trace.con commit diff-lib: allow ita entries treated as "not yet exist in index" (425a28e)
   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                        warning("could not open '%s' for tracing: %s",
  65                                trace, strerror(errno));
  66                        trace_disable(key);
  67                } else {
  68                        key->fd = fd;
  69                        key->need_close = 1;
  70                }
  71        } else {
  72                warning("unknown trace value for '%s': %s\n"
  73                        "         If you want to trace into a file, then please set %s\n"
  74                        "         to an absolute pathname (starting with /)",
  75                        key->key, trace, key->key);
  76                trace_disable(key);
  77        }
  78
  79        key->initialized = 1;
  80        return key->fd;
  81}
  82
  83void trace_disable(struct trace_key *key)
  84{
  85        normalize_trace_key(&key);
  86
  87        if (key->need_close)
  88                close(key->fd);
  89        key->fd = 0;
  90        key->initialized = 1;
  91        key->need_close = 0;
  92}
  93
  94static int prepare_trace_line(const char *file, int line,
  95                              struct trace_key *key, struct strbuf *buf)
  96{
  97        static struct trace_key trace_bare = TRACE_KEY_INIT(BARE);
  98        struct timeval tv;
  99        struct tm tm;
 100        time_t secs;
 101
 102        if (!trace_want(key))
 103                return 0;
 104
 105        set_try_to_free_routine(NULL);  /* is never reset */
 106
 107        /* unit tests may want to disable additional trace output */
 108        if (trace_want(&trace_bare))
 109                return 1;
 110
 111        /* print current timestamp */
 112        gettimeofday(&tv, NULL);
 113        secs = tv.tv_sec;
 114        localtime_r(&secs, &tm);
 115        strbuf_addf(buf, "%02d:%02d:%02d.%06ld ", tm.tm_hour, tm.tm_min,
 116                    tm.tm_sec, (long) tv.tv_usec);
 117
 118#ifdef HAVE_VARIADIC_MACROS
 119        /* print file:line */
 120        strbuf_addf(buf, "%s:%d ", file, line);
 121        /* align trace output (column 40 catches most files names in git) */
 122        while (buf->len < 40)
 123                strbuf_addch(buf, ' ');
 124#endif
 125
 126        return 1;
 127}
 128
 129static void trace_write(struct trace_key *key, const void *buf, unsigned len)
 130{
 131        if (write_in_full(get_trace_fd(key), buf, len) < 0) {
 132                normalize_trace_key(&key);
 133                warning("unable to write trace for %s: %s",
 134                        key->key, strerror(errno));
 135                trace_disable(key);
 136        }
 137}
 138
 139void trace_verbatim(struct trace_key *key, const void *buf, unsigned len)
 140{
 141        if (!trace_want(key))
 142                return;
 143        trace_write(key, buf, len);
 144}
 145
 146static void print_trace_line(struct trace_key *key, struct strbuf *buf)
 147{
 148        strbuf_complete_line(buf);
 149        trace_write(key, buf->buf, buf->len);
 150        strbuf_release(buf);
 151}
 152
 153static void trace_vprintf_fl(const char *file, int line, struct trace_key *key,
 154                             const char *format, va_list ap)
 155{
 156        struct strbuf buf = STRBUF_INIT;
 157
 158        if (!prepare_trace_line(file, line, key, &buf))
 159                return;
 160
 161        strbuf_vaddf(&buf, format, ap);
 162        print_trace_line(key, &buf);
 163}
 164
 165static void trace_argv_vprintf_fl(const char *file, int line,
 166                                  const char **argv, const char *format,
 167                                  va_list ap)
 168{
 169        struct strbuf buf = STRBUF_INIT;
 170
 171        if (!prepare_trace_line(file, line, NULL, &buf))
 172                return;
 173
 174        strbuf_vaddf(&buf, format, ap);
 175
 176        sq_quote_argv(&buf, argv, 0);
 177        print_trace_line(NULL, &buf);
 178}
 179
 180void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
 181                     const struct strbuf *data)
 182{
 183        struct strbuf buf = STRBUF_INIT;
 184
 185        if (!prepare_trace_line(file, line, key, &buf))
 186                return;
 187
 188        strbuf_addbuf(&buf, data);
 189        print_trace_line(key, &buf);
 190}
 191
 192static struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
 193
 194static void trace_performance_vprintf_fl(const char *file, int line,
 195                                         uint64_t nanos, const char *format,
 196                                         va_list ap)
 197{
 198        struct strbuf buf = STRBUF_INIT;
 199
 200        if (!prepare_trace_line(file, line, &trace_perf_key, &buf))
 201                return;
 202
 203        strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000);
 204
 205        if (format && *format) {
 206                strbuf_addstr(&buf, ": ");
 207                strbuf_vaddf(&buf, format, ap);
 208        }
 209
 210        print_trace_line(&trace_perf_key, &buf);
 211}
 212
 213#ifndef HAVE_VARIADIC_MACROS
 214
 215void trace_printf(const char *format, ...)
