Merge branch 'gk/tracing-optimization'

The tracing infrastructure has been optimized for cases where no
tracing is requested.

* gk/tracing-optimization:
  trace: improve performance while category is disabled
  trace: remove trace key normalization
This commit is contained in:
Junio C Hamano 2017-12-19 11:33:57 -08:00
commit 1974f4791a
2 changed files with 43 additions and 35 deletions

27
trace.c
View File

@ -24,26 +24,14 @@
#include "cache.h"
#include "quote.h"
/*
* "Normalize" a key argument by converting NULL to our trace_default,
* and otherwise passing through the value. All caller-facing functions
* should normalize their inputs in this way, though most get it
* for free by calling get_trace_fd() (directly or indirectly).
*/
static void normalize_trace_key(struct trace_key **key)
{
static struct trace_key trace_default = { "GIT_TRACE" };
if (!*key)
*key = &trace_default;
}
struct trace_key trace_default_key = { "GIT_TRACE", 0, 0, 0 };
struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
/* Get a trace file descriptor from "key" env variable. */
static int get_trace_fd(struct trace_key *key)
{
const char *trace;
normalize_trace_key(&key);
/* don't open twice */
if (key->initialized)
return key->fd;
@ -81,8 +69,6 @@ static int get_trace_fd(struct trace_key *key)
void trace_disable(struct trace_key *key)
{
normalize_trace_key(&key);
if (key->need_close)
close(key->fd);
key->fd = 0;
@ -128,7 +114,6 @@ static int prepare_trace_line(const char *file, int line,
static void trace_write(struct trace_key *key, const void *buf, unsigned len)
{
if (write_in_full(get_trace_fd(key), buf, len) < 0) {
normalize_trace_key(&key);
warning("unable to write trace for %s: %s",
key->key, strerror(errno));
trace_disable(key);
@ -167,13 +152,13 @@ static void trace_argv_vprintf_fl(const char *file, int line,
{
struct strbuf buf = STRBUF_INIT;
if (!prepare_trace_line(file, line, NULL, &buf))
if (!prepare_trace_line(file, line, &trace_default_key, &buf))
return;
strbuf_vaddf(&buf, format, ap);
sq_quote_argv(&buf, argv, 0);
print_trace_line(NULL, &buf);
print_trace_line(&trace_default_key, &buf);
}
void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
@ -188,8 +173,6 @@ void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
print_trace_line(key, &buf);
}
static struct trace_key trace_perf_key = TRACE_KEY_INIT(PERFORMANCE);
static void trace_performance_vprintf_fl(const char *file, int line,
uint64_t nanos, const char *format,
va_list ap)
@ -215,7 +198,7 @@ void trace_printf(const char *format, ...)
{
va_list ap;
va_start(ap, format);
trace_vprintf_fl(NULL, 0, NULL, format, ap);
trace_vprintf_fl(NULL, 0, &trace_default_key, format, ap);
va_end(ap);
}

51
trace.h
View File

@ -11,7 +11,10 @@ struct trace_key {
unsigned int need_close : 1;
};
extern struct trace_key trace_default_key;
#define TRACE_KEY_INIT(name) { "GIT_TRACE_" #name, 0, 0, 0 }
extern struct trace_key trace_perf_key;
extern void trace_repo_setup(const char *prefix);
extern int trace_want(struct trace_key *key);
@ -77,24 +80,42 @@ extern void trace_performance_since(uint64_t start, const char *format, ...);
* comma, but this is non-standard.
*/
#define trace_printf(...) \
trace_printf_key_fl(TRACE_CONTEXT, __LINE__, NULL, __VA_ARGS__)
#define trace_printf_key(key, ...) \
do { \
if (trace_pass_fl(key)) \
trace_printf_key_fl(TRACE_CONTEXT, __LINE__, key, \
__VA_ARGS__); \
} while (0)
#define trace_printf_key(key, ...) \
trace_printf_key_fl(TRACE_CONTEXT, __LINE__, key, __VA_ARGS__)
#define trace_printf(...) trace_printf_key(&trace_default_key, __VA_ARGS__)
#define trace_argv_printf(argv, ...) \
trace_argv_printf_fl(TRACE_CONTEXT, __LINE__, argv, __VA_ARGS__)
#define trace_argv_printf(argv, ...) \
do { \
if (trace_pass_fl(&trace_default_key)) \
trace_argv_printf_fl(TRACE_CONTEXT, __LINE__, \
argv, __VA_ARGS__); \
} while (0)
#define trace_strbuf(key, data) \
trace_strbuf_fl(TRACE_CONTEXT, __LINE__, key, data)
#define trace_strbuf(key, data) \
do { \
if (trace_pass_fl(key)) \
trace_strbuf_fl(TRACE_CONTEXT, __LINE__, key, data);\
} while (0)
#define trace_performance(nanos, ...) \
trace_performance_fl(TRACE_CONTEXT, __LINE__, nanos, __VA_ARGS__)
#define trace_performance(nanos, ...) \
do { \
if (trace_pass_fl(&trace_perf_key)) \
trace_performance_fl(TRACE_CONTEXT, __LINE__, nanos,\
__VA_ARGS__); \
} while (0)
#define trace_performance_since(start, ...) \
trace_performance_fl(TRACE_CONTEXT, __LINE__, getnanotime() - (start), \
__VA_ARGS__)
#define trace_performance_since(start, ...) \
do { \
if (trace_pass_fl(&trace_perf_key)) \
trace_performance_fl(TRACE_CONTEXT, __LINE__, \
getnanotime() - (start), \
__VA_ARGS__); \
} while (0)
/* backend functions, use non-*fl macros instead */
__attribute__((format (printf, 4, 5)))
@ -108,6 +129,10 @@ extern void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
__attribute__((format (printf, 4, 5)))
extern void trace_performance_fl(const char *file, int line,
uint64_t nanos, const char *fmt, ...);
static inline int trace_pass_fl(struct trace_key *key)
{
return key->fd || !key->initialized;
}
#endif /* HAVE_VARIADIC_MACROS */