MYSQL-NOBLOCK(1) MYSQL-NOBLOCK(1)
NAME
query_runner_init, query_runner_execute, query_runner_get_response_fd,
query_runner_get_request_fd, query_runner_handle_all_results,
query_runner_handle_next_result, query_runner_shutdown,
SYNOPSIS
#include "mysql-noblock.h"
#define RUNNER_RESULT_EAGAIN -1
#define RUNNER_RESULT_SQL_ERROR 0
#define RUNNER_RESULT_ROWS 1
#define RUNNER_RESULT_NONE 2
query_runner *query_runner_init(char *hostname, char *user,
char *password, char *database);
void query_runner_execute(query_runner *runner, char *query,
query_runner_callback callback,
void *callback_data );
int query_runner_get_response_fd(query_runner *runner);
int query_runner_get_request_fd(query_runner *runner);
void query_runner_shutdown(query_runner * runner);
int query_runner_handle_next_result(query_runner *runner);
void query_runner_handle_all_results(query_runner *runner);
typedef void (*query_runner_callback)(int, MYSQL_RES *, void *);
DESCRIPTION
A simple library for integrating MySQL into non-blocking, event-driven
applications. All queries are submitted to a separate thread which sig‐
nals query completion by writing to a UNIX pipe. You can find out when
the result is ready by using the file descriptor of the pipe in your
own event loops using select(), poll(), etc.
USAGE
First write a callback for your query:
void sql_results_callback(int result_code,
MYSQL_RES *res,
void *user_data) {
if (result_code == RUNNER_RESULT_SQL_ERROR) {
print("Query Failed!");
return;
}
/* Now do something with res (see mysql manual) */
}
Next you will need to start the runner somewhere in your program:
query_runner_init("myhost","username","password","database");
To integrate into your I/O event loop, you will need the runner's fd:
int runner_response_fd = query_runner_get_response_fd();
To submit queries, use query_runner_execute():
query_runner_execute(runner,
"SELECT foo FROM bar",
sql_results_callback,
my_data);
When the query is complete, runner_response_fd will become ready for
reading. DO NOT read directly from the fd, but instead use query_run‐
ner_handle_all_results() or query_runner_handle_next_result(). If there
are no results ready these functions will do nothing.
23 January 10 MYSQL-NOBLOCK(1)