->buf, buf->len, err_msg);
 147        strbuf_release(buf);
 148}
 149
 150static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
 151                             const char *format, va_list ap)
 152{
 153        struct strbuf buf = STRBUF_INIT;
 154
 155        if (!prepare_trace_line(file, line, key, &buf))
 156                return;
 157
 158        strbuf_vaddf(&buf, format, ap);
 159        print_trace_line(key, &buf);
 160}
 161
 162static void trace_argv_vprintf_fl(const char *file, int line,
 163                                  const char **argv, const char *format,
 164                                  va_list ap)
 165{
 166        struct strbuf buf = STRBUF_INIT;
 167
 168        if (!prepare_trace_line(file, line, NULL, &buf))
 169                return;
 170
 171        strbuf_vaddf(&buf, format, ap);
 172
 173        sq_quote_argv(&buf, argv, 0);
 174        print_trace_line(NULL, &buf);
 175}
 176
 177void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
 178                     const struct strbuf *data)
 179{
 180        struct strbuf buf = STRBUF_INIT;
 181
 182        if (!prepare_trace_line(file, line, key, &buf))
 183                return;
 184
 185        strbuf_addbuf(&buf, data);
 186        print_trace_line(key, &buf);
 187}
 188
 189static struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
 190
 191static void trace_performance_vprintf_fl(const char *file, int line,
 192                                         uint64_t nanos, const char *format,
 193                                         va_list ap)
 194{
 195        struct strbuf buf = STRBUF_INIT;
 196
 197        if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
 198                return;
 199
 200        strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
 201
 202        if (format && *format) {
 203                strbuf_addstr(&buf, ": ");
 204                strbuf_vaddf(&buf, format, ap);
 205        }
 206
 207        print_trace_line(&trace_perf_key, &buf);
 208}
 209
 210#ifndef HAVE_VARIADIC_MACROS
 211
 212void trace_printf(const char *format, ...)
 213{
 214        va_list ap;
 215        va_start(ap, format);
 216        trace_vprintf_fl(NULL, 0, NULL, format, ap);
 217        va_end(ap);
 218}
 219
 220void trace_printf_key(struct trace_key *key, const char *format, ...)
 221{
 222        va_list ap;
 223        va_start(ap, format);
 224        trace_vprintf_fl(NULL, 0, key, format, ap);
 225        va_end(ap);
 226}
 227
 228void trace_argv_printf(const char **argv, const char *format, ...)
 229{
 230        va_list ap;
 231        va_start(ap, format);
 232        trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
 233        va_end(ap);
 234}
 235
 236void trace_strbuf(struct trace_key *key, const struct strbuf *data)
 237{
 238        trace_strbuf_fl(NULL, 0, key, data);
 239}
 240
 241void trace_performance(uint64_t nanos, const char *format, ...)
 242{
 243        va_list ap;
 244        va_start(ap, format);
 245        trace_performance_vprintf_fl(NULL, 0, nanos, format, ap);
 246        va_end(ap);
 247}
 248
 249void trace_performance_since(uint64_t start, const char *format, ...)
 250{
 251        va_list ap;
 252        va_start(ap, format);
 253        trace_performance_vprintf_fl(NULL, 0, getnanotime() - start,
 254                                     format, ap);
 255        va_end(ap);
 256}
 257
 258#else
 259
 260void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
 261                         const char *format, ...)
 262{
 263        va_list ap;
 264        va_start(ap, format);
 265        trace_vprintf_fl(file, line, key, format, ap);
 266        va_end(ap);
 267}
 268
 269void trace_argv_printf_fl(const char *file, int line, const char **argv,
 270                          const char *format, ...)
 271{
 272        va_list ap;
 273        va_start(ap, format);
 274        trace_argv_vprintf_fl(file, line, argv, format, ap);
 275        va_end(ap);
 276}
 277
 278void trace_performance_fl(const char *file, int line, uint64_t nanos,
 279                              const char *format, ...)
