Various memory optimization

include/c_tokenizer.h

@@ -28,7 +28,7 @@ extern "C" {
 tokenizer_t tokenizer( const char* s, const char* delimiters, int empties );
 const char* free_tokenizer( tokenizer_t* tokenizer );
 const char* tokenize( tokenizer_t* tokenizer );
-char * mysql_query_digest_and_first_comment(char *s , int len , char **first_comment);
+char * mysql_query_digest_and_first_comment(char *s , int len , char **first_comment, char *buf);
 void c_split_2(const char *in, const char *del, char **out1, char **out2);
 #ifdef __cplusplus
 }

include/mysql_connection.h

@@ -150,7 +150,13 @@ class MySQL_Connection {
 
 
 	void async_free_result();
-	bool IsActiveTransaction();
+	bool IsActiveTransaction() {
+		bool ret=false;
+			if (mysql) {
+				ret = (mysql->server_status & SERVER_STATUS_IN_TRANS);
+			}
+		return ret;
+	}
 	bool IsAutoCommit();
 	bool MultiplexDisabled();
 	void ProcessQueryAndSetStatusFlags(char *query_digest_text);

include/proxysql_structs.h

@@ -352,8 +352,10 @@ class MySQL_HostGroups_Manager;
 
 #ifndef PROXYSQL_STRUCTS
 #define PROXYSQL_STRUCTS
+#define QUERY_DIGEST_BUF 128
 
 struct __SQP_query_parser_t {
+	char buf[QUERY_DIGEST_BUF];
 	uint64_t digest;
 	uint64_t digest_total;
 	char *digest_text;

lib/Query_Processor.cpp

@@ -656,8 +656,15 @@ Query_Processor_Output * Query_Processor::process_mysql_query(MySQL_Session *ses
 	if (qi) {
 		qp=(SQP_par_t *)&qi->QueryParserArgs;
 	}
+#define stackbuffer_size 128
+	char stackbuffer[stackbuffer_size];
 	unsigned int len=size-sizeof(mysql_hdr)-1;
-	char *query=(char *)l_alloc(len+1);
+	char *query=NULL;
+	if (len < stackbuffer_size) {
+		query=stackbuffer;
+	} else {
+		query=(char *)l_alloc(len+1);
+	}
 	memcpy(query,(char *)ptr+sizeof(mysql_hdr)+1,len);
 	query[len]=0;
 	if (__sync_add_and_fetch(&version,0) > _thr_SQP_version) {
@@ -940,7 +947,11 @@ __internal_loop:
 	
 __exit_process_mysql_query:
 	// FIXME : there is too much data being copied around
-	l_free(len+1,query);
+	if (len < stackbuffer_size) {
+		// query is in the stack
+	} else {
+		l_free(len+1,query);
+	}
 	if (sess->mirror==false) { // we process comments only on original queries, not on mirrors
 		if (qp && qp->first_comment) {
 			// we have a comment to parse
@@ -1002,7 +1013,7 @@ void Query_Processor::query_parser_init(SQP_par_t *qp, char *query, int query_le
 	qp->first_comment=NULL;
 	qp->query_prefix=NULL;
 	if (mysql_thread___query_digests) {
-		qp->digest_text=mysql_query_digest_and_first_comment(query, query_length, &qp->first_comment);
+		qp->digest_text=mysql_query_digest_and_first_comment(query, query_length, &qp->first_comment, ((query_length < QUERY_DIGEST_BUF) ? qp->buf : NULL));
 		// the hash is computed only up to query_digests_max_digest_length bytes
 		int digest_text_length=strnlen(qp->digest_text, mysql_thread___query_digests_max_digest_length);
 		qp->digest=SpookyHash::Hash64(qp->digest_text, digest_text_length, 0);
@@ -1517,7 +1528,9 @@ bool Query_Processor::query_parser_first_comment(Query_Processor_Output *qpo, ch
 
 void Query_Processor::query_parser_free(SQP_par_t *qp) {
 	if (qp->digest_text) {
-		free(qp->digest_text);
+		if (qp->digest_text != qp->buf) {
+			free(qp->digest_text);
+		}
 		qp->digest_text=NULL;
 	}
 	if (qp->first_comment) {

lib/c_tokenizer.c

@@ -165,7 +165,7 @@ static char is_digit_string(char *f, char *t)
 }
 
 
-char *mysql_query_digest_and_first_comment(char *s, int _len, char **first_comment){
+char *mysql_query_digest_and_first_comment(char *s, int _len, char **first_comment, char *buf){
 	int i = 0;
 
 	char cur_comment[FIRST_COMMENT_MAX_LENGTH];
@@ -177,8 +177,10 @@ char *mysql_query_digest_and_first_comment(char *s, int _len, char **first_comme
 	if (_len > mysql_thread___query_digests_max_query_length) {
 		len = mysql_thread___query_digests_max_query_length;
 	}
-	char *r = (char *) malloc(len + SIZECHAR);
-
+	char *r = buf;
+	if (r==NULL) {
+		r = (char *) malloc(len + SIZECHAR);
+	}
 	char *p_r = r;
 	char *p_r_t = r;
 

lib/mysql_connection.cpp

@@ -1396,6 +1396,7 @@ void MySQL_Connection::async_free_result() {
 	}
 }
 
+/*
 bool MySQL_Connection::IsActiveTransaction() {
 	bool ret=false;
 	if (mysql) {
@@ -1403,6 +1404,7 @@ bool MySQL_Connection::IsActiveTransaction() {
 	}
 	return ret;
 }
+*/
 
 bool MySQL_Connection::IsAutoCommit() {
 	bool ret=false;