mysql plugin 开发_19.5. MySQL Plugin-阿里云开发者社区
19.5.3. MySQL fifo
mysql-fifo-plugin
MySQL Pipes (FIFOs) Plugin
Build
cd /usr/local/src/
git clone https://github.com/netkiller/mysql-fifo-plugin.git
cd mysql-fifo-plugin/
cmake .
make
make install
or
gcc -O3 -g -I/usr/include/mysql -I/usr/include -fPIC -lm -lz -shared -o libfifo.so fifo.c
sudo mv libfifo.so /usr/lib/mysql/plugin/
Plugin Install and Uninstall
Install
create function fifo_create returns string soname 'libfifo.so';
create function fifo_remove returns string soname 'libfifo.so';
create function fifo_read returns string soname 'libfifo.so';
create function fifo_write returns string soname 'libfifo.so';
Uninstall
drop function fifo_create;
drop function fifo_remove;
drop function fifo_read;
drop function fifo_write;
Testing
创建管道
mysql> create function fifo_create returns string soname 'libfifo.so';
Query OK, 0 rows affected (0.02 sec)
mysql> select fifo_create('/tmp/myfifo');
+----------------------------+
| fifo_create('/tmp/myfifo') |
+----------------------------+
| ture |
+----------------------------+
1 row in set (0.00 sec)
查看管道是否创建
$ ls /tmp/myfifo
/tmp/myfifo
覆盖测试，正确应该返回false
mysql> select fifo_create('/tmp/myfifo');
+----------------------------+
| fifo_create('/tmp/myfifo') |
+----------------------------+
| false |
+----------------------------+
1 row in set (0.00 sec)
删除管道
mysql> select fifo_remove('/tmp/myfifo');
+----------------------------+
| fifo_remove('/tmp/myfifo') |
+----------------------------+
| true |
+----------------------------+
1 row in set (0.00 sec)
mysql> select fifo_remove('/tmp/my');
+------------------------+
| fifo_remove('/tmp/my') |
+------------------------+
| false |
+------------------------+
1 row in set (0.00 sec)
删除不存在的管道会提示 false
读管道
在一个终端窗口中运行
mysql> select fifo_read('/tmp/myfifo');
+--------------------------+
| fifo_read('/tmp/myfifo') |
+--------------------------+
| Hello world |
+--------------------------+
1 row in set (7.85 sec)
在另一个终端窗口中运行
mysql> select fifo_write('/tmp/myfifo','Hello world !!!');
+---------------------------------------------+
| fifo_write('/tmp/myfifo','Hello world !!!') |
+---------------------------------------------+
| true |
+---------------------------------------------+
1 row in set (0.00 sec)
或者
在命令行运行
$ echo "Hello world" > /tmp/myfifo
在SQL客户端中运行
mysql> select fifo_read('/tmp/myfifo');
+--------------------------+
| fifo_read('/tmp/myfifo') |
+--------------------------+
| Hello world
|
+--------------------------+
1 row in set (0.00 sec)
注意上面echo会自动增加换行符，-n参数可以避免
$ echo -n "Hello world" > /tmp/myfifo
mysql> select fifo_read('/tmp/myfifo');
+--------------------------+
| fifo_read('/tmp/myfifo') |
+--------------------------+
| Hello world |
+--------------------------+
1 row in set (0.01 sec)
写管道
mysql> select fifo_write('/tmp/myfifo','Hello world !!!');
+---------------------------------------------+
| fifo_write('/tmp/myfifo','Hello world !!!') |
+---------------------------------------------+
| true |
+---------------------------------------------+
1 row in set (0.00 sec)
$ cat /tmp/myfifo
Hello world !!!
管道 /tmp/nofifo 不存在会返回false
mysql> select fifo_write('/tmp/nofifo',concat(mobile,'\r\n')) from demo;
+-------------------------------------------------+
| fifo_write('/tmp/nofifo',concat(mobile,'\r\n')) |
+-------------------------------------------------+
| false |
| false |
| false |
| false |
| false |
+-------------------------------------------------+
5 rows in set (0.01 sec)