ThemisPool.py

# coding=utf-8
"""
@Author  : 周灿
@Summary : 自己封装的基于pymysql的Python连接池
"""

import configparser
import os
import queue
import threading
import time

import pymysql


class Config(object):
    def __init__(self, configFileName='db.cnf'):
        file = os.path.join(os.path.dirname(__file__), configFileName)
        self.config = configparser.ConfigParser()
        self.config.read(file)

    def getSections(self):
        return self.config.sections()

    def getOptions(self, section):
        return self.config.options(section)

    def getContent(self, section):
        result = {}
        for option in self.getOptions(section):
            value = self.config.get(section, option)
            result[option] = int(value) if value.isdigit() else value
        return result


# 获取配置文件参数
class parameter(object):
    def __init__(self, password, database, host="localhost", port="3306", user="root", initsize=3, maxsize=6):
        self.host = str(host)
        self.port = int(port)
        self.user = str(user)
        self.password = str(password)
        self.database = str(database)
        self.maxsize = int(maxsize)
        self.initsize = int(initsize)


class ThemisPool(parameter):
    def __init__(self, fileName='db.cnf', configName='mysql'):
        self.config = Config(fileName).getContent(configName)
        super(ThemisPool, self).__init__(**self.config)
        self.pool = queue.Queue(maxsize=self.maxsize)
        self.idleSize = self.initsize
        self._lock = threading.Lock()
        # 初始化连接池
        for i in range(self.initsize):
            self.pool.put(self.createConn())
        # print('')
        print('\033[1;32m ThemisPool connect database {database}, login is {user} \033[0m'.format(database=self.database,
                                                                                 user=self.user))
    # 生产连接
    def createConn(self):
        return pymysql.connect(host=self.host,
                               port=self.port,
                               user=self.user,
                               password=self.password,
                               database=self.database,
                               charset='utf8')

    # 获取连接
    def getConn(self):
        self._lock.acquire()
        try:
            # 如果池中连接够直接获取
            if not self.pool.empty():
                self.idleSize -= 1
            else:
                # 否则重新添加新连接
                if self.idleSize < self.maxsize:
                    self.idleSize += 1
                    self.pool.put(self.createConn())
        finally:
            self._lock.release()
            return self.pool.get()

    # 释放连接
    def releaseCon(self, conn=None):
        try:
            self._lock.acquire()
            # 如果池中大于初始值就将多余关闭，否则重新放入池中
            if self.pool.qsize() < self.initsize:
                self.pool.put(conn)
                self.idleSize += 1
            else:
                try:
                    # 取出多余连接并关闭
                    surplus = self.pool.get()
                    surplus.close()
                    del surplus
                    self.idleSize -= 1
                except pymysql.ProgrammingError as e:
                    raise e
        finally:
            self._lock.release()

    # 拉取数据（查询）
    def fetchone(self, sql):
        themis = None
        cursor = None
        try:
            themis = self.getConn()
            cursor = themis.cursor()
            cursor.execute(sql)
            return cursor.fetchall()
        except pymysql.ProgrammingError as e:
            raise e
        except pymysql.OperationalError as e:
            raise e
        except pymysql.Error as e:
            raise e
        finally:
            cursor.close()
            self.releaseCon(themis)

    # 更新
    def update(self, sql):
        themis = None
        cursor = None
        try:
            themis = self.getConn()
            cursor = themis.cursor()
            cursor.execute(sql)
            return cursor.lastrowid
        except pymysql.ProgrammingError as e:
            raise e
        except pymysql.OperationalError as e:
            raise e
        except pymysql.Error as e:
            raise e
        finally:
            themis.commit()
            cursor.close()
            self.releaseCon(themis)

    def __del__(self):
        try:
            while True:
                conn = self.pool.get_nowait()
            if conn:
                conn.close()
        except queue.Empty:
            pass