mysql_trace.cc File Reference

#include "mysql_trace.h"
#include <assert.h>
#include "my_inttypes.h"
#include "my_sys.h"
#include "mysql.h"
#include "mysql/service_mysql_alloc.h"

Macros
#define	GET_DATA(TI)   (TI)->trace_plugin_data
#define	GET_STAGE(TI)   (TI)->stage
#define	TEST_STAGE(TI, X)   (GET_STAGE(TI) == PROTOCOL_STAGE_##X)
#define	protocol_stage_get_name(X)
#define	trace_event_get_name(X)

Functions
void	mysql_trace_start (MYSQL *m)
	Initialize tracing in a given connection. More...
void	mysql_trace_trace (MYSQL *m, enum trace_event ev, struct st_trace_event_args args)
	Report a protocol trace event to trace plugin. More...
const char *	protocol_stage_name (enum protocol_stage stage)
const char *	trace_event_name (enum trace_event ev)

Variables
struct st_mysql_client_plugin_TRACE *	trace_plugin = nullptr
	The global trace_plugin pointer. More...

Detailed Description

---

Client-side protocol tracing infrastructure

If a plugin of type MYSQL_CLIENT_TRACE_PLUGIN is loaded into libmysql and its instance is pointed by the global trace_plugin pointer, this plugin is notified of various protocol trace events. See include/mysql/plugin_trace.h for documentation of trace plugin methods and the list of possible trace events.

These trace events are generated with MYSQL_TRACE() macro put in relevant places in libmysql code. The macro calls mysql_trace_trace() function defined here. This function calls trace plugin's trace_event() method, if it is defined.

For each traced connection, the state is kept in st_mysql_trace_info structure (see mysql_trace.h).

To correctly interpret each trace event, trace plugin is informed of the current protocol stage (see include/mysql/plugin_trace.h for list of stages). The current protocol stage is part of the connection tracing state. It is updated with MYSQL_TRACE_STAGE() hooks within libmysql code.

Macro Definition Documentation

GET_DATA

#define GET_DATA

(

TI

)

(TI)->trace_plugin_data

GET_STAGE

#define GET_STAGE

(

TI

)

(TI)->stage

protocol_stage_get_name

#define protocol_stage_get_name

(

X

)

Value:

  case PROTOCOL_STAGE_##X:         \
    return #X;

TEST_STAGE

#define TEST_STAGE	(		TI,
			X
	)		(GET_STAGE(TI) == PROTOCOL_STAGE_##X)

trace_event_get_name

#define trace_event_get_name

(

X

)

Value:

  case TRACE_EVENT_##X:         \
    return #X;

Function Documentation

mysql_trace_start()

void mysql_trace_start

(

MYSQL *

m

)

Initialize tracing in a given connection.

This function is called from MYSQL_TRACE_STAGE() when the initial CONNECTING stage is reported. It allocates and initializes trace_info structure which is then attached to the connection handle.

mysql_trace_trace()

void mysql_trace_trace	(	MYSQL *	m,
		enum trace_event	ev,
		struct st_trace_event_args	args
	)

Report a protocol trace event to trace plugin.

Calls plugin's trace_event() method, if it is defined, passing to it the event, the current protocol stage and event arguments (if any).

Terminates tracing of the connection when appropriate.

Parameters

m	MYSQL connection handle
ev	trace event to be reported
args	trace event arguments

protocol_stage_name()

const char * protocol_stage_name

(

enum protocol_stage

stage

)

trace_event_name()

const char * trace_event_name

(

enum trace_event

ev

)

Variable Documentation

trace_plugin

struct st_mysql_client_plugin_TRACE* trace_plugin = nullptr

The global trace_plugin pointer.

If it is not NULL, it points at a loaded trace plugin which should be used to trace all connections made to the server.