Enhancements for issue #329

- added global variables mysql-query_digests
- initialization if either mysql_thread___commands_stats or mysql_thread___query_digests are enabled
- query_parser_free() checks if QueryParserArgs was initialized
- Query_Processor::query_parser_init() checks the command type only if mysql_thread___commands_stats is true
- Query_Processor::query_parser_init() run mysql_query_digest() only if mysql_thread___query_digests is true
- Query_Processor::query_parser_update_counters() updates query digests only if digest_text is not null
- start time is always update (this is relevant for issue #327)

include/MySQL_Thread.h

@@ -262,6 +262,7 @@ class MySQL_Threads_Handler
 		uint8_t default_charset;
 		bool servers_stats;
 		bool commands_stats;
+		bool query_digests;
 		bool default_reconnect;
 		bool have_compress;
 		int max_transaction_time;

include/proxysql_structs.h

@@ -686,6 +686,7 @@ __thread int mysql_thread___poll_timeout_on_failure;
 __thread bool mysql_thread___have_compress;
 __thread bool mysql_thread___servers_stats;
 __thread bool mysql_thread___commands_stats;
+__thread bool mysql_thread___query_digests;
 __thread bool mysql_thread___default_reconnect;
 __thread bool mysql_thread___sessions_sort;
 
@@ -733,6 +734,7 @@ extern __thread int mysql_thread___poll_timeout_on_failure;
 extern __thread bool mysql_thread___have_compress;
 extern __thread bool mysql_thread___servers_stats;
 extern __thread bool mysql_thread___commands_stats;
+extern __thread bool mysql_thread___query_digests;
 extern __thread bool mysql_thread___default_reconnect;
 extern __thread bool mysql_thread___sessions_sort;
 

lib/MySQL_Session.cpp

@@ -87,9 +87,9 @@ void Query_Info::begin(unsigned char *_p, int len, bool mysql_header) {
 	QueryPointer=NULL;
 	QueryLength=0;
 	QueryParserArgs=NULL;
-	if (mysql_thread___commands_stats) {
+	start_time=sess->thread->curtime;
+	if (mysql_thread___commands_stats || mysql_thread___query_digests) {
 		init(_p, len, mysql_header);
-		start_time=sess->thread->curtime;
 		query_parser_init();
 		query_parser_command_type();
 	}
@@ -106,7 +106,6 @@ void Query_Info::init(unsigned char *_p, int len, bool mysql_header) {
 	QueryPointer=(unsigned char *)l_alloc(QueryLength+1);
 	memcpy(QueryPointer,(mysql_header ? _p+5 : _p),QueryLength);	
 	QueryPointer[QueryLength]=0;
-	//QueryPointer=(mysql_header ? _p+5 : _p);
 	QueryParserArgs=NULL;
 	MyComQueryCmd=MYSQL_COM_QUERY_UNKNOWN;
 }
@@ -121,8 +120,10 @@ enum MYSQL_COM_QUERY_command Query_Info::query_parser_command_type() {
 }
 
 void Query_Info::query_parser_free() {
-	GloQPro->query_parser_free(QueryParserArgs);
+	if (QueryParserArgs) {
-	QueryParserArgs=NULL;
+		GloQPro->query_parser_free(QueryParserArgs);
+		QueryParserArgs=NULL;
+	}
 }
 