 216{
 217        va_list ap;
 218        va_start(ap, format);
 219        trace_vprintf_fl(NULL, 0, NULL, format, ap);
 220        va_end(ap);
 221}
 222
 223void trace_printf_key(struct trace_key *key, const char *format, ...)
 224{
 225        va_list ap;
 226        va_start(ap, format);
 227        trace_vprintf_fl(NULL, 0, key, format, ap);
 228        va_end(ap);
 229}
 230
 231void trace_argv_printf(const char **argv, const char *format, ...)
 232{
 233        va_list ap;
 234        va_start(ap, format);
 235        trace_argv_vprintf_fl(NULL, 0, argv, format, ap);
 236        va_end(ap);
 237}
 238
 239void trace_strbuf(struct trace_key *key, const struct strbuf *data)
 240{
 241        trace_strbuf_fl(NULL, 0, key, data);
 242}
 243
 244void trace_performance(uint64_t nanos, const char *format, ...)
 245{
 246        va_list ap;
 247        va_start(ap, format);
 248        trace_performance_vprintf_fl(NULL, 0, nanos, format, ap);
 249        va_end(ap);
 250}
 251
 252void trace_performance_since(uint64_t start, const char *format, ...)
 253{
 254        va_list ap;
 255        va_start(ap, format);
 256        trace_performance_vprintf_fl(NULL, 0, getnanotime() - start,
 257                                     format, ap);
 258        va_end(ap);
 259}
 260
 261#else
 262
 263void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
 264                         const char *format, ...)
 265{
 266        va_list ap;
 267        va_start(ap, format);
 268        trace_vprintf_fl(file, line, key, format, ap);
 269        va_end(ap);
 270}
 271
 272void trace_argv_printf_fl(const char *file, int line, const char **argv,
 273                          const char *format, ...)
 274{
 275        va_list ap;
 276        va_start(ap, format);
 277        trace_argv_vprintf_fl(file, line, argv, format, ap);
 278        va_end(ap);
 279}
 280
 281void trace_performance_fl(const char *file, int line, uint64_t nanos,
 282                              const char *format, ...)
