git/trace2/tr2_cfg.c
Jeff Hostetler ee4512ed48 trace2: create new combined trace facility
Create a new unified tracing facility for git.  The eventual intent is to
replace the current trace_printf* and trace_performance* routines with a
unified set of git_trace2* routines.

In addition to the usual printf-style API, trace2 provides higer-level
event verbs with fixed-fields allowing structured data to be written.
This makes post-processing and analysis easier for external tools.

Trace2 defines 3 output targets.  These are set using the environment
variables "GIT_TR2", "GIT_TR2_PERF", and "GIT_TR2_EVENT".  These may be
set to "1" or to an absolute pathname (just like the current GIT_TRACE).

* GIT_TR2 is intended to be a replacement for GIT_TRACE and logs command
  summary data.

* GIT_TR2_PERF is intended as a replacement for GIT_TRACE_PERFORMANCE.
  It extends the output with columns for the command process, thread,
  repo, absolute and relative elapsed times.  It reports events for
  child process start/stop, thread start/stop, and per-thread function
  nesting.

* GIT_TR2_EVENT is a new structured format. It writes event data as a
  series of JSON records.

Calls to trace2 functions log to any of the 3 output targets enabled
without the need to call different trace_printf* or trace_performance*
routines.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-22 15:27:59 -08:00

91 lines
2.0 KiB
C

#include "cache.h"
#include "config.h"
#include "tr2_cfg.h"
#define TR2_ENVVAR_CFG_PARAM "GIT_TR2_CONFIG_PARAMS"
static struct strbuf **tr2_cfg_patterns;
static int tr2_cfg_count_patterns;
static int tr2_cfg_loaded;
/*
* Parse a string containing a comma-delimited list of config keys
* or wildcard patterns into a list of strbufs.
*/
static int tr2_cfg_load_patterns(void)
{
struct strbuf **s;
const char *envvar;
if (tr2_cfg_loaded)
return tr2_cfg_count_patterns;
tr2_cfg_loaded = 1;
envvar = getenv(TR2_ENVVAR_CFG_PARAM);
if (!envvar || !*envvar)
return tr2_cfg_count_patterns;
tr2_cfg_patterns = strbuf_split_buf(envvar, strlen(envvar), ',', -1);
for (s = tr2_cfg_patterns; *s; s++) {
struct strbuf *buf = *s;
if (buf->len && buf->buf[buf->len - 1] == ',')
strbuf_setlen(buf, buf->len - 1);
strbuf_trim_trailing_newline(*s);
strbuf_trim(*s);
}
tr2_cfg_count_patterns = s - tr2_cfg_patterns;
return tr2_cfg_count_patterns;
}
void tr2_cfg_free_patterns(void)
{
if (tr2_cfg_patterns)
strbuf_list_free(tr2_cfg_patterns);
tr2_cfg_count_patterns = 0;
tr2_cfg_loaded = 0;
}
struct tr2_cfg_data {
const char *file;
int line;
};
/*
* See if the given config key matches any of our patterns of interest.
*/
static int tr2_cfg_cb(const char *key, const char *value, void *d)
{
struct strbuf **s;
struct tr2_cfg_data *data = (struct tr2_cfg_data *)d;
for (s = tr2_cfg_patterns; *s; s++) {
struct strbuf *buf = *s;
int wm = wildmatch(buf->buf, key, WM_CASEFOLD);
if (wm == WM_MATCH) {
trace2_def_param_fl(data->file, data->line, key, value);
return 0;
}
}
return 0;
}
void tr2_cfg_list_config_fl(const char *file, int line)
{
struct tr2_cfg_data data = { file, line };
if (tr2_cfg_load_patterns() > 0)
read_early_config(tr2_cfg_cb, &data);
}
void tr2_cfg_set_fl(const char *file, int line, const char *key,
const char *value)
{
struct tr2_cfg_data data = { file, line };
if (tr2_cfg_load_patterns() > 0)
tr2_cfg_cb(key, value, &data);
}