 unsigned long long Query_Info::query_parser_update_counters() {

lib/MySQL_Thread.cpp

@@ -168,6 +168,7 @@ static char * mysql_thread_variables_names[]= {
 	(char *)"server_version",
 	(char *)"sessions_sort",
 	(char *)"commands_stats",
+	(char *)"query_digests",
 	(char *)"servers_stats",
 	(char *)"default_reconnect",
 	(char *)"session_debug",
@@ -226,6 +227,7 @@ MySQL_Threads_Handler::MySQL_Threads_Handler() {
 	variables.poll_timeout_on_failure=100;
 	variables.have_compress=true;
 	variables.commands_stats=true;
+	variables.query_digests=true;
 	variables.sessions_sort=true;
 	variables.servers_stats=true;
 	variables.default_reconnect=true;
@@ -359,6 +361,7 @@ int MySQL_Threads_Handler::get_variable_int(char *name) {
 	if (!strcasecmp(name,"ping_timeout_server")) return (int)variables.ping_timeout_server;
 	if (!strcasecmp(name,"have_compress")) return (int)variables.have_compress;
 	if (!strcasecmp(name,"commands_stats")) return (int)variables.commands_stats;
+	if (!strcasecmp(name,"query_digests")) return (int)variables.commands_stats;
 	if (!strcasecmp(name,"sessions_sort")) return (int)variables.sessions_sort;
 	if (!strcasecmp(name,"servers_stats")) return (int)variables.servers_stats;
 	if (!strcasecmp(name,"default_reconnect")) return (int)variables.default_reconnect;
@@ -498,6 +501,9 @@ char * MySQL_Threads_Handler::get_variable(char *name) {	// this is the public f
 	if (!strcasecmp(name,"commands_stats")) {
 		return strdup((variables.commands_stats ? "true" : "false"));
 	}
+	if (!strcasecmp(name,"query_digests")) {
+		return strdup((variables.query_digests ? "true" : "false"));
+	}
 	if (!strcasecmp(name,"sessions_sort")) {
 		return strdup((variables.sessions_sort ? "true" : "false"));
 	}
@@ -869,6 +875,17 @@ bool MySQL_Threads_Handler::set_variable(char *name, char *value) {	// this is t
 		}
 		return false;
 	}
+	if (!strcasecmp(name,"query_digests")) {
+		if (strcasecmp(value,"true")==0 || strcasecmp(value,"1")==0) {
+			variables.query_digests=true;
+			return true;
+		}
+		if (strcasecmp(value,"false")==0 || strcasecmp(value,"0")==0) {
+			variables.query_digests=false;
+			return true;
+		}
+		return false;
+	}
 	if (!strcasecmp(name,"sessions_sort")) {
 		if (strcasecmp(value,"true")==0 || strcasecmp(value,"1")==0) {
 			variables.sessions_sort=true;
@@ -1501,6 +1518,7 @@ void MySQL_Thread::refresh_variables() {
 	mysql_thread___poll_timeout_on_failure=GloMTH->get_variable_int((char *)"poll_timeout_on_failure");
 	mysql_thread___have_compress=(bool)GloMTH->get_variable_int((char *)"have_compress");
 	mysql_thread___commands_stats=(bool)GloMTH->get_variable_int((char *)"commands_stats");
+	mysql_thread___query_digests=(bool)GloMTH->get_variable_int((char *)"query_digests");
 	mysql_thread___sessions_sort=(bool)GloMTH->get_variable_int((char *)"sessions_sort");
 	mysql_thread___servers_stats=(bool)GloMTH->get_variable_int((char *)"servers_stats");
 	mysql_thread___default_reconnect=(bool)GloMTH->get_variable_int((char *)"default_reconnect");

lib/Query_Processor.cpp

@@ -786,11 +786,13 @@ void Query_Processor::update_query_processor_stats() {
 
 void * Query_Processor::query_parser_init(char *query, int query_length, int flags) {
 	SQP_par_t *qp=(SQP_par_t *)malloc(sizeof(SQP_par_t));
-	libinjection_sqli_init(&qp->sf, query, query_length, FLAG_SQL_MYSQL);
+	if (mysql_thread___commands_stats)
+		libinjection_sqli_init(&qp->sf, query, query_length, FLAG_SQL_MYSQL);
 	qp->digest_text=NULL;
-	qp->digest_text=mysql_query_digest(query, query_length);
+	if (mysql_thread___query_digests) {
-	qp->digest=SpookyHash::Hash64(qp->digest_text,strlen(qp->digest_text),0);
+		qp->digest_text=mysql_query_digest(query, query_length);
-
+		qp->digest=SpookyHash::Hash64(qp->digest_text,strlen(qp->digest_text),0);
+	}
 	return (void *)qp;
 };
 
@@ -806,24 +808,25 @@ unsigned long long Query_Processor::query_parser_update_counters(MySQL_Session *
 
 	SQP_par_t *qp=(SQP_par_t *)p;
 
-	uint64_t hash2;
+	if (qp->digest_text) {
-	SpookyHash *myhash=new SpookyHash();
+		// this code is executed only if digest_text is not NULL , that means mysql_thread___query_digests was true when the query started
-	myhash->Init(19,3);
+		uint64_t hash2;
-	assert(sess);
+		SpookyHash *myhash=new SpookyHash();
-	assert(sess->client_myds);
+		myhash->Init(19,3);
-	assert(sess->client_myds->myconn);
+		assert(sess);
-	assert(sess->client_myds->myconn->userinfo);
+		assert(sess->client_myds);
-	MySQL_Connection_userinfo *ui=sess->client_myds->myconn->userinfo;
+		assert(sess->client_myds->myconn);
-	assert(ui->username);
+		assert(sess->client_myds->myconn->userinfo);
-	assert(ui->schemaname);
+		MySQL_Connection_userinfo *ui=sess->client_myds->myconn->userinfo;
-	myhash->Update(ui->username,strlen(ui->username));
+		assert(ui->username);
-	myhash->Update(&qp->digest,sizeof(qp->digest));
+		assert(ui->schemaname);
-	myhash->Update(ui->schemaname,strlen(ui->schemaname));
+		myhash->Update(ui->username,strlen(ui->username));
-	myhash->Final(&qp->digest_total,&hash2);
+		myhash->Update(&qp->digest,sizeof(qp->digest));
-	delete myhash;
+		myhash->Update(ui->schemaname,strlen(ui->schemaname));
-
+		myhash->Final(&qp->digest_total,&hash2);
-	update_query_digest(qp, ui, t, sess->thread->curtime);
+		delete myhash;
-
+		update_query_digest(qp, ui, t, sess->thread->curtime);
+	}
 	return ret;
 }