diff options
Diffstat (limited to 'trace.c')
| -rw-r--r-- | trace.c | 428 |
1 files changed, 428 insertions, 0 deletions
@@ -0,0 +1,428 @@ +/* + * GIT - The information manager from hell + * + * Copyright (C) 2000-2002 Michael R. Elkins <me@mutt.org> + * Copyright (C) 2002-2004 Oswald Buddenhagen <ossi@users.sf.net> + * Copyright (C) 2004 Theodore Y. Ts'o <tytso@mit.edu> + * Copyright (C) 2006 Mike McCormack + * Copyright (C) 2006 Christian Couder + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "git-compat-util.h" +#include "abspath.h" +#include "environment.h" +#include "quote.h" +#include "setup.h" +#include "trace.h" + +struct trace_key trace_default_key = { "GIT_TRACE", 0, 0, 0 }; +struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE); +struct trace_key trace_setup_key = TRACE_KEY_INIT(SETUP); + +/* Get a trace file descriptor from "key" env variable. */ +static int get_trace_fd(struct trace_key *key, const char *override_envvar) +{ + const char *trace; + + /* don't open twice */ + if (key->initialized) + return key->fd; + + trace = override_envvar ? override_envvar : getenv(key->key); + + if (!trace || !strcmp(trace, "") || + !strcmp(trace, "0") || !strcasecmp(trace, "false")) + key->fd = 0; + else if (!strcmp(trace, "1") || !strcasecmp(trace, "true")) + key->fd = STDERR_FILENO; + else if (strlen(trace) == 1 && isdigit(*trace)) + key->fd = atoi(trace); + else if (is_absolute_path(trace)) { + int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666); + if (fd == -1) { + warning("could not open '%s' for tracing: %s", + trace, strerror(errno)); + trace_disable(key); + } else { + key->fd = fd; + key->need_close = 1; + } + } else { + warning("unknown trace value for '%s': %s\n" + " If you want to trace into a file, then please set %s\n" + " to an absolute pathname (starting with /)", + key->key, trace, key->key); + trace_disable(key); + } + + key->initialized = 1; + return key->fd; +} + +void trace_override_envvar(struct trace_key *key, const char *value) +{ + trace_disable(key); + key->initialized = 0; + + /* + * Invoke get_trace_fd() to initialize key using the given value + * instead of the value of the environment variable. + */ + get_trace_fd(key, value); +} + +void trace_disable(struct trace_key *key) +{ + if (key->need_close) + close(key->fd); + key->fd = 0; + key->initialized = 1; + key->need_close = 0; +} + +static int prepare_trace_line(const char *file, int line, + struct trace_key *key, struct strbuf *buf) +{ + static struct trace_key trace_bare = TRACE_KEY_INIT(BARE); + struct timeval tv; + struct tm tm; + time_t secs; + + if (!trace_want(key)) + return 0; + + /* unit tests may want to disable additional trace output */ + if (trace_want(&trace_bare)) + return 1; + + /* print current timestamp */ + gettimeofday(&tv, NULL); + secs = tv.tv_sec; + localtime_r(&secs, &tm); + strbuf_addf(buf, "%02d:%02d:%02d.%06ld %s:%d", tm.tm_hour, tm.tm_min, + tm.tm_sec, (long) tv.tv_usec, file, line); + /* align trace output (column 40 catches most files names in git) */ + while (buf->len < 40) + strbuf_addch(buf, ' '); + + return 1; +} + +static void trace_write(struct trace_key *key, const void *buf, unsigned len) +{ + if (write_in_full(get_trace_fd(key, NULL), buf, len) < 0) { + warning("unable to write trace for %s: %s", + key->key, strerror(errno)); + trace_disable(key); + } +} + +void trace_verbatim(struct trace_key *key, const void *buf, unsigned len) +{ + if (!trace_want(key)) + return; + trace_write(key, buf, len); +} + +static