 280{
 281        va_list ap;
 282        va_start(ap, format);
 283        trace_performance_vprintf_fl(file, line, nanos, format, ap);
 284        va_end(ap);
 285}
 286
 287#endif /* HAVE_VARIADIC_MACROS */
 288
 289
 290static const char *quote_crnl(const char *path)
 291{
 292        static struct strbuf new_path = STRBUF_INIT;
 293
 294        if (!path)
 295                return NULL;
 296
 297        strbuf_reset(&new_path);
 298
 299        while (*path) {
 300                switch (*path) {
 301                case '\\': strbuf_addstr(&new_path, "\\\\"); break;
 302                case '\n': strbuf_addstr(&new_path, "\\n"); break;
 303                case '\r': strbuf_addstr(&new_path, "\\r"); break;
 304                default:
 305                        strbuf_addch(&new_path, *path);
 306                }
 307                path++;
 308        }
 309        return new_path.buf;
 310}
 311
 312/* FIXME: move prefix to startup_info struct and get rid of this arg */
 313void trace_repo_setup(const char *prefix)
 314{
 315        static struct trace_key key = TRACE_KEY_INIT(SETUP);
 316        const char *git_work_tree;
 317        char *cwd;
 318
 319        if (!trace_want(&key))
 320                return;
 321
 322        cwd = xgetcwd();
 323
 324        if (!(git_work_tree = get_git_work_tree()))
 325                git_work_tree = "(null)";
 326
 327        if (!prefix)
 328                prefix = "(null)";
 329
 330        trace_printf_key(&key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
 331        trace_printf_key(&key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
 332        trace_printf_key(&key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
 333        trace_printf_key(&key, "setup: cwd: %s\n", quote_crnl(cwd));
 334        trace_printf_key(&key, "setup: prefix: %s\n", quote_crnl(prefix));
 335
 336        free(cwd);
 337}
 338
 339int trace_want(struct trace_key *key)
 340{
 341        return !!get_trace_fd(key);
 342}
 343
 344#if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC)
 345
 346static inline uint64_t highres_nanos(void)
 347{
 348        struct timespec ts;
 349        if (clock_gettime(CLOCK_MONOTONIC, &ts))
 350                return 0;
 351        return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec;
 352}
 353
 354#elif defined (GIT_WINDOWS_NATIVE)
 355
 356static inline uint64_t highres_nanos(void)
 357{
 358        static uint64_t high_ns, scaled_low_ns;
 359        static int scale;
 360        LARGE_INTEGER cnt;
 361
 362        if (!scale) {
 363                if (!QueryPerformanceFrequency(&cnt))
 364                        return 0;
 365
 366                /* high_ns = number of ns per cnt.HighPart */
 367                high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart;
 368
 369                /*
 370                 * Number of ns per cnt.LowPart is 10^9 / frequency (or
 371                 * high_ns >> 32). For maximum precision, we scale this factor
 372                 * so that it just fits within 32 bit (i.e. won't overflow if
 373                 * multiplied with cnt.LowPart).
 374                 */
 375                scaled_low_ns = high_ns;
 376                scale = 32;
 377                while (scaled_low_ns >= 0x100000000LL) {
 378                        scaled_low_ns >>= 1;
 379                        scale--;
 380                }
 381        }
 382
 383        /* if QPF worked on initialization, we expect QPC to work as well */
 384        QueryPerformanceCounter(&cnt);
 385
 386        return (high_ns * cnt.HighPart) +
 387               ((scaled_low_ns * cnt.LowPart) >> scale);
 388}
 389
 390#else
 391# define highres_nanos() 0
 392#endif
 393
 394static inline uint64_t gettimeofday_nanos(void)
 395{
 396        struct timeval tv;
 397        gettimeofday(&tv, NULL);
 398        return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
 399}
 400
 401/*
 402 * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
 403 * (i.e. favoring high precision over wall clock time accuracy).
 404 */
 405uint64_t getnanotime(void)
 406{
 407        static uint64_t offset;
 408        if (offset > 1) {
 409                /* initialization succeeded, return offset + high res time */
 410                return offset + highres_nanos();
 411        } else if (offset == 1) {
 412                /* initialization failed, fall back to gettimeofday */
 413                return gettimeofday_nanos();
 414        } else {
 415                /* initialize offset if high resolution timer works */
 416                uint64_t now = gettimeofday_nanos();
 417                uint64_t highres = highres_nanos();
 418                if (highres)
 419                        offset = now - highres;
 420                else
 421                        offset = 1;
 422                return now;
 423        }
 424}
 425
 426static uint64_t command_start_time;
 427static struct strbuf command_line = STRBUF_INIT;
 428
 429static void print_command_performance_atexit(void)
 430{
 431        trace_performance_since(command_start_time, "git command:%s",
 432                                command_line.buf);
 433}
 434
 435void trace_command_performance(const char **argv)
 436{
 437        if (!trace_want(&trace_perf_key))
 438                return;
 439
 440        if (!command_start_time)
 441                atexit(print_command_performance_atexit);
 442
 443        strbuf_reset(&command_line);
 444        sq_quote_argv(&command_line, argv, 0);
 445        command_start_time = getnanotime();
 446}