 283{
 284        va_list ap;
 285        va_start(ap, format);
 286        trace_performance_vprintf_fl(file, line, nanos, format, ap);
 287        va_end(ap);
 288}
 289
 290#endif /* HAVE_VARIADIC_MACROS */
 291
 292
 293static const char *quote_crnl(const char *path)
 294{
 295        static struct strbuf new_path = STRBUF_INIT;
 296
 297        if (!path)
 298                return NULL;
 299
 300        strbuf_reset(&new_path);
 301
 302        while (*path) {
 303                switch (*path) {
 304                case '\\': strbuf_addstr(&new_path, "\\\\"); break;
 305                case '\n': strbuf_addstr(&new_path, "\\n"); break;
 306                case '\r': strbuf_addstr(&new_path, "\\r"); break;
 307                default:
 308                        strbuf_addch(&new_path, *path);
 309                }
 310                path++;
 311        }
 312        return new_path.buf;
 313}
 314
 315/* FIXME: move prefix to startup_info struct and get rid of this arg */
 316void trace_repo_setup(const char *prefix)
 317{
 318        static struct trace_key key = TRACE_KEY_INIT(SETUP);
 319        const char *git_work_tree;
 320        char *cwd;
 321
 322        if (!trace_want(&key))
 323                return;
 324
 325        cwd = xgetcwd();
 326
 327        if (!(git_work_tree = get_git_work_tree()))
 328                git_work_tree = "(null)";
 329
 330        if (!prefix)
 331                prefix = "(null)";
 332
 333        trace_printf_key(&key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
 334        trace_printf_key(&key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
 335        trace_printf_key(&key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
 336        trace_printf_key(&key, "setup: cwd: %s\n", quote_crnl(cwd));
 337        trace_printf_key(&key, "setup: prefix: %s\n", quote_crnl(prefix));
 338
 339        free(cwd);
 340}
 341
 342int trace_want(struct trace_key *key)
 343{
 344        return !!get_trace_fd(key);
 345}
 346
 347#if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC)
 348
 349static inline uint64_t highres_nanos(void)
 350{
 351        struct timespec ts;
 352        if (clock_gettime(CLOCK_MONOTONIC, &ts))
 353                return 0;
 354        return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec;
 355}
 356
 357#elif defined (GIT_WINDOWS_NATIVE)
 358
 359static inline uint64_t highres_nanos(void)
 360{
 361        static uint64_t high_ns, scaled_low_ns;
 362        static int scale;
 363        LARGE_INTEGER cnt;
 364
 365        if (!scale) {
 366                if (!QueryPerformanceFrequency(&cnt))
 367                        return 0;
 368
 369                /* high_ns = number of ns per cnt.HighPart */
 370                high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart;
 371
 372                /*
 373                 * Number of ns per cnt.LowPart is 10^9 / frequency (or
 374                 * high_ns >> 32). For maximum precision, we scale this factor
 375                 * so that it just fits within 32 bit (i.e. won't overflow if
 376                 * multiplied with cnt.LowPart).
 377                 */
 378                scaled_low_ns = high_ns;
 379                scale = 32;
 380                while (scaled_low_ns >= 0x100000000LL) {
 381                        scaled_low_ns >>= 1;
 382                        scale--;
 383                }
 384        }
 385
 386        /* if QPF worked on initialization, we expect QPC to work as well */
 387        QueryPerformanceCounter(&cnt);
 388
 389        return (high_ns * cnt.HighPart) +
 390               ((scaled_low_ns * cnt.LowPart) >> scale);
 391}
 392
 393#else
 394# define highres_nanos() 0
 395#endif
 396
 397static inline uint64_t gettimeofday_nanos(void)
 398{
 399        struct timeval tv;
 400        gettimeofday(&tv, NULL);
 401        return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
 402}
 403
 404/*
 405 * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
 406 * (i.e. favoring high precision over wall clock time accuracy).
 407 */
 408uint64_t getnanotime(void)
 409{
 410        static uint64_t offset;
 411        if (offset > 1) {
 412                /* initialization succeeded, return offset + high res time */
 413                return offset + highres_nanos();
 414        } else if (offset == 1) {
 415                /* initialization failed, fall back to gettimeofday */
 416                return gettimeofday_nanos();
 417        } else {
 418                /* initialize offset if high resolution timer works */
 419                uint64_t now = gettimeofday_nanos();
 420                uint64_t highres = highres_nanos();
 421                if (highres)
 422                        offset = now - highres;
 423                else
 424                        offset = 1;
 425                return now;
 426        }
 427}
 428
 429static uint64_t command_start_time;
 430static struct strbuf command_line = STRBUF_INIT;
 431
 432static void print_command_performance_atexit(void)
 433{
 434        trace_performance_since(command_start_time, "git command:%s",
 435                                command_line.buf);
 436}
 437
 438void trace_command_performance(const char **argv)
 439{
 440        if (!trace_want(&trace_perf_key))
 441                return;
 442
 443        if (!command_start_time)
 444                atexit(print_command_performance_atexit);
 445
 446        strbuf_reset(&command_line);
 447        sq_quote_argv(&command_line, argv, 0);
 448        command_start_time = getnanotime();
 449}