void print_trace_line(struct trace_key *key, struct strbuf *buf) +{ + strbuf_complete_line(buf); + trace_write(key, buf->buf, buf->len); +} + +static void trace_vprintf_fl(const char *file, int line, struct trace_key *key, + const char *format, va_list ap) +{ + struct strbuf buf = STRBUF_INIT; + + if (!prepare_trace_line(file, line, key, &buf)) + return; + + strbuf_vaddf(&buf, format, ap); + print_trace_line(key, &buf); + strbuf_release(&buf); +} + +static void trace_argv_vprintf_fl(const char *file, int line, + const char **argv, const char *format, + va_list ap) +{ + struct strbuf buf = STRBUF_INIT; + + if (!prepare_trace_line(file, line, &trace_default_key, &buf)) + return; + + strbuf_vaddf(&buf, format, ap); + + sq_quote_argv_pretty(&buf, argv); + print_trace_line(&trace_default_key, &buf); + strbuf_release(&buf); +} + +void trace_strbuf_fl(const char *file, int line, struct trace_key *key, + const struct strbuf *data) +{ + struct strbuf buf = STRBUF_INIT; + + if (!prepare_trace_line(file, line, key, &buf)) + return; + + strbuf_addbuf(&buf, data); + print_trace_line(key, &buf); + strbuf_release(&buf); +} + +static uint64_t perf_start_times[10]; +static int perf_indent; + +uint64_t trace_performance_enter(void) +{ + uint64_t now; + + if (!trace_want(&trace_perf_key)) + return 0; + + now = getnanotime(); + perf_start_times[perf_indent] = now; + if (perf_indent + 1 < ARRAY_SIZE(perf_start_times)) + perf_indent++; + else + BUG("Too deep indentation"); + return now; +} + +static void trace_performance_vprintf_fl(const char *file, int line, + uint64_t nanos, const char *format, + va_list ap) +{ + static const char space[] = " "; + struct strbuf buf = STRBUF_INIT; + + if (!prepare_trace_line(file, line, &trace_perf_key, &buf)) + return; + + strbuf_addf(&buf, "performance: %.9f s", (double) nanos / 1000000000); + + if (format && *format) { + if (perf_indent >= strlen(space)) + BUG("Too deep indentation"); + + strbuf_addf(&buf, ":%.*s ", perf_indent, space); + strbuf_vaddf(&buf, format, ap); + } + + print_trace_line(&trace_perf_key, &buf); + strbuf_release(&buf); +} + +void trace_printf_key_fl(const char *file, int line, struct trace_key *key, + const char *format, ...) +{ + va_list ap; + va_start(ap, format); + trace_vprintf_fl(file, line, key, format, ap); + va_end(ap); +} + +void trace_argv_printf_fl(const char *file, int line, const char **argv, + const char *format, ...) +{ + va_list ap; + va_start(ap, format); + trace_argv_vprintf_fl(file, line, argv, format, ap); + va_end(ap); +} + +void trace_performance_fl(const char *file, int line, uint64_t nanos, + const char *format, ...) +{ + va_list ap; + va_start(ap, format); + trace_performance_vprintf_fl(file, line, nanos, format, ap); + va_end(ap); +} + +void trace_performance_leave_fl(const char *file, int line, + uint64_t nanos, const char *format, ...) +{ + va_list ap; + uint64_t since; + + if (perf_indent) + perf_indent--; + + if (!format) /* Allow callers to leave without tracing anything */ + return; + + since = perf_start_times[perf_indent]; + va_start(ap, format); + trace_performance_vprintf_fl(file, line, nanos - since, format, ap); + va_end(ap); +} + +static const char *quote_crnl(const char *path) +{ + static struct strbuf new_path = STRBUF_INIT; + + if (!path) + return NULL; + + strbuf_reset(&new_path); + + while (*path) { + switch (*path) { + case '\\': strbuf_addstr(&new_path, "\\\\"); break; + case '\n': strbuf_addstr(&new_path, "\\n"); break; + case '\r': strbuf_addstr(&new_path, "\\r"); break; + default: + strbuf_addch(&new_path, *path); + } + path++; + } + return new_path.buf; +} + +void trace_repo_setup(void) +{ + const char *git_work_tree, *prefix = startup_info->prefix; + char *cwd; + + if (!trace_want(&trace_setup_key)) + return; + + cwd = xgetcwd(); + + if (!(git_work_tree = get_git_work_tree())) + git_work_tree = "(null)"; + + if (!startup_info->prefix) + prefix = "(null)"; + + trace_printf_key(&trace_setup_key, "setup: git_dir: %s\n", quote_crnl(get_git_dir())); + trace_printf_key(&trace_setup_key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir())); + trace_printf_key(&trace_setup_key, "setup: worktree: %s\n", quote_crnl(git_work_tree)); + trace_printf_key(&trace_setup_key, "setup: cwd: %s\n", quote_crnl(cwd)); + trace_printf_key(&trace_setup_key, "setup: prefix: %s\n", quote_crnl(prefix)); + + free(cwd); +} + +int trace_want(struct trace_key *key) +{ + return !!get_trace_fd(key, NULL); +} + +#if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC) + +static inline uint64_t highres_nanos(void) +{ + struct timespec ts; + if (clock_gettime(CLOCK_MONOTONIC, &ts)) + return 0; + return (uint64_t) ts.tv_sec * 1000000000 + ts.tv_nsec; +} + +#elif defined (GIT_WINDOWS_NATIVE) + +static inline uint64_t highres_nanos(void) +{ + static uint64_t high_ns, scaled_low_ns; + static int scale; + LARGE_INTEGER cnt; + + if (!scale) { + if (!QueryPerformanceFrequency(&cnt)) + return 0; + + /* high_ns = number of ns per cnt.HighPart */ + high_ns = (1000000000LL << 32) / (uint64_t) cnt.QuadPart; + + /* + * Number of ns per cnt.LowPart is 10^9 / frequency (or + * high_ns >> 32). For maximum precision, we scale this factor + * so that it just fits within 32 bit (i.e. won't overflow if + * multiplied with cnt.LowPart). + */ + scaled_low_ns = high_ns; + scale = 32; + while (scaled_low_ns >= 0x100000000LL) { + scaled_low_ns >>= 1; + scale--; + } + } + + /* if QPF worked on initialization, we expect QPC to work as well */ + QueryPerformanceCounter(&cnt); + + return (high_ns * cnt.HighPart) + + ((scaled_low_ns * cnt.LowPart) >> scale); +} + +#else +# define highres_nanos() 0 +#endif + +static inline uint64_t gettimeofday_nanos(void) +{ + struct timeval tv; + gettimeofday(&tv, NULL); + return (uint64_t) tv.tv_sec * 1000000000 + tv.tv_usec * 1000; +} + +/* + * Returns nanoseconds since the epoch (01/01/1970), for performance tracing + * (i.e. favoring high precision over wall clock time accuracy). + */ +uint64_t getnanotime(void) +{ + static uint64_t offset; + if (offset > 1) { + /* initialization succeeded, return offset + high res time */ + return offset + highres_nanos(); + } else if (offset == 1) { + /* initialization failed, fall back to gettimeofday */ + return gettimeofday_nanos(); + } else { + /* initialize offset if high resolution timer works */ + uint64_t now = gettimeofday_nanos(); + uint64_t highres = highres_nanos(); + if (highres) + offset = now - highres; + else + offset = 1; + return now; + } +} + +static struct strbuf command_line = STRBUF_INIT; + +static void print_command_performance_atexit(void) +{ + trace_performance_leave("git command:%s", command_line.buf); +} + +void trace_command_performance(const char **argv) +{ + if (!trace_want(&trace_perf_key)) + return; + + if (!command_line.len) + atexit(print_command_performance_atexit); + + strbuf_reset(&command_line); + sq_quote_argv_pretty(&command_line, argv); + trace_performance_enter(); +} |