Mysql连接池上篇
#endif
mysql_connect.cpp
#include
#include
#include
#include "mysql_connect.h"
ConnectionPool*
ConnectionPool::pool = nullptr;
//private
//构造函数
ConnectionPool::ConnectionPool(std::string name, std::string pwd, std::string nurl, int maxSize):
username(name), password(pwd), url(nurl), poolSize(maxSize)
{
//得到mysql驱动
driver = get_driver_instance();
//开始初始化大小一半
initConnectPool(poolSize/2);
}
//析构函数
ConnectionPool::~ConnectionPool()
{
destoryPool();
}
//得到连接池大小
int
ConnectionPool::getPoolSize()
{
return conList.size();
}
//增加连接
void
ConnectionPool::addConn(int size)
{
for(int i = 0; i < size; ++i)
{
//创建连接
Connection *conn = driver->connect(url, username, password);
std::shared_ptr sp(conn,
[](Connection *conn){
delete conn;
});
conList.push_back(std::move(sp));
}
}
//初始化连接池
void
ConnectionPool::initConnectPool(int initialSize)
{
//加锁，增添一个连接
std::lock_guard locker(lock);
addConn(initialSize);
}
//销毁一个连接
void
ConnectionPool::destoryOneConn()
{
//智能指针加std::move转移一个连接的“所有权”，当出作用域时，自动调用关闭connect
std::shared_ptr &&sp = std::move(conList.front());
sp->close();
--poolSize;
}
//销毁整个连接池
void
ConnectionPool::destoryPool()
{
for(auto &conn : conList)
{
//依次转移所有权，出作用域时，关闭连接，出作用域时智能指针自动释放
std::shared_ptr &&sp = std::move(conList.front());
sp->close();
}
}
//扩大连接池
void
ConnectionPool::expandPool(int size)
{
std::lock_guard locker(lock);
addConn(size);
poolSize += size;
}
//缩小连接池
void
ConnectionPool::reducePool(int size)
{
std::lock_guard locker(lock);
//减小的大小不能超过存储的大小
if(size > poolSize)
{
return;
}
for(int i = 0; i < size; i++)
{
//sp point new object, old object r