MINOR: trace: implement a call to a decode function

The trace() call will support an optional decoding callback and 4
arguments that this function is supposed to know how to use to provide
extra information. The output remains unchanged when the function is
NULL. Otherwise, the message is pre-filled into the thread-local
trace_buf, and the function is called with all arguments so that it
completes the buffer in a readable form depending on the expected
level of detail.
This commit is contained in:
Willy Tarreau 2019-08-19 16:28:07 +02:00
parent 5da408818b
commit bfd14fc6eb
2 changed files with 30 additions and 5 deletions

View File

@ -34,7 +34,11 @@
extern struct list trace_sources;
extern THREAD_LOCAL struct buffer trace_buf;
void __trace(enum trace_level level, uint64_t mask, struct trace_source *src, const struct ist where, const struct ist msg);
void __trace(enum trace_level level, uint64_t mask, struct trace_source *src, const struct ist where,
const void *a1, const void *a2, const void *a3, const void *a4,
void (*cb)(enum trace_level level, uint64_t mask, const struct trace_source *src, const struct ist where,
const void *a1, const void *a2, const void *a3, const void *a4),
const struct ist msg);
/* return a single char to describe a trace state */
static inline char trace_state_char(enum trace_state st)
@ -66,10 +70,14 @@ static inline void trace_register_source(struct trace_source *source)
}
/* sends a trace for the given source */
static inline void trace(enum trace_level level, uint64_t mask, struct trace_source *src, const struct ist where, const struct ist msg)
static inline void trace(enum trace_level level, uint64_t mask, struct trace_source *src, const struct ist where,
const void *a1, const void *a2, const void *a3, const void *a4,
void (*cb)(enum trace_level level, uint64_t mask, const struct trace_source *src, const struct ist where,
const void *a1, const void *a2, const void *a3, const void *a4),
const struct ist msg)
{
if (unlikely(src->state != TRACE_STATE_STOPPED))
__trace(level, mask, src, where, msg);
__trace(level, mask, src, where, a1, a2, a3, a4, cb, msg);
}
#endif /* _PROTO_TRACE_H */

View File

@ -49,7 +49,11 @@ REGISTER_PER_THREAD_ALLOC(alloc_trace_buffers_per_thread);
REGISTER_PER_THREAD_FREE(free_trace_buffers_per_thread);
/* write a message for the given trace source */
void __trace(enum trace_level level, uint64_t mask, struct trace_source *src, const struct ist where, const struct ist msg)
void __trace(enum trace_level level, uint64_t mask, struct trace_source *src, const struct ist where,
const void *a1, const void *a2, const void *a3, const void *a4,
void (*cb)(enum trace_level level, uint64_t mask, const struct trace_source *src, const struct ist where,
const void *a1, const void *a2, const void *a3, const void *a4),
const struct ist msg)
{
struct ist line[8];
@ -87,7 +91,20 @@ void __trace(enum trace_level level, uint64_t mask, struct trace_source *src, co
line[1].len = 10;
}
line[2] = ist("] ");
line[3] = msg;
if (cb) {
/* decode function passed, we want to pre-fill the
* buffer with the message and let the decode function
* do its job, possibly even overwriting it.
*/
b_reset(&trace_buf);
b_istput(&trace_buf, msg);
cb(level, mask, src, where, a1, a2, a3, a4);
line[3].ptr = trace_buf.area;
line[3].len = trace_buf.data;
}
else
line[3] = msg;
if (src->sink)
sink_write(src->sink, line, 4);