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        strbuf_complete_line(buf);
 126
 127        write_or_whine_pipe(get_trace_fd(key), buf->buf, buf->len, err_msg);
 128        strbuf_release(buf);
 129}
 130
 131static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
 132                             const char *format, va_list ap)
 133{
 134        struct strbuf buf = STRBUF_INIT;
 135
 136        if (!prepare_trace_line(file, line, key, &buf))
 137                return;
 138
 139        strbuf_vaddf(&buf, format, ap);
 140        print_trace_line(key, &buf);
 141}
 142
 143static void trace_argv_vprintf_fl(const char *file, int line,
 144                                  const char **argv, const char *format,
 145                                  va_list ap)
 146{
 147        struct strbuf buf = STRBUF_INIT;
 148
 149        if (!prepare_trace_line(file, line, NULL, &buf))
 150                return;
 151
 152        strbuf_vaddf(&buf, format, ap);
 153
 154        sq_quote_argv(&buf, argv, 0);
 155        print_trace_line(NULL, &buf);
 156}
 157
 158void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
 159                     const struct strbuf *data)
 160{
 161        struct strbuf buf = STRBUF_INIT;
 162
 163        if (!prepare_trace_line(file, line, key, &buf))
 164                return;
 165
 166        strbuf_addbuf(&buf, data);
 167        print_trace_line(key, &buf);
 168}
 169
 170static struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
 171
 172static void trace_performance_vprintf_fl(const char *file, int line,
 173                                         uint64_t nanos, const char *format,
 174                                         va_list ap)
 175{
 176        struct strbuf buf = STRBUF_INIT;
 177
 178        if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
 179                return;
 180
 181        strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
 182
 183        if (format && *format) {
 184                strbuf_addstr(&buf, ": ");
 185                strbuf_vaddf(&buf, format, ap);
 186        }
 187
 188        print_trace_line(&trace_perf_key, &buf);
 189}
 190
 191#ifndef HAVE_VARIADIC_MACROS
 192
 193void trace_printf(const char *format, ...)
 194{
 195        va_list ap;
 196        va_start(ap, format);
 197        trace_vprintf_fl(NULL, 0, NULL, format, ap);
 198        va_end(ap);
 199}
 200
 201void trace_printf_key(struct trace_key *key, const char *format, ...)
 202{
 203        va_list ap;
 204        va_start(ap, format);
 205        trace_vprintf_fl(NULL, 0, key, format, ap);
 206        va_end(ap);
 207}
 208
 209void trace_argv_printf(const char **argv, const char *format, ...)
 210{
 211        va_list ap;
 212        va_start(ap, format);
 213        trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
 214        va_end(ap);
 215}
 216
 217void trace_strbuf(struct trace_key *key, const struct strbuf *data)
 218{
 219        trace_strbuf_fl(NULL, 0, key, data);
 220}
 221
 222void trace_performance(uint64_t nanos, const char *format, ...)
 223{
 224        va_list ap;
 225        va_start(ap, format);
 226        trace_performance_vprintf_fl(NULL, 0, nanos, format, ap);
 227        va_end(ap);
 228}
 229
 230void trace_performance_since(uint64_t start, const char *format, ...)
 231{
 232        va_list ap;
 233        va_start(ap, format);
 234        trace_performance_vprintf_fl(NULL, 0, getnanotime() - start,
 235                                     format, ap);
 236        va_end(ap);
 237}
 238
 239#else
 240
 241void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
 242                         const char *format, ...)
 243{
 244        va_list ap;
 245        va_start(ap, format);
 246        trace_vprintf_fl(file, line, key, format, ap);
 247        va_end(ap);
 248}
 249
 250void trace_argv_printf_fl(const char *file, int line, const char **argv,
 251                          const char *format, ...)
 252{
 253        va_list ap;
 254        va_start(ap, format);
 255        trace_argv_vprintf_fl(file, line, argv, format, ap);
 256        va_end(ap);
 257}
 258
 259void trace_performance_fl(const char *file, int line, uint64_t nanos,
 260                              const char *format, ...)
 261{
 262        va_list ap;
 263        va_start(ap, format);
 264        trace_performance_vprintf_fl(file, line, nanos, format, ap);
 265        va_end(ap);
 266}
 267
 268#endif /* HAVE_VARIADIC_MACROS */
 269
 270
 271static const char *quote_crnl(const char *path)
 272{
 273        static char new_path[PATH_MAX];
 274        const char *p2 = path;
 275        char *p1 = new_path;
 276
 277        if (!path)
 278                return NULL;
 279
 280        while (*p2) {
 281                switch (*p2) {
 282                case '\\': *p1++ = '\\'; *p1++ = '\\'; break;
 283                case '\n': *p1++ = '\\'; *p1++ = 'n'; break;
 284                case '\r': *p1++ = '\\'; *p1++ = 'r'; break;
 285                default:
 286                        *p1++ = *p2;
 287                }
 288                p2++;
 289        }
 290        *p1 = '\0';
 291        return new_path;
 292}
 293
 294/* FIXME: move prefix to startup_info struct and get rid of this arg */
 295void trace_repo_setup(const char *prefix)
 296{
 297        static struct trace_key key = TRACE_KEY_INIT(SETUP);
 298        const char *git_work_tree;
 299        char *cwd;
 300
 301        if (!trace_want(&key))
 302                return;
 303
 304        cwd = xgetcwd();
 305
 306        if (!(git_work_tree = get_git_work_tree()))
 307                git_work_tree = "(null)";
 308
 309        if (!prefix)
 310                prefix = "(null)";
 311
 312        trace_printf_key(&key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
 313        trace_printf_key(&key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
 314        trace_printf_key(&key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
 315        trace_printf_key(&key, "setup: cwd: %s\n", quote_crnl(cwd));
 316        trace_printf_key(&key, "setup: prefix: %s\n", quote_crnl(prefix));
 317
 318        free(cwd);
 319}
 320
 321int trace_want(struct trace_key *key)
 322{
 323        return !!get_trace_fd(key);
 324}
 325
 326#if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC)
 327
 328static inline uint64_t highres_nanos(void)
 329{
 330        struct timespec ts;
 331        if (clock_gettime(CLOCK_MONOTONIC, &ts))
 332                return 0;
 333        return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec;
 334}
 335
 336#elif defined (GIT_WINDOWS_NATIVE)
 337
 338static inline uint64_t highres_nanos(void)
 339{
 340        static uint64_t high_ns, scaled_low_ns;
 341        static int scale;
 342        LARGE_INTEGER cnt;
 343
 344        if (!scale) {
 345                if (!QueryPerformanceFrequency(&cnt))
 346                        return 0;
 347
 348                /* high_ns = number of ns per cnt.HighPart */
 349                high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart;
 350
 351                /*
 352                 * Number of ns per cnt.LowPart is 10^9 / frequency (or
 353                 * high_ns >> 32). For maximum precision, we scale this factor
 354                 * so that it just fits within 32 bit (i.e. won't overflow if
 355                 * multiplied with cnt.LowPart).
 356                 */
 357                scaled_low_ns = high_ns;
 358                scale = 32;
 359                while (scaled_low_ns >= 0x100000000LL) {
 360                        scaled_low_ns >>= 1;
 361                        scale--;
 362                }
 363        }
 364
 365        /* if QPF worked on initialization, we expect QPC to work as well */
 366        QueryPerformanceCounter(&cnt);
 367
 368        return (high_ns * cnt.HighPart) +
 369               ((scaled_low_ns * cnt.LowPart) >> scale);
 370}
 371
 372#else
 373# define highres_nanos() 0
 374#endif
 375
 376static inline uint64_t gettimeofday_nanos(void)
 377{
 378        struct timeval tv;
 379        gettimeofday(&tv, NULL);
 380        return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
 381}
 382
 383/*
 384 * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
 385 * (i.e. favoring high precision over wall clock time accuracy).
 386 */
 387uint64_t getnanotime(void)
 388{
 389        static uint64_t offset;
 390        if (offset > 1) {
 391                /* initialization succeeded, return offset + high res time */
 392                return offset + highres_nanos();
 393        } else if (offset == 1) {
 394                /* initialization failed, fall back to gettimeofday */
 395                return gettimeofday_nanos();
 396        } else {
 397                /* initialize offset if high resolution timer works */
 398                uint64_t now = gettimeofday_nanos();
 399                uint64_t highres = highres_nanos();
 400                if (highres)
 401                        offset = now - highres;
 402                else
 403                        offset = 1;
 404                return now;
 405        }
 406}
 407
 408static uint64_t command_start_time;
 409static struct strbuf command_line = STRBUF_INIT;
 410
 411static void print_command_performance_atexit(void)
 412{
 413        trace_performance_since(command_start_time, "git command:%s",
 414                                command_line.buf);
 415}
 416
 417void trace_command_performance(const char **argv)
 418{
 419        if (!trace_want(&trace_perf_key))
 420                return;
 421
 422        if (!command_start_time)
 423                atexit(print_command_performance_atexit);
 424
 425        strbuf_reset(&command_line);
 426        sq_quote_argv(&command_line, argv, 0);
 427        command_start_time = getnanotime();
 428}