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, 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 };
  28struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
  29
  30/* Get a trace file descriptor from "key" env variable. */
  31static int get_trace_fd(struct trace_key *key)
  32{
  33        const char *trace;
  34
  35        /* don't open twice */
  36        if (key->initialized)
  37                return key->fd;
  38
  39        trace = getenv(key->key);
  40
  41        if (!trace || !strcmp(trace, "") ||
  42            !strcmp(trace, "0") || !strcasecmp(trace, "false"))
  43                key->fd = 0;
  44        else if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
  45                key->fd = STDERR_FILENO;
  46        else if (strlen(trace) == 1 && isdigit(*trace))
  47                key->fd = atoi(trace);
  48        else if (is_absolute_path(trace)) {
  49                int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
  50                if (fd == -1) {
  51                        warning("could not open '%s' for tracing: %s",
  52                                trace, strerror(errno));
  53                        trace_disable(key);
  54                } else {
  55                        key->fd = fd;
  56                        key->need_close = 1;
  57                }
  58        } else {
  59                warning("unknown trace value for '%s': %s\n"
  60                        "         If you want to trace into a file, then please set %s\n"
  61                        "         to an absolute pathname (starting with /)",
  62                        key->key, trace, key->key);
  63                trace_disable(key);
  64        }
  65
  66        key->initialized = 1;
  67        return key->fd;
  68}
  69
  70void trace_disable(struct trace_key *key)
  71{
  72        if (key->need_close)
  73                close(key->fd);
  74        key->fd = 0;
  75        key->initialized = 1;
  76        key->need_close = 0;
  77}
  78
  79static int prepare_trace_line(const char *file, int line,
  80                              struct trace_key *key, struct strbuf *buf)
  81{
  82        static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
  83        struct timeval tv;
  84        struct tm tm;
  85        time_t secs;
  86
  87        if (!trace_want(key))
  88                return 0;
  89
  90        set_try_to_free_routine(NULL);  /* is never reset */
  91
  92        /* unit tests may want to disable additional trace output */
  93        if (trace_want(&trace_bare))
  94                return 1;
  95
  96        /* print current timestamp */
  97        gettimeofday(&tv, NULL);
  98        secs = tv.tv_sec;
  99        localtime_r(&secs, &tm);
 100        strbuf_addf(buf, "%02d:%02d:%02d.%06ld ", tm.tm_hour, tm.tm_min,
 101                    tm.tm_sec, (long) tv.tv_usec);
 102
 103#ifdef HAVE_VARIADIC_MACROS
 104        /* print file:line */
 105        strbuf_addf(buf, "%s:%d ", file, line);
 106        /* align trace output (column 40 catches most files names in git) */
 107        while (buf->len < 40)
 108                strbuf_addch(buf, ' ');
 109#endif
 110
 111        return 1;
 112}
 113
 114static void trace_write(struct trace_key *key, const void *buf, unsigned len)
 115{
 116        if (write_in_full(get_trace_fd(key), buf, len) < 0) {
 117                warning("unable to write trace for %s: %s",
 118                        key->key, strerror(errno));
 119                trace_disable(key);
 120        }
 121}
 122
 123void trace_verbatim(struct trace_key *key, const void *buf, unsigned len)
 124{
 125        if (!trace_want(key))
 126                return;
 127        trace_write(key, buf, len);
 128}
 129
 130static void print_trace_line(struct trace_key *key, struct strbuf *buf)
 131{
 132        strbuf_complete_line(buf);
 133        trace_write(key, buf->buf, buf->len);
 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        strbuf_release(&buf);
 147}
 148
 149static void trace_argv_vprintf_fl(const char *file, int line,
 150                                  const char **argv, const char *format,
 151                                  va_list ap)
 152{
 153        struct strbuf buf = STRBUF_INIT;
 154
 155        if (!prepare_trace_line(file, line, &trace_default_key, &buf))
 156                return;
 157
 158        strbuf_vaddf(&buf, format, ap);
 159
 160        sq_quote_argv_pretty(&buf, argv);
 161        print_trace_line(&trace_default_key, &buf);
 162        strbuf_release(&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        strbuf_release(&buf);
 176}
 177
 178static void trace_performance_vprintf_fl(const char *file, int line,
 179                                         uint64_t nanos, const char *format,
 180                                         va_list ap)
 181{
 182        struct strbuf buf = STRBUF_INIT;
 183
 184        if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
 185                return;
 186
 187        strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
 188
 189        if (format && *format) {
 190                strbuf_addstr(&buf, ": ");
 191                strbuf_vaddf(&buf, format, ap);
 192        }
 193
 194        print_trace_line(&trace_perf_key, &buf);
 195        strbuf_release(&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, &trace_default_key, 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_pretty(&command_line, argv);
 433        command_start_time = getnanotime();
 434}