mirror of
https://github.com/git/git.git
synced 2024-12-04 15:34:05 +08:00
ee4512ed48
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>
68 lines
1.5 KiB
C
68 lines
1.5 KiB
C
#include "cache.h"
|
|
#include "trace2/tr2_sid.h"
|
|
|
|
#define TR2_ENVVAR_PARENT_SID "GIT_TR2_PARENT_SID"
|
|
|
|
static struct strbuf tr2sid_buf = STRBUF_INIT;
|
|
static int tr2sid_nr_git_parents;
|
|
|
|
/*
|
|
* Compute a "unique" session id (SID) for the current process. This allows
|
|
* all events from this process to have a single label (much like a PID).
|
|
*
|
|
* Export this into our environment so that all child processes inherit it.
|
|
*
|
|
* If we were started by another git instance, use our parent's SID as a
|
|
* prefix. (This lets us track parent/child relationships even if there
|
|
* is an intermediate shell process.)
|
|
*
|
|
* Additionally, count the number of nested git processes.
|
|
*/
|
|
static void tr2_sid_compute(void)
|
|
{
|
|
uint64_t us_now;
|
|
const char *parent_sid;
|
|
|
|
if (tr2sid_buf.len)
|
|
return;
|
|
|
|
parent_sid = getenv(TR2_ENVVAR_PARENT_SID);
|
|
if (parent_sid && *parent_sid) {
|
|
const char *p;
|
|
for (p = parent_sid; *p; p++)
|
|
if (*p == '/')
|
|
tr2sid_nr_git_parents++;
|
|
|
|
strbuf_addstr(&tr2sid_buf, parent_sid);
|
|
strbuf_addch(&tr2sid_buf, '/');
|
|
tr2sid_nr_git_parents++;
|
|
}
|
|
|
|
us_now = getnanotime() / 1000;
|
|
strbuf_addf(&tr2sid_buf, "%" PRIuMAX "-%" PRIdMAX, (uintmax_t)us_now,
|
|
(intmax_t)getpid());
|
|
|
|
setenv(TR2_ENVVAR_PARENT_SID, tr2sid_buf.buf, 1);
|
|
}
|
|
|
|
const char *tr2_sid_get(void)
|
|
{
|
|
if (!tr2sid_buf.len)
|
|
tr2_sid_compute();
|
|
|
|
return tr2sid_buf.buf;
|
|
}
|
|
|
|
int tr2_sid_depth(void)
|
|
{
|
|
if (!tr2sid_buf.len)
|
|
tr2_sid_compute();
|
|
|
|
return tr2sid_nr_git_parents;
|
|
}
|
|
|
|
void tr2_sid_release(void)
|
|
{
|
|
strbuf_release(&tr2sid_buf);
|
|